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Published online 12 March 2009 | Nature | doi:10.1038/news.2009.165
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Copenhagen summit urges immediate action on climate change
Scientists report intensifying impact of global warming.
Climate experts who met this week in Denmark have warned that the overall prognosis on climate change is worse than previous estimates have suggested.
More than 2,000 delegates - including climatologists, social scientists and economists - from 80 nations gathered for the International Scientific Conference on Climate Change in Copenhagen from 10–12 March.
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Another doom and gloom gathering to further their own agenda. "Immediate action" for results that their own experts say will take centuries to reverse. The TOP estimate of the IPCC report gave a sea rise 0.59 metres by the end of the Century but ONE climatologist says it "could rise as much as 1 metre". On the basis of that IMMEDIATE action, causing immeassurable economic loss to the world, must be taken by world governments? Give us a break. In the meantime the US National Science and Technology Council is reanalysing Climate data to understand acknowledged failures in their own models. Failures such as the failure to observe any summertime warming trend over the Great Plains of the United States and the absence of a warming trend in both winter and summer over portions of the southern United States during the period 1951 to 2006. Also the failure to observe any discernible trend during this period in annual average North American precipitation - so much for the doom and gloom of crippling droughts and famines. This despite finding that seven of the warmest ten years for annual surface temperatures from 1951 to 2006 occurred in the last decade and virtually all of the warming since 1951 has occurred after 1970. In fact they say that drought conditions for the western United States are considerably less severe and protracted than those that have been estimated for time periods in the twelfth and thirteenth centuries - a time when there were no cars and factories and the world was "green". The fact is climate is never stationary, it has been warmer and colder than it is today and the pitiful recommendations of the pitiful actions do not have a hope in hell of changing this. "A clear statement from 2,000 scientists" can be blown away by just one well reasoned argument.
So, if I get the gist of your post correctly, the reason that climate can change - in shorter but also longer cyles - in unpredictable ways, even without human impact, allows us to just *ignore* the results of our actions? Let us set aside the aspect of 'immesurable economic loss' (so who is the doomsayer here), this type of logic seems similar to saying: "there are probably millions of species that have become extinct in the process of natural selection in the history of our planet, so we need not concern ourselves with the fact that human actions will add only some thousand more to this list".
The dam is leaking? Well, it always leaked a bit let's not make a fuss about it. Let's shower and play in the water that leaks, the new cracks are great because more people can join, nothing will happen...
The scientific community operates under the most rigorous intellectual disciplines achieved by human kind. There is a strong empirical understanding of the mechanisms by which greenhouse gases trap heat in the atmosphere and influence surface temperature and we know we would not exist without greenhouse gases. The composition of the atmosphere can be measured to very high levels of accuracy. Ice core studies show that the levels of carbon dioxide in the atmosphere track historical temperature levels. The feedback mechanisms by which increasing temperatures can trigger the release of reservoirs of trapped greenhouse gases that dramatically increase green house gas concentrations and therefore temperatures are well understood. Those people who discount the possibility of human forced climate change and argue for inaction need to realise they are making significant assumptions which are untested and contrary to common sense. Their arguments take various forms. They look for the existence of localised counter-examples that contradict the major trends. They delight in one scientist questioning aspects of the work of another, forgetting that it is precisely this process that ensures the integrity and quality of scientific study. They use time lines to make negative changes seem acceptable. A one metre sea level rise over 100 years seems minor but not if it is a mere way point on a process that will result in sea level rises of 70 metres over 400 years and which became irreversible in 2030. For the average person this situation is confusing and the vested interest groups seek to maximise the sense of confusion and uncertainty in order to undermine calls to action from environmental groups. It seems the best way to approach the issue of climate change is from a risk management perspective and common sense. A major source of human greehouse gas emissions relate to the burning of fossil fuels such as oil and coal in vehicles, power stations and industry. Fossil fuel reserves are finite and will be exhausted within the next few generations. In the long run, the oil and motor companies that derive their existence from the use of fossil fuels will either evolve or die. In absolute terms, their market capitalisation is a tiny fraction of the net financial worth of the world and their survival is not in any way essential. It is inevitable that humanity will need to adopt sustainable energy sources that are as directly linked to the sun as possible and constrain our use of planetary resources to ensure our long term survival on Earth. Therefore, given that scientists have identified mechanisms by which human-linked changes in the concentrations of atmospheric greenhouse gases can have a major effect on global temperatures, ice sheets and sea levels and our understanding of how such changes will affect our civilisation, there is no point in delaying the transition to a sustainable lifestyle. The world economy has been tipped into chaos by the actions of a few fools in the financial services industry abetted by laissez faire politicians. The inundation of low altitude infrastructure and farm land by rising sea levels; the decimation of agricultural production by drought and temperature changes; the loss of fresh water supplies from glacial-linked precipitation and rivers; forced migrations away from barren landscapes; and the prospect of conflict over scarce resources will destroy vastly larger amounts of wealth and cause immense suffering and personal tragedy. In these times of economic retrenchment, a serious redirection of huuman resources and activities towards the adoption of low-carbon sustainable energy and transport systems would provide a much needed stimulus that would pay tremendous dividends well into the future. I believe it really is time to act - the risks of doing nothing are too high.
