Beyond 'dangerous' climate change: emission scenarios for a new world.
The Copenhagen Accord reiterates the international community's commitment to 'hold the increase in global temperature below 2 degrees Celsius'. Yet its preferred focus on global emission peak dates and longer-term reduction targets, without recourse to cumulative emission budgets, belies seriously the scale and scope of mitigation necessary to meet such a commitment. Moreover, the pivotal importance of emissions from non-Annex 1 nations in shaping available space for Annex 1 emission pathways received, and continues to receive, little attention. Building on previous studies, this paper uses a cumulative emissions framing, broken down to Annex 1 and non-Annex 1 nations, to understand the implications of rapid emission growth in nations such as China and India, for mitigation rates elsewhere. The analysis suggests that despite high-level statements to the contrary, there is now little to no chance of maintaining the global mean surface temperature at or below 2°C. Moreover, the impacts associated with 2°C have been revised upwards, sufficiently so that 2°C now more appropriately represents the threshold between 'dangerous' and 'extremely dangerous' climate change. Ultimately, the science of climate change allied with the emission scenarios for Annex 1 and non-Annex 1 nations suggests a radically different framing of the mitigation and adaptation challenge from that accompanying many other analyses, particularly those directly informing policy.
Tyndall Centre for Climate Change Research, School of Mechanical, Aerospace and Civil Engineering, University of Manchester, PO Box 88, Manchester M60 1QD, UK.
Kevin
K
Anderson
Alice
A
Bows
D000383:Agriculture; D000818:Animals; D002245:Carbon Dioxide / Q000737:chemistry; D057231:Climate Change; D003247:Conservation of Natural Resources; D018534:Earth, Planet; D004463:Ecology; D057232:Global Warming; D006801:Humans; D007391:International Cooperation; D008962:Models, Theoretical; D011640:Public Policy; D012106:Research / Q000639:trends; D013696:Temperature; D014881:Water Supply
D002245:Carbon Dioxide