Joshua and list

   1.  Thanks for the alert.   Besides your excerpt below, there is another 
(well hidden, but is in Section E8, with "Irreversibility" in the Section 
Title) place in the Summary where CDR appears (albeit indirectly).  I found it 
as I was reading today's RealClimate summary of the Summary.  The Comment I 
left  (slightly modified here) said:


1.   The Real Climate summary above is only partly accurate when it says at the 
end of the first section on global warming:

    "A large part of the warming will be irreversible: from the point where 
emissions have dropped to zero, global temperature will remain almost constant 
for centuries at the elevated level reached by that time. (This is why the 
climate problem in my opinion is a classic case for the precautionary 
principle.)"

2.   But the just released actual IPCC report has an important added qualifier  
on page 20 in Section E8:

    "A large fraction of anthropogenic climate change resulting from CO2 
emissions is irreversible on a multi-century to millennial time scale, except 
in the case of a large net removal of CO2 from the atmosphere over a sustained 
period."

3.  This added clause introduces in these IPCC series for the first time the 
hugely important concept of Carbon Dioxide Removal  (CDR)  - which can be 
accomplished, and which I hope Real Climate and its readers can get behind 
wholeheartedly.

Ron 

ps:  Anyone found any other place?


On Sep 27, 2013, at 5:57 AM, Josh Horton <joshuahorton...@gmail.com> wrote:

> It's finally out and here's what it says about geoengineering:
> 
> http://www.climatechange2013.org/images/uploads/WGIAR5-SPM_Approved27Sep2013.pdf
> 
> Methods that aim to deliberately alter the climate system to counter climate 
> change, termed geoengineering, have been proposed. Limited evidence precludes 
> a comprehensive quantitative assessment of both Solar Radiation Management 
> (SRM) and Carbon Dioxide Removal (CDR) and their impact on the climate 
> system. CDR methods have biogeochemical and technological limitations to 
> their potential on a global scale. There is insufficient knowledge to 
> quantify how much CO2 emissions could be partially offset by CDR on a century 
> timescale. Modelling indicates that SRM methods, if realizable, have the 
> potential to substantially offset a global temperature rise, but they would 
> also modify the global water cycle, and would not reduce ocean acidification. 
> If SRM were terminated for any reason, there is high confidence that global 
> surface temperatures would rise very rapidly to values consistent with the 
> greenhouse gas forcing. CDR and SRM methods carry side effects and long-term 
> consequences on a global scale. {6.5, 7.7} (p. 21)
> 
> Not quite what the Guardian was reporting last week ...
> 
> Josh
> 
> 
> 
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