I HAVE been asked several times ‘why am I so sceptical of the anthropogenic global warming (AGW) hypothesis’? There are many reasons, some of which I have documented in previous articles at this weblog, but these have relied on sometimes complex calculations which I admit can be difficult to appreciate. So I would like to outline here a few of my reasons based only on simple consistency with the AGW proponents’ own data.
1. The AGW movement claims there has been a global temperature rise of 0.5C over the last 60 years and that this is due to increasing CO2. Both AGW proponents and sceptics accept that the relationship between energy retained and CO2 concentration is logarithmic (a constant increase in retained energy for each doubling of CO2). The AGW movement data also shows that since 1900 CO2 has risen by very close to half a doubling over this 60 year period.
IPCC have claimed in their 4th assessment report (summary for policy makers), that the most likely temperature rise by 2070, when CO2 will have risen by a further half doubling to twice the level in 1900, is a further 3C rise (page 12). Why would the first half doubling give 0.5C rise while the second half doubling gives 3C or 6 times as much rise?
2. One claim I have heard is that it takes the climate a long time to respond to the change in CO2 concentration and we have not yet seen the entire rise from the first half doubling. The same IPCC 4th assessment report (page 12, 13 and 14) indicates that if CO2 were stabilised at the current level, the temperature would rise by a further 0.2C over 2 decades stabilising at 0.7C above the 1900 level.
If the current temperature rise is not yet at the equilibrium level then for the business as usual scenario the temperature rise by 2070 will also not be at the equilibrium level. Yet the IPCC data suggests the equilibrium rise from the first half doubling is not even one quarter of the less than equilibrium rise from the second half doubling. To me this is illogical.
3. IPCC claim an increase in retained energy of around 3.7 watts/sqM for each doubling of CO2 (1.66 watts/sqM for the current rise page 4). They admit this is much too small to result in a 3+ degree temperature rise. The large temperature rise is based on claims of very large net positive feedback in the climate system.
Yet, every natural stable system I can think of exhibits net negative feedback. Indeed the terms stability and negative feedback are synonymous since negative feedback is what causes stability. By contrast, positive feedback causes instability (such as tipping points where a large change in output occurs for a small change in input). Stability does not mean zero change, it means the response to changes in input are small enough and sufficiently controlled so as to not cause system destruction or runaway. If you want to argue that the climate system is not stable then I would why it has remained conducive to continued life on this planet for billions of years. This is despite all the change in CO2 levels, volcanic eruptions, changes in solar output and orbital changes over the millennia. To me, that is a very good definition of climate stability.
4. The AGW modellers claim cloud feedback is positive. AGW advocates seem to divide clouds into two categories, low clouds and high clouds. Every report I have read acknowledges that low clouds cause cooling. With regard to high clouds there is some dispute but the AGW modellers claim they cause warming. Further they claim a warming planet results in a bias away from low clouds and towards high clouds thus exacerbating warming, hence contributing to positive feedback.
At the same time they claim constant relative humidity in their models. This means that as the temperature rises, more water must be evaporating. Now unless we want to predict that the amount of water in the atmosphere is going to continuously rise until the oceans are suspended over our heads, more evaporation must imply more precipitation ie: more rain. However, rain only comes from low clouds not high clouds, so more rain means more low cloud mass not less low cloud mass. This contradicts the previous position. If the claim is that both increase, then that means significantly more cloud mass in total. Clouds are the biggest contributor to Earth’s albedo (the fraction of incoming solar energy reflected back out to space). Rising total cloudiness means increasing albedo and the albedo is very strongly cooling. The albedo already causes 100 watts/sqM to be reflected away from Earth. To cancel out the entire impact claimed by IPCC for doubling CO2 only requires an increase in cloudiness from 60% to 62.4%.
An increase in temperature, leading to more evaporation, in turn leading to more cloudiness which reduces the solar input to Earth thus reducing temperatures is a description of negative feedback not positive feedback.
5. The claimed “proof” of positive feedback is a model prediction of a hot spot in the tropics at mid troposphere levels. However all the experimental evidence from many, many measurements has failed to find any evidence of such a hot spot. In science, a clear prediction that is falsified experimentally means the underlying hypothesis on which the prediction is based is wrong.
