THE SCIENCE OF GLOBAL WARMING:


THE DEVIL IS IN THE DETAIL (REVISED VERSION FOR YOUR INTEREST)

An informal overview by Bill Peddie

Global warming is not the first issue which has attracted a great deal of ill-informed debate and nor should we be surprised, given the difficulty in mastering the scientific background of what in fact is a very complex field.  There is a problem for the general public to work out who to believe, since even the scientists are usually specialist in relatively narrow fields and both the politicians and the media commentators are often forced to make judgements without the luxury of knowing the relevant scientific literature and the appropriate questions to ask.  Having read some of the claims on global warming and noting that some of those making the claims are forgetting to mention substantial contrary observations from competing areas of expertise, I am submitting the following in the somewhat optimistic hope that it might stimulate some debate and gain some support for relevant research.  As one with training and experience in science education, I hope to be able to draw attention to some issues which seem to me to have escaped mainstream media commentary, yet which seem important in gaining some degree of perspective.  I stress I am not a climate expert.  What I can offer is a relatively broad general science knowledge and considerable experience in interpreting the scientific literature for a lay audience.

Given the grave prognostications, the current media fascination with global warming is understandable, but despite the millions of words now published on the topic it is of some concern that naïve over-simplification and misrepresentation of fact remains the order of the day.   But first I should lay my cards on the table.   I am not a global warming sceptic in that I accept there is evidence for some global warming over the last few decades.   Further more I can accept a human generated component (albeit tiny) to recent warming trends. It is just I shudder when I know an important issue is being misrepresented and dumbed-down in order to support both the case for and against global warming..

We start with a current mainstream political view.

The Maori myth of the god Maui using a flax net to lasso the Sun in order to slow its progress across the sky is a great story which now has an equally improbable modern counterpart in the form of Chancellor Angela Merkel.  At a recent G8 summit Chancellor Merkel has explained how carbon dioxide emission control can limit the global temperature rise to 2 degrees Celsius.   This two degrees has now assumed the status of a universal mantra and became the focus target for such international conferences as the Copenhagen Summit conference on climate change. My only problem with this is that since, as will be shown,  the global warming and cooling history show far greater shifts than 2 degrees Celsius partly in response to well documented changes in radiation from the Sun, should we now presume that once again we have some god-like being who can control our local Star?

One of the most difficult concepts for a lay person to understand is that science concepts such as the assertion that the increase in greenhouse gas carbon dioxide is responsible for global warming can at one stage represent the best that science can presume – and yet may also come to be recognised as a grossly distorted oversimplification as more information comes to light. Since detailed geology and geophysics are not part of the layperson’s general education the key questions are rarely part of the debate.   For example if more  were aware of the research into carbon dioxide levels in the Paleozoic era which began 600 million years ago where for instance carbon dioxide levels are now generally accepted as several orders of magnitude higher than they are today with no corresponding evidence of exceptionally high global temperatures, then more questions of the please explain nature would be directed at the IPCC who for a variety of reasons seem to be content with insisting that the current levels are at an all time high and very dangerous.   For those wishing to look at the data for themselves a relatively non technical introduction to the overview can be found at Climate and the Carboniferous Period.

Another point at which probing questions should be asked relate to the Intergovernmental Panel on Climate Change (IPCC) temperature record showing an abrupt leap in global temperatures at the beginning of the 1990s.   Here the issue is that something of the order of two thirds of the world’s temperature data gathering stations were expunged from the record from 1990 onwards on the grounds that for various technical reasons they were considered unreliable.   What is not clear is how it was then established that the abrupt shift in temperatures was not at least partly due to this change to the sources of data gathering. This is of particular significance since the leap in global averages did not appear to be reflected in a host of biological and geological annual data which is normally thought to accompany temperature change.

It is true that a majority of science commentators currently accept a view that some recent global warming has happened and many of these support the claim that this is related to carbon dioxide levels in the atmosphere.  Unfortunately associations of this sort are not necessarily causal, and more to the point, it is distinctly unscientific to ignore and denigrate those who challenge mainstream beliefs by highlighting the current uncertainties.  It is also inescapable that some of the protesting experts are poor public communicators.   Clive James in a BBC address in December 2009 described one of these, Fred Singer, while a man with undoubted high intelligence, as someone whose spoken deliberation is not only too slow for radio, but too slow for smoke signals!   Nevertheless Singer’s careful paper some years ago criticising IPCC presentations of data trends couldn’t be clearer.   For those interested it is suggested they might look on the net at “The Road from Rio to Kyoto: How Climatic Science was Distorted to Support Ideological Objectives.” There among other points they would find Singer saying that in choosing the last six hundred years as the frame of reference for the present phase of global warming, the IPCC accidentally – or even deliberately if you are a conspiracy theorist – avoided any focus on the little ice age of the medieval ages from which the current trend might be thought of as a recovery.   He also pointed us to the data typically showing that temperature rises before the carbon dioxide rises – not the other way around which would be more expected if carbon dioxide was the causal agent.

For those believing that global warming is accepted by most scientists as leading towards what Clive James mischievously  referred to as the bodies of fried polar bears floating past your penthouse windows, they could do worse than read James Hogan’s book, “Kicking the Sacred Cow” and see just how many scientists wish to question the mainstream view and why.   It is probably still true that if you were to poll scientists, in all likelihood you would find a majority prepared to go along with the mainstream view that global warming is a serious problem and further that there is a strong component contribution from greenhouse gases produced by human activities. Yet if you look closer there are some awkward problems with polling.   In 1997 President Clinton produced a list of 2,500 scientists who had approved the 1996 Intergovernmental Panel on Climate Change preparing for Kyoto.   If Singer is to be believed, most of those who had signed were not climate scientists but rather international governmental representatives, with a preponderance of those with social science qualifications, whose actual contributions were merely restricted to offering support.  To make matters worse, the executive summary for their views was purged of all traces of doubt, qualified opinion and scepticism – after it had been signed: which not unexpectedly drew a howl of protest from those who felt they had been thereby misrepresented.  From the other side of the debate, when Britain’s Daily Telegraph of the 30 May 2008 reported a presentation of 31,000 scientists denying global warming, the IPCC in their turn denounced the petition as including a good number without even the qualification of PhD.   Perhaps the best we can say about this shonky way of proving the case by popularity of view is that in the eyes of a good number, there are still many unconvinced.

There are certainly some issues which are unlikely to go away without more definitive research.   Even using the IPCC figures, only 3.4% of the current carbon dioxide level is considered to be caused by human activity.  Of that again according to IPCC figures, only 1.8% gets into the atmosphere with the rest being absorbed by various sink activity eg photosynthesis of plants, absorption by the sea, rock weathering etc.  Whether that 1.8% contribution from a gas typically present in very low concentration is sufficient to force the overall temperature to change more than the myriad of contributing natural processes may be more uncertain than some would have us believe.

Of course there are some recent and spectacular weather disasters. Droughts, hurricanes, floods, areas of tropical coral reef dead or dying, and salt water contamination of ground water supplies are just some of the regular items in the news.  Yet there is a note of caution.   Those who keep watch on the hurricanes do not observe a present trend towards fiercer hurricanes and many scientists claim that while some areas are currently devastated in some form or other this is not new, even if population increase and redistribution finds more people currently affected than was the case in the past.

The prognostications of lurid doom are almost as old as written history, and world wide floods are talked of in the Bible. Those who have visited the city of York in England, might have come across the windows of All Saints Church in North St which provide an ancient stained glass comic book version of the 600 year old “Pricke of Conscience”.  This work of art depicts some of the predictions from the 10.000 word poem of the same name in which among other things, 60 foot high floods are prophesised.  In this immensely popular work which incidentally outsold the Canterbury Tales in its day we would for instance read:

The sea shall ryse, as the bukes say.
Abouten the height of ilka mountayne,
Full forty cubits certayne…

Yet popularity of an idea has never necessarily equated with scientific accuracy.  The headlines about climate change in the late 19th century through to the present day reflect some remarkable swings of opinion.  Ian Wishart’s book Air Con enumerates some sample articles , some of which follow. In the eighteen nineties through to about 1925, geologists and scientists were regularly warning of an impending ice age. For example The New York Times February 24 1895 had the headline “Geologists think the World might be frozen up again”, Los Angeles Times Oct 7, 1912 “Fifth Ice Age is on the Way”, on that same day The New York Times, “Prof Schmidt “Warns us of an Encroaching Ice Age” and Chicago Tribune August 9 1923: “Scientist says Arctic Ice will wipe out Canada.”.   In the 1930s, through the 1950s on balance the Scientists were identifying global warming with a series of headlines pointing to glacier recession, a trend of warmer global temperatures, loss of Arctic Ice, permafrost in Russia melting etc.   Through the 1970s we were back to global cooling, with Science Journals and major newspapers alike printing the reports of scientists queuing up to warn us of the frozen disasters that awaited.   Something of their flavour is encountered with Nigel Calder (retired editor of New Scientist), telling us solemnly in International Wildlife July-August 1975 that “The threat of a new ice age must stand alongside nuclear war as a likely source of death and misery for mankind.”

My problem with the swinging positions issue as a recently retired science educator is that not only am I old enough to remember the 70s as a time when I was taking these warnings of an impending ice age from the mainstream scientists on trust but that I also distinctly remember when the notion of global warming then re-emerged in the 80s as a relatively mainstream idea and  recall apparently respectable scientists predicting ten metre rises in sea level by the year 2010, and what is more, gaining widespread acceptance for their apparently timely warnings.

The vagaries of the present situation are illustrated by the July 2009 National Geographic article by James Cameron summarising the dramatic greening of parts of the Sahara Desert in response to the increased rainfall.  If this continues, according to Cameron, these rains could revitalize traditional drought-ravaged regions, reclaiming them for farming communities.

According to the article, this desert-shrinking trend is supported by climate models, which predict a return to conditions that turned the Sahara into a verdant savannah some 12,000 years ago.   Satellite images of regions affected by the greening include the Sahel, a semi-desert zone bordering the Sahara to the south that stretches some 2,400 miles (3,860 kilometers).

Further evidence comes from satellite images since 1982  revealing extensive re-greening throughout the Sahel, according to a new study in the journal Biogeosciences. The study suggests huge increases in vegetation in areas including central Chad and western Sudan. The transition may be occurring because hotter air has more capacity to hold moisture, which in turn creates more rain, said Martin Claussen of the Max Planck Institute for Meteorology in Hamburg, Germany, who was not involved in the new study.

If you take a continent like North America some of the complexities become apparent.  Areas currently adversely affected by cold are improved by the increase in frost free days as global warming kicks in generally extending growing seasons while elevated carbon dioxide levels act as a fertiliser for most form of plant growth.   Conversely, areas where too much warmth damages crops are adversely affected by increased temperature. That does not excuse us from worrying about the plight of East Africans currently experiencing drought conditions, but it is at least a reminder that world weather patterns are complex and difficult to dismiss with simplified sound bytes. Please note that none of that need suggest there is dispute with the observation that the Earth has been warming. It may however begin to suggest that this alone might give rise to mixed fortunes.

Certainly a number of findings appear largely beyond dispute.   For example the scientific consensus is that for the last few centuries there has been widespread evidence of some climate warming and it is also clear that some molecular forms like the well publicised greenhouse gases of carbon dioxide and methane may well help the atmosphere trap heat.   The anthropogenic (human produced) contribution is much more uncertain since other gases like water, ozone, nitrogen oxides, methane, CFCs  and various sulfur compound aerosols also impact on the atmosphere’s ability to hold heat, and depending on what stage the Sun has reached in terms of its longer term cycles, the atmosphere itself plays a variable role.

It is admittedly blindingly obvious that humans have been able to have some effect on this climate change particularly on a local scale where humans engage in large scale removal of trees, burn fossil fuels with little regard for the consequences and add pollutants to the air in vast quantities.  The orange shimmering sun seen dimly though the brown acrid haze is a feature of some of the world’s bigger cities, particularly in some third world countries, which cannot be good for anyone. Urbanisation and industrialisation can radically affect the local environment

Eg a cold year in 1952 in London saw a corresponding increase in smog which was trapped by a layer of cold air and produced record air pollution.  This particular smog is thought to have killed 4000 people. Visibility reduced to one or two metres, (causing the closing of a number of theatres since only those in the front rows could see the screen)  An airliner got lost while taxiing at Heathrow after an instrument landing and those who went out to rescue it also lost their way.

Nitrogen and oxygen (the main components of air) do not normally combine at room temperature but within furnaces or the ignition chamber of car engines it is common for nitrogen oxygen compounds to form. Modern smogs in large cities are often toxic with nitrogen dioxide from cars reacting with the other chemicals from produced by various processes to produce a particularly nasty soup called PAN (peroxyacyl nitrate for the chemically literate).   Small soot particles are also nasty because the some of the complex hydrocarbons in them are carcinogens.   This does not excuse us from oversimplification when we are thinking of climate change, since some of these activities, eg the industrial production of sulfur compounds in the form of aerosols and even the natural production of water clouds at appropriate heights, actually increase reflectivity of solar radiation which makes it hard to be certain what is happening.

Even the standard argument that planting trees fights global warming by removing carbon dioxide needs some qualification.    For example removing trees in areas towards the poles is thought to have a cooling effect since it exposes white snow which then reflects sunlight back into space. Planting trees in temperate or tropical regions has more potential but even there, there are complications.   Oil palms, often the trees of choice in subtropical regions are not nearly as good as the hardwoods they replace at removing carbon dioxide, while other trees photosynthesise effectively but also pump large quantities of water into the air from the ground by transpiration.  Since the water molecule is also a greenhouse gas this does not necessarily lower the temperature of the Earth’s atmosphere.

