ENVIRONMENT: by Peter WestmoreNews Weekly
IPCC report: triumph of spin over substance
, October 26, 2013
When the Intergovernmental Panel on Climate Change (IPCC) released its latest summary for policy-makers, it was uncritically endorsed by various media outlets, European governments and environmental organisations, but was the subject of robust criticism from some of the world’s leading climate scientists.
Commenting on IPCC claims that there was a 95 per cent certainty that human activity was causing unprecedented climate change, British Prime Minister David Cameron said, "If someone said there is a 95 per cent chance that your house might burn down, even if you are in the 5 per cent that doesn’t agree with it, you still take out the insurance.”
However, climate scientists who looked below the headlines reached a different conclusion.
Roger Pielke, Jr, is professor of environmental studies at Colorado University, Boulder, and a well-known commentator on climate-change issues, particularly the links between extreme weather events and climate change.
After looking at the report, he highlighted the fact that in its detailed statements, the fine print, the IPCC report was far more qualified than its headlines.
Referring to "extreme events” — the growing number of which are said to prove that human activity causes climate change — Professor Pielke noted a number of the IPCC report’s own statements which contradict its headline conclusions:
- "Overall, the most robust global changes in climate extremes are seen in measures of daily temperature, including, to some extent, heat waves. Precipitation extremes also appear to be increasing, but there is large spatial variability.”
- "There is limited evidence of changes in extremes associated with other climate variables since the mid-20th century.”
- "Current datasets indicate no significant observed trends in global tropical cyclone frequency over the past century…. No robust trends in annual numbers of tropical storms, hurricanes and major hurricanes counts have been identified over the past 100 years in the North Atlantic basin.”
- "In summary, there continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale.”
- "In summary, there is low confidence in observed trends in small-scale severe weather phenomena such as hail and thunderstorms because of historical data inhomogeneities and inadequacies in monitoring systems.”
- "In summary, the current assessment concludes that there is not enough evidence at present to suggest more than low confidence in a global-scale observed trend in drought or dryness (lack of rainfall) since the middle of the 20th century due to lack of direct observations, geographical inconsistencies in the trends, and dependencies of inferred trends on the index choice. Based on updated studies, AR4 [IPCC 4th Assessment Report 2007] conclusions regarding global increasing trends in drought since the 1970s were probably overstated. However, it is likely that the frequency and intensity of drought has [sic] increased in the Mediterranean and West Africa and decreased in central North America and north-west Australia since 1950.” (The IPCC does not appear to know that north-west Australia is desert).
- "In summary, confidence in large-scale changes in the intensity of extreme extratropical cyclones since 1900 is low.”
The exact opposite has been stated by politicians and environmentalists since the IPCC report was released, and the headline summary of the IPCC report supports this misinterpretation of the data.
Professor Pielke said, "The IPCC report already is being spun silly. Underneath the spin is an important core message. The IPCC itself is still engaged in PR spin and messaging.”
Writing in the Wall Street Journal, author Rupert Darwall highlighted the discrepancy between the IPCC’s alarmist claim of 95 per cent certainty that human activity is causing climate change with its statement that temperatures are "likely” to rise less than previously estimated over the next 50 years.
He commented: "This is a glaring discrepancy. How can the IPCC be more confident that more than half the temperature rise since the mid-20th century is caused by greenhouse-gas emissions when it is less sure of the climatic impact of carbon dioxide? The explanation is that IPCC reports, especially the summaries for policymakers, are primarily designed for political consumption.”
He added: "This time around, the greatest difficulty faced by the IPCC was explaining the ongoing 15-year pause in atmospheric temperature increases....
"Other than saying that short periods do not reflect long-term trends, the IPCC ducked out of a dilemma of its own making. One lead author, Jochem Marotzke, explained to reporters that the issue had come a bit late in the process.”
In fact, it has been the subject of public controversy for the past 10 years.
Darwall asked: "Is it plausible to believe that if the story had been temperatures rising faster than expected, the IPCC and climate journals would have remained silent? Evidently nature has embarrassed the climate-science consensus.”