The IPCC’s “Extreme Weather” Report
November 20, 2011 2 Comments
According to its latest report, the IPCC has “low confidence” that tropical cyclones have become more frequent (based on real world observations). Also, it has “limited to medium evidence available” (insufficient evidence) to determine whether or not climatic factors have changed the frequency of floods.
For example, “Observed: Low confidence at global scale regarding (climate-driven) observed changes in the magnitude and frequency of floods” because of “limited evidence”, but “Projected: Likely increase in heavy precipitation indicators in East Africa.” (p.27)
So, despite “low confidence” on whether the frequency of floods has risen or fallen on a global scale, it projects that these will increase in some areas in the distant future (after 20-30+ years) based on computer models! (p.12)
Notwithstanding Richard Black and others writing a “disclaimer”—”It’s also explicit in laying out that the rise in impacts we’ve seen from extreme weather events cannot be laid at the door of greenhouse gas emissions”, an affirmative line is still being spun by most of the media as: IPCC Confirms Link Between Extreme Weather Events and Climate Change.
SustainableBusiness.com: “A definitive report from the the U.N. Intergovernmental Panel on Climate Change (IPCC) released today says it now certain that human emissions of greenhouse gases and warming aerosols like black carbon are increasing the frequency and intensity of extreme weather by putting more heat energy into the climate system.”
The report found nothing of the sort! Did these hacks even bother to read it?
Below is a review of the first, carefully leaked draft, from November 2, 2011. Was it radically different from the later draft, or as above, was it distorted by the media?
“A DRAFT UN report three years in the making finds that man-made climate change has boosted the frequency or intensity of heatwaves, wildfires, floods and cyclones and that such disasters are likely to increase in future.
The draft being discussed by the Intergovernmental Panel for Climate Change says the severity of the impacts vary, and some regions are more vulnerable.
Agence France-Presse has obtained a copy of the draft report’s 20-page summary for policymakers, which is subject to revision by governments before release on November 18.”
Climate change ‘will boost disasters’: UN report
BBC’s Environment correspondent Richard Black:
“The draft, which has found its way into my possession, contains a lot more unknowns than knowns.
On the one hand, it says it is “very likely” that the incidence of cold days and nights has gone down and the incidence of warm days and nights has risen globally.
And the human and financial toll of extreme weather events has risen.
But when you get down to specifics, the academic consensus is far less certain.
There is “low confidence” that tropical cyclones have become more frequent, “limited-to-medium evidence available” to assess whether climatic factors have changed the frequency of floods, and “low confidence” on a global scale even on whether the frequency has risen or fallen.
In terms of attribution of trends to rising greenhouse gas concentrations, the uncertainties continue.
While it is “likely” that anthropogenic influences are behind the changes in cold days and warm days, there is only “medium confidence” that they are behind changes in extreme rainfall events, and “low confidence” in attributing any changes in tropical cyclone activity to greenhouse gas emissions or anything else humanity has done…
And for the future, the draft gives even less succour to those seeking here a new mandate for urgent action on greenhouse gas emissions, declaring: “Uncertainty in the sign of projected changes in climate extremes over the coming two to three decades is relatively large because climate change signals are expected to be relatively small compared to natural climate variability”.
It’s also explicit in laying out that the rise in impacts we’ve seen from extreme weather events cannot be laid at the door of greenhouse gas emissions: “Increasing exposure of people and economic assets is the major cause of the long-term changes in economic disaster losses (high confidence).
“Long-term trends in normalized economic disaster losses cannot be reliably attributed to natural or anthropogenic climate change.”
Mixed messages on climate ‘vulnerability’
According Jean Plautikof, we only have to wait 60 years to see the effects of global warming on extreme weather!
“According to Jean Palutikof, director of the National Climate Change Adaptation Research Facility at Griffith University, the effects of climate change on extreme weather will be clear by 2070. She says the highest certainty will most likely be in heatwaves. “This will be the first clear signal,” Palutikof says. “It will appear sooner than others and will be recognised as due to global warming. Droughts would be the next most certain, with floods and wind storms more difficult to establish.” ”
There are some odd omissions, and additions, in the IPCC report:
“One of the major reasons why extreme weather events are of abiding interest to both the public and policy makers is the potential loss of life that they can cause. Imagine, therefore, writing a “Special Report” on managing the risks of extreme weather and climatic events but being virtually silent on whether deaths from such events had increased or decreased over the recent past. Who knows, but that information might even be useful in helping identify factors that could help manage those risks in the future. Yet, the Summary for Policy Makers (SPM) of the IPCC’s Special Report on extreme weather and climate events (SREX) does precisely that…
…[A digression: “Fatalities” are also mentioned in footnote 4 explaining that the above figures are based on data for “all disasters associated with weather, climate, and geophysical events.” (Emphasis added.) Why are geophysical events—earthquakes and landslides—included in the death tally in this climate change report? But back to the main story.]”
The Odd Omission in IPCC’s Summary for Policy Makers for SREX on Extreme Weather and Climatic Events
IPCC SREX Summary for Policymakers
No Evidence For Intensifying Weather Trend
No Upward Trend In Cyclonic Activity