The so-called carbon tax assumes a simple relationship between growing trees and removal of carbon-dioxide from the air.  There is in practice a relatively small window of opportunity for carbon removal since when trees reach maturity they typically have sufficient living cells for the net cell respiration to overtake photosynthesis and add carbon to the air rather than remove it. It is true that typically a plantation of 30 year old pinus radiata can store on average of the order of 230  tonnes of carbon per hectare but since only about half of that is in the form of useable wood, rest in the form of tree stumps, branches, pine needles etc will break down after harvest and return to the atmosphere.  Only very large stands of forest with a good proportion of regenerating growth can hold their carbon in perpetuity – always assuming there is no substantial harvesting or incidence of forest fire. Even after delivery of harvested wood to a building site it is typically estimated that a further 15% of the wood becomes unusable usually as off cuts.  In the case of New Zealand the end result is that 4000 hectares is required to grow sufficient pine to remove the carbon emitted from an average sized 400MW gas fired power station.  Since this tree growing must compete with farming land normally set aside for food production the equation is not simple or necessarily cost effective.

Complications abound.   For example there is a serious contention in the current scientific literature that having greenhouse gases like carbon dioxide in the air may even be lowering global temperature since air warmed by the greenhouse effect at ground level rises during the day to a height where the heat can be dissipated into space at night.   At present far too little is known about this aspect of the climate to be certain that this is indeed true. What is far more certain is that fossil fuel burning, deforestation and wide scale pollution remain serious issues and there is no question that they require urgent attention.   By all means we can justify cleaning up our air and water and are certainly not obliged follow the previous White House regime in using scientific uncertainty to divert action away from conservation of nature and fossil fuels, but this is not quite the same as accepting we are ready or even have the means to restore the Earth to its hypothetical steady state temperature range.  Indeed it is my contention that the assumption that all is understood and potentially controllable when it comes to climate change is wildly exaggerated.

Because natural cycles of cooling and warming are dimly understood we cannot extrapolate from the figures in to date to say with confidence that therefore we know enough to know how to fix the current trends. It might seem to follow that if humans can help mess up the atmosphere, if they were to desist from their climate interfering behaviour, all would be better. There is unlikely to be argument with the proposition that we should be prepared to clean up the mess we make in our environment.  The difficulty comes when the issues are presented as if that is all there is to global warming.  There is also the ethical question as to why anyone pointing out these complications should be dismissed as a global warming denier or presumed to be in the pay of the oil companies.

For those of us brought up with familiarity with graphs from simplistic school laboratory experiments, those comforting and precise looking lines plotting temperature change over millions of years, or even plots of recent temperatures or carbon dioxide levels with time convey an implied accuracy of measurement which is quite unwarranted.   Measuring temperature in a beaker is hardly the same problem as measuring temperature of the whole world when local temperatures as little as five Km apart can show more than a 5 degree centigrade difference, or for that matter showing that carbon dioxide is causing a temperature rise when a host of other equally plausible causal factors are continually changing at the same time.   By way of example in New Zealand eleven of so called representative temperature data collection sites have been used to show that since 1930 there has been approximately a 1degree centigrade temperature rise.    Unfortunately only four of these stations existed in 1930, and as two were mountain region sites the base line temperature could be argued to be artificially skewed when compared with the later averages.

This sampling problem is particularly worth noting with the recent history of the famous hockey stick graph, a leading global warming icon of a few years ago. That famous graph which became the key rallying picture for the Kyoto summit, was based on very limited sampling and not only purported to plot unprecedented recent global temperature rises – but was extrapolated in a variant of an exponential curve to predict which was said by its author Michael Mann to represent runaway global warming.

This graph was initially hailed as a most important indicator of the doom that lay ahead.    When it was discovered that much of the data on the graph had been generated from looking at the tree rings from a single ancient bristlecone tree and it was pointed out that such tree rings being affected by soil nutrients, wet and dry growing seasons and a host of other factors are notoriously unreliable as a single measure of temperature variation, support for the graph subsided to a somewhat embarrassed silence.  The final blow to the graph’s credibility came when a sceptical critic used Mann’s statistical procedure for smoothing his data on random data and found that even random data generated the same hockey stick graph.

From a personal point of view graph incidentally caused me some embarrassment at a public meeting where I had gone along to listen to a public lecture in late 2006, well after Mann’s graph had been roundly rubbished by the scientific establishment, and witnessed the lecturer showing Mann’s then suspect graph and heard him assuring the audience that the IPCC were confirming that not only the statistics supported the graph but that he (the lecturer) could confirm that 2006 would be the hottest yet.  Because I had seen the data put out by the East Anglia Hadley group showing that the temperature was no longer rising, and admittedly only skim read the rubbishing of Mann’s graph, I challenged the speaker on both points.    I was accused by the speaker of talking without facts and publicly berated for not having references with me to “proper science publications” to substantiate my “global warming denier” stance!

To be fair to the lecturer, he may well have missed hearing about the problems with the graph. Having pinned faith and reputation on earlier statements about the graph being essentially correct the IPCC and US National Academy of Science (the NAS) had been understandably reticent and muted in their eventual inevitable rejection of Mann’s work, so much so that the graph itself continued to feature in global warming literature and Mann was almost able to get away with his claim that his study had been vindicated by the NAS report on his work.   The Mann graph continued to find its way into countless texts and educational publications. Eventually Mann’s insistence that one of his frequent critics Lawrence Solomon was a liar, needled Solomon so much that he followed it up and discovered, then publicised, that both Dr Gerald North (chairman of the NAS panel on Mann’s work) and panel member Peter Bloomfield had admitted under oath to the Senate House Committee on Energy and Commerce Committee, that they had agreed with the criticisms of Mann’s work.  The committee went on to summarise their findings on Mann’s work as “bad mathematics”.

In 2009 a surprise paper by Professor Eric Steig in collaboration with the same Michael Mann presented a radical new collection of “evidence” claiming to show that whereas prior measurements to date had shown that it was only West Antarctica that was warming, now Steig and Mann could now show that East Antarctica was also warming.    This time, perhaps remembering being burned once by accepting Mann’s work as gospel, both the IPCC and NAS were cautious and examined the data carefully. Their caution was justified. They discovered with the assistance of one of Mann’s earlier critics McIntyre, that the researchers had mixed up data from two sites and simply guessed at other data at intervening points between these sites to compensate for the fact that there were insufficient observation stations in the area.   This produced an entirely artificial trend that may have suited the Global warming camp but did nothing to support the reputations of the two researchers or their case.   It did not however prevent Greenpeace and a host of other Copenhagen Summit attendees from seizing on the Steig and Mann paper to justify their prognostications.

To update the old dictum, there are three kinds of lies — lies, damned lies and global warming science.

Sophisticated methods can be used to measure the concentration of gases in the atmosphere, but the atmosphere is subject to many changes at a local level producing serious sampling problems.    Carbon dioxide enters the atmosphere from burning, from respiration (from all living cells), from decay particularly of plant material, from all life in the sea, warming sea or land, from volcanoes and so on.    It is removed by photosynthesis of plants, held in store by a host of methods like carbonate formation, sequestered by plant material which is either still living eg growing trees or being preserved in fossil form (eg fossil fuel such as coal or peat).   The annual change of 18% in the carbon dioxide level in the Northern hemisphere during the growing plant season shows just how easily this level can be affected by natural and relatively predictable processes/  However having said that,  when a large volcano occurs, or large patch of sea warms this can radically alter the local and even global concentration of CO2.   Since activities like burning fossil fuels only represents a relatively tiny contribution to the total carbon dioxide present it is difficult to be certain how much effect changing this form of human behaviour might have on global temperature.   On a number of occasions in recorded history single large volcano has been known to alter the entire temperature for the world for several years.

The simplified version of green philosophy whereby we reduce emissions by replacing fuel powered cars with electric cars, insist on after burners for petrol driven cars, change to bio-fuels or hydrogen powered vehicles where possible and replace fossil fuel power generation with nuclear, and other forms of power generation (eg wind, tide, solar etc) may all help in some way with the task of cleaning up the atmosphere but there are still questions to ask.

Several studies have pointed out that since in most countries, surplus electricity must be produced by burning fossil fuels, and since no energy process is 100% efficient, burning fossil fuels to make the electricity to charge the cars to run on electricity finishes up by burning more fossil fuel, than would be the case if the fossil fuel is burned directly in the vehicles.  Bio-fuels are also something of a problem. Palm oil trees grow well in tropical and subtropical climates, but are not as good as the rain forests they replace for converting carbon dioxide back to oxygen.   Where the land for producing bio-fuels is currently used for producing food and animal feed-stocks – converting it to fuel production produces spikes in food prices and shortages which particularly hit third world countries.

Since science now provides some improving ways of following temperature trends of the past we should acknowledge that we can be relatively certain that of the last 6 million years there was a three million year period when the average temperature was warmer than it is today followed by a three million year, predominantly cooling period during which there were a number of relatively frequent cold and warm climate cycles. Although some of the climate changes appear to follow changes in the Sun’s output others are far from predicable.  We can be grateful that much of the relatively recent human development has occurred at a time when we have had a relatively warm and benign 10,000 years of interglacial climate. But what should be stressed is that for more than 90 per cent of the last two million years, the climate has been colder, and generally much colder, than today. The reality of the climate record is that a sudden natural cooling is far more to be feared, and will do infinitely more social and economic damage, than the late 20th century phase of gentle warming.

The most recent few years’ record is a little embarrassing right now in view of the apparent recent agreement about warming in the scientific community, and that is that the steep increase in global temperatures through the 1980s and 1990s has now effectively flat-lined despite the steady increase of carbon dioxide and other greenhouse gases in the last ten years.   The temperature figures from 2001 through to the end of December 2007 are summarised in the following graph, the red line summarising the grouped annual data, the white representing the movement in annual temperature, and the blue dotted line the monthly averages.  The scale currently up to 0.6 Celsius represents the rise above the temperature set at zero degrees Celsius near the beginning of last century.

There is no question that in the few decades prior to 1981 on balance there was evidence that global temperature was trending upward but the initial notion that this was somehow largely due to rising human influenced carbon dioxide levels must now be brought into some question.

It even turns out that the sea level rise in the highly publicised case of the tiny coral atoll of Tuvalu is a non starter in that the sea level monitoring equipment installed in 1993 has detected no effective overall rise in the vicinity of Tuvalu and it turns out the inundation problems had more to do with erosion brought on by sand mining, construction and local industry depleting the water table and drawing in salt water.

Although the main media focus has been on the state of our surrounding atmosphere, this should not cause us to overlook that most of our atmospheric heat comes from the Sun and a smaller proportion from beneath us in the Earth. Since our main source of heat is solar, it matters that through the centuries the Sun has not been a completely stable heat source.  There are several reasons why this should be.

The Earth does not stay a fixed distance from the Sun.   The Earth’s orbit is partly elliptical and within this there is a pronounced wobble.  There is also a gravitational related physical reaction of the Sun as it counterbalances the rest of the Solar system resulting in up to a one million Km change in the position of the Sun relative to Earth.  Since summer in a hemisphere occurs when that hemisphere is tilted towards the Sun, whether or not it is a particularly hot summer partly depends on whether or not the summer comes when the Earth is approaching a near point to the Sun in the orbit.  The tilt of the Earth on its axis also varies and fluctuates between 24 degrees and 22 degrees off upright.  Since the tilt is responsible for the difference between summer and winter an increased tilt produces more extremes of temperature between summer and winter.

The fact that the Earth itself wobbles slowly like a slightly off- balanced top as it spins and orbits, provides a further complication.   The Earth’s wavering distance from the Sun, and the fact that the solar system itself is continuing to move through our home galaxy, cause us to encounter varying concentrations of cosmic rays which in turn appear to affect the formation of high clouds in our atmosphere which are generally thought to moderate the degree of cooling or warming.

The Sun itself is undergoing a complex series of nuclear reactions, one of which involves hydrogen atoms being fused together to make helium and subsequently a range of nuclear reactions leading to other elements.   Since the heat from these nuclear reactions sets up convection currents with variations in magnetic flux compounded by a rotating sun in which the core rotates at a different speed to the perimeter, the Sun is always changing.

Some of these changes are cyclical.  At varying intervals, magnetic storms on the outside of the Sun occur (usually in linked pairs of sun spots).  These typically have a diameter of an average of about 37 000 km and since the temperature within the spots is a few hundred Kelvin above the rest of the outside photosphere, an excess of sun spots increases heat radiation and consequently results in an increase in temperature of the Earth’s atmosphere.  These peak on average every 11.1 years (part of the so-called Schwabe cycle) so we get imposed cycles of heating and cooling.  Other cyclic changes like the larger 75-90 year (Gleissberg cycle) can affect the length and intensity of the sun spot cycle.  These larger cycles including the 200-500 year Seuss cycle and the 1,100-1500 year Bond cycle which can have substantial effects that swamp the effects of the 11.1 year cycle and a number of initial studies suggest these correlate with much larger changes in surface Earth temperature.