6. The reports documenting man’s CO2 emission use some scarily large numbers but these have to be viewed in the light of the overall system size. For example, a million dollars is an extremely large amount of money for a private individual but it is almost petty cash for a government. If we want to put the numbers into perspective we need to relate them to the size of the system. Why not express CO2 quantities in terms of how many PPM 1 year’s emissions will raise or lower the atmospheric CO2 level (if all of it stayed in the atmosphere). We could call that PPM equivalents.
In those terms, human emissions amount to about 2.7 PPM equivalents. Now NASA have published a diagram showing annual CO2 transfers for the planet. This shows terrestrial plants absorbing about 61 PPM equivalents. We know that both rising CO2 and rising temperature favour faster plant growth. That’s why horticulturalists artificially raise CO2 levels in glass houses to about 1000 PPM. It is also why plants grow faster in the tropics than in cooler locations on earth. More to the point, a recent study showed average plant growth has accelerated by about 6% over the last 30 years. A 6% increase in plant growth means a 6% increase in absorbed CO2, from 61PPM equivalents to 64.7 PPM equivalents. This means that human emissions have increased by 2.7 PPM equivalents but plants have increased their absorption by an extra 3.7 PPM equivalents over the same period. The increased plant growth is consuming more than 100% of human emissions. Is there another (natural) factor contributing to CO2 increases?
This response, more CO2 leading to faster plant growth which in turn consumes more CO2 is another example of the widespread bias towards negative feedback I alluded to earlier. Apart from which, is increased plant growth and thus agricultural productivity bad? I would have thought it was highly desirable.
7. The AGW hypothesis is based on temperature rises between about 1975 and 1998 or about 25 years worth of data. This is claimed to be definitive yet the last 10 years worth of data shows falling global temperatures. This is claimed to be a short term aberration and of no consequence. I do not see how 25 years can be considered definitive beyond dispute while 10 years of data is a short term aberration, too short to be significant. I would have thought at least a 10:1 ratio would be necessary to make such a claim.
8. If I adopt this 10:1 ratio by looking at the last 100 years worth of data I find 1910-1940 temperatures rising while CO2 was not. 1940 to 1975 temperatures falling while CO2 rising, 1975 to 1998 temperatures rising while CO2 rising and 1998 to 2009 temperatures falling while CO2 rising. Three quarters of the period shows no correlation or negative correlation with CO2 and only one quarter shows positive correlation. I do not understand how one can claim a hypothesis proven when ¾ of the data set disagrees with it. To me it is the clearest proof that the hypothesis is wrong.
9. For the last 10 years the global temperature data shows either no atmospheric temperature rise or indeed a falling global temperature. Recently this has been claimed to be due to a combination of a quiet sun and changes in ocean circulation superimposed on the underlying warming trend. The further claim is that when these effects reverse, warming will start again with a vengeance.
If these natural processes can cancel out the impact of AGW then they are as powerful as AGW. If they can overwhelm the impact of AGW to cause cooling they are more powerful, yet IPCC and other AGW proponents have claimed in previous assessment reports that solar influences are only a minor contributor compared to CO2.
The sun was unusually active during the latter half of the 20th century in contrast to its current inactivity and the ocean circulation was the opposite of what is now happening. Thus the natural effects claimed to be causing cooling now would have been causing warming in the late 20th century. If these natural effects are as large as the AGW impact then they would have caused half the observed 20th century warming. If the natural effects now outweigh the AGW impact to cause cooling then they would have been responsible for more than half the observed 20th century warming.
This is not only in contradiction of the earlier IPCC claims, it also means that the actual impact of CO2 increases since 1900 is much less than the claimed 0.5C. At most 0.25C and possibly much less even than that.
If in fact the temperature returns to the long term average over the next few years (as seems to be increasingly likely), it suggests that these natural processes were responsible for essentially all the observed temperature changes over the 20th century with negligible impact from CO2 changes.
10. I have looked at the raw temperature record for the USA (USHCN data) and the Bureau of Meteorology data for Victoria, Australia. Both show fluctuations of temperature with time but zero underlying trend for the last century. By contrast, the official IPCC endorsed data shows a strong underlying upwards trend. When I investigate why the difference, I find that the raw data has been adjusted for several supposed factors and every one of these adjustments created a warming trend. This implies that the claimed warming trend is due to the adjustments, not the raw data. In any less controversial scientific issue, such a result would be viewed with the greatest possible scepticism and would be extremely unlikely to be accepted.
