Posted by Jeff Id on June 6, 2011
Guest post by Tony Brown
Two weeks ago I started a thread over at Climate Etc. entitled ‘The futility of Carbon reduction?’ (note the important question mark.)
It came about when I received some calculations on likely temperature reductions from carbon mitigation policies, from a colleague, Ed Hoskins, who in turn had run them past the Chief Scientist of the UK’s powerful Department of Energy and Climate Change.
The article explores the likely cost of an aggressive carbon reduction policy and the practicalities of achieving it, but at its heart was a desire to find out what would be the end result in terms of an actual temperature reduction. Here is the question as posed.
Question: Temperatures are expected to rise by 3 degree Centigrade because of actions we have already taken. If the world collectively closed down their carbon economies what temperature reduction could be achieved?
a) By 2100 b) By 2200
(source IPCC AR4 WG1 SPM report pp. 13 and 18 and 350.org (20.5)
Please describe your calculations together with caveats or provide a reference/link.
I hope readers here will go through the article to put it all into context as it includes a useful chart of emissions by major countries and the likely cost to of reducing them, according to such official documents as the Stern report.
Climate Etc attracts an eclectic mix of sceptics and ardent warmists and every shade of opinion in between. Consequently what transpired was somewhat remarkable as with over 630 responses to date only one or two people attempted any sort of answer.
This led me to briefly believe that Ed and I were geniuses for thinking up a question that no one had asked before, but reality quickly re-asserted itself that it would be irresponsibility on a grand scale if those advising our governments had failed to undertake the calculations themselves. So those calculations surely exist, but those who believe in CAGW seem reluctant to promote them.
Is it because the answer is one they don’t like? That the vast costs of mitigation and the astonishing social and technological upheavals needed to achieve them would result in a temperature mitigation so tiny as to go unnoticed?
Jeff kindly agreed that I could re-state the question in this forum in the hope that readers will supply answers-complete with their calculations- or alternatively provide a link to an existing study that directly answers the question.
Tony Brown (tonyb)