"On 10 March, climatologist Konrad Steffen of the University of Colorado at Boulder said that sea levels could rise as much as 1 metre by 2100, according to new analyses of ice loss from Greenland." How is that news, or even scientific? Of course "sea levels could rise as much as 1 metre by 2100". What did he say the probability was that sea levels would rise by more than 1 metre by 2100? What did he say about the most probable sea level rise in the 90 years until 2100? What did he say was the most probable sea level rise in 2020? In 2040?
Richard Mitchell-Lowe "the most rigorous intellectual disciplines achieved by human kind" are not based on the opinions of one climate scientist with 2,000 others saying hear hear like parrots. The article itself states "The information presented this week in Copenhagen will ..not have the rigor or the authority of the IPCC assessments". You have stated that "Ice core studies show that the levels of carbon dioxide in the atmosphere track historical temperature levels". Actually they dont. Historical temperature levels are tracked by levels of CO2, by a lag, on the average, of several centuries. Do you pretend to know all the answers without question about our future climate? Can you explain how despite the trillions of tons our cars and factories are combining carbon with oxygen, oxygen levels are not reducing anywhere in the world? The living eco-system has kept not only the natural consumption of oxygen in balance but has supported civilisation's massive industrial consumption. If you believe it is time to "act" what action do you suggest? Climate scientists are not engineers nor necessarily do they have political acumen. Is your recomended action practical? Assuming your suggested "action" is acted upon in unison by all the world - can you quantify what effect this will have on global warming? On our future climate? Do you really believe we can design our own climate for the future?
The information presented this week in Copenhagen WILL FORM the basis of a 30-page document, (YET) to be published. It WILL BE peer reviewed. The conclusions have already been reached however. This is the very antithesis of science. "The most rigorous intellectual disciplines achieved by human kind"?? Give me a break.
First, as someone who was in Copenhagen last week, thanks for the clear insight and straight talk in this most difficult story. There is true scientific agreement, but with such difficult news to deliver, I understand that many find it too painful to believe the implications of the research. I personally think that if we can stare the hard news in the face, we can grieve together the loss of our beautiful imagined future and then get to work on creating the best one we can manage. A bit like facing the loss from a divorce before you can build the next stage of your life.
Richard Dawson "Can you explain how despite the trillions of tons our cars and factories are combining carbon with oxygen, oxygen levels are not reducing anywhere in the world?" Oxygen levels have decreased roughly 0.1% from preindustrial times (Keeling). We are now at 20.9% O2 and humans will suffocate at 19.5% O2, so at the current rate we may concentrate on the effects of increased atmospheric CO2. The oceans are indeed suffering from oxygen depletion, so we better do something about it or humans will finish the work of being the main cause of the holocene extinction event faster than anybody would like. Your comment "Historical temperature levels are tracked by levels of CO2, by a lag, on the average, of several centuries." is a fact that shows that CO2 was not the driving force in the last many glaciations. That does in no way rule out the very well documented greenhouse effect of CO2. The greenhouse effect can runaway due to CO2, which is what happened to Venus.
Richard Dawson asks "Can you explain how despite the trillions of tons our cars and factories are combining carbon with oxygen, oxygen levels are not reducing anywhere in the world?" I for one would love to hear you scientists try to explain that one away. Bah! Much like Mr. Dawson, I also scoff at scientists and their ridiculous theories of "combustion" and "deforestation", and their liberal "save the world" agenda.
Jacob Bock Axelsen your statement that oxygen levels have decreased by 0.1% since preindustrial times and humans will suffocate at 19.5% is typical of the scaremongering statements put out by climate scientists who lose scientific objectivity. According to Dr Keeling, on whose authority you have based this statement, the total ESTIMATED atmosphereic oxygen CONSUMPTION due to industrial use since the industrial revolution should have been 0.095% of the atmospheric oxygen. This does not take into account the oxygen added to the atmosphere by living organisms, who were responsible for the oxygen being in the atmosphere in the first place. Again according to Dr Keeling "the oxygen loss is too small to be much of a concern." I dont know where you get your figure of humans suffocating at 19.5% oxygen, but oxygen levels on the Peruvian plateau and Tibet should be less than 19.5% those on sea level and humans have adapted there quite well. Oxygen levels on Earth have varied between 15% and 30% during the past few hundred million years and animals have adapted quite well to the differing levels. High oxygen levels are associated with shorter lifespans though. That historical temperature levels are tracked by levels of CO2, by a lag, on the average, of several centuries not only shows that CO2 was not the driving force in the last many glaciations but it was not the driving force in the last many global warmings. The last many global warmings were in fact the driving force of the CO2 increases. Now however the CO2 increase is claimed as the driving force of the global warming, quite without historical precedent. Venus is 1/3 of the distance closer to the sun than us. Could that also have been a factor in their run-away greenhouse effect?
Richard Dawson I was referring to the fact that a normal person will be affected at 19.5% oxygen, however you can acclimatize down to 10%, where it becomes impossible to increase the capacity of your oxygen delivery system without EPO and other drugs. Therefore it is CO2 that is of concern for now. Remember also that climate changes are occurring at a rate (centuries) where multicellular organisms will only have on the order of ten generations or less to adapt to radically different ambient conditions. Therefore we may lose most of wild mammalian lifeforms within the 21st century. Regarding Venus it is outside the habitable zone where it can sustain liquid water, which combined with the absence of a carbon cycle is why the greenhouse effect took over. The CO2 greenhouse effect increases the surface temperature on Venus more than 400 degrees Celsius (day and night) and that is even when 60% sunlight is reflected by clouds. On Earth it is only 30C. Mercury is 400C at day and -200C at night because it does not have a atmosphere. CO2 was not a driving force in historical glaciations, why does that preclude it from being a driving force now? It is understood in full detail to be true from quantum mechanical calculations and both simple and detailed weather models through laboratory experiments to satellite observations.