When I examine the raw temperature data record for cities compared with nearby suburban or rural areas, I find an extremely high signature of urban heat island effect. Yet the people doing the temperature adjustments claim that urban heat island effects are negligible and do not require correction. This is despite the fact that a significant proportion of the measurement stations are in cities.
Such a clear factor not corrected for while other more subtle claimed factors are corrected casts further doubt on the correction protocol. If there is an upwards bias in the corrections, it means the claimed warming trend is exaggerated and may in fact not exist at all.
11. The mainstream media keep reporting that the current situation is increasingly dire and is much worse than even the previous pessimistic projections. When I examine this statement I find that previous projections predicted rapid atmospheric warming during the last 10 years whereas in fact we have had cooling. They predicted rapid increase in rate of rise of sea level when in fact the rate of sea level rise has recently declined. They predicted a very rapid increase in Arctic summer sea ice loss whereas in fact, for the last 2 years, it has been increasing. They predicted a rapid rise in hurricane incidence and severity when in fact there has been a decline. To me the media’s many claims are not supportable. I also consider it to be beyond simple error. At best it is unpardonable gross carelessness in checking the data they are reporting and at worst it is deliberate bias in reporting.
12. More recently, in response to the data showing no warming for the last 10 years, I have seen new claims that global land temperatures are now deemed irrelevant. The newly discovered measure of importance is the rise in ocean temperature, since it is now claimed that this is by far the largest planetary heat sink. If that claim is true, it makes all the previous data claiming to show strong global warming over the period 1975 to 1998 also irrelevant. To suggest that from 1975 to 1998, the energy went into warming the land and air and then abruptly in 1998 it stopped doing that and the heat instead went into heating the oceans is, to me, completely absurd. Nature simply does not work that way. It is like claiming you put the kettle on, for the first minute the energy goes into heating the water and then abruptly it stops heating the water and starts heating the room instead.
13. Looking further at the claim of warming ocean temperatures. Late last century it was realised that the method of measuring ocean temperatures was extremely inaccurate and unreliable. To overcome that, a sophisticated, global system of buoys was designed and implemented at very considerable cost and effort. These buoys repeatedly dive down to measure temperatures and then resurface to report back findings This network is called the Argo network and it became operational in 2003. Since becoming operational, it has shown ocean cooling. Yet the scientists who claim ongoing ocean warming exclude the Argo data and the satellite data instead relying entirely on the earlier poor reliability methods.
The same scientific community which claimed a method was inaccurate and unreliable, designed and implemented a new high accuracy measurement system, are now rejecting the new high accuracy data in favour of the older data they themselves viewed as unreliable. How can that be justified? Why is the data from the older less reliable method correct, while results from the new, high accuracy methodology are wrong? What does that say about the scientists who designed the Argo system but apparently don’t trust its output? To me it suggests selecting data to prove a favoured hypothesis, commonly called cherry picking.
Some sites are talking about “correcting” the Argo data. Why should a carefully thought out, brand new, high accuracy system already require adjustment to its outputs? Was a mistake made in the design? Why are the proposed adjustments again in the direction of exacerbating the claimed warming? When the raw data contradicts the hypothesis yet the “adjustments and corrections” all reverse that result so as to support the championed hypothesis, it’s time to start worrying.
14. What mankind is doing by consuming fossil fuels is recycling CO2 that used to be in the atmosphere but got trapped in the distant past. Is there a “correct” level of CO2? What I have read suggests that the Earth was a more verdant place before the CO2 got locked up in fossil fuels. Would the Earth be more or less pleasant a place if the carbon currently locked up in fossil fuels were again available to the biosphere. Not just for humans but for all living things, plants and animals. Surely we should consider that before we pick some arbitrary recent point in time and declare that the CO2 level at that time is the ideal to be maintained at all costs.
FROM a slightly different but related perspective, I see the AGW story continuously changing. When one measure no longer trends the wanted way, a change is made to a new measure (change from surface to ocean temperatures and ocean acidity). In one report, an effect is claimed to be negligible when that suits the hypothesis yet the same measure is later used as a reason to explain away embarrassing trends (Solar influence and ocean currents). All the observed effects are very moderate (less than 0.5C) if present at all yet hysteria is generated on the basis of hypothesised extreme future outcomes (up to 6C rise and 10 meter sea level rises). Outcomes far enough in the future so as to be un-testable yet close enough to impact people being born today. Claims based on abstract models that fail even short term validation tests. As a practicing scientist, I have seen this scenario more than once before, changing benchmarks and indicative parameters, rewriting predictions and predicted causes after the event, excusing erroneous predictions. These are clear signs of propping up a false hypothesis.
