The Current Wisdom: The Short-Term Climate Trend Is Not Your Friend
The Current Wisdom is a series of monthly posts in which Senior Fellow Patrick J. Michaels reviews interesting items on global warming in the scientific literature that may not have received the media attention that they deserved, or have been misinterpreted in the popular press.
The Current Wisdom only comments on science appearing in the refereed, peer-reviewed literature, or that has been peer-screened prior to presentation at a scientific congress.
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It seems like everyone, from exalted climate scientists to late-night amateur tweeters, can get a bit over-excited about short-term fluctuations, reading into them deep cosmic and political meaning, when they are likely the statistical hiccups of our mathematically surly atmosphere.
There’s been some major errors in forecasts of recent trends. Perhaps the most famous were made by NASA’s James Hansen in 1988, who overestimated warming between then and now by a whopping 40% or so.
But it is easy to get snookered by short-term fluctuations. As shown in Figure 1, it is quite obvious that there has been virtually no net change in temperature since 1997, allowing for the fact that measurement errors in global average surface temperature are easily a tenth of a degree or more. (The magnitude of those errors will be considered in a future Current Wisdom).
Figure 1. Annual global average surface temperature anomaly (°C), 1997-2010 (data source: Hadley Center).
Some who are concerned about environmental regulation without good science have seized upon this 13-year stretch as “proof” that there is no such thing as global warming driven by carbon dioxide. More on that at the end of this Wisdom.
Similarly, periods of seemingly rapid warming can prompt scientists to see changes where there aren’t any.
Consider a landmark paper published in 2000 in Geophysical Research Letters by Tom Karl, a prominent researcher who is the head of our National Climatic Data Center (NCDC) and who just finished a stint as President of the American Meteorological Society. He couldn’t resist the climatic blip that was occurred prior to the current stagnation of warming, namely the very warm episode of the late 1990s.
Cooler heads at the time noted that it was an artifact of the great El Nino of 1997-98, a periodic warming of the tropical Pacific that has been coming and going for millions of years.
Nonetheless, the paper was published and accompanied by a flashy press release titled “Global warming may be accelerating.”
What Karl did was to examine the 16 consecutive months of record-high temperatures (beginning in May, 1997) and to calculate the chance that this could happen, given the fairly pokey warming rate—approximately 0.17°C (0.31°F) per decade, that was occurring. He concluded there was less than a five percent probability, unless the warming rate had suddenly increased.
UN Climate Official Steps In It, Then Aside
There are numerous possible reasons for UN climate chief Yvo de Boer’s decision to resign—from his inability to cobble together a new climate treaty last December in Copenhagen (where he wept on the podium), to recent revelations of his agency’s mishandling of climate change data.
What the climate science community and the public should focus on now are the ramifications of de Boer’s resignation. For one thing, it signals that hope is dead for a UN-brokered global treaty that would have any meaningful effect on global temperatures. It also means that the UN intends to keep its Intergovernmental Panel on Climate Change pretty much intact under the leadership of the scientifically compromised Rajenda Pauchari, who should have resigned along with de Boer.
This development guarantees that the Obama administration will have an unmitigated mess on its hands when signatories to the Framework Convention sit down in Mexico City this November in yet another meeting intended to produce a climate treaty. The Mexico City meeting convenes six days after U.S. midterm elections, in which American voters are fully expected to rebuke Obama for policies including economy-crippling proposals to combat climate change.
In short, Mexico City is about as likely to produce substantive policy decisions as the TV show ‘The View.’ Backers of radical climate change measures are now paying the price for over two decades of telling the public—in this case literally—that the sky is falling.
New Study: Hadley Center and CRU Apparently Cherry-picked Russia’s Climate Data
Yesterday, the Moscow-based Institute of Economic Analysis (IEA), of which I am President, issued a study (in Russian), “How Warming Is Being Made: The Case of Russia.” The report, prepared by IEA director Natalya Pivovarova, suggests that the Hadley Center for Climate Change based at the headquarters of the British Meteorological Office in Exeter (Devon, England) and the Climate Research Unit of the University of East Anglia (CRU) in Norwich (England) apparently cherry-picked Russian climate data.
The IEA report shows that Russian meteorological-station data in the last 130 years did not substantiate the rate of warming on Russian territory suggested by the Hadley Climate Research Unit Temperature (HadCRUT) database, which has now been partially released.
IEA analysts point out that Russian meteorological stations cover most of the country’s territory, while the HadCRUT used data from only 25% of such stations in their calculations. Over 40% of Russian territory was not included in their global temperature calculations even though there was no lack of meteorological stations and observations. The data of stations located in areas not listed in the HadCRUT survey often shows slight cooling or no substantial warming in the second part of the 20th century and the early 21st century.
The HadCRUT database includes specific stations providing shorter observations and incomplete data highlighting the warming process, rather than stations providing longer and uninterrupted observations not demonstrating significant warming. On the whole, HadCRUT specialists use the incomplete findings of meteorological stations far more often than those providing complete observations. IEA analysts found that the climatologists used the data of stations located in large populated centers that are influenced by the “urban heat effect” more frequently than the unbiased data from the stations located in less populated places.
The IEA authors calculated that the scale of actual warming for the Russian territory in 1877-1998 was probably exaggerated by 0.64°C. Since Russia accounts for 12.5% of the world’s land mass, such an exaggeration for Russia alone should have an impact on the IPCC claim that the global temperature in the last century has risen by 0.76°C.
If similar procedures have been used for processing climate data from other national data sources, the impact on the rate of change in global temperature would be considerable.
The IEA report concludes that it is necessary to recalculate all global temperature data in order to assess the real rate of temperature change during the last century. Global temperature data will have to be modified because the calculations used by Copenhagen Conference on Climate Change analysts are based on HadCRUT research.
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