… and then, as I’m sure you’re aware, there is also the contraction and convergence approach to working out remaining carbon space to keep below 450 ppm allocated on a per capita basis. Graphics, documents etc can be found at: http://www.gci.org.uk/
Best wishes Peter Professor Peter Newell Department of International Relations School of Global Studies University of Sussex Brighton East Sussex BN1 9SN UK T: (0044) 1273 873159 E: [email protected]<mailto:[email protected]> My latest book, Globalization and the Environment, is now available from Polity: http://www.politybooks.com/book.asp?ref=0745647227 From: [email protected] [mailto:[email protected]] On Behalf Of Susanne Moser Sent: 06 August 2012 14:50 Cc: Gep-Ed ([email protected]) Subject: Re: [gep-ed] IPCC question Stacy - Yes, it depends on the temp target, but in the real world (ie not politics) it also depends on the sensitivity of the climate, and for all intents and purposes everything seems to happen faster and sooner indicating that the climate system may be more sensitive than we thought. Another approach to this, ultimately to be turned into percentages if you wish, is that propagated in the America's Climate Choices (Limiting/Mitigation) report (NRC, 2012). They essentially took an emissions/carbon budget approach, saying that if we want to stay under x temperature, then we have a carbon budget of y, and at the current rate of emissions, we will have used that remaining budget up by year z. To stay within that budget we have to reduce some percent per year starting... well, yesterday. It gives you a simple math approach to seeing that 2 degrees C is all but an economically (well, o.k. back to THAT real world... i.e. politically) infeasible goal. Hope that helps (even if just for the US and not global, but similar papers have been written for global carbon budgets), Susi On 8/5/2012 6:25 PM, Soledad Aguilar wrote: I use this one also from AR4 which includes sea level rise, which I find interesting to discuss with students living near coastlines as it gives them something they can easily relate to. Soledad Aguilar Investigadora Principal FLACSO Argentina Programa en Desarrollo, Innovación y Sociedad Síguenos en el Foro de Cambio Climático y Comercio http://www.ambienteycomercio.org<http://www.ambienteycomercio.org/><http://www.ambienteycomercio.org/> On Aug 5, 2012, at 3:41 PM, Avery Cohn wrote: Actually, the 450ppm target is for 2050, not for 2020. The 25-40% reduction for Annex I countries (from 1990 levels) is an intermediate target-- sort of a way station. Annex I countries would need to continue to reduce emissions at a similar rate until 2050. Ultimately the Annex I cuts would need to be much deeper to hit 450ppm. Though I find the Annex I responsibilities a useful way to measure our lack of progress (even in commitments) in the near term (see http://iopscience.iop.org/1748-9326/5/3/034013/fulltext/), they are a confusing way to think about global emissions reductions. I think it is more straightforward to think of it this way. According to the fourth assessment report, by 2050, GLOBAL emissions would need to fall 50-85% from 2000 levels in order to stabilize warming at 2-2.4 degrees Celsius over the pre-industrial equilibrium (http://www.ipcc.ch/publications_and_data/ar4/wg3/en/spmsspm-d.html see chart SPM.5 ) . Best, Avery On Sun, Aug 5, 2012 at 11:48 AM, Radoslav Dimitrov <[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:[email protected]>> wrote: Depends on the temperature target: To keep global temperature rise below 2 degrees C, carbon-equivalent atmospheric concentrations must be kept below 450 ppm - which can be achieved by reducing emissions by 25-40% by 2020. The latter range is in the 2007 IPCC report and was the policy target advocated officially by the European Unionat the Bali conference. This was a subject of intense negotiations. No one else in the industrialized camp supported the EU on this. As a result, the Bali text only contains a footnote that indirectly refers to the IPCC-endorsed target, without actually containing the 25-40 numbers. Radoslav S. Dimitrov, Ph.D. Associate Professor Department of Political Science University of Western Ontario Social Science Centre London, Ontario Canada N6A 5C2 Tel. +1(519) 661-2111 ext. 85023<tel:%2B1%28519%29%20661-2111%20ext.%2085023> Fax +1(519) 661-3904<tel:%2B1%28519%29%20661-3904> Email: [email protected]<mailto:[email protected]><mailto:[email protected]><mailto:[email protected]> On 2012-08-05, at 1:27 PM, VanDeveer, Stacy wrote: Hi all, I got a question from a summer school student, and I am trying to find the ‘consensus’ answer in IPCC documents and I seem to be finding different numbers. So here is the question: The IPCC estimates that global emissions must fall by how much, to stabilize the climate systems during this century. Are the best estimates from the 2007 report (which gives quite large ranges for each of four warming scenarios)?? Stacy D. VanDeveer Associate Professor University of New Hampshire Dept. of Political Science Horton SSC Durham, NH 03824 USA [email protected]<mailto:[email protected]><mailto:[email protected]><mailto:[email protected]> tel: fax: mobile: Skype ID: (+1) 603-862-0167 <http://www.plaxo.com/click_to_call?lang=en&src=jj_signature&To=%28%2B1%29+603%2D862%2D0167&[email protected]><http://www.plaxo.com/click_to_call?lang=en&src=jj_signature&To=%28%2B1%29+603%2D862%2D0167&[email protected]> (+1) 603-862-0178<tel:%28%2B1%29%20603-862-0178> (+1) 781-321-5880 <http://www.plaxo.com/click_to_call?lang=en&src=jj_signature&To=%28%2B1%29+781%2D321%2D5880&[email protected]><http://www.plaxo.com/click_to_call?lang=en&src=jj_signature&To=%28%2B1%29+781%2D321%2D5880&[email protected]> stacy.d.vandeveer Want to always have my latest info?<https://www.plaxo.com/add_me?u=51539758810&src=client_sig_212_1_banner_join&invite=1&lang=en><https://www.plaxo.com/add_me?u=51539758810&src=client_sig_212_1_banner_join&invite=1&lang=en> Want a signature like this?<http://www.plaxo.com/signature?src=client_sig_212_1_banner_sig&lang=en><http://www.plaxo.com/signature?src=client_sig_212_1_banner_sig&lang=en> <image001.jpg> -- Avery Simon Cohn | Ph.D. Candidate | Environmental Science, Policy & Management | UC Berkeley | skype: avery.cohn | +1 (510) 410-3731 US