Jacob Bock Axelsen I couldnt let the innacuracies in your post go without comment. Any normal person will not be affected by 19.5% oxygen in the open atmosphere. The OSH standards for closed spaces do not apply to the open atmosphere. In a confined space, like an underground cave, a well, a submarine or the space station, every breath you take, ups the CO2 content of the space, this is not true of the open atmosphere. A drop of 19.5% from the current 20.95% represents a 7% drop approximately. Atmospheric pressure falls about 3% for every 1000 ft in altitude. Applying Boyle's Law at an altitude of a mere 2300 ft the atmospheric oxygen would be less than 19.5% of the amount at sea level and millions of people live at this altitude. The Tibetan Plateau has an average height of 15,000 ft. At that altitude the Oxygen levels are a mere 11.5% of that at sea level and humans have adapted there just fine too. .On Mt Everest at 28,000 ft the O2 levels are are less than 3.5% that at sea level and it has been climbed many times without oxygen. Then again is it LIKELY that the O2 levels will fall to 19.5% of their present value? The answer from direct measurements is a resounding NO. Over a 10 year period, from 1991 to 2001 one station calculated a total decline of 0.0003%, which means that the living eco-system has not only kept natural oxygen consumption in balance, but for all practical purposes has supported our massive industrial consumption also. Dr Keelings opinion that the oxygen loss is "too small to be much of a concern" is correct. I agree that there is nothing to stop CO2 being a driving force in the present global warming observed over the last few decades, but there is nothing to stop natural causes such as the sun's radiation being a driving force either. The amount of sunlight shining on the surface of the Earth has an excellent historical corelation with global warming and cooling whereas co2 has none.
Richard Dawson - even as a student of climate science I find the correlations between anthropogenic greenhouse gas emissions and global temperature rise to be blindingly obvious. The current atmospheric CO2 concentration is 383ppm, a great deal more than the range (approximately 180-280ppm) which has occurred naturally over the last 2 million years, through ice ages and interglacials. We know the chemistry behind the effect that CO2, methane and other greenhouse gases have on increasing global temperatures. Go read the literature, it is indisputable, their radiative forcing values are well documented. Unless you have a research background in molecular chemistry and you wish to dispute the fact, globally acknowledged by the scientific community, that greenhouse gases regulate ambient temperatures on Earth? We know that human civilisation, over the last 200 years, has been pumping out immense quantities of greenhouse gases, largely through burning fossil fuels. If you don't believe that the atmospheric CO2 increase is due to humans, what is your explanation? As has been explained above, it is not just the magnitude of global climate change that is at issue, but the rate of change - which may be too quickly to allow many species (including us) to adapt. But finally, if the IPCC found in 2007 that human warming of the climate system is 'unequivocal', I can't see how we should be expected to listen to just one person such as yourself. Even though the vast majority of the global scientific community, and politicians, accept the reality of climate change, there will always be naysayers such as yourself who protest "the world is flat, the world is flat". As Stern and others have demonstrated, the economic consequences of doing nothing are far greater (5-20% world GDP) than those of mitigation (approx 1% world GDP). The risks are high, global opinion is practically unanimous, so it's time for the blogs and comments of the world to stop debating whether climate change is happening and start debating what we are going to do about it! In my humble opinion :)
Richard Dawson The measured 30 ppmv (0.0003%) drop in atmospheric oxygen over 1991-2001 is the offset created by consuming oxygen through the burning of fossil fuels which have caused a 15 ppmv increase in CO2 during the same period. This rate tranfers well to the entire industrial period and leads to a total drop of 0.1%. The ecosystem is therefore certainly not keeping natural oxygen in balance. It is also well-known that variability in solar radiation at the surface (+-0.2 W/m2) is roughly one order of magnitude lower than the forcing of man-made greenhouse gases (+4 W/m2). Sun spot theories and the influence of cosmic rays seems both to be of minor influence. Your claim that CO2 has had no historical influence is wrong, since the hot-cold transitions are much slower than the cold-hot transitions (the latter known to be influenced strongly by CO2 positive feedback). Regarding adaptability to low oxygen: at least 200 mountaineers have perished while trying to climb Mt. Everest with severe hypoxia known to have been contributing to their fate in the hostile environment. The tibetan plateau is populated at the acclimatization boundary of 10% oxygen, but many of these native highlanders (including peoples in the Andes and African higlands) do indeed suffer from chronic mountain sickness. These examples show the problem with the current rate in man-made climate changes: it is occuring at catastrophic rate compared to the required adaptation times (when the physical parameters allows for adaptation at all, that is). In summa: we run the risk of being the most despised generation of multicellular life on Earth of all times if we do not wisen up and start being efficient.