Since sun spots increase the effective solar radiation, they are associated with an increase in the so called solar wind whereby charged particles stream out from the sun through the solar system.   Among other things this wind appears to interact with the Earth’s magnetic field to produce an effective shield in the Earth’s atmosphere from deep space cosmic rays which are currently thought to increase high cloud formation.  While not all climatologists accept that enough is known to be certain about this mechanism, there appears to be some cautious support for the following.  With fewer high clouds the temperature rises still higher in the atmosphere. When the sun is less bright the opposite occurs. When more cosmic rays can get through to Earth’s atmosphere in the absence of the solar wind shield, more clouds form, and the planet cools more than would otherwise be the case if we thought in terms of direct solar effects alone. This may help explain then what happened from the middle of the 17th century to the early 18th century, when the solar energy input to our atmosphere, as indicated by the number of sunspots recorded, was at a minimum and the planet was stuck in the Little Ice Age.  Because the details of different level cloud effect on atmospheric temperature is only partially understood, apart from some agreement that this is likely to modify temperature, those who produce the computer climate models are far from sure about the relative weighting that should be given to this effect.

The changes in solar radiance are now claimed by the Union of Concerned Scientists to play a relatively minor role in overall global temperatures, but in the 3 June, 2009 writing in the journal Nature, Lockwood et al. published a study entitled “A Doubling of the Sun’s Coronal Magnetic Field during the last 100 years” in which they suggest an important role for the Sun as did a series of papers by Scarfetta and West showing that the total Solar Irradiance was increasing between 1980 and 2000 .  To a number of these scientists this pointed to the Sun being a main factor in the increasing global temperature over that time.

Nevertheless, in plain English, changes in the output of the sun modified by a range of other factors including cosmic ray exposure, may well have caused some or even most of the most recent extremes of climate change. The weighting given to any specific component has been attempted but not to every scientist’s satisfaction. Dr Veizer and others writing in Nature in 2000 questioned the direct link between high carbon dioxide levels and high temperatures when the ice ages 440 million and 150 million years ago both showed evidence for very high carbon dioxide levels.   According to Veizer there was for example a time when the soils show a level of approximately 16 times the present carbon dioxide level, and evidence for glaciation occurring at the same time.

While CO2 variations show periods of some correlation with our planet’s climate on long, medium and even short time scales, the previously mentioned inconvenient exceptions in the record such as Veizer’s observation of two ice ages where there were much higher levels of carbon dioxide than the levels at present, and numerous periods where there is an apparent complete lack of correlation suggest there is still much to learn.  Another question which is by no means settled is whether or not CO2 levels are a cause or effect factor in global temperature changes.   Since more carbon dioxide is produced by a variety of oxidation processes at higher temperatures and since more carbon dioxide can be trapped by the sea at lower temperatures temperature affects should be reflected in changing carbon dioxide levels without necessarily being a prime causal factor.   The bubbles of CO2 trapped in layers of ice of varying thickness (depending on ambient temperature of ice formation) suggest that raised temperature is actually followed by elevated carbon dioxide levels rather than the other way around.

In 2002, Daniel H. Rothman of the Massachusetts Institute of Technology also raised objections to the current popular view after studying carbon dioxide clues present in marine rocks. Writing in The Proceedings of the National Academy of Sciences, he said that with one exception — the recent cool period of the last 50 million years — he could find “no systematic correspondence” between carbon dioxide and climate shifts.

It is understandable that initially scientists should have thought carbon dioxide to be the key factor for increasing global temperature. Carbon dioxide is clearly currently increasing in the Earth’s atmosphere. For the last few decades since the levels have been monitored it has averaged virtually a steady slope upward. This coincided with a period of global warming. Pre-industrial levels for carbon dioxide were about 285 parts per million (ppm). It is currently closer to 390 ppm.   But the devil is in the detail. Since 1960 when accurate annual measurements became more reliable it appears to have increased steadily from about 315 ppm.   The period 1980-98 was also one of clear temperature increase of about 0.5 degrees C (CO2 rose from 340 parts per million (ppm) to 370ppm) which told the scientists they appeared to have found a causal relationship. Certainly from the global temperatures as used by the US National Oceanic and Atmospheric Administration, the UK’s Met. Office (from the Hadley Centre at East Anglia) and the IPCC (as confirmed by Al Gore) roughly identical rises were noted from 1980 until 1998.

Unfortunately  for the supporters of the carbon dioxide causal argument since then, the global temperature has been effectively unchanged  (albeit wobbling up and down) despite the CO2  rising from 370ppm (parts per million)to an average of 380ppm and even getting up to almost 390 at its peak ). This flat-lining means that the global temperature today is about 0.3 deg less than it would have been had the rapid increase continued in step with the carbon dioxide increase.   This would not surprise the paleo-geologists who insist that there are strong indicators of Carbon dioxide levels at 6000 ppm in the distant past coinciding with temperatures very similar to those today.

Historically it is worth noting that the scientist thought largely responsible for the theory that carbon dioxide was a primary cause of global warming, Roger Revelle, subsequently in effect retracted this proposition as more detail came to light. Revelle, an Oceanographer and director of the Scripps Oceanographic Institute at La Jolla, San Diego had collaborated with the climate chemist Hans Seuss to write the initial proposed theory in 1957.   Revelle also hired the geochemist David Keeling who figured out a way of measuring and monitoring  the carbon dioxide level in the atmosphere and is responsible for the so-called Keeling curve which has been used ever since. By the late 1980’s Revelle who incidentally had inspired one of his students , Al Gore to lead the fight against Carbon Dioxide emissions and given the UN the basic research it needed to launch its Intergovernmental Panel on Climate Change, was having second thoughts. But after collecting more data 1988 he wrote two warning letters to members of Congress. His letters included: “My own personal belief is that we should wait another 10 or 20 years to really be convinced that the greenhouse effect is going to be important for human beings, in both positive and negative ways.” And in case there was any misunderstanding “…we should be careful not to arouse too much alarm until the rate and amount of warming becomes clearer.”

In 1991 Revelle collaborated with Fred Singer, the first director of the U.S. Weather Satellite Service  and Chauncey Starr, an early director of the Electric Power Research Institute, to write an article published in Cosmos. This called for further research and pleaded with scientists and governments not to move too fast to curb greenhouse CO2 emissions because as the authors explained, the true impact of carbon dioxide was not at all certain, and curbing the use of fossil fuels could have a huge, negative impact on the economy, jobs, and developed nations’ standard of living.

There is always a problem in explaining physics to the non scientist, but nevertheless since so much of the current policy debate focuses on the carbon dioxide heat energy absorption effect some really basic physics must be at least acknowledged.   Molecules like nitrogen and oxygen are pairs of atoms and do not absorb and trap the Sun’s energy in the same way that molecules with three or more atoms can do.   Carbon dioxide is an energy trapping Greenhouse gas because it has three atoms but they are so arranged and bonded that the carbon dioxide can only substantially absorb at three narrow bands in the Sun’s energy spectrum.   Water on the other hand, also has three atoms, but its bent arrangement and different electron arrangement enables it to absorb over a much wider range of the Sun’s energy.   In other words water is a much more effective green house gas than carbon dioxide.   Since processes like respiration and burning carbon based fuels produce water as well as carbon dioxide and since current estimates for the two molecules (water and carbon dioxide) give at least twice as much contributory effect to the water in the atmosphere, it is not surprising some papers suggested up to 95% of the effect is caused by the presence of water. The Global warming supporters claim that although water is potentially a much greater contributor to global warming since water stays for a shorter time in the atmosphere and that because carbon dioxide has a much longer retention time, the water has a corresponding smaller effect.    This however suggests a serious misunderstanding of how gases behave.   Although it is the gases like water, methane and carbon dioxide which are the energy trappers, when we measure temperature it is predominantly the gas molecules which have collided with these energised molecules that are the ones being measured.

With beginning chemistry students I would first tell them that gas particles have a variety of speeds (some easily as fast as a jet plane) then show them that when we set up a 30 cm tube with hydrogen chloride gas diffusing from one end and ammonia gas from the other – it is several minutes before the white rings of the ammonium chloride are seen.    In other words rather than progressing in a straight line there are constant collisions and consequent energy transfers taking place in the giant game of billiards in the tube.  If the atmosphere behaves the same way, since the energised molecules should be expected to lose energy in collision, surely the concentration at any one time is more important for the ability of the air mix to take up energy from the Sun than how long a particular molecule stays in the mix.   If this is the case water, with its superior energy trapping ability should have a much greater effect than carbon dioxide with a lower concentration and more limited ability to trap the Sun’s energy.  Whether or not a water tax would have the same emotional appeal as a carbon tax is a moot point.

At the very least, if the greenhouse effect is what it is thought to be in the mainstream media, the Earth’s temperature should have continued to rise as the carbon dioxide levels increased.   It hasn’t over the last decade. Whether or not those now committed to the recent global industry of carbon trading are prepared to look at this complication objectively remains to be seen.

Although the recent temperatures have fluctuated, the hard fact is that the world has not warmed in the last five years. Putting it bluntly, as indicated above, global warming has apparently stopped for now. This is not an opinion or a sceptic’s convenient inaccuracy. It’s an observational fact. It must be stressed however that there is no excuse for ignoring the general warming trend of the last few decades.  Certainly on average the past 30 years have been warmer than the previous few decades and we also have to admit there is abundant evidence (in the northern hemisphere at least) that the world weather patterns have been responding to those elevated temperatures. But, like it or not, the evidence shows that global warming as such has ceased if only for the brief time-being. What is more, we have no way of knowing for certain that this is a respite or the beginning of a new trend. To go with mainstream environmentalists we would probably claim this to be a temporary aberration but since a number of the solar physicists are predicting the beginning of a cooling period based on variations in the sunspot cycles we need more data before we can be sure what is happening and why.

There is plenty of incidental evidence to follow both the changes on number of sun spots and indications of changing temperature.   It has been relatively common scientific knowledge for some years that the sun spot variation has a parallel in changes of global temperature.   Sunspots have been known and counted for several hundred years but the correlation with other phenomena makes it possible to trace the record further back.

Since sunspots subsequently affect the concentration of Carbon 14 in our atmosphere, the record of sunspots can be reflected in various geological records like the layered varves in the bottom of lakes and fjords and annual changes in layers of ice in Arctic and Antarctic regions.  The other indicators scientists use for monitoring the geological record for Earth temperature (which they call “proxies”) include fossil and living tree rings, signs of shifting ocean level, pollen studies to show shifts in tropical and temperate vegetation and the general fossil record of plant and animal life.

And yes, we have to admit clear evidence for a regular 11.1 year cycle of Sun spot intensity approximately correlating with global temperatures…and what is more, in the sediment, and in diatom and fish-scale records for example, there appear longer period cycles, all apparently correlating to some extent with those other well-known regular solar variations and variation of distance. Hence we note marine productivity cycles that are claimed to match well with the sun’s 75 year + “Gleissberg Cycle,” the 200+ year “Suess Cycle” and the more than thousand-year “Bond Cycle.” It is complex in that the strength of these cycles is seen to vary over time, fading in and out over the millennia. The variation in the sun’s brightness over these longer cycles appears to have had an effect many times greater in magnitude than that measured over the short Schwabe cycle.

This has implications for the current mainstream acceptance of the carbon dioxide effect since we are currently on just beginning to shift from the 11.1 year sun spot cycle where atmospheric carbon dioxide appears to have had a measurable relationship to temperature and we are now moving to the verge of a more extreme cycle where the carbon dioxide effect is relatively poorly known.

One set of scientists are currently arguing that the oceans themselves have a heat store and release cycle.  It is not yet clear how this interacts with Solar cycles.


In the last few years [the Pacific Ocean] has been losing its warmth and has recently started to cool down

Professor Don Easterbrook from Western Washington University summarised his research in November 2009 in which he claims it is clear that the oceans and global temperatures are correlated.

The most important of the warming cooling cycle says Easterbrook is the Pacific decadal oscillation (PDO).   For much of the 1980s and 1990s, it was in a positive cycle, ie warmer than average. And observations have revealed that global temperatures were warm too.  In the last few years it has been losing its warmth and has recently started to cool down.

According to his findings these cycles in the past have typically lasted for nearly 30 years.  The global cooling from 1945 to 1977 coincided with one of these cold Pacific cycles. According to Easterbook the cool sector of the cycle has kicked in once more and now we are virtually assured of several years cooling as a result.

It should be stressed the things we still don’t know about climatic factors far exceed the areas of relatively secure knowledge.    For example our accurate temperature readings and precise mapping of sun spots are relatively recent products of advances in technology.   Past ice ages and periods of extreme warming are beyond our ability to monitor with any degree of precision.    While it is true that other gases like methane appear to be on the rise it is actually hard to establish whether they come from human interference or are simple artefacts from natural phenomena.   For example bubbles of methane are coming out of the ground in vast areas as the Siberian tundra goes through its current warming phase.   It is hard to establish if a molecule of methane detected came from such a source or from a cow chewing its cud, and even harder to know whether it is a cause or an effect of the warming phase.  A warmer sea also releases more carbon dioxide. Since warm temperature also accelerates the breakdown of plant material and since an end product of this breakdown is carbon dioxide it is again hard to distinguish cause from effect in the rising levels.

For those sensing doom in the recent global warming trends, take heart. 6,000 years ago proxy evidence strongly suggests it was about 3C warmer than now.  Even the rate of warming is not at an historical high.  Ten thousand years ago, while the world was coming out of the thousand-year-long “Younger Dryas” cold episode, temperatures rose as much as 6C in a decade — 100 times faster than the past century’s 0.6C warming that has so upset environmentalists.

In those pre-industrial times it seems highly unlikely these large changes can be blamed on human intervention.  From this combined record we note at times in the relatively recent past, temperatures have been considerably higher than today, and occasionally, temperatures were far colder.   Presumably this is why there is fossil evidence to show that as well as the famed frozen mammoths there were once crocodiles in Hudson Bay, lemurs in Spitzbergen and subtropical forests in Antarctica.  A clearer understanding of these extremes might even be a little comforting. A currently melting ice sheet in the far north might be less worrying if we remember that within recorded history there have been several times when the North West passage has been open to shipping.

