Because Kevin Anderson says that it is “improbable” that levels could now be restricted to 650 parts per million (ppm). Which blows Hansens target 350 out of the water. Not that it requires a luminary of KA standing to do that. Quite why the grauniad is using breathless climate-snuff-porn prose to report the bleedin’ obvious I don’t know – perhaps it really is true that people read the papers for titillation rather than news. Those with appropriate access can read what looks to be like the source paper (which begins with something I’ve been saying for a while, but he gets to say it in a nice academic place and dressed in nice academic prose: In the absence of global agreement on a metric for delineating dangerous from acceptable climate change, 2oC has, almost by default, emerged as the principal focus of international and national policy.).
But the reason for writing this is not to lay into Hansen, but to lay into Anderson (or at least the Anderson reported by the grauniad – I didn’t hear his talk and for all I know he didn’t say the nonsense they attribute to him. But I fear otherwise). Despite the political rhetoric, the scientific warnings, the media headlines and the corporate promises, he would say, carbon emissions were soaring way out of control – far above even the bleak scenarios considered by last year’s report from the Intergovernmental Panel on Climate Change (IPCC) and the Stern review. The battle against dangerous climate change had been lost, and the world needed to prepare for things to get very, very bad. is just wrong. As they note lower down, atmospheric CO2 is increasing at somewhere between 2-3 ppm/y, at a level of 380, which is to say well below 1%/y, which is the basic scenario that many climate models are fed with (more old stuff refers).
Someone must know where there is a pic comparing current CO2 levels against SRES starting in 1990 or somesuch (there is one in IPCC ’92 fix Ax.4 but the scale is so small you can’t tell anything useful from it… by eye, its says 2008 CO2 under is92a will be about 400 ppm).
Or perhaps we care about emission more than actual CO2 levels?
Wiki says that emissions were 8.4 GtC in 2006 (and if you find numbers nearer 30, remember you have to convert by (32+12)/12 = 44/12). IPCC ’92 fig A.3.1 thinks that the range of possible emissions might be between 7 and 11 (doing it by eye and using the Beano christmas activity book as a ruler). I suppose emissions went up in 2007, but I doubt they went over 11 GtC, so the idea that we are over the most pessimistic projections is tosh. Is92 looks to be about 9 GtC in 2007, from the graph, so at a guess we’re about on the line.
Someone has produced pretty pix of this recently… where?
[Update: some of the pix are at http://www.globalcarbonproject.org/global/ppt/GCP_CarbonBudget_2007.ppt, and there is more at http://initforthegold.blogspot.com/2007/11/carbon-cycle-misfortunes.html, inclusing inconclusive discussion of how much we should care -W]
[Update: also http://iceblog.over-blog.com/article-23249141.html (saperlipopette!). From which perhaps the major point is… see how hard it is to tell which line we’re on -W]
wmconnolley: scienceblogs.com/stoat archive 