Shelley Moore there many things that are "blindingly obvious" but not true. Appearances can be deceptive. "Blindingly" is the operative word. You ask "If you don't believe that the atmospheric CO2 increase is due to humans, what is your explanation?" I can?t answer that question as I do believe that atmospheric CO2 has increased due to human industrial activity - I never said I didn't. What many climate scientists (and Al Gore) say is that the CO2 increase caused by humans is the cause of global warming of the last 3 decades or so. CO2 has gone up and so has the temperature. CO2 is also a greenhouse gas - so QED! - CO2 (and by extension humans) is responsible for global warming. Very neat, very "blindingly obvious" but very NOT "unequivocally" true. You say that "if the IPCC found in 2007 that human warming of the climate system is 'unequivocal', I can't see how we should be expected to listen to just one person such as yourself". Fortunately even the IPCC, whose science has been clouded by politics and bureaucracy, doesn?t say that. What it said was "Warming of the climate system is unequivocal". "Human" is something you have inserted. To be fair they did say that "there is a 90% chance" that global warming is caused by "human activity". But then the IPCC also waived around the infamous "hockey stick" as their triumphal "proof" of global warming. Nothing about today's climate is unique. The Earth has been warmer and colder than today. The Earth has had more and less CO2 than today. The only thing that maybe unique is (possibly) the rate of increase of CO2. Even this is doubtful as the Earth has been far more volcanic in the past. Massive volcanic eruptions of the past could quite possibly have dwarfed human emissions of CO2 today. Ice core data shows that the historical global CO2 levels follows that of global temperatures very well. But with a lag. CO2 levels fall and rise AFTER temperature has done so. It cannot therefore have been the cause of the temperature rise or fall, which must have been due to other reasons. The fact is we have very little understanding of our climate to attribute simplistic causes to climatic phenomena. There are wide gaps in our evidence and knowledge. We have very little data on solar radiation, which is taken to be constant but is in fact not. A NASA funded study published in 2003 found that since the late 1970s, the amount of solar radiation the sun emits, during times of quiet sunspot activity, had increased by nearly 0.05 percent per decade. This could cause "significant climate change" according to the lead researcher Richard Willson. He also said "Historical records of solar activity indicate that solar radiation has been increasing since the late 19th century. If a trend, comparable to the one found in this study, persisted throughout the 20th century, it would have provided a significant component of the global warming the Intergovernmental Panel on Climate Change reports to have occurred over the past 100 years". There is evidence of global warming on Mars and Jupiter also during the last 3 decades. It is arrogant and naive to assume that we can control our climate simply by fine tuning our CO2 emissions. Global warming may not be as catastrophic as Al Gore makes it out to be. It has not proved to be so far. Global cooling would be far more catastrophic. America and Europe could not survive if they were covered with several metres of permanent ice. And finally it is not only me who has these views. Richard S Lindzen, Professor of Meteorology at MIT and contributor to the IPCC has this to say "there is no consensus, unanimous or otherwise, about long-term climate trends and what causes them" and "I cannot stress this enough - we are not in a position to confidently attribute past climate change to carbon dioxide or to forecast what the climate will be in the future..." And recently a Panel of Japanese scientists ridiculed the IPCC and anthropogenic global warming likening it to "ancient astrology" saying "We should be cautious, IPCC's theory that atmospheric temperature has risen since 2000 in correspondence with CO2 is nothing but a hypothesis." And "(The IPCC's) conclusion that from now on atmospheric temperatures are likely to show a continuous, monotonous increase, should be perceived as an unprovable hypothesis, .. Before anyone noticed, this hypothesis has been substituted for truth... The opinion that great disaster will really happen must be broken."
Mark - The maximum number for sea level rise in the ipcc 2007 report was 0.59m by 2100 and that didn?t account for ice sheet dynamics. Now Steffen and other glaciolgoists have been able to put a number on the contribution to sea level rise from the actual discharge of glaciers into the ocean, based on new models that incorporate more than just surface melting. And the results show that sea levels could rise by a maximum of 1m by 2100. I don?t know if he put numbers on mid way points but what's important is the end of century figure, as that?s comparatively high relative to other previous projections.
Richard - The whole point of the conference was to update the science since the IPCC's 2007 assessment and to produce a summary report, just like the IPCC summary report. Science that has yet not been published can be fed into this summary, on the basis that there have been important findings since 2007, and the overall document will be peer reviewed by the Earth System science partnership, and by the conference convenors. I'm guessing that's why the statements at the end of the conference were rather general. Of course one could ask how rigorous the peer review will be - I don't know the answer to that. what I do know is that it won't have the political vetting of the IPCC reports.
Jacob Bock Axelsen, in science we have to believe evidence over theory. Theoretically we should have consumed 0.1% of our oxygen since the industrial revolution, around the 1840's, till now according to Dr Keeling's detailed calculations. But on actual measurement during a time of peak Oxygen consumption the drop was only seen to be 0.0003% per decade. Extrapolating from this in the 25 decades since the Industrial revolution the drop would have been only 0.0075% or 13.3 times less. That is only 7.5% of the expected fall. Clearly 92.5% of the consumption has been made up by our ecosystem. As I pointed out, with Oxygen levels at 19.5% of the atmosphere we will have absolutely no problem in breathing and surviving. A simple calculation shows that, even at the current measured rate of depletion, it will take 483,000 years to reach that level. So maybe we could cease any alarmist talk about suffocating due to lack of oxygen. Regarding CO2, we are making a huge fuss about CO2 levels being around 384 ppm. 100 to 250 million years ago the CO2 content was considerably more, varying between 1,000 to 2,000 ppm. Yet the temperatures were estimated to vary between no more than -2 to 6 degrees higher than today (periods when the temperature were 2 degrees less and up to 6 degrees more than today). There was no run-away greenhouse effect. In fact we managed to fit in long glacial periods between 175 and 300 million years ago when the CO2 levels were sizzlingly high. Clearly this would not be possible if CO2 were the only cause of global temperatures. All evidence contrary to CO2 being the cause for imminent catastrophe is vigorously attacked and denied. In fact as the Copenhagen summit has shown prophesies of doom based on CO2 are getting more shrill and urgent. We are urged to take action on a hypothesis that the Japanese scientists quite rightly have likened to "ancient astrology".