When it comes to predicting regional climate changes, there are massive complications.   The giant conveyer belt of ocean currents that variously bathe coastal regions in temperate, cool or warm water and hence affect their local temperature as heat is redistributed, can shift to the side, stop or even reverse in response to local changes in salinity and land or water temperature.  For example although Arctic Ice on one point of this conveyor has been going through a warming cycle (although I note that in the last annual bulletin there was 9.8% more ice at the summer minimum in 2009 than for the previous year and the very latest graph shows that the cover for April 2010 has now returned to the average for the previous decade) there is heaps more ice in the Antarctic where one of the more recent big projects announced is drilling down through 4 km of ice to the rock beneath. It is also relatively well established that a one degree change in surface sea temperature can have a substantial effect on the frequency, intensity and duration of hurricane systems.

The melting of ice sheets at the two poles is not a simple correlate with the local air temperatures at those latitudes.    The global conveyer belt of warm water

occasionally brings warmer water to the poles but for the last few years this has had a much greater effect on the North Pole than the South.    Even the moon appears to have some effect.   There is a cycle called the 18.6 year lunar nodal cycle whereby  the moons trajectory moves further North over the equator, then back again due to the Sun’s gravity.   For example in the year 2006 there was a maximum year in this cycle creating tidal currents which brought larger volumes of warm water to the Arctic than is the case for the minimum part of the cycle.   As was expected this caused some fairly dramatic ice melting.   At the same time it is worth remembering that the equivalent period in the 1930s saw more dramatic melting and for those worried about irreversible melting, they might take comfort in the fact that by 2010 there was substantially less loss of summer ice. Whereas the North Polar ice sheet shrank relatively dramatically soon after the turn of the century, in the South it was largely only in West Antarctica and then mainly on the Peninsula which comes out beyond the Antarctic circle that the effect was most easily noticed.   Earlier this year it was noticed that the point at which the West Antarctic shelf was broken had a local warmer current meeting the ice.   It also should be of comfort to remember that while icebergs have broken off in recent years, over the last three hundred years there have been much more dramatic ice shelf fractures and on several occasions icebergs one hundred mile square in size or more have been observed in the Southern oceans.  For example The American Navigator (an authoritative annual text) reported in 1854 a crescent shaped iceberg in the South Atlantic with horns at either end being described as 40 and 60 miles long, 40 miles between the tips.   In 1927 a berg 100 miles long by 100 miles wide was reported and in 1956 a US icebreaker reported one 208 miles long by 60 miles wide.  No long term effects of this dramatic ice loss as a harbinger of impending doom were noted.

It is curious that the popular press continues to stress the evidence for complete and catastrophic melting of the Arctic ice when any student of the history of the area would confirm that up until now it appears a cyclic phenomenon.  Bill McKibben, an authority from the Al Gore camp,  is quoted as saying “by the end of the summer season in 2008, so much ice had melted that   both the North West and North East passages were open…. The computer models, which are just a few years old, said that this shouldn’t have happened until sometime late in the 21st Century.”   Then he added triumphantly “even sceptics can’t dispute such alarming events.”  (Quoted in “Think Again” Foreign Policy January/February 2009 Issue) Quite apart from the failure of those same computer models to predict the horrendously cold temperatures for Europe and Britain of January 2010 (which the global warming experts had been predicting as a mild winter) and that the actual ice cover for the year turned out to be significantly greater than the minimum for the previous year there was some humour for cynical observers when an environmentalist set out on a kayak  mid summer to paddle all the way to the North Pole to draw attention to the serious problem and had to abandon his trip after a few days when he got caught in some very solid pack ice 900k from the pole.

Henny Penny may well be joining Al Gore and Bill McKibben as they head to the hills to avoid the inevitable sea level rise, but I must regretfully decline to panic just yet.   After all without the advantage of Bill McKibben to tell him it would be impossible, Roald Amudsen took a ship through the North West passage in 1903 .  In the 1940s a Royal Canadian Mounted Police ketch on Arctic patrol made several trips through the impossible passage 1940, 1942 and 1944 and as recently as 2000 we learn that the “St  Roche II has crossed through the North West Passage in just three weeks…..so little ice that most of the trip was smooth sailing except for the occasional iceberg floating by.”

Now the graphing of ice cover is better established there is another difficulty for the “warmist” camp in that as at the beginning of April 2010 not only had the graph for the Arctic sea now shown a return to so called normal cover – but the other six main ocean ice areas in the Northern hemisphere all showed a greater ice cover than had been the case in previous years.

When it comes to sea level, measurement problems confound those trying to find out what is happening.   Measuring sea level sounds easy but not when some parts of the coast are rising and others sinking, quite apart from the fact that changes in air pressure also cause fluctuations. For example the IPCC reset its ocean rise models based on results from a tidal gauge off Hong Kong, yet at the same time satellite measurements showed a much smaller increase.  Under-sea volcanos and global tech-tonic shifts are simply too unpredictable to factor into the measurement. Another form of measurement based on the spin rate of the earth, using the same physics as an ice skater uses to change the speed of their spin depending on how far they extend their arms shows the average increase of sea level to be less than 1.1mm per year.  This is less than the “massive” 2mm per year (NOT cm!) experienced by Tuvalu and the reader should look on a ruler to see the height of the required sea wall to keep this at bay.  A very slow amble would be enough to keep ahead of that rate of inundation. For those seriously worried about sea level rise, but are unwilling to face the complexities of a scientific report, they could do worse than go onto the internet and seek out the record of an interview with a world sea level expert Dr Nils Axel Morner (entitled) “Claim that Sea Level is Rising is a Total Fraud”

The first detailed quantitative analysis of physical changes in 27 atoll islands in the central Pacific over a 60-year period conducted by scientists from the School of Environment at New Zealand’s University of Auckland and from the South Pacific Applied Geoscience Commission in Fijisuggested that  in so far as these islands were typical, if anything most islands in the Pacific are stable or expanding.  The study published last month in Global and Planetary Change entitled: The dynamic response of reef islands to sea level rise: evidence from multi-decadal analysis of island change in the central pacific, showed that while 14% of the islands studied showed a decline in area, 43% were stable and 43% expanded in size. None of the changes in area were dramatic.

According to the researchers , the islands are dynamic,  and can be likened to organisms that are continually adapting to the environment. As seen by examining satellite images and historical aerial photography over a 19 to 61 year period in 27 atoll islands, islands continually changed form and tended to grow because they are composed of coral debris. Because corals are living creatures that propagate themselves, islands are continually replenished with new landmass. Islands can also increase by accumulating debris from storms. For example even Tuvalu’s main island increased by 10% in 1972, when hurricane Bebe deposited 140 hectares of sedimentary debris onto its eastern reef.

It is hard not to believe that, always assuming this study is confirmed when further atolls are sampled that the feared erosion of Pacific Islands from rising sea levels is overly simplistic and apparently based on abstract climate change theory bereft of an understanding of the formation and ecology of islands. Pacific islanders will not be forced to evacuate their homes, as the world’s media has many times reported.

Any single way of measuring temperature back through the ages is at best approximate. Tree rings might well reflect temperature but a host of other factors also affect tree growth and the sampling of tree rings is still relatively sparse and unequally distributed.  Even the temperature today is hard to measure. The grid method of temperature sampling now employed for global figures glosses over the awkward truth that some places get much more attention and are measured more accurately than others in the sampling.

When it comes to thermometers, it is not only doctors who are faced with options where to place them. Temperature measurement in the atmosphere is hard to interpret since above average temperatures higher in the atmosphere might correspond with lower than average temperatures nearer ground level and vice versa.   In any case if you wanted to measure the temperature at the top of the atmosphere there is a problem since the top of the atmosphere can raise or lower through 50 Km height variation.  Even deciding where best to base the thermometers on land is by no means certain.  The industrial phase of the human contribution to atmospheric temperatures appears unequally distributed.   For example temperatures taken in industrial or urban city situations where most thermometers are situated are typically reading up to 2 degrees above those in the nearby countryside and can be as much as 20 degrees C different.   Apart from greenhouse gases produced by burning fossil fuels we would expect some temperature changes from urbanisation in that large areas of concrete and asphalt have very different heat absorption and reflectivity when compared with green bush or forest.  This then raises the question whether a temperature rise in a populated area is due more to increased greenhouse gases or the use of inappropriate building and construction material. Although the three main centres collating global temperature information have similar figures, the variation between the centres is sufficient to be uncertain of the nature and size of some of the trends.

One of the most embarrassing global warming glitches occurred when the IPCC announced with gloomy satisfaction that October 2008 had been the warmest October for world temperatures on record.   Since China, many parts of Europe and the US had reported exceptionally cold averages for that particular October there was a please explain request from a number of quarters.   Red faced officials admitted as quietly as possible they had accidentally accepted the repeat of the previous months figures for the entire set of Russian figures which had artificially raised the average accordingly.   Not really of great comfort when even the US figures which are considered the best set of  temperature data available in following the current “crisis”  are known to have quite high errors of measurement.  We might also remember in passing that the best possible current models also predicted a mild winter for the US, Europe and the UK for the 2009-2010 winter.   In practice President Obama returned from Copenhagen to weather so cold that it was impossible to fly back to the White House, and to say that the winter was mild for the US, UK and Europe could not be further from the reality.

Some cynics in the denier camp have also pointed out that the claimed overall temperature rise of 0.5 degrees Celsius for last century actually falls within the demonstrated error of measurement and may in fact not even be real.  Although for what it is worth, I personally would not accept that and come down on the side of those who accept the IPCC reported measurements as the best indications we can have of what we appear to know, yet I would have thought the new improvements in the measurement system as a whole are simply too recent to be talking with certainty about the significance of much of the data as indications of a long term trend.

Which brings us back to Chancellor Merkel.   In the very short term she may well be hard to refute.  But given the fact that there are numerous difficulties in finding out what is going on and an overwhelming body of evidence to show substantial changes in global temperature are not a new phenomenon, should we share in her certainty that if we follow her advice stability will return? Whatever else has remained stable, long term stable climate has never been a feature of this planet’s geological record. The only constant relating to climate is change and given the little we do know there is every reason to think that not even a politician will be able to prevent future hot and cold spells.

See also Climate Change An Information Statement of the American Meteorological Society

(Adopted by AMS Council on 1 February 2007) Bull. Amer. Met. Soc.88


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64 Responses to THE SCIENCE OF GLOBAL WARMING:

  1. Bruce Rankin says:

    Hello Bill,
    Courtesy of Bryan Bates email I’ve just read your fascinating article from end to end on the Science of Global Warming. The best perspective I’ve read on the subject….. as one who does have a science and engineering background (CBHS & BE Electrical from Canty Univ), but nonetheless struggles somewhat as to what to make of all the conflicting media and policical outpourings. For some time I’ve felt that – yes – greenhouse gases must have some impact on increasing global temperatures, but what percentage impact compared to the sun constantly warming the earth and the ongoing cyclical effects of sun spot activity etc? You’ve answered that very well! There are so many variables we can’t be certain of anything. I read recently a quote “How can you say with such precision that the world’s temperature will rise by an average of 2 Deg C over the next 60 years when you can’t even forecast tomorrow’s weather accurately?” But from a pollution and environmental degradation point of view we should certainly be doing whatever is practical to limit the damage. In China for example the effects of smoking (world’s biggest consumers) and pollution must surely have horrendous adverse long term consequences for the health of Chinese people.

    With regard to volcanos I received an email about the recent Iceland volcano (can’t spell or pronounce the name!) that said in part: “The volcanic ash emitted into the Earth’s atmosphere in just four days – yes – FOUR DAYS ONLY by that volcano in Iceland, has totally erased every single effort you have made to reduce the evil beast, carbon. And there are around 200 active volcanoes on the planet spewing out this crud any one time – EVERY DAY.”

    “I don’t really want to rain on your parade too much, but I should mention that when the volcano Mt Pinatubo erupted in the Philippines in 1991, it spewed out more greenhouse gases into the atmosphere than the entire human race had emitted in its entire YEARS on earth. Yes folks, Mt Pinatubo was active for over one year – think about it.”

    “Of course I shouldn’t spoil this touchy-feely tree-hugging moment and mention the effect of solar and cosmic activity and the well-recognized 800-year global heating and cooling cycle, which keep happening, despite our completely insignificant efforts to affect climate change.”

    “And I do wish I had a silver lining to this volcanic ash cloud but the fact of the matter is that the bush fire season across the western USA and Australia this year alone will negate your efforts to reduce carbon in our world for the next two to three years. And it happens every year.” End of Quote

    I noted you’ve also written a book on Azaria Chamberlain. Are you in touch with Michael? I presume you’re aware that he’s an Old Boy (1962) when you were there (1957-62) according to The Years Between? I along with Frank Pickering (hostel 57-59), Maurice Ryan and Anson Austin (the tenor), established the Sydney Old Boys branch last year and have had 3 meetings over the last year, with Michael Chamberlain as guest speaker in November. A fascinating talk where he answered every question we asked of him. He is endeavouring to get a 4th inquest convened by the NT Government – hopefully to finally decide that a dingo did indeed take Azaria. The 3rd inquest would not conclude that, which effectively means that Lindy is still deemed a liar, despite being pardoned and I think declared that she did not kill Azaria. (not sure of exact declarations/terminology). As the organiser have spoken to and got to know Micheal a bit. He is very genuine and I “know” Lindy didn’t do it.

