Economic and political debate

Increased publicity of the scientific findings surrounding global warming has resulted in political and economic debate. Poor regions, particularly Africa, appear at greatest risk from the projected effects of global warming, while their emissions have been small compared to the developed world. At the same time, developing country exemptions from provisions of the Kyoto Protocol have been criticized by the United States and Australia, and used as part of a rationale for continued non-ratification by the U.S. In the Western world, the idea of human influence on climate has gained wider public acceptance in Europe than in the United States.^[121][122]

The issue of climate change has sparked debate weighing the benefits of limiting industrial emissions of greenhouse gases against the costs that such changes would entail. There has been discussion in several countries about the cost and benefits of adopting alternative energy sources in order to reduce carbon emissions. Business-centered organizations, conservative commentators, and companies such as the Competitive Enterprise Institute and ExxonMobil have downplayed IPCC climate change scenarios, funded scientists who disagree with the scientific consensus, and provided their own projections of the economic cost of stricter controls. Likewise, environmental organizations and a number of public figures have emphasized the potential risks of climate change and promote the implementation of GHG emissions reduction measures. Some fossil fuel companies have scaled back their efforts in recent years, or called for policies to reduce global warming.

Another point of contention is the degree to which emerging economies such as India and China should be expected to constrain their emissions. According to recent reports, China's gross national CO₂ emissions may now exceed those of the U.S. China has contended that it has less of an obligation to reduce emissions since its per capita emissions are roughly one-fifth that of the United States. India, also exempt from Kyoto restrictions and another of the biggest sources of industrial emissions, has made similar assertions. The U.S. contends that if it must bear the cost of reducing emissions, then China should do the same.

Economic

Responses to global warming

Main articles: Mitigation of global warming, Kyoto Protocol, Geoengineering, and Adaptation to global warming

The broad agreement among climate scientists that global temperatures will continue to increase has led some nations, states, corporations and individuals to implement responses. These responses to global warming can be divided into mitigation of the causes and/or effects of global warming, and adaptation to the changing global environment.

Mitigation

Emissions reduction

By far the largest amount of political time and effort has gone into reducing in greenhouse gas emissions, principally through the Kyoto protocol. These efforts have been largely unsuccessful. Other approaches include carbon sequestration and certain geoengineering techniques.

The world's primary international agreement on combating global warming is the Kyoto Protocol, an amendment to the UNFCCC negotiated in 1997. The Protocol now covers more than 160 countries globally and over 55 percent of global greenhouse gas emissions.^[102] Only the United States and Kazakhstan have not ratified the treaty, with the United States historically being the world's largest emitter of greenhouse gases. This treaty expires in 2012, and international talks began in May 2007 on a future treaty to succeed the current one.

Many environmental groups encourage individual action against global warming, often by the consumer, but also by community and regional organizations. Others have suggested a quota on worldwide fossil fuel production, citing a direct link between fossil fuel production and CO₂

emissions.

There has also been business action on climate change, including efforts at increased energy efficiency and limited moves towards use of alternative fuels. In January 2005 the European Union introduced its European Union Emission Trading Scheme, a greenhouse gas emissions trading scheme through which companies, in conjunction with government, agree to cap their emissions or to purchase credits from those below their allowances. Australia announced its Carbon Pollution Reduction Scheme in 2008. United States President Barack Obama has announced he will introduce an economy wide cap and trade scheme.

The IPCC's Working Group III is responsible for crafting reports that deal with the mitigation of global warming and analyzing the costs and benefits of different approaches. In the 2007 IPCC Fourth Assessment Report, they conclude that no one technology or sector can be completely responsible for mitigating future warming. They find there are key practices and technologies in various sectors, such as energy supply, transportation, industry, and agriculture, that should be implemented to reduced global emissions. They estimate that stabilization of carbon dioxide equivalent between 445 and 710 ppm by 2030 will result in between a 0.6 percent increase and three percent decrease in global gross domestic product.

Geoengineering

Geoengineering would involve the deliberate modification of Earth's environment on a large scale "to suit human needs and promote habitability". It can be divided two major approaches. The first is remediation, in which greenhouse gases would be removed from the atmosphere, principally by carbon sequestration methods such as air capture.^[109] The second is solar radiation management, in which incoming solar radiation would be reduced, such as by the insertion of stratospheric sulfur aerosols. The slow pace of action to reduce greenhouse gas cool roof and tree planting projects are underway, no planetary-scale geoengineering has yet been attempted. emissions have led some scientists to suggest that these techniques may be necessary. Whilst some

Adaptation

The effects of global warming are wide in their scope, and a similarly wide variety of measures have been suggested for adaptation to global warming. These range from the trivial, such as the installation of air-conditioning equipment, up to major infrastructure projects, such as abandonment of settlements threatened by rising sea levels. Measures including water conservation, changes to agricultural practices, construction of flood defences, and interventions to protect threatened species have all been suggested. A wide ranging study of the possible opportunities for adaptation of infrastructure has been published by the Institute of Mechanical Engineers changes to medical care,

Notes

1. ^ Global surface temperature is defined in the IPCC Fourth Assessment Report as the average of near-surface air temperature over land and sea surface temperature.
2. ^ The 2001 joint statement was signed by the scientific academies of Australia, Belgium, Brazil, Canada, the Caribbean, China, France, Germany, India, Indonesia, Ireland, Italy, Malaysia, New Zealand, Sweden, and the UK. The 2005 statement added Japan, Russia, and the U.S. The 2007 statement added Mexico and South Africa. Professional societies include American Association for the Advancement of Science, American Astronomical Society, American Chemical Society, American Geophysical Union, American Institute of Physics, American Meteorological Society, American Physical Society, American Quaternary Association, Australian Meteorological and Oceanographic Society, Canadian Foundation for Climate and Atmospheric Sciences, Canadian Meteorological and Oceanographic Society, European Academy of Sciences and Arts, European Geosciences Union, European Science Foundation, Geological Society of America, Geological Society of London-Stratigraphy Commission, InterAcademy Council, International Council of Academies of Engineering and Technological Sciences, International Union of Geodesy and Geophysics, International Union for Quaternary Research, National Research Council (US), Network of African Science Academies, and Royal Meteorological Society (UK).
3. Note that the Greenhouse Effect produces a temperature increase of about 33 °C (59 °F) with respect to black body predictions and not a surface temperature of 33 °C (91 °F) which is 32°F higher. The average surface temperature is about 14 °C (57 °F). Also note that both the Celsius and Fahrenheit temperatures are expressed to 2 significant figures even though the conversion formula produces 3.