Four degrees and beyond: the potential for a global temperature increase of four degrees and its implications: Introduction

New, Mark, Liverman, Diana, Schroder, Heike ORCID: and Anderson, Kevin (2011) Four degrees and beyond: the potential for a global temperature increase of four degrees and its implications: Introduction. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 369 (1934). pp. 6-19. ISSN 1364-503X

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The 1992 UN Framework Convention on Climate Change commits signatories to preventing ‘dangerous anthropogenic interference with the climate system’, leaving unspecified the level of global warming that is dangerous. In the late 1990s, a limit of 2°C global warming above preindustrial temperature was proposed as a ‘guard rail’ below which most of the dangerous climate impacts could be avoided. The 2009 Copenhagen Accord recognized the scientific view ‘that the increase in global temperature should be below 2 degrees Celsius’ despite growing views that this might be too high. At the same time, the continued rise in greenhouse gas emissions in the past decade and the delays in a comprehensive global emissions reduction agreement have made achieving this target extremely difficult, arguably impossible, raising the likelihood of global temperature rises of 3°C or 4°C within this century. Yet, there are few studies that assess the potential impacts and consequences of a warming of 4°C or greater in a systematic manner. Papers in this themed issue provide an initial picture of the challenges facing a world that warms by 4°C or more, and the difficulties ahead if warming is to be limited to 2°C with any reasonable certainty. Across many sectors—coastal cities, agriculture, water stress, ecosystems, migration—the impacts and adaptation challenges at 4°C will be larger than at 2°C. In some cases, such as farming in sub-Saharan Africa, a +4°C warming could result in the collapse of systems or require transformational adaptation out of systems, as we understand them today. The potential severity of impacts and the behavioural, institutional, societal and economic challenges involved in coping with these impacts argue for renewed efforts to reduce emissions, using all available mechanisms, to minimize the chances of high-end climate change. Yet at the same time, there is a need for accelerated and focused research that improves understanding of how the climate system might behave under a +4°C warming, what the impacts of such changes might be and how best to adapt to what would be unprecedented changes in the world we live in.

Item Type: Article
Additional Information: This article has a correction. Please see: Correction for New et al., Introduction. Four degrees and beyond: the potential for a global temperature increase of four degrees and its implications - March 13, 2011
Uncontrolled Keywords: cumulative carbon emissions,dangerous climate-change,water availability,4-degrees-c world,governance,adaptation,copenhagen,trends,policy,cycle,sdg 13 - climate action ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School: Faculty of Social Sciences > School of International Development
Faculty of Science > School of Environmental Sciences
University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups: Faculty of Social Sciences > Research Groups > Globalisation and CSR
Faculty of Social Sciences > Research Groups > Global Environmental Justice
Faculty of Social Sciences > Research Groups > Climate Change
University of East Anglia Schools > Faculty of Science > Tyndall Centre for Climate Change Research
Faculty of Science > Research Centres > Tyndall Centre for Climate Change Research
Depositing User: Julie Frith
Date Deposited: 21 Nov 2012 15:08
Last Modified: 15 Jun 2023 10:30
DOI: 10.1098/rsta.2010.0303

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