    Funnily enough I only discovered recently that Michael’s father Ivan and my father were at School together, and knew each other as Dad as a Wright Stephenson’s seed agent knew many farmers from the Ellesmere to Cheviot/Parnassus. Their farm was at Chamberlain’s Ford on the Selwyn River and usually in Jan/Feb Dad would ring Ivan to ok for us and several other families to have family picnics on their farm by the river – back in the 50’s and 60’s. Swimming in the water holes and catching eels! Michael still lives at Cooranbong north of Sydney with his wife Ingrid…. I suspect you probably know all this.

    If you’re in Sydney it would be great if you could deliver a talk to an Old Boys function here.

    Best wishes, Bruce

  2. peddiebill says:

    NOTE FROM BILL: I have just received this very long and detailed post which makes detailed points of criticism. Since there is so much to answer I have made an arbitrary decision to break the post up and make some brief comments on each part. I would like to start by thanking the critic who has obviously spent a great deal of time going through the paper and then producing the critique.

    ERIC says: Much of what you have written I would agree with especially regarding the
    minimal consequences and risks of warming, but some of what you wrote is
    not correct. You wrote: “Even using the IPCC figures, only 3.4% of the
    current carbon dioxide level is considered to be caused by human activity”
    then he goes on:
    That is not correct. The increase from pre-industrial levels, around
    280ppm, to current levels, around 390ppm, is 100% human caused. You
    correctly mentioned that natural processes such as warming oceans will
    raise CO2 levels. But what has happened in the last 100 or so years is
    that natural processes have absorbed part of the human contribution and
    the rest has built up in the atmosphere causing the 280 to 390 rise. How
    much CO2 was produced by natural processes from natural warming following
    the Little Ice Age (a few ppm perhaps) is not at all relevant when the
    atmospheric CO2 increases annually by about 1/2 of what we produce (the
    former from measurements, the latter from fossil fuel usage, cement, and
    some tree loss).

    Bill’s Reply: Read again what I wrote. According to Enersbee’s article on
    the oceans (Carbon Dioxide and the Oceans) in Focus 151:20-21 the long term
    global average temperature of the average seas temperature is 15 degrees C
    At 15 C at sea level seawater dissolves its own volume of CO2 At 10 C it
    dissolves 19% more and at 20 C 12% less If there has been a little
    warming of the sea (and if there hasn’t why are we worrying?!) then it
    releases more CO2 – unless of course there is some other data I don’t know
    about. Since the increase has been relatively slight how can you be so
    certain none of it comes from the sea when the physics and the chemistry
    says some of it must come from that source. This might also explain some of the proxy measures which a number of researchers claim that show temperature goes up first and Carbon Dioxide follows. Since most of the current CO2 level has a multitude of sources you must first prove that all other factors were kept constant.
    As temperature clearly wasn’t – or what are we talking about – you haven’t yet
    convinced me that warming the sea won’t have had any effect on the released
    concentration of carbon dioxide. (And I haven’t even started on what
    happens on the ground)
    >
    ERIC You wrote: “When it was discovered that much of the data on [Mann’s]
    graph had been generated from looking at the tree rings from a single ancient bristlecone tree…” Not correct. Read The Hockey Stick Illusion.

    BILL’s reply: Read McIntyre S and McKitrick R 2003:” corrections to the
    Mann et al Proxy data base and Northern Hemisphere temperature series, 1998″
    Energy and Environment 14 751-771 ( I know the Skeptical website have their own answer but I feel rather more certain when I am reading refereed literature because I lack the knowledge to be certain about any claim. For example another critic told me I didn’t understand the science of global warming and it turned out that his area of expertise was pressure cookers.
    >
    ERIC You wrote: “The annual change of 18% in the carbon dioxide level in the Northern hemisphere during the growing plant season shows just how easily this level can be affected by natural and relatively predictable processes/ However having said that, when a large volcano occurs, or large patch of sea warms this can radically alter the local and even global concentration of CO2.”
    >
    First part is true, the latter is false. Volcanoes and local ocean warming have virtually no effect on global CO2 and little effect on local CO2 other than very short term.

    Bill’s reply – I got that bit of information from a geologist. However I
    think I need to make it clear I am talking about the super volcanoes like Toba and the myriad of undersea volcanoes. It was you who said on your site that the CO2 stays around for virtually forever (apart from being used by plants) But if you can point me to contrary data I would be grateful. Eg how much CO2 was estimated to come from Toba – and how much is normal from human activity?

    ERIC You then wrote: “Since activities like burning fossil fuels only
    represents a relatively tiny contribution to the total carbon dioxide
    present it is difficult to be certain how much effect changing this form
    of human behaviour might have on global temperature. On a number of
    occasions in recorded history single large volcano has been known to alter
    the entire temperature for the world for several years.
    >
    First the “tiny contribution” is wrong. Second is a non sequitur: a
    volcano can cool the world, but volcanoes have not warmed the world for
    100’s of millions of years.

    Bill’s Reply I never said the volcanoes were heating the world. I said altering the temperature.Volcanoes actually tend to cool the world. The Toba volcano affected the climate for two years, Taupo for much longer.

    ERIC
    You wrote: “The reality of the climate record is that a sudden natural
    cooling is far more to be feared, and will do infinitely more social and
    economic damage, than the late 20th century phase of gentle warming.”
    I agree with that, except for the word infinitely. There is no doubt that warming is better than cooling for the human endeavour.

    BILL’S REPLY Sorry about the use of “infinite” but even today many more die from the cold than do from the heat. The ice ages were indeed infinitely worse if the geological record is anything to go by. You may have heard of mass extinctions. In my reading that would be a bit more unpleasant than a few degrees of frost.

    ERIC You described your graph The temperature figures from 2001 through to
    the end of December 2007 are summarised in the following graph, That
    is too short a period and too arbitrary. From the 1980’s to the 1990’s to
    the 2000’s there is warming on every temperature chart.

    BILL No there isn’t, I’m looking at one right now. There happens to be considerable argument but consensus still leaves 1998 as the coldest year followed closely by a date in the 1930s But surely the point is that Carbon Dioxide from the IR measurements has been rising steadily since that 1998 date and if it is the main driver of temperature surely you would want to argue that the temperature should have carried on rising. That isn’t what the measurements show.
    >
    ERIC You wrote: “Since summer in a hemisphere occurs when that hemisphere is
    tilted towards the Sun, whether or not it is a particularly hot summer
    partly depends on whether or not the summer comes when the Earth is
    approaching a near point to the Sun in the orbit”
    >
    Not sure what you are talking about but incorrect by my intepretation. The
    earth is closest to the sun in January and farthest in July. That doesn’t
    appreciably change from summer to summer. IOW, each northern hemisphere
    summer in our lifetimes the earth is the same distance from the sun. But
    over thousands of years the tilt will change so that NH summer will become
    closer to the sun (that condition is what ends most ice ages). Maybe
    that’s what you meant to say?

    Bill’s reply: It is true that tilt is a big factor and it is also true that I oversimplified on this point. But if you look at graphs of ice cover in Northern hemisphere you will see they are typically below average and in the South above average. (From memory the 3% closer approach than the 7 July gives a measurable difference in radiation) It is true we are still coming out of an ice age but a further complication is that land ( which is concentrated in the North) is faster to heat and cool than ocean which is more in the South. I am happy to concede that in my general article I did not point to some of these complications but since my aim was to show the system as infinitely more complicated than is normally portrayed in the media as a simply “global warming is caused by man made Carbon Dioxide” I am happy for you to increase the complications. (I do actually know of a lot more complications but I thought this is about all I could get away with in a general article)
    >
    ERIC It is true that the cosmic rays vary depending on galactic factors, but
    those generally increase low clouds (not high) and not in a way that
    predictably causes cooling. You wrote “an excess of sun spots increases
    heat radiation and consequently results in an increase in temperature of
    the Earth’s atmosphere” Not true. Sunspots generally decrease total
    solar irradiation. The cyclic nature is generally true, but not well
    understood. You then wrote “When more cosmic rays can get through to
    Earth’s atmosphere in the absence of the solar wind shield, more clouds
    form, and the planet cools more than would otherwise be the case if we
    thought in terms of direct solar effects alone.” Generally true, but
    low clouds form which may be generally cooling. High clouds are generally
    > warming. Certainly other factors are at work such as lowered ultraviolet.

    Bill’s reply. Perhaps you misunderstand the solar physics. The Sunspot itself has less
    irradiation, but the halo effect where the flare re-enters the Sun gives off
    heaps more. More Sun Spots has frequently been noted to cause a higher
    temperature on earth. You might have come across another reason. If so lets hear it.
    The Cosmic ray stuff is still being worked through by the atmospheric
    physicists and because I dont understand it very well I would prefer not to
    comment on the latest papers. I have been told that there is a trade off between reflectivity of the cloud and heat generated in the cloud by condensation of droplets but I repeat this is totally outside my field and I haven’t read enough of the latest literature to have anything sensible to contribute.
    ERIC You wrote “This however suggests a serious misunderstanding of how gases behave. Although it is the gases like water, methane and carbon dioxide
    which are the energy trappers, when we measure temperature it is
    predominantly the gas molecules which have collided with these energised
    molecules that are the ones being measured.”
    >
    This is true and a good point, but it is also true that the N2 and O2 do
    not re-radiate energy to any significant extent. So to calculate
    radiation from the atmosphere, both out into space and back towards earth,
    the proportion of greenhouse gases matters.

    Bill Again I think we must be reading different text books. The reason
    why N2 and O2 are not greenhouse gases is not they cannot interchange
    energy – they do so by collision, but because diatomic molecules don’t have the ability to absorb the Sun’s energy at the appropriate frequencies. >

    ERIC
    You wrote: “Putting it bluntly, as indicated above, global warming has
    apparently stopped for now. Slowed, but not stopped (yet). You wrote
    In the last few years [the Pacific Ocean] has been losing its warmth
    and has recently started to cool down Generally true, but the important detail is that the Pacific sea surface temperature still reaches records during warm cycles (El Nino).

    BILL REPLIES
    In abnormal El Nino and La Nina the hot in one place is counterbalanced by cold in another. That provides the driver for the circulation. As far as I know the average is still close to the same. (I don’t actually know much about it!)
    >
    ERIC You wrote: “A currently melting ice sheet in the far north might be less
    worrying if we remember that within recorded history there have been
    several times when the North West passage has been open to shipping”
    Sporadic in the 40’s at best. Current ice seems to be at century scale
    lows. You wrote. Quite apart from the failure of those same computer
    models to predict the horrendously cold temperatures for Europe and
    Britain of January 2010 (which the global warming experts had been
    predicting as a mild winter) and that the actual ice cover for the year
    turned out to be significantly greater than the minimum for the previous
    year…” True about the models and cold in Europe but 2010 ended up
    with less ice than 2009 thanks to El Nino and that European cold (that
    same circulation sent some warmth up around Greenland).

    Bill True about the ice in the North (not in the South).

    ERIC Otherwise there are some good points and facts in this article. But
    someone will have to review again after it is rewritten.

    BILL REPLIES: Thanks again for the detailed criticisms. The only problem in finding an acceptable reviewer is that very few are genuine experts in all areas. Maybe you are qualified. Could you slip me a range of the titles of your articles in the refereed science literature then I can see which are your specialities? (I am only a generalist!)

  3. KAP says:

    1. When discussing climate of the very distant past, one must always bear in mind that the Sun’s output was lower then than it is today. During the mid-paleozoic, the Sun’s output was about 3% lower than today, which roughly balances the increase in forcing from elevated levels of CO2 then. This is a very critical point which is absent both from your discussion and in the link you posted.

    In order to obviate that important difference, one must look to the more recent geological past. The last time CO2 levels were as high as they are today was the middle Miocene, 15 to 20 million years ago. During that time, the Earth’s temperature was about 5° C warmer than today and sea levels were 100 feet higher than today. The last time CO2 levels were at 1000 ppm — which is where we may be at the end of this century, if we continue to do nothing — was 30 to 100 million years ago, when temps were as much as 16° C (29° F) higher than today, and sea levels were hundreds of feet higher than today. So if the past is our guide, that’s where we’re headed.

    • petersonericd says:

      KAP said The last time CO2 levels were as high as they are today was the middle Miocene, 15 to 20 million years ago. During that time, the Earth’s temperature was about 5° C warmer than today and sea levels were 100 feet higher than today.

      Warmth during the Miocene came from geological factors:
      http://rivernet.ncsu.edu/courselocker/PaleoClimate/Pagani%20et%20al,%201999%20Miocene%20CO2.PDF

      • peddiebill says:

        I’m sure warmth comes from Geological factors ….and the Sun…..and whats happening in the atmosphere which again goes back to what is happening in the sea, on the sea floor, in space etc. I would have thought it is actually quite complicated and I am amazed how simple so many can find it.

  4. KAP says:

    2. You said: “something of the order of two thirds of the world’s temperature data gathering stations were expunged from the record from 1990 onwards on the grounds that for various technical reasons they were considered unreliable.”

    The reason for the dropout was not unreliability, it was oversampling. In order to correctly guage global temperature, stations nearby each other must be averaged into a unified grid, so that areas with a lot of stations don’t swamp the signal from areas with few stations. This means that station-rich areas (like the US) are vastly oversampled compared to the amount actually needed to determine global temperatures. The dropout was not because some stations were inherently unreliable, it was to simplify and standardize data gathering. The stations chosen to remain in the network were simply the most reliable — and nothing more.

    You said: “What is not clear is how it was then established that the abrupt shift in temperatures was not at least partly due to this change to the sources of data gathering. This is of particular significance since the leap in global averages did not appear to be reflected in a host of biological and geological annual data which is normally thought to accompany temperature change.”