There does seem to be clear evidence that temperature changed several times over the 20th century both up and down. There is far less evidence for any underlying upwards trend due to CO2 and many reasons to question the data analysis that tries to demonstrate such a trend.
One of the arguments I often hear is “well even if AGW is not absolutely proven we should take action just in case its correct” – the precautionary principle. I see two reasons to disagree with that.
Firstly, if rising CO2 should bring about some warming it is by no means certain that this would be catastrophically bad or for that matter whether it would be bad at all. It seems quite likely to me that the cure would be worse than the disease.
Secondly, and to me much more importantly, there is another issue we need to consider and that is the law of unintended consequences. Briefly this states that whenever you take action there will always be consequences you did not consider in advance and did not intend. Since there are many more ways to be wrong than to be right there is a better than 50:50 chance that these consequences will be bad. If the original action is based on a false premise it greatly increases the risk of bad unintended consequences. The precautionary principle is based on the belief that there is no down side to taking action. The law of unintended consequences tells us that there is always a down side and the cost versus benefit always needs to be carefully evaluated before acting.
We are already seeing some very bad unintended consequences of the action taken so far over global warming. The government driven initiative to use less fossil fuel by diluting it with ethanol is causing massive forest clearing the Amazon basin (to grow the ethanol feedstock) and is very significantly raising food prices causing even worse starvation in 3rd world countries. Terrible as it is, this has not greatly impacted on western society but the next phase most certainly will.
There is another very serious unintended consequence that I would like to raise here; one that concerns me very deeply. When I listen to the public AGW debate I hear very high profile politicians and prominent public figures calling for people who openly disagree with AGW to be put on trial for treason. I hear many cases of people losing their jobs because of voicing sceptical opinions. I hear prominent global warming advocates refusing to enter into debates or trying to avoid debates by claiming the science is settled, and by claiming we do not have time, we have only weeks to act. I hear AGW advocates resorting to personal attacks against people who disagree rather than addressing the technical issues they raise.
I hear AGW proponents claiming to be the under funded underdogs, fighting to protect the planet against greedy capitalists, yet the reality is their funding is at least 1000 times greater than the sceptics funding. I see many reports of scientists refusing to release their workings, thus preventing review of their methodology, despite the fact that their work was funded by public money.
I see how the established media abandons balance in reporting by strongly favouring proponents of AGW, ignoring or denigrating sceptics and forcing most onto blog sites like this one. I hear some environmental groups and activists publicly claim that its OK and even necessary to exaggerate the threat so as to get the public to engage. I see the courts condoning acts of vandalism and even violence against essential public infrastructure. I see high profile public figures supporting such acts and claiming them to be reasonable and justified.
In short I see our society abandoning some of our most vital democratic freedoms over this hysteria: Free speech, impartial enforcement of the law, balance in reporting, freedom of information. These are freedoms our forebears gave their lives to bequeath to us, they are our most valuable inheritance and we seem to be throwing them away over an unproven hysterical hypothesis.
More recently I have read articles from England advocating individual ration cards for petrol, heating oil, gas, electricity. Is water and food next? War time austerity as an ongoing future way of life? A return to the agrarian poverty of the middle ages? I note the new film “Not evil just wrong” has had to be distributed via the internet rather than traditional media. One step from distribution through an underground network? Will that apply to all future sceptical writing? What about other writing contrary to the popular opinion of the day?
These are the issues that differentiate between a free democracy and a totalitarian regime and the further one goes down this path the harder it is to pull back. History has shown us that the disease is far easier to acquire than to get rid of.
Notes and Links
Michael Hammer graduated with a Bachelor of Engineering Science and Master of Engineering Science from Melbourne University. Since 1976 he has been working in the field of spectroscopy with the last 25 years devoted to full time research for a large multinational spectroscopy company.
To read more from Mr Hammer click here and scroll down: http://jennifermarohasy.com/blog/author/michael-hammer/