The bit that jarred with me was the IPCC comment about the hydro cycle under SRM. I don't think it expresses the science well. SRM doesn't disrupt the hydro cycle, it just doesn't fix hydro and temperature by exactly the same amount. Running SRM actually RESTORES the hydro cycle, rather than disrupts it. I'm sure that's just down to unfortunate wording rather than bad science, but these things matter!
A On Sep 27, 2013 10:31 PM, "Ronal W. Larson" <[email protected]> wrote: > 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 <[email protected]> > 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 > > > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