    Acutally, that’s very clear. There was no such abrupt shift in the temperature record, and there was no such leap. The station dropout actually coincided with cooler temperatures in the surface station averages. See my blog posing here for details.

    • peddiebill says:

      Perhaps it is unfortunate that I turned to your source of authority and found it was a) a blogspot and b)labelled scientists you disagreed with as deniers. I hope that does not mean you are not trying to be objective.
      It is true that the data I referred to in the way the temperature data for this claim came from NOAA and NASA’S GISS and was graphed by someone you call a denier Ross McKitrick, a statistician and associate professor in environmental economics, but I (possibly naively) thought the data was reliable since it comes from standard authorities and was published in an accepted journal.
      US Meteorolgist Joe D’Aleo came out with a paper confirming McKitrick’s explanation, but more importantly Douglas Hoyt pointed out that the apparent temperature change at the time was not being confirmed by the various proxies or changes in biological organisms, chemical changes etc
      Sorry I went to these folk as my sources instead of your blogspot, but I am always a bit cautious in accepted a claim unless I see for myself that it is from refereed literature. Anyone can claim anything – and some frequently do!

      • KAP says:

        Here’s a link to NASA’s global temperature data; Here’s the UK’s Met Office data; and here’s NCDC’s data; here’s the UAH satellite data; and here’s RSS’s satellite data. All of these are compiled using peer-reviewed methods. If there’s an “abrupt shift in temperatures” that coincides the the station dropout, in either the surface or satellite record, I certainly don’t see it.

        The larger issue here, Bill, is that you’ve been misinformed (and apparently repeatedly), but by whom, I don’t know and can’t say. I will say, however, that perhaps you should start being more skeptical of the skeptics. They’ve apparently been giving you some bum steers.

      • peddiebill says:

        Submitted on 2011/01/24 at 7:23 am | In reply to KAP.
        First yes I have seen the data you refer to, and spoken with some of the professionals in the field who have told me why it all has to be taken with great caution, especially when it comes to seeing trends. I dont share your same horror of literature that doesnt fit preconceptions. For example the recent debate over the the role of cosmic rays ( and extra terrestial dust) has given rise to some fairly impressive new observations and constructive work. Not giving attention and consideration to the opposition is a sure way of missing the new knowledge. Read a bit more Popper! I doubt if I could be more skeptical or just about everything. If you can ever get yourself away from the current topic, take a quick look at the other articles on this site (starting with the one one Galton and the testing of Prayer, and you will see what I mean.

  5. KAP says:

    3. You said: “Unfortunately associations of this sort [CO2 and temperatures] are not necessarily causal”.

    Not necessarily, that’s true; but in the case of CO2 and temperature, the causality mechanism is well known: it’s basic physical chemistry. Why should we doubt that which is not in doubt?

    You said: “it is distinctly unscientific to ignore and denigrate those who challenge mainstream beliefs by highlighting the current uncertainties.”

    I don’t know of anyone who’s being ignored. In fact, skeptical scientists are given airtime and webspace far in excess of their relative proportion in the climatological community.

    • petersonericd says:

      CO2 causes warming, but not catastrophic warming at the doubling of CO2 we are likely to get. To get catastrophic warming requires some other positive feedback that is unlikely at current temperatures. The feedbacks like water vapor which are strong during dry glacial periods are weak in the interglacials. That is why interglacials always stop around the current temperature.

  6. KAP says:

    4. You paraphrased “Singer saying that in choosing the last six hundred years as the frame of reference for the present phase of global warming, the IPCC accidentally – or even deliberately if you are a conspiracy theorist – avoided any focus on the little ice age of the medieval ages from which the current trend might be thought of as a recovery.”

    First, the Little Ice Age occurred during 1750-1850, so the 600 year timeframe fully includes it. Second, the best evidence suggests that the LIA and its recovery were caused by solar changes, which can be ruled out as the cause of the post-1975 warming.

    You said: “He also pointed us to the data typically showing that temperature rises before the carbon dioxide rises – not the other way around which would be more expected if carbon dioxide was the causal agent.”

    CO2 in the air is in equilibrium with CO2 in the oceans; and the conditions of that equilibrium are governed by Henry’s Law (complicated considerably in the case of CO2 because it has several ionic states, but the crux is the same: warmer water holds less CO2). That means that CO2 and temperature are in a positive feedback loop: higher sea temps release more CO2 into the air, which causes more greenhouse effect, which causes higher sea temps. In this situation, it ultimately doesn’t matter whether CO2 or temps rise first: a rise in either one will start the feedback loop rolling. In the geologically short timeframes of the Quaternary, orbital forcing has been the inital cause for temperatures to start that feedback loop. That in no way implies that CO2 does not act as a greenhouse gas.

  7. KAP says:

    5. You said: “Perhaps the best we can say about this shonky way of proving the case by popularity of view is that in the eyes of a good number, there are still many unconvinced.”

    There are two ways you can determine scientific consensus: you can do a poll. Or you can look at the literature. Both of these methods have been tried, and both methods indicate that among actively publishing climate scientists — that is, the people who know the most about the subject — 97% to 98% accept the current consensus that the world is warming and we are primarily responsible. You can find about the same level of consensus among biologists for the theory of evolution. In other words, in a scientific context, anyone not accepting the consensus is pretty much on the fringe.

    • petersonericd says:

      KAP is misdirecting. Mankind is certainly responsible for some warming, that comes from the physics of CO2 that we have added the atmosphere. The debate is whether that warming will lead to catastrophic warming through water vapor feedback. There is not a consensus of 97% of climate scientists about that. Comparison to the consensus evolution is a typical part of the propaganda war against the so-called “luke warmers”, those who believe mankind is warming the world but that it will not result in catastrophe.

      • Bill Peddie says:

        I am also puzzled why CO2 has to be the main concern. Warming, warms the sea and we know from elementary physics that this puts both extra water and extra CO2 into the air. We also know that water has by far the greatest effect as an energy trapper. We know there is more extra water than there is CO2 and as they are released simultaneously why is it that KAP insists it is all CO2’s fault. Surely collision theory shows that the energy is promply passed on in the next set of collisions, so the old idea that CO2 stays longer in the air, therefore has more effect no longer holds up.

  8. KAP says:

    6. You said: “There are certainly some issues which are unlikely to go away without more definitive research. Even using the IPCC figures, only 3.4% of the current carbon dioxide level is considered to be caused by human activity. Of that again according to IPCC figures, only 1.8% gets into the atmosphere with the rest being absorbed by various sink activity eg photosynthesis of plants, absorption by the sea, rock weathering etc.”

    I’m sorry, but this is a serious misreading of the science. You’re describing CO2 fluxes, not stored amounts. The greenhouse effect is determined solely by stored amounts, and specifically the amount stored in the atmosphere. We know from industrial records that we have burned about 1200 gigatons of fossil carbon since 1750, and we know from modern measurements and ice core data that the atmosphere has about 250 more gigatons of carbon in it now than it did in 1750 (or at any earlier time in the past million years). So it doesn’t take a genius to figure out where that extra 250 gigatons came from. That’s a 40% increase in the stored amount, all of which has occurred since the invention of the steam engine.

    • petersonericd says:

      KAP is correct above, currently we are adding over 8Gt per year and about 1/2 of that accumulates.

      • Bill Peddie says:

        The key figure is how much is added from warming sea water.
        That is easily worked out because we can get the satellite figures for the temperature mapping. If more is added from the sea than from people processes I find it hard to understand how only the sea produced CO2 is removed leaving the main contribution from people. Still I guess someone will be able to explain.

  9. KAP says:

    7. “Those who keep watch on the hurricanes do not observe a present trend towards fiercer hurricanes”

    This has, in fact, been observed. See Webster et. al. 2005.

    • petersonericd says:

      KAP is correct in theory. The trend toward fiercer hurricanes is true using the novel “percentage of cat 4 and 5 storms” metric. Previously used metrics such as normalized storm damage show no trend. These researchers were looking for a particular result and they found it.

  10. KAP says:

    8. You said: “The anthropogenic (human produced) contribution is much more uncertain since other gases like water, ozone, nitrogen oxides, methane, CFCs and various sulfur compound aerosols also impact on the atmosphere’s ability to hold heat, and depending on what stage the Sun has reached in terms of its longer term cycles, the atmosphere itself plays a variable role.”

    Actually, nearly all of these are either directly observable or easy to calculate from physics. For example, we are obviously responsible for all atmospheric CFC’s. Methane, N2O and CO2 were at stable levels in the atmosphere for thousands of years prior to the industrial revolution, and all have suddenly lept to much higher levels since then. It is therefore reasonable to conclude that we are responsible for that increase, and that conclusion is supported by isotopic analysis of the gases themselves. Ozone has increased in the troposphere, but it is stratospheric ozone that is critical to the greenhouse effect, and there we are responsible for the “hole” over the Antarctic. The forcing contributions of all these gases are well known from physical chemistry and are not in dispute. The contribution of sulfate aerosols is much less clear, but we do have ballpark figures that are of the right order of magnitude.

    The Sun’s output has been monitored directly by satellite since 1978, and that monitoring has allowed us to develop quite accurate models of the Sun’s output from known values of its magnetic field. Those models now allow us to compute the Sun’s output accurately backward for several centuries. From this we know that the Sun’s output reached a modern peak in 1958 and has been declining since that time, as the Earth has warmed.

    • petersonericd says:

      KAP neglected to mention that there is a lag in warming from peak solar output just like with CO2 warming using the same ocean heat storage mechanism. Also TSI (what he terms solar output) is not the final determiner of temperature. The spectral composition is important because more UV means more stratospheric warming, less blocking and thus warming. It is indirect warming via weather changes. UV has increased more than TSI has.

  11. KAP says:

    9. You said: “there is a serious contention in the current scientific literature that having greenhouse gases like carbon dioxide in the air may even be lowering global temperature since air warmed by the greenhouse effect at ground level rises during the day to a height where the heat can be dissipated into space at night. At present far too little is known about this aspect of the climate to be certain that this is indeed true.”

    I know of no such contention at all. Do you have a citation for this? Also, we need to be careful about terms here: we we talk about global warming, we’re speaking of warming at the surface. It is well known (and well observed) that greenhouse warming at the surface is accompanied by stratospheric cooling. (Indeed that must be the case: since the greenhouse effect causes surface warming without any net increase in solar input, the energy must come from somewhere.) In other words, the observed stratospheric cooling is strong evidence that the current warming is caused by enhanced greenhouse, rather than, say, the Sun. As far as I’m aware, none of this is controversial.

  12. KAP says:

    10. “Because natural cycles of cooling and warming are dimly understood we cannot extrapolate from the figures in to date to say with confidence that therefore we know enough to know how to fix the current trends.”

    On the contrary, as mentioned in point 8 above, the basic figures are well known and derived from basic physics.
    Change in forcing from CO2 since 1750: +1.8 W/m².
    Change in forcing from all other anthropogenic LLGGs since 1750: +1.0 W/m².
    Change in forcing from anthropogenic aerosols since 1750: ~ -0.8 W/m².
    Total change in forcing from anthropogenic sources: ~ 2.0 W/m².
    Change in forcing from solar irradiance since 1750: +0.4 W/m².

    Fraction of 2.4 W/m² total forcing that’s anthropogenic: 83%.
    Fraction of 2.4 W/m² total forcing that’s CO2: 75%.

    If we were to choose a shorter timeframe (say, since 1950 instead of since 1750), it just gets worse, because solar output has overall declined since 1950; which means we’re responsible for essentially all of the warming since that time.

    “There is also the ethical question as to why anyone pointing out these complications should be dismissed as a global warming denier or presumed to be in the pay of the oil companies.”

    Mostly because, as you yourself demonstrate in this post, those who point out these difficulties are actually unaware of the true levels of uncertainty (in the scientific sense), and therefore are vulnerable to the arguments of those (like the oil companies) who have multi-billion-dollar skin in the game and therefore have strong reason to bias the political discussion. Indeed, one of the top US conservative media consultants, Frank Luntz, openly advised Republican political operatives to concentrate on alleged “scientific uncertainty” as a way of winning the political discussion. Are you really that certain that what you’re talking about here is honest scientific uncertainty, rather than political spin? Have you read the papers of Hansen (or Jones, or Christy), that discuss his methods for deriving global temperature, and the uncertainties thereof? Or are you just taking things on faith, from some blogger somewhere?

  13. KAP says:

    11. When it was discovered that much of the data on the graph had been generated from looking at the tree rings from a single ancient bristlecone tree and it was pointed out that such tree rings being affected by soil nutrients, wet and dry growing seasons and a host of other factors are notoriously unreliable as a single measure of temperature variation, support for the graph subsided to a somewhat embarrassed silence.

    This is, I’m sorry to say, simply untrue. Mann’s work has been replicated in over a dozen similar studies since it first appeared, and no similar study has found any substantial difference from what Mann found. Regarding the single bristlecone pine, one works with the data one has at the time, and in 1998, that was what he had (which is why that study went back only to 1350). The real issue is not the amount of data, but its quality. Since 1998, as more data has become available, more data has been used; and, as noted, Mann continues to be confirmed at every turn. Even the study of Loehle 2008, which used no tree-ring proxies at all, confirms Mann. Support for the general conclusion of Mann is, therefore, stronger than it has ever been.

    The final blow to the graph’s credibility came when a sceptical critic used Mann’s statistical procedure for smoothing his data on random data and found that even random data generated the same hockey stick graph.

