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Most countries are Parties to the United Nations Framework Convention on Climate Change (UNFCCC).[200] The ultimate objective of the Convention is to prevent dangerous human interference of the climate system.[201] As is stated in the Convention, this requires that GHG concentrations are stabilized in the atmosphere at a level where ecosystems can adapt naturally to climate change, food production is not threatened, and economic development can proceed in a sustainable fashion.[202] The Framework Convention was agreed in 1992, but since then, global emissions have risen.[203] During negotiations, the G77 (a lobbying group in the United Nations representing 133 developing nations)[204]:4 pushed for a mandate requiring developed countries to "[take] the lead" in reducing their emissions.[205] This was justified on the basis that: the developed world's emissions had contributed most to the stock of GHGs in the atmosphere; per-capita emissions (i.e., emissions per head of population) were still relatively low in developing countries; and the emissions of developing countries would grow to meet their development needs.[88]:290 This mandate was sustained in the Kyoto Protocol to the Framework Convention,[88]:290 which entered into legal effect in 2005.[206] In ratifying the Kyoto Protocol, most developed countries accepted legally binding commitments to limit their emissions. These first-round commitments expired in 2012.[206] US President George W. Bush rejected the treaty on the basis that "it exempts 80% of the world, including major population centers such as China and India, from compliance, and would cause serious harm to the US economy."[204]:5 At the 15th UNFCCC Conference of the Parties, held in 2009 at Copenhagen, several UNFCCC Parties produced the Copenhagen Accord.[207] Parties associated with the Accord (140 countries, as of November 2010)[208]:9 aim to limit the future increase in global mean temperature to below 2 °C.[209] A preliminary assessment published in November 2010 by the United Nations Environment Programme (UNEP) suggests a possible "emissions gap" between the voluntary pledges made in the Accord and the emissions cuts necessary to have a "likely" (greater than 66% probability) chance of meeting the 2 °C objective.[208]:10–14 The UNEP assessment takes the 2 °C objective as being measured against the pre-industrial global mean temperature level. To having a likely chance of meeting the 2 °C objective, assessed studies generally indicated the need for global emissions to peak before 2020, with substantial declines in emissions thereafter. The 16th Conference of the Parties (COP16) was held at Cancún in 2010. It produced an agreement, not a binding treaty, that the Parties should take urgent action to reduce greenhouse gas emissions to meet a goal of limiting global warming to 2 °C above pre-industrial temperatures. It also recognized the need to consider strengthening the goal to a global average rise of 1.5 °C.[210] Scientific discussion See also: Scientific opinion on climate change and Surveys of scientists' views on climate change Most scientists agree that humans are contributing to observed climate change.[85][211] A meta study of academic papers concerning global warming, published between 1991 and 2011 and accessible from Web of Knowledge, found that among those whose abstracts expressed a position on the cause of global warming, 97.2% supported the consensus view that it is man made.[212] In an October 2011 paper published in the International Journal of Public Opinion Research, researchers from George Mason University analyzed the results of a survey of 489 American scientists working in academia, government, and industry. Of those surveyed, 97% agreed that that global temperatures have risen over the past century and 84% agreed that "human-induced greenhouse warming" is now occurring, only 5% disagreeing that human activity is a significant cause of global warming.[213][214] National science academies have called on world leaders for policies to cut global emissions.[215] In the scientific literature, there is a strong consensus that global surface temperatures have increased in recent decades and that the trend is caused mainly by human-induced emissions of greenhouse gases. No scientific body of national or international standing disagrees with this view.[216][217] Discussion by the public and in popular media Main articles: climate change denial, global warming controversy and media coverage of climate change The global warming controversy refers to a variety of disputes, substantially more pronounced in the popular media than in the scientific literature,[218][219] regarding the nature, causes, and consequences of global warming. The disputed issues include the causes of increased global average air temperature, especially since the mid-20th century, whether this warming trend is unprecedented or within normal climatic variations, whether humankind has contributed significantly to it, and whether the increase is wholly or partially an artifact of poor measurements. Additional disputes concern estimates of climate sensitivity, predictions of additional warming, and what the consequences of global warming will be. From 1990–1997 in the United States, conservative think tanks mobilized to challenge the legitimacy of global warming as a social problem. They challenged the scientific evidence, argued that global warming will have benefits, and asserted that proposed solutions would do more harm than good.[220] Some people dispute aspects of climate change science.[211][221] Organizations such as the libertarian Competitive Enterprise Institute, conservative commentators, and some companies such as ExxonMobil have challenged IPCC climate change scenarios, funded scientists who disagree with the scientific consensus, and provided their own projections of the economic cost of stricter controls.[222][223][224][225] Some fossil fuel companies have scaled back their efforts in recent years,[226] or called for policies to reduce global warming.[227] Surveys of public opinion Main article: Public opinion on climate change Researchers at the University of Michigan have found that the public's belief as to the causes of global warming depends on the wording choice used in the polls.[228] In 2007–2008 Gallup Polls surveyed 127 countries. Over a third of the world's population was unaware of global warming, with people in developing countries less aware than those in developed, and those in Africa the least aware. Of those aware, Latin America leads in belief that temperature changes are a result of human activities while Africa, parts of Asia and the Middle East, and a few countries from the Former Soviet Union lead in the opposite belief.[229] There is a significant contrast of the opinions of the concept and the appropriate response between Europe and the United States. Nick Pidgeon of Cardiff University said that "results show the different stages of engagement about global warming on each side of the Atlantic", adding, "The debate in Europe is about what action needs to be taken, while many in the US still debate whether climate change is happening."[230][231] A 2010 poll by the Office for National Statistics found that 75% of UK respondents were at least "fairly convinced" that the world's climate is changing, compared to 87% in a similar survey in 2006.[232] A January 2011 ICM poll in the UK found 83% of respondents viewed climate change as a current or imminent threat, while 14% said it was no threat. Opinion was unchanged from an August 2009 poll asking the same question, though there had been a slight polarisation of opposing views.[233] By 2010, with 111 countries surveyed, Gallup determined that there was a substantial decrease in the number of Americans and Europeans who viewed global warming as a serious threat. In the US, a little over half the population (53%) now viewed it as a serious concern for either themselves or their families; this was 10% below the 2008 poll (63%). Latin America had the biggest rise in concern, with 73% saying global warming was a serious threat to their families.[234] That global poll also found that people are more likely to attribute global warming to human activities than to natural causes, except in the USA where nearly half (47%) of the population attributed global warming to natural causes.[235] A March–May 2013 survey by Pew Research Center for the People & the Press polled 39 countries about global threats. According to 54% of those questioned, global warming featured top of the perceived global threats.[236] In a January 2013 survey, Pew found that 69% of Americans say there is solid evidence that the Earth's average temperature has been getting warmer over the past few decades, up six points since November 2011 and 12 points since 2009.[237] Etymology According to Erik M. Conway, global warming became the dominant popular term after June 1988, when NASA climate scientist James Hansen used the term in a testimony to Congress[238] when he said: "global warming has reached a level such that we can ascribe with a high degree of confidence a cause and effect relationship between the greenhouse effect and the observed warming."[239] Conway claims that this testimony was widely reported in the media and subsequently global warming became the commonly used term by both the press and in public discourse. However, he also points out that "global climate change" is the more scientifically accurate term, because changes in Earth systems are not limited to surface temperatures.[238] |
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