Richard Dawson If oxygen drops 30 ppmv over 25 decades you end at a total of 750 ppmv which is 750/210,000 = 0.4% (Keeling had 0.1%). The linear extrapolation overshoots because we are actually burning fossil fuels faster and faster. Therefore, evidence shows that photosynthesis is absolutely not keeping atmospheric oxygen levels steady. Your claims about both Mt. Everest and highlanders were not examples of good adaptation. Re. the supervolcano argument you have to consider the net effect of what the volcanoes inject into the atmosphere. The huge amounts of CO2 would increase the greenhouse effect, but conversely the huge amounts of particles would increase albedo and thus it is speculated they could trigger small ice ages. Re. the difference in levels of CO2 and the temperature in the distant past: there is not just one unique attracting state defined solely by these two variables. The Earth is not static over millions of years and the stable fixpoint has drifted in conjunction with ocean cooling, sea level variations and continental reconfiguration. Man made climate change is not just about sensitivity to perturbations at the current value of the fixpoint. A sudden increase in CO2 could cause a sudden increase in temperature no matter when or where - particularly when CO2 is low (as it is now). Re. the Sun and the Solar system: no global warming has been reported of Mercury, Venus, Saturn, Uranus and their many satelites not forgetting our own Moon i.e. for more than 170 objects. The reported slight warming of Mars has been calculated to be related to lowering in albedo from redistribution of dark dust in huge storms during the Martian summers. The climate on Jupiter is always changing, but there is no clear evidence that is it warming up globally, since the poles are also cooling. There are similar warming claims about both Triton and Neptune, but their orbit time is 165 years so the effects seen there are better explained by heat fluxes related to seasonal changes (the same goes for Pluto). For example, since Triton receives 1.5 W/m2 the reported 2K change cannot physically be explained by the 1/1000 W/m2 variability in solar irradiance. I will not cease being alarmed by humans causing the largest extinction event in 65 million years.
Jacob Bock Axelsen there is nothing wrong with the calculation that it will take 483,000 years to reach 19.5% of the oxygen levels of today. No one lives on Mt Everest so of course they cannot adapt to those conditions, but the inhabitants of the Tibetan and Peruvian Plateau, not to mention those at lower altitudes, have adapted very well there. Without quibbling over small details or irrelevancies, the message is there is nothing to worry about the oxygen levels for hundreds of thousands of years to come. I said there is some evidence that there has been global warming on other planets. You are quite sure there has been none. You are quite sure about the sun's irradiance. However those who are measuring this, NASA's SOURCE, are not quite as confident as you. This is what they have to say "Despite all that scientists have learned about solar irradiance over the past few decades, they are still a long way from forecasting changes in the solar cycles or incorporating these changes into climate models...the most accurate estimates of the long-term average TSI ARE UNCERTAIN BY SEVERAL TIMES THE AMPLITUDE OF THE 11 YEAR CYCLE...Even larger uncertainties exist for measurements of the amount of solar radiation that is absorbed by the Earth?s atmosphere, ocean, and land.. WITH SOLAR RADIATION, A 5 PERCENT DIFFERENCE IS HUGE. A DIFFERENCE OF EVEN 1 PERCENT WOULD COMPLETELY THROW OFF CLIMATE MODELS OF GLOBAL WARMING.." CO2 climate change advocates while trying to explain why 2008 has been the coldest in this century or 2009 pretty cold so far say there is "nothing unusual" about this and say "the anthropogenic influence on global temperatures, while surely omnipresent, is not of a magnitude which prevents the influence of natural variations within the earth?s climate system from dominating the global temperature record for periods of years to perhaps even decades..." Well if natural causes can swamp anthropogenic influences, and in view of the uncertainties of these causes, how can the IPCC say that Global Warming is "Very Likely" caused by humans? Would it not be more honest to say instead like Richard Lindzen that "we are not in a position to confidently .. forecast what the climate will be in the future"? or attribute it to anthropogenic CO2? Is it not possible that Global warming is due to natural causes, in view of some evidence towards that as I pointed out? You would agree that Obama and other political leaders would not be able to reduce the suns radiance by legislation.
