Global Warming

Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Warming of the climate system is unequivocal, and scientists are more than 90% certain that it is primarily caused by increasing concentrations of greenhouse gases produced by human activities such as the burning of fossil fuels and deforestation. These findings are recognized by the national science academies of all major industrialized nations.

Climate model projections were summarized in the 2007 Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change (IPCC). They indicated that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C (2 to 5.2 °F) for their lowest emissions scenario and 2.4 to 6.4 °C (4.3 to 11.5 °F) for their highest. The ranges of these estimates arise from the use of models with differing sensitivity to greenhouse gas concentrations.

According to AR4, warming and related changes will vary from region to region around the globe. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with the continuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming include a more frequent occurrence of extreme-weather events including heat waves, droughts and heavy rainfall, ocean acidification and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the loss of habitat from inundation.

Proposed policy responses to global warming include mitigation by emissions reduction, adaptation to its effects, and possible future geoengineering. Most countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC), whose ultimate objective is to prevent dangerous anthropogenic (i.e., human-induced) climate change. Parties to the UNFCCC have adopted a range of policies designed to reduce greenhouse gas emissions and to assist in adaptation to global warming. Parties to the UNFCCC have agreed that deep cuts in emissions are required, and that future global warming should be limited to below 2.0 °C (3.6 °F) relative to the pre-industrial level. Reports published in 2011 by the United Nations Environment Programme and the International Energy Agency suggest that efforts as of the early 21st century to reduce emissions may be inadequate to meet the UNFCCC's 2 °C target.

Read more about Global WarmingObserved Temperature Changes, Initial Causes of Temperature Changes (external Forcings), Feedback, Climate Models, Observed and Expected Environmental Effects, Observed and Expected Effects On Social Systems, Views On Global Warming, Etymology

Other articles related to "global warming, warming, global":

Global Warming - Etymology
... The term global warming was probably first used in its modern sense on 8 August 1975 in a science paper by Wally Broecker in the journal Science called "Are we on ... new and represented a significant recognition that the climate was warming previously the phrasing used by scientists was "inadvertent climate modification," because while it was ... The National Academy of Sciences first used global warming in a 1979 paper called the Charney Report, which said "if carbon dioxide continues to increase ...
Stanley B. Goldenberg
... temperature trends (which some attribute to anthropogenic global warming) ... of many scientists that have challenged the notion of scientific consensus on global warming as far from scientifically conclusive, stating that "It is a blatant lie put forth in the media that makes ...
Lawrence Solomon - Global Warming
... to Solomon, contradicts what he calls the alarmist view of global warming presented by Al Gore, the IPCC, the media and the consensus of thirty four National Academies of Science ... Commerce's Institute for 21st Century Energy sponsored a debate about global warming between Lawrence Solomon and Dr ... Jay Gulledge of the Pew Center on Global Climate Change, who took the opposite view ...
Sustainable Retreat - Career - Climate
... in January 2006, Lovelock argued that, as a result of global warming, "billions of us will die and the few breeding pairs of people that survive will be in ... Population Trust), which campaigns for a gradual decline in the global human population to a sustainable level ... portray Lovelock as continuing his concern over global warming while at the same time criticizing extremism and suggesting alternatives to oil, coal and the green ...
Solar-powered Refrigerator - Rationale
... technologies including contribution to ozone layer depletion and global warming ... Refrigerators which contain ozone depleting and global warming substances such as chlorofluorocarbons (CFCs), in their insulation foam or their refrigerant cycle, are the ... Both are environmentally destructive as potential global warming chemicals ...

Famous quotes containing the words warming and/or global:

    Thine age asks ease, and since thy duties be
    To warm the world, that’s done in warming us.
    Shine here to us, and thou art everywhere;
    This bed thy center is, these walls, thy sphere.
    John Donne (1572–1631)

    The Sage of Toronto ... spent several decades marveling at the numerous freedoms created by a “global village” instantly and effortlessly accessible to all. Villages, unlike towns, have always been ruled by conformism, isolation, petty surveillance, boredom and repetitive malicious gossip about the same families. Which is a precise enough description of the global spectacle’s present vulgarity.
    Guy Debord (b. 1931)