    This is also untrue. McIntyre and McKitrick generated 10,000 random datasets, and selected 100 of those 10,000 (1%) on which to do further analysis. Those 1% were selected on the basis of having the most hockey-stick-like shapes. Thus the hockey sticks were actually present in the data that M&M used, and were not merely an artifact of statistical procedures.

    • petersonericd says:

      Loehle (and other studies) show no hockey stick http://www.freesundayschoollessons.org/pdfs/climate-history.pdf

      McIntyre duplicated Mann’s method which incorrectly normalized data on the instrument record instead of the full interval. This had the effect of increasing the variance of hockey stick shaped series. The selection of principal components was then biased towards those series. I suggest to you also to read the Hockey Stick Illusion or McIntyre’s website for a full explanation.

      • peddiebill says:

        I am puzzled. I agree with McIntyre. Why are you talking to me as if I dont. I refer to this directly in my paper

  14. KAP says:

    12. Having pinned faith and reputation on earlier statements about the graph being essentially correct the IPCC and US National Academy of Science (the NAS) had been understandably reticent and muted in their eventual inevitable rejection of Mann’s work

    This is also untrue. Mann’s graph appears in the lastest IPCC report (IPCC 2007, Working Group 1, Chapter 6, Figure 6.10, page 467) along with many confirming studies. And the NAS has also confirmed the results of Mann in essentially the same terms that Mann originally used. For example, Mann concluded, “Though expanded uncertainties prevent decisive conclusions for the period prior to AD 1400, our results suggest that the latter 20th century is anomalous in the
    context of at least the past millennium. The 1990s was the warmest decade, and 1998 the warmest year, at moderately high levels of confidence.” The NRC’s conclusion is quite similar: “The Research Council committee found the Mann team’s conclusion that warming in the last few decades of the 20th century was unprecedented over the last thousand years to be plausible, but it had less confidence that the warming was unprecedented prior to 1600”.

    • petersonericd says:

      The “confirming” studies use the same critical proxies as Mann’s study including stripbark trees which were not recommended for temperature proxies by the NAS panel. The NAS panel then contradicted itself by using other studies that included the bristlecones. Without a small handful of such proxies there is no hockey stick shape.

      • peddiebill says:

        I am afraid I dont have a high regard for the hockey stick anyway. If it is true now we are ten years on along the curve there should now be rapid temperature changes upwards – and there isnt – we are still near enough at the 1998 level. If the 1998 figure was aberrant then there is no hockey stick to explain. Remember a hockey stick is supposed to be the sign of an exponential growth. Take the hockey stick as presented at Kyoto and plot the figures ten years on yourself and compare it with what is currently measured. (Actually since my criticisms of Mann would take about two pages to explain and since it is handled far better by the experts go on to their sites and argue with them) I actually agree with the Wegman report summary but please understand I am not an expert.

  15. KAP says:

    13. “when a large volcano occurs, or large patch of sea warms this can radically alter the local and even global concentration of CO2.”

    Locally, perhaps, although I know of no such measurements. (Do you?) Globally, this is simply untrue. Pinatubo erupted in 1991, yet no evidence of that exists in the Mauna Loa or South Pole CO2 time series. The same is true of El Chichon and Mt. St. Helens. In fact, you can search both of these time series in vain for even the slightest clue that any volcano has ever had any effect on the record.

    “Since activities like burning fossil fuels only represents a relatively tiny contribution to the total carbon dioxide present …”

    As noted in point 6 above, this is a serious misreading of the science, if not an outright falsehood.

    “… it is difficult to be certain how much effect changing this form of human behaviour might have on global temperature. On a number of occasions in recorded history single large volcano has been known to alter the entire temperature for the world for several years.”

    This is very, very misleading. Volcanoes alter the global temperature because they throw massive amounts of dust into the stratosphere, cooling the planet for a year or two. The greenhouse effects of volcanoes are utterly insignificant compared to human fossil fuel burning.

    • Bill Peddie says:

      Do I know of any – yes – but rather than go to the original papers you’ll find mention of it in the following newspaper account. Oh dear – so you think an outright falsehood. I suppose it wont help to say I am simply doing my best with limited knowledge. Oh, to have the comfort of universal omniscient knowledge and only say stuff which is true for all time. Again read the clipping – but please address the charge of falsehood to the so called experts quoted in the article. It was them – not me that originally say these things. I just read and accept them until contrary information comes along.
      First I no longer agree with Professor Plimer’s earlier (1992) estimate that volcanoes produce more CO2 than all the cars and human burning combined. However it is not insignificant on the scale on emissions talked about for carbon trading purposes.

      From a newspaper cutting earlier last year (And the rest is entirely not my work!) Iceland’s Eyjafjoell volcano is emitting between 150,000 and 300,000 tonnes of carbon dioxide (CO2) per day, a figure placing it in the same emissions league as a small-to-medium European economy, experts said on Monday.

      Assuming the composition of gas to be the same as in an earlier eruption on an adjacent volcano, “the CO2 flux of Eyjafjoell would be 150,000 tonnes per day,” Colin Macpherson, an Earth scientist at Britain’s University of Durham, said in an email.

      Patrick Allard of the Paris Institute for Global Physics (IPGP) gave what he described as a “top-range” estimate of 300,000 tonnes per day.

      Both insisted that these were only approximate estimates.

      Extrapolated over a year, the emissions would place the volcano 47th to 75th in the world table of emitters on a country-by-country basis, according to a database at the World Resources Institute (WRI), which tracks environment and sustainable development.

      A 47th ranking would place it above Austria, Belarus, Portugal, Ireland, Finland, Bulgaria, Sweden, Denmark and Switzerland, according to this list, which relates to 2005.

      Experts stressed that the volcano contributed just a tiny amount – less than a third of one percentage point – of global emissions of greenhouse gases.

      One extra volcano-related aside: with European carbon market prices fluctuating around the €14 per tonne mark at present, this would mean that Eyjafjallajokull would theoretically be liable to a maximum daily bill of €4.2m if it were a fully fledged, carbon-trading nation or corporation. But who would dare get close enough to present it with an invoice?

    • peddiebill says:

      Do I know of any – yes – but rather than go to the original papers you’ll find mention of it in the following newspaper account. Oh dear – so you think an outright falsehood. I suppose it wont help to say I am simply doing my best with limited knowledge. Oh, to have the comfort of universal omniscient knowledge and only say stuff which is true for all time. Again read the clipping – but please address the charge of falsehood to the so called experts quoted in the article. It was them – not me that originally say these things. I just read and accept them until contrary information comes along.
      First I no longer agree with Professor Plimer’s earlier (1992) estimate that volcanoes produce more CO2 than all the cars and human burning combined. However it is not insignificant on the scale on emissions talked about for carbon trading purposes.

      From a newspaper cutting earlier last year (And the rest is entirely not my work!) Iceland’s Eyjafjoell volcano is emitting between 150,000 and 300,000 tonnes of carbon dioxide (CO2) per day, a figure placing it in the same emissions league as a small-to-medium European economy, experts said on Monday.

      Assuming the composition of gas to be the same as in an earlier eruption on an adjacent volcano, “the CO2 flux of Eyjafjoell would be 150,000 tonnes per day,” Colin Macpherson, an Earth scientist at Britain’s University of Durham, said in an email.

      Patrick Allard of the Paris Institute for Global Physics (IPGP) gave what he described as a “top-range” estimate of 300,000 tonnes per day.

      Both insisted that these were only approximate estimates.

      Extrapolated over a year, the emissions would place the volcano 47th to 75th in the world table of emitters on a country-by-country basis, according to a database at the World Resources Institute (WRI), which tracks environment and sustainable development.

      A 47th ranking would place it above Austria, Belarus, Portugal, Ireland, Finland, Bulgaria, Sweden, Denmark and Switzerland, according to this list, which relates to 2005.

      Experts stressed that the volcano contributed just a tiny amount – less than a third of one percentage point – of global emissions of greenhouse gases.

      One extra volcano-related aside: with European carbon market prices fluctuating around the €14 per tonne mark at present, this would mean that Eyjafjallajokull would theoretically be liable to a maximum daily bill of €4.2m if it were a fully fledged, carbon-trading nation or corporation. But who would dare get close enough to present it with an invoice?

      • KAP says:

        Thanks for the reference, which was interesting. 300,000 tons of CO2 per day sounds like a lot … until you realize that fossil fuel burning amounts to (currently) 84 million tons of CO2 per day. Which is why the best current estimates put volcanic emissions of CO2 at between 1% and 0.1% of fossil fuel emissions.

        I do apologize if I in any way implied that you personally were dishonest; that was certainly not my intent. But I also believe that you have been seriously misled by people who are not as honest as you are. The carbon flux numbers are a classic example of this. Suppose in my backyard I had one of those artificial waterfalls: a pool at the bottom and a pump. Suppose that the pump is rated at 100 gallons per hour, and the pool currently holds 500 gallons. I could let the pump run day and night all summer, and the pool would lose a little to evaporation, and gain a little from rainfall, but overall the amount of the water in the pool wouldn’t change much, or at least not very fast, under normal weather conditions. Now suppose that I take a gallon jug of water from the kitchen and dump it into the pool. I go back to the kitchen, refill the jug, and go back to the pool and dump it in. That process takes one minute. And I keep it up for, say, six hours continuously, one gallon at a time. At the end of six hours, the amount of water in the pool has risen from 500 gallons to 860 gallons. Now here’s the question: what is responsible for that increase? I argue that I’m responsible. Some deceptive people want you to believe that the pump is responsible, because the pump works 100 times faster than I do. But that ignores a very important fact: the pump removes water just as fast as it puts water in. And that’s the way it is with CO2 in the air. Natural processes put 200 gigatons of carbon from the air every year, and natural processes remove 204 gigatons of carbon into the air every year. Humans put in 8 gigatons of carbon into the air every year … and remove zero. We are responsible for putting that extra water into the pool, in spite of the pump, because we’re not removing what we put in. Nature is in balance. We’re not.

      • peddiebill says:

        I am glad you brought up the example of water. We all agree dont we that the world has been warming a bit – for whatever the reason. Basic physics insists that when seawater at the surface warms it releases more carbon dioxide. Now there is more carbon dioxide in the air as a result. Why exactly is it that we must have put it there when we know it will happen in response to the warming. In any event the warming started way back at the end of the ice age and Fred Flinstone’s car hardly burnt anything.

  16. KAP says:

    14. “Several studies have pointed out that since in most countries, surplus electricity must be produced by burning fossil fuels, and since no energy process is 100% efficient, burning fossil fuels to make the electricity to charge the cars to run on electricity finishes up by burning more fossil fuel, than would be the case if the fossil fuel is burned directly in the vehicles.”

    As a general rule, large turbine generators are much more efficient than IC engines, and electric motors are at least three times more efficient than IC engines. Considering also that a substantial (and hopefully increasing) amount of electricity is generated from non-fossil sources, electrics and PHEVs are a major step forward. Most studies I have read put PHEVs at 1/3 or less of the carbon footprint of an IC vehicle.

    • peddiebill says:

      You have missed the point. Electric cars are efficient. BUT they run on Electricity which has to be generated before it can be efficiently used. In the UK the only electricity left to run the extra electric cars has to be generated. This extra generation comes from buring fossil fuels. Fuel is also needed for all the contributing processes in manufacture.It turns out that more fuel is thereby burned to eventually make the cars go than if you stuck the fuel straight in the tank.. (or so the UK studies I read claimed) The last step – electricity to charge car to run efficiently is after the electricity has been generated and at present this generation is not nearly as efficient as you suggest. It may be in the future but I am not hopeful For example at present to have a clean burning coal electric generation plant you need a footprint of about 16 acres. A plant without the clean up is about 2 acres and despite all the talk of how efficient future coal burning is going to be I notice they are still buying the two acres parcels of land to put them on.

  17. KAP says:

    15. “The reality of the climate record is that a sudden natural cooling is far more to be feared, and will do infinitely more social and economic damage, than the late 20th century phase of gentle warming.”

    But it’s not the late 20th century we’re worried about. It’s the late 21st century, when climate change will be upon us full force and it will by then be too late to stop it. Kemfert (Germany) puts the cost of doing nothing at $20 trillion annually by 2100. Watkiss et. al. (EU) put the cost of doing nothing at $26 trillion annually by 2100, rising to over $70 trillion by 2200. The Stern Report (UK) puts the cost of doing nothing on climate change at 5% to 20% of global GDP by 2100; while the cost of early mitigation is relatively cheap, at 2-3% of GDP.

    I don’t know if you’ve ever studied thermodynamics, but the paper by physicist Tim Garrett deserves mention here. He applied the basic equations of thermodynamics to civilization as a whole. His conclusion: our entire civilization faces collapse unless we do something, and now, about the energy/warming problem.

    • petersonericd says:

      As we have seen recently, the Australian floods are a little smaller than 1974 and smaller than the late 1800’s. The cost of adaptation to extreme weather is necessary whether or not catastrophic climate change causes an increased frequency of extreme events. There is no evidence that it does on a large scale (e.g. river basin). There is however evidence that extremes are more frequent on small scales (e.g. single rain gauges recording more extremes than before).

      Spending extra money now on wind, smart grid, etc can be cost effective in the long run but it won’t do much for the CO2 buildup. To lower CO2 or even get close to reducing the buildup requires a very drastic increase in fuels for living and driving and is politically unacceptable.

      • peddiebill says:

        I agree about the impracticality of doing anything about it on a serious scale. Lindzen and others seem to be saying that it is overreaction in the wrong direction.

  18. KAP says:

    16. “the steep increase in global temperatures through the 1980s and 1990s has now effectively flat-lined despite the steady increase of carbon dioxide and other greenhouse gases in the last ten years.”