Richard Dawson A yearly 3 ppmv drop in oxygen to 19.5% would take (209,460-195,000)/3 = 4,800 years. The actual (short-term) adaptation limit is bounded below by the alveolar oxygen pressure of 13kPa, but that does not prevent chronic mountain sickness from occuring in the highland population in both Tibet and Qinghai provinces of China as has been very well documented. There even exists an active scientific journal named High Altitude Medical Biology. Fast adaptation is not something you can count on, which is why half of all mammals may become extinct during the 21st century. Re. solar irradiance: the best estimates from both satelite and proxy evidence of solar irradiance gives a 0.1 W/m2 surface increase since 1750. You are confused by the calibration error of the sensors of NASA's Earth Observatory satelites, which they use as an argument to gain more funding, and quite correctly so. Nowhere does NASA claim that 5% or even 1% increase in solar irradiance occured in the last 250 years. If you are looking at 2009 being cold and concluding that the theory failed, you could not be more wrong. The Copenhagen Summit revealed that the climate is worse than predicted i.e. including the current cold spell. You argue that humans are dwarfed by natural events, which is true. The climate superimposes different mechanisms such as f.ex. El Niño which caused the hot spike in 1998 and Pinatubo which caused cooling in 1993. Take out 1998 from the record, and the whole of the 21st century is significantly warmer than the last 2,000 years. Humans is just one of the mechanisms, and we are causing the atmosphere to retain heat. It has been calculated and demonstrated. Re. the planets heating up, it is not an issue of taking side. I have just referred the sources. The physics is clear: Mars is the only planet that is heating up, but it is much less than Earth (corrected for distance) and probably not because of the sun. Richard Lindzen personally endorsed the 2001 IPCC technical report, so your qoute seems to indicate that he thinks the predictability of models should be better. It always should, though it has been shown that the models can reliably hindcast the 20th century. Also, Lindzen thinks the link between smoking and lung cancer is not perfectly established - so he keeps on smoking. That is bad risk management and not recommendable for Earth.
Jacob Bock Axelsen, I revisited my calculations and I have made a mistake. The drop was 0.0003% per decade and not 0.00003%, which I used. This would take 48,333 years or 48,000 years if you wish, but not 4,800 years as you have worked out. Whereas mountain sickness may occur in some small percentage of the population of Tibet, and the data is very sparse, the big majority of them do not suffer from it. One study in 2006 among children in Tintaya, Peru at an altitude of 4,000 metres, found only 1% with heart problems that could possibly be attributed to high altitude. This is from the High Altitude Medicine & Biology journal. All this points to adaptation by the populations. NASA has not claimed that solar irradiance has increased by 1% or 5% in 250 years, because as NASA has confessed, it simply does not know. However if we extrapolate an actual measurement of 0.05% increase per decade over 25 decades we get an increase of 1.25%. Or would you only extrapolate where it convenient for your hypothesis? Also solar irradiance effects climate in many ways as yet poorly understood, such as that absorbed by the Earth's atmosphere, ocean, and land. Even NOAA claims that by their best estimate (best guess) only 50% of the current global warming is attributable to human causes and 50% to natural causes. Natural causes both cool and warm. And they do this cyclically, sometimes with small cycles, as the medieval warming period and little ice-age has shown. You have acknowledged that natural causes can overwhelm anthropogenic warming. Also we have no control over natural causes. No wonder we cannot predict our future climate. Let us pray therefore for a warmer period as another ice age - little or big - would be catastrophic for humanity.
Richard Dawson The CSIRO has measured a 3 ppmv drop in atmospheric O2 per year from 1978 to 2001, in accordance with Keeling's numbers and mass conservation laws related to the burning of hydrocarbons (remember: 3 ppmv = 3/1,000,000 = 0.000003 = 0.0003% per year). The living ecosystem is not keeping atmospheric oxygen in balance, otherwise there would have been no excess CO2. According to Encyclopedia Britannica native human highlanders are not adapted, only acclimatized, to the reduced oxygen which can lead to chronic mountain sickness (CMS). Indicative of this is that upon descent their physiological state reverts to normal. The concensus statement on high altitude diseases published in High Alt Med & Biol (2005) mentions that 5-10% of all highlanders could develop CMS or pulmonary hypertension making it common. Real adaptation to low oxygen, as you imply, has not occurred. Willson's solar irradiance study conflicts with other satellite measurements of the same period (Lockwood & Froelich (2008), Scafetta (2007)). The actual solar radiative forcing of 0.1 W/m2 comes from the record of sunspots and radiometry of C-14 and Be-10, as acknowledged by NASA Goddard Inst. Lacking a solid causal explanation you cannot extrapolate an uncertain rate arbitrarily from a single decade of observations. If so, we should have had constant zero sunlight 20,000 years in the past. I would at anytime concede that humans can be superceded by other events without contradicting myself. For example, just contemplate that solar irradiance drops a full 100% at night, hugely dwarfing any conceivable human influence 50% of the time. The result in terms of radiative forcing is still that humans have and are influencing the climate by emitting greenhouse gasses. That NOAA puts this influence at 50% is uncontroversial. Re. your previous question about changing solar irradiance through legislation: it is speculated to be achievable by placing a 10 billion USD 'sun shade' at the Earth-Sun L1 Lagrange point. Personally, I would prefer a simple switch to local production of algae fuel and pump part of the oil back into currently depleted oil fields for later use when we need to avert ice ages.
Jacob Bock Axelsen it is not correct that CSIRO has measured a 3 ppmv drop in atmospheric O2 per year from 1978 to 2001. In 20 years from 1978 to 1998 it "measured" (actually calculated - with wide margins of error of you read the details) a drop of 0.0003% per year. If this were to drop linearly at the same rate it would take 23,000 years approx for the oxygen levels to decrease to 19.5% and not 4,800 years, as oxygen is only 20.95% of the atmosphere, so you have to divide this by 0.2095. You would get the same result if you calculated how much it would take to drop by 6.9212% of its present value. However Oxygen levels are not dropping linearly as subsequent "measurements" have shown. In subsequent computations by the CSIRO over a 7 year period from 1994 to 2001 the TOTAL drop was 0.0003% which works out to be a drop of 0.00004286% per year. By doing a similar calculation, if oxygen were to drop at this linear rate, it would take 161,500 years to drop by 6.9212% to 19.5% of the atmosphere. It was noted by the CSIRO that the oxygen drop was less than expected (if we take consumption by fossil fuel burning alone) possibly due to increased plant photosynthesis which maybe increasing due to warmer conditions and increased CO2 in the atmosphere. Whereas it does seem like, at the moment, the biosystem is not keeping up with oxygen consumption, the clear evidence is that the oxygen loss is too small to be much of a concern. Compare this to your message that it is alarming and humans would "suffocate" at 19.5% oxygen, which is not true as millions, possibly billions manage with this amount or less every day.
