Skeptical Science: Uncertain Times at the Royal Society?

Uncertain Times at the Royal Society?

by MarkR, Skeptical Science, October 2, 2010

Following complaints, the Royal Society has published a guide to climate science which counts 2 self selected “skeptics” among its co-authors. Traditional skeptical sources have enjoyed the release, including the Global Warming Policy Foundation (GWPF) and The Daily Mail, with the Mail quoting the Foundation’s Director;

"The Royal Society now also agrees with the GWPF that the warming trend of the 1980s and 90s has come to a halt in the last 10 years."

And gleefully reporting that the Royal Society “admits that there are ‘uncertainties’” - I remember a Professor who drilled "numbers mean nothing without uncertainties!" into students, so this shouldn't surprise most people with scientific experience!

The Intergovernmental Panel on Climate Change (IPCC) carefully includes them with all its statements. The Society report is worth reading if you have time but if you want detail then read the IPCC report: the two agree on everything they both cover.

The Society split simple statements into 3 sections: widespread scientific agreement, widespread consensus but active discussion, and ‘not well understood’. 

Widespread agreement

• 0.8 ± 0.2 °C warming since 1850.
• Rise in CO₂ caused by humans.
• IPCC heating or ‘radiative forcing’ values.
• Doubling CO2 causes 1 °C of direct warming, feedbacks are expected to add more.

Wide consensus but continuing debate and discussion

• Solar heating less than 10% of CO₂’s, but research is checking to see if it’s magnified somehow.
• Doubling CO will cause 2-4.5 °C global warming (the IPCC says “likely to be in the range 2 to 4.5 °C with a best estimate of about 3 °C“), and IPCC global warming projections are repeated. 
• Sea levels will rise at least at the rate they have been.

Not well understood

• Models struggle with clouds, regional changes, and long term carbon cycle feedback.
• Models don’t catch ice sheet breakup, so sea level rise they give is a minimum.

Summary

Non-model evidence for future sea level rise and global warming are ignored. This tends to suggest that doubling CO2 will cause 2-4.5 °C warming and new evidence suggests that sea level rise will be 100%+ more than IPCC estimates.

The GWPF concludes that; 

"The UK now formally joins the ranks of denier nations,"

which seems remarkable from the Society's statement that; 

"There is strong evidence that changes in greenhouse gas concentrations due to human activity are the dominant cause of the global warming that has taken place over the last half century. "

Finally, what of the GWPF’s claim that the Society now agrees global warming has halted? Another case of confusing short term trends, being ignorant of heat on Earth and seemingly based on;

"This warming has... been largely concentrated... from around 1975 to around 2000,"

but ignoring;

"The decade 2000-2009 was, globally, around 0.15 °C warmer than the decade 1990-1999."

Make of that what you will.   

Link:  http://www.skepticalscience.com/Uncertain-Royal-Society.html

NOTE: This blog post has been added to the list of rebuttals to skeptic arguments as the rebuttal to "Royal Society embrace skepticism".