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Avoiding dangerous climate change (also expressed with equivalent terms such as preventing dangerous anthropogenic interference with the climate system) is a major objective of both scientific research and in international governmental development of climate policy. The concept expressed by these phrases was central to the "IPCC Second Assessment: Climate Change 1995" published by the International Panel on Climate Change.〔IPCC 1995. (Second Assessment Report: Climate change 1995 ), commonly known as "Second Assessment Report" or "SAR".〕 In 2002, the United Nations Framework Convention on Climate Change (UNFCCC),〔The Kyoto Protocol is a protocol to the UNFCCC.〕 an international organization established by treaty in 1992, incorporated the concept as the focus of its formal Framework Convention policy: :"ARTICLE 2. OBJECTIVE. The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would ''prevent dangerous anthropogenic interference with the climate system''. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner." (Emph. added)〔UNFCC 2002. (Framework Convention )〕 Avoiding dangerous climate change and its equivalent terms have continued in common usage in the policy community,〔IPCC 2001. (Third Assessment Report: Climate change 2001 ).〕〔IPCC 2007. (Fourth Assessment Report: Climate change 2007 ).〕 scientific literature〔Schneider, S. (2009). (The worst-case scenario ). Nature (458:7242, p.1104-1105).〕〔Lenton, T. (2011). (2 °C or not 2 °C? That is the climate question. ) Nature (473:7).〕 and news media,〔UPI. 27 Oct. 2011. (Review: Warming target needs action now )〕〔Reuters. 23 May 2011. (Climate change warnings add heat to Australia CO2 price ).〕〔The Australian. 1 June 2011. (Clash of cultures, economics and ideology )〕 and in 2005 a scientific conference (see below) focused on the concept and used the phrase in its title. The problem that arises is to decide what level of interference would lead to "dangerous" change. The relevance of the issue is increasing as existing Earth System Models project that as early as 2020 in tropical areas, 2047 on average globally, the Earth's surface temperature could move beyond historical analogs, potentially impacting over 3 billion people and the most diverse places on Earth. ==Setting temperature rise goals== Limiting the average global surface temperature increase of 2°C (3.6°F) over the pre-industrial average has, since the 1990s, been commonly regarded as an adequate means of avoiding dangerous climate change, in science and policy making.〔den Elzen M.; Meinshausen M. (2005). Netherlands Env. Assessment Agency. (Meeting the EU 2°C climate target: global and regional emission implications. )〕〔Rogelj, J.; Hare, B,; Nabel, J.; Macey, K.; Schaeffer, M.; Markmann, K.; Meinshausen, M. (2009). (Halfway to Copenhagen, no way to 2°C. Nature Reports Climate Change. )〕 However, recent science has shown that the weather, environmental and social impacts of 2°C rise are much greater than the earlier science indicated, and that impacts for a 1°C rise are now expected to be as great as those previously assumed for a 2°C rise.〔 In a July 2011 speech, climate scientist Kevin Anderson explained that for this reason, avoiding dangerous climate in the conventional sense is no longer possible, because the temperature rise is already close to 1°C, with effects formerly assumed for 2°C.〔Anderson, K. (2011). Multi-media presentation. (Climate Change: Going beyond dangerous -- Brutal numbers, tenuous hope, or cognitive dissonance? ) July 2011.〕〔Anderson, K.; Bows, A. (2011). (Beyond 'dangerous' climate change: emission scenarios for a new world ). Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences (369:1934, p.20-44).〕 Moreover, Anderson's presentation demonstrates reasons why a temperature rise of 4°C by 2060 is a likely outcome, given the record to date of action on climate, economic realities, and short window of time remaining for limiting the average surface temperature rise to 2°C or even 3°C.〔 He also states that a 4°C rise would likely be an unstable state, leading to further increases in following decades regardless of mitigation measures that may be taken.〔 The consequences of failing to avoid dangerous climate change have been explored in two recent scientific conferences: the 4 degrees and beyond climate change conference held at Oxford University in 2009; and the Four Degrees Or More? Australia in a Hot World held at the University of Melbourne in July 2011. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「avoiding dangerous climate change」の詳細全文を読む スポンサード リンク
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