You are selective in your choice of evidence and fanciful in your choice of solutions. I did not suggest that the solar irradiance be extrapolated linearly. Only to point out how willing you were to similarly deal with oxygen levels when it suited you. A "sun-shade" at the L1 langrange point would have unmanageable technological problems to maintain and manipulate. If you could so easily manage solar irradiance why not have a fresnel lens and reflectors also at the lagrange point to concentrate the sun when warmth is needed (not to mention power). Why can we not then also manufacture oxygen and pump it into the atmosphere. As for your choice to solve the world's energy problems algae fuel, I believe it costs more than double the amount of other leading biofuels not to mention coal and petroleum thus we will not see it in the foreseeable future. Coming back to the basic question about anthropogenic global warming and the alarmist message from Copenhagen - I stand by my basic message. We do not know what our future long term climate will be. We have no idea because we cannot predict natural causes that cause fluctuations. At present we have very little knowledge of how these natural causes effect climate. Mathematical models of global warming make huge assumptions of other factors remaining constant in predicting the future temperatures and climates. As per these models global warming is relentless and unstoppable over several centuries even if we were to reduce carbon emmissions today. Why then are they jumping up and down with feeble suggestions that will have no effect on global warming even by their own calculations? They even predict a run-away greenhouse effect like what happened on Venus, which you also suggested. All these alarmist predictions are unfounded and even if some of them, like long-term global warming, do prove to be coincidentally correct they cannot be taken as proof of their models, any more than an astrological chart can be taken as proof of a future prediction. Global warming may not be all that bad. You could have a summer home on Baffin Island and the weather in Moscow may not be quite as beastly.
PS Oxygen 4,800 years and 33,600 years to drop to 19.5% basic message remains the same - oxygen loss is "too small to be much of a concern".
Richard Dawson The uncertainty in measuring O2 is 0.1 ppmv, as the seasonal variations are clearly discernible. Keeling and Manning accurately measured a drop of 220 meg O2/N2 from 1991 to 2004 giving 3 ppmv/year. CSIRO issued a press release in 1997 where you find data showing that O2 drops from 209,425 ppmv in 1978 to 209,365 ppmv in 1997 giving 3 ppmv per year = 0.0003%/year. This was found from precise laboratory analysis of pristine air samples and is considered very good evidence. You seem to be confused: 0.0003%/year total air volume fraction drop in O2 is 0.0014% relative, and a relative drop to 19.5% is (20.95-19.5)/20.95 = 6.92% leading to 6.92%/0.0014%/year = 4,800 years. Your cited 1% highlander children with heart disease is at least an alarming 100,000, which is a clear sign of maladaptation. The oceans are currently being slowly depleted of oxygen, and deserts are growing at 200,000 km2 per year, so there is good reason to be alarmed about the oxygen drop as part of the whole picture. You cannot extrapolate a satellite observation of solar irradiance without documenting a plausible process that causes it - particularly when other measurements even contradict it. In the case of oxygen levels we know that combustion of hydrocarbons took place during the whole period, so I am allowed to extrapolate as a first approximation. You dismiss algae fuel because the technology is in its infancy. The price will naturally drop when improved and mass produced. Perhaps an increased oil price is what we do have to pay for our recklessness, but since oil production has peaked and the world population is increasing, both in numbers and individual consumption, this seems inevitable. I can easily appreciate a solution that demands no change in transportation infrastructure and which promises a huge reduction in environmental impact. You think that because humans can be overwhelmed by natural events it proves your point, but by the push of a button we could easily cause a climatic disaster dwarfing any natural events. You claim that we do not know what our future long term climate will be, but according to the past 2 million years we will enter into another ice age within 100,000 years. Claiming that climate science is coincidentally correct is not true. Global temperatures was predicted to rise by 5-6 C with a doubling in CO2 by Svante Arrhenius in 1896. The IPCC found that the modern estimate is 2-4.5 C. Global warming was predicted, the factors measured, the causes modelled and subsequently explained. All the leaders in the western world are working with advisors that knows this.