    CO2 isn’t the only thing that affects climate, and that’s especially true on the short term. El Niño and La Niña are very big short term, as are volcanoes (if present). There are longer term ocean cycles that affect the climate on decadal scales, like the PDO, NAO, and AMO. Also, sulfates, which cool the Earth, and which had been declining during the 80’s and 90’s are back on the rise again. And all that makes for a lot of short-term noise that can mask the long-term signal.

    The thing is, though, that all these are relatively short-term compared to CO2, which only goes up. If you take a longer term look than just five years, or just ten years, the overall upward trend continues. For example, 2010 was either the warmest or second warmest year in the historical record. Either way, it was a “top ten” year for warmth. More significantly, we have had a “top ten” year for warmth for the last 17 years in a row. The last time we had a top ten coolest year was 1918.

    • petersonericd says:

      The natural fluctuations are evidence of the variability of amplification of warming. CO2 will eventually warm by a degree or so on average, but the natural factors that control weather will redistribute that warming unevenly. Then weather in each local area determines the ultimate response. In some areas like the desert and Antarctica it is fairly simple, CO2 warming will be amplified. In other areas such as the tropics it will likely be damped (e.g. Lindzen’s hypothesis applies there even if you don’t believe it can be extended beyong the tropics).

      • peddiebill says:

        You may be right – but becuse I know Lindzen is a recognised authority and I dont know how much experience you have my gut feeling is that Lindzen still knows what he is talking about. However it seems to me that since the effect of water in the atmosphere is actually far greater (see elsewhere on this site) I wouldnt personally over emphasise CO2 in this context.

  19. KAP says:

    17. “It even turns out that the sea level rise in the highly publicised case of the tiny coral atoll of Tuvalu is a non starter in that the sea level monitoring equipment installed in 1993 has detected no effective overall rise in the vicinity of Tuvalu and it turns out the inundation problems had more to do with erosion brought on by sand mining, construction and local industry depleting the water table and drawing in salt water.”

    Sea level is highly variable from place to place, and it would be a mistake to rely on a single tidal guage to determine of sea level is rising. Satellite records (which are global) go back to the early 1990’s and confirm that (a) sea level is currently rising by 3.2 mm/yr, which is about double the overall 20th century rate; and (b) that rate is accelerating. Further, future sea level rise depends on the stability of the Greenland and West Antarctic ice sheets, and ice sheet loss is known to be non-linear. Previous episodes of deglaciation have seen sea level rises of several meters per century.

    • Bill Peddie says:

      Well in fact for Tuvalu the satellite figures say 2mm per year (Tonga is 10 mm) Other places it is dropping. Aerial phots of Tuvalu show that it increased considerably in size since 1930 (see the University of Auckland study). You are right about the complications though. For example there is some geological evidence that the ocean is deepening, there is evidence that a prevailing wind for several months can cause the water to pile up on one side of a sea against land. But for serius ocean rise you will have to take my word for it that I have seen what happens when a king tide happens at the same time as a low pressure and please believe me when I say a couple of metres is more than 2 mm. Some sedimentary stuff sinks – and whole atolls will sink well beneath the ocean given the right circumstances. Even Darwin knew that. In New Zealand one side of the North Island is rising and the other sinking in at least one place. There is also a rebound effect when for instance a large ice sheet on land melts and the rebound can mean calculations about ocean rise are all shot. But in any case I thought my article was attempting to show that the whole picture is a little more complicated than is usually portrayed by the simple “global warming is just caused by human produced CO2” brigade. Telling me I have left out a few complications doesnt quite convince me I have failed. If I wanted to cover more I would have to write a text book – and I still would only cover a fraction of what is really happening.

  20. KAP says:

    18. “Since summer in a hemisphere occurs when that hemisphere is tilted towards the Sun, whether or not it is a particularly hot summer partly depends on whether or not the summer comes when the Earth is approaching a near point to the Sun in the orbit. ”

    This is essentially untrue. Earth reaches perihelion (the point in its orbit closest to the Sun) during the first week of January every year. That date does change slowly, but it takes tens of thousands of years to make a complete cycle around the calendar. Thus the severity of the summer is (for the scale of a human lifetime) independent of Earth’s orbit.

    “The tilt of the Earth on its axis also varies and fluctuates between 24 degrees and 22 degrees off upright. Since the tilt is responsible for the difference between summer and winter an increased tilt produces more extremes of temperature between summer and winter.”

    Again these changes take tens of thousands of years. Earth’s axial tilt has changed only 0.13 degrees during the past 1000 years.

    • peddiebill says:

      So all that stuff in the textbooks about wobbles in the orbit is wrong.

      • KAP says:

        No, it’s not wrong, but your text makes it seem as if orbital changes can cause significant differences between one year and the next. They can’t. Orbital changes are thousand-year and ten-thousand year timescale events. And it’s also worth mentioning, in this context, that since Earth’s orbit can be computed accurately for thousands of years into the past and future, we know that orbital forcing peaked 6000 years ago, and has been slowly cooling the Earth since that time; see Imbrie & Imbrie 1980. So orbital forcing can be ruled out as a cause for the current warmth.

    • petersonericd says:

      I definitely agree with KAP on this. Your reply above was that the NH land heats faster than the SH ocean (true but not relevant). But statements about relative summer temperatures do not follow from that (since the tilt is always the same every summer, differences in summer temperatures come from elsewhere).

      • peddiebill says:

        I am curious that you know the tilt is always the same. I thought that not only does the tilt change from 22 – 24 degrees but that because the Sun is not constant the angle at which you are facing the Sun can give measurable differences. It isnt my personal area of expertise so if you know better that’s great.

      • petersonericd says:

        Bill, as KAP pointed out the wobbles in orbit are long term so they are not a possible cause for any warmer or cooler summers. The wobbles are explained here http://www.ncdc.noaa.gov/paleo/milankovitch.html and basically they state that we are in the “cool summer, warm winter” phase of the wobble because the earth is closest to the sun in NH winter and farthest in NH summer. Since you are SH, you would look at it as earth is closest to the sun in your summer and farthest in your winter.

      • peddiebill says:

        I totally agree about the effect of orbital shape on temperature, but I would not have thought it was that simple. For example if you are close to the Sun when Sun spots are active it is going to be a bit different to being close to a quiet Sun. I thought our orbit was slightly affected by where the planets were but I have never bothered to do any calculations. Another unknown – to me I mean – is why el Nino suddenly seems to swap over to La Nina. If the Earth trundles along over the same path into predictable distances from a stable Sun why should a major driver of the weather suddenly change. I asm sure it is common knowledge somewhere, but I certainly dont know the answer.

  21. KAP says:

    19. “The Earth’s wavering distance from the Sun, and the fact that the solar system itself is continuing to move through our home galaxy, cause us to encounter varying concentrations of cosmic rays which in turn appear to affect the formation of high clouds in our atmosphere which are generally thought to moderate the degree of cooling or warming.”

    The cosmic ray theory was all the rage a few years ago when Stensmark proposed it. As a result, a lot of people studied the question, and now the results are in: it’s been thoroughly debunked, in study after study. Time to drop this one.

    • peddiebill says:

      You had better send a message to Auckland University Physics Department and tell them to stop wasting their time then! They are still under the naive impression that clouds are still not well understood and think they are beginning to learn more by their experiments.

      • KAP says:

        I certainly hope someone at Auckland U. is already aware of, e.g., Kazil et. al. 2006, Sloan and Wolfendale 2008, Kristjansson et. al. 2008, Calogovic et. al. 2010, and Kulmala et. al. 2010, none of whom found a relationship between clouds and cosmic ray flux, in spite of looking for one. I know of no study that has confirmed the cosmic ray hypothesis; so until (if) such data appears, it is safest to assume that this idea is a non-starter as explanatory of the current warmth. This may be another case (like solar activity) of a small natural forcing being overwhelmed by the large anthropogenic one.

      • peddiebill says:

        121.74.133.4 Submitted on 2011/01/22 at 11:07 pm | In reply to KAP.
        Oh for heaven’s sake. Surely we shouldnt only read papers that you have heard of. For example if I should know about your papers you should equally know about papers that say the opposite. For example Laken, Kniveton, and Frogley have found just such a a connection between Cosmic Rays and cloud formation. Because you appear to want to examine me on every small detail of the science of what I presented as a paper for the populist market – ie non scientists with great reluctance I give you the the abstract and select passages from the paper, along with a link to the full paper:

        Atmos. Chem. Phys., 10, 10941-10948, 2010

        doi:10.5194/acp-10-10941-2010

        Cosmic rays linked to rapid mid-latitude cloud changes

        B. A. Laken , D. R. Kniveton, and M. R. Frogley

        Abstract. The effect of the Galactic Cosmic Ray (GCR) flux on Earth’s climate is highly uncertain. Using a novel sampling approach based around observing periods of significant cloud changes, a statistically robust relationship is identified between short-term GCR flux changes and the most rapid mid-latitude (60°–30° N/S) cloud decreases operating over daily timescales; this signal is verified in surface level air temperature (SLAT) reanalysis data. A General Circulation Model (GCM) experiment is used to test the causal relationship of the observed cloud changes to the detected SLAT anomalies. Results indicate that the anomalous cloud changes were responsible for producing the observed SLAT changes, implying that if there is a causal relationship between significant decreases in the rate of GCR flux (~0.79 GU, where GU denotes a change of 1% of the 11-year solar cycle amplitude in four days) and decreases in cloud cover (~1.9 CU, where CU denotes a change of 1% cloud cover in four days), an increase in SLAT (~0.05 KU, where KU denotes a temperature change of 1 K in four days) can be expected. The influence of GCRs is clearly distinguishable from changes in solar irradiance and the interplanetary magnetic field. However, the results of the GCM experiment are found to be somewhat limited by the ability of the model to successfully reproduce observed cloud cover. These results provide perhaps the most compelling evidence presented thus far of a GCR-climate relationship. From this analysis we conclude that a GCR-climate relationship is governed by both short-term GCR changes and internal atmospheric precursor conditions.

        (Well maybe this will turn out to be incorrect in the long run. Certainly Newton didnt go too well after Einstein came along. But lighten up. Science will continue to discover more and gradually we will all have to start noticing what is discovered and not get too cross because others havent noticed the tiny corner we know about.)

    • petersonericd says:

      There is a relationship shown from cosmic rays to low clouds but no relationship from those low clouds to global temperatures.

      • peddiebill says:

        I think with due respect the Jury may be still out on that one. I am assured by climate scientists that there is a complex balance between warming (mainly through condensation) and reflectivity from cloud tops and a host of minor complications. However if you have got it all sussed thats fine by me.

      • petersonericd says:

        I don’t have GCR influences all figured out, far from it. I am still interested and still researching it. However the simple answer for now is that the fluctuations in low clouds during recent GCR fluctuations has not resulted in noticeable changes in climate.

      • peddiebill says:

        I would have thought that they are still at the sorting out what happens with clouds and local weather. When they have that sussed, I guess they will be ready for the much more sophisticated questions about climate. All those factors like evaporation, water condensing, cloud reflecting, dust involvement, aerial bacteria involvement, heat store, pollution of air, species present, cloud type as well as height etc etc keep messing up the measurements. eg sea surface surface temperature has a lot to do with green house gases like water and carbon dioxide and this varies widely from place to place. When those researching clouds tell me it is complicated and only dimly understood, I actually find that quite plausible. Cosmic dust appears a greater influence on cloud formation than first thought as well.

  22. KAP says:

    20. “in the 3 June, 2009 writing in the journal Nature, Lockwood et al. published a study entitled “A Doubling of the Sun’s Coronal Magnetic Field during the last 100 years” in which they suggest an important role for the Sun as did a series of papers by Scarfetta and West showing that the total Solar Irradiance was increasing between 1980 and 2000 . To a number of these scientists this pointed to the Sun being a main factor in the increasing global temperature over that time.”

    First, Lockwood’s paper was 1999, not 2009. Second, while the role of the Sun’s irradiance is well known, the role (if any) of the Sun’s magnetic field on Earth’s climate is speculative at best. Third, there is a rather significant difference between the TSI (total solar irradiance) values derived from satellite; two groups, called ACRIM and PMOD, show significant differences, with the ACRIM data showing an increase since 1980 and PMOD showing a decrease. The Scafetta (note spelling) & West paper was relying on the increasing ACRIM data. But recently multiple studies have confirmed PMOD data as being more accurate: it fits UV data better, it fits sunspot data better, it fits alternate satellite data better, and it fits solar magnetogram data better. It also fits solar TSI proxy data better. At this point, the debate is essentially over: there has been no increase in TSI since 1980, and in fact the reverse is true.

    • peddiebill says:

      You never give up!!

    • peddiebill says:

      Yes of course I made a careless mistake about the date and admit the careless spelling of Scafetta as Scarfetta…what was I thinking?
      You may be right in fact – yet since a number of papers have been published making the same claim – and since we can have absolutely no idea for example on the relative contribution of all ways in which the Sun interacts with the Earths magnetic field – and hence with the protection against cosmic rays which in turn helps control the cloud cover which which in turn reflects and also generates heat as water drops condense etc etc isnt it possible that the Solar changes change the weather. When I talk to the Solar physicists they appear far less certain about the final answers than you do, so please help them sort it out. In the professional science world the debate is never over even if in Readers Digest land all is clear and sorted for all time.

    • petersonericd says:

      TSI is a red herring. Lockwood’s work explains phenomena like the current blocking weather patterns and similar patterns in the 70’s. Blocking is obviously not the same as cooling and it is a mistake to try to correlate solar activity to temperature.

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