Jacob Bock Axelsen I made a correction in my last post above to say that IF we lose O2 from the atmosphere at the rate of 0.0003%/year, we will reach 19.5% of O2 in the atmosphere in 4,800 years. But we wont (either lose it at that rate or ever reach 19.5% of the atmosphere, even if we burn all the fossil fuel reserves of the world). A later computation from Cape Grimm put the loss at much less than that. You are again using Keeling to paint an alarmist picture of atmospheric O2 when he has stated that the atmospheric oxygen loss is "too small to be much of a concern". I invite you and other readers to listen to his talk here on this subject. http://www.youtube.com/watch?v=CsnaXlhctLY You have also said that there is good cause for alarm at oxygen depletion in the oceans because of loss of atmospheric oxygen. Reduction of dissolved oxygen would take place if the oceans warmed but certainly not by the minuscule depletion of atmospheric oxygen. The Sahara and other deserts have been growing over thousands of years long before alleged anthropogenic global warming and the Earth has been warming ever since the last ice age. The cost of a product is a good indication whether it is feasible or not. And it causes many technologies to die in their infancy. Algae fuel is unlikely to be the saviour of the world energy crisis. If by "the push of a button" you are referring to all out nuclear war - global warming will be the least of our concerns. There would be no more burning of fossil fuels as civilisation would have collapsed and the Earth would settle into a "nuclear winter" and possibly an ice-age. Assuming this does not happen and we continue to burn fossil fuels at our current rate, natural causes, such as the very recent little ice age, due to the quieting of the sun, could swamp any anthropogenic greenhouse warming effect. Climate science is far from an exact science. We do not know where 50% of the CO2 we are producing is going. We do not know how the sun is going to behave in the future. The actual temperature increase over the last 100 years has been far less then that predicted by the climate models. To say that Svante Arrhenius knew better in 1896 is not very credible.
Richard Dawson Svante Arrhenius predicted global warming to be 5-6 C from doubling CO2 already in 1896 because he used black body radiation, water vapour feedback and new measurements of the solar radiation. He predicted the warming to be stronger off the equator, which has come true. He happened to be right, not by coincidence, but because he was a genius. The Charney report from 1979 predicted 1.5-4.5 C increase from doubling of CO2 which has come true since then. Advanced modern climate models can produce the actual trajectory of the 0.8 C increase in the 20th century with an accuracy of 0.1 C. When a scientific discipline can predict the future and understand the past, explained from planetary to molecular scale, then it is much more than an exact science. Re. oxygen, your claim was that the living ecosystem is keeping oxygen in balance, when it clearly is not. In his talk Keeling shows the evidence that oxygen drops at 3 ppmv/year, twice the rate that CO2 increases. There are no reference to 'computations from Cape Grimm' contradicting this. Nowhere do I claim that the oceanic oxygen depletion is driven by the drop in atmospheric oxygen. After watching Keelings talk you claim that we do not know where 50% of CO2 is going: we currently emit 26.6 GtCO2/year, where 15.2 remains in the air, 8.1 is absorbed by the ocean and 3.3 by land. We actually know what the sun will do in the future: the irradiance increase has been 0.1-0.6% since the Maunder minimum, so it will most likely not exceed 0.2% in the 21st century and according to periodicity patterns it is predicted that the activity will probably drop to the Maunder minimum level in 500 years. You acknowledge that humans can easily exceed natural events, so your point about nature exceeding humans proves nothing. Using e.g. algae we can 'reuse' CO2 one extra time and automatically stabilize emissions to match the sink rates. Many companies are working on the technology, the US gov't is once again funding research in it, so we will see it in 5 to 10 years from now.
Jacob Bock Axelsen you say that "The Charney report from 1979 predicted 1.5-4.5 C increase from doubling of CO2 which has come true since then." How can this be? CO2 has not doubled since then. And the temperature has not increased by even 1.5 C in the last 100 years. In 1979 the CO2 was around 337 ppm of the atmosphere, today it is around 387 ppm (from NOAA). CO2 has increased by only 14.8%. The pre-industrial CO2 levels around 1880 were estimated to be around 280 ppm (from NOAA), an increase of 38.21% to date. The Globally averaged land temperatures has increased by only 0.64 C from 1880, since records began, to 2007 and sea surface temperatures by only 0.12 C (from NOAA). The sea forms 70% of the Earths surface. Thus we can compute the Globally averaged temperatures to have increased by 0.276 C from the annual mean. The paper has failed to predict the future. Clearly the Charney report is wrong in its prediction and Svante Arrhenius much more so. Re: Oxygen, one third of the present industrial consumption of O2 is being made up by our biosphere, which however is irrelevant to the issue. I reiterate the important part, which is that we will never reach 19.5%, even if we consume all the oil, gas and coal reserves of the world and that there is no cause for alarm about the oxygen levels today or in the future, due to our industrial consumption. When science gets clouded by politics it gets corrupted. I suspected IPCC's scientific credentials ever since they trumped around Mann's "Hockey Stick" as "proof" of run-away global warming in the past 2-3 decades. They are too eager to seize on any "evidence" that points towards anthropogenic global warming. There is no empirical historical evidence that changes in concentrations of atmospheric carbon dioxide have been the principal cause of temperature and climate change. Our dominant climatic feature during the past 2 million years has been the ice ages, which we should really fear, the warm periods have been relatively brief of 10,000 years or so. Global warming may well be beneficial to the Earth and humanity as whole rather than harmful. Try convincing a person in Siberia, or for that matter Germany or Poland why they should not wish for a warmer climate.
I am tired of these self appointed "experts", who in their infatuated arrogance, fail to see we are not alone, and that India, China and the likes, contribute more to the problem. If we have a problem. Which I am unsure of, since they also fail to give any consideration to natural cycles. That weigh in much heavier than the puny emissions of humanity. Meanwhile these "experts" should worry instead about the anal emissions of the planet's assorted herbivores, and cease spreading their alarmist moanings. A few years ago it was the ozone hole, a hole in their brains, since nothing happened, and it looks like said hole, is undergoing a natural change. I wonder if in the puny minds of these neo-ludites, civilization should also take the blame for the reversal of the magnetic poles, of which I heard some hysterical squeals lately.