How Madrid talks fell short on climate ambition

This year's U.N. climate negotiations in Madrid, the longest in 25 nearly annual such gatherings, ended Sunday with major polluters resisting calls to ramp up efforts to keep global warming at bay.

Fighting climate change, protecting nature go hand in hand

The preservation of Earth's pristine wildernesses and oceans, long treated as a separate issue to curbing climate change, is taking on more importance as scientists say they really need to go hand in hand.

UN talks struggle to stave off climate chaos

United Nations climate negotiations in Madrid were set to wrap up on Friday with even the best-case outcome likely to fall well short of what science says is needed to avert a future ravaged by global warming.

Mammoth field fires up Norway's oil industry

Under yellow metal legs stretching beneath the sea, billions of dollars lie buried. As the world tries hard to halt global warming, a huge oil field breathes new life into Norway's oil sector.

Could we cool the Earth with an ice-free Arctic?

The Arctic region is heating up faster than any other place on Earth, and as more and more sea ice is lost every year, we are already feeling the impacts. IIASA researchers explored strategies for cooling down the oceans ...

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Global warming

Global warming is the increase in the average temperature of the Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the last century. The Intergovernmental Panel on Climate Change (IPCC) concludes that increasing greenhouse gas concentrations resulting from human activity such as fossil fuel burning and deforestation are responsible for most of the observed temperature increase since the middle of the 20th century. The IPCC also concludes that variations in natural phenomena such as solar radiation and volcanoes produced most of the warming from pre-industrial times to 1950 and had a small cooling effect afterward. These basic conclusions have been endorsed by more than 45 scientific societies and academies of science, including all of the national academies of science of the major industrialized countries.

Climate model projections summarized in the latest IPCC report indicate that the global surface temperature will probably rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the twenty-first century. The uncertainty in this estimate arises from the use of models with differing sensitivity to greenhouse gas concentrations and the use of differing estimates of future greenhouse gas emissions. Some other uncertainties include how warming and related changes will vary from region to region around the globe. Most studies focus on the period up to the year 2100. However, warming is expected to continue beyond 2100 even if emissions stop, because of the large heat capacity of the oceans and the long lifetime of carbon dioxide in the atmosphere.

An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, probably including expansion of subtropical deserts. The continuing retreat of glaciers, permafrost and sea ice is expected, with warming being strongest in the Arctic. Other likely effects include increases in the intensity of extreme weather events, species extinctions, and changes in agricultural yields.

Political and public debate continues regarding climate change, and what actions (if any) to take in response. The available options are mitigation to reduce further emissions; adaptation to reduce the damage caused by warming; and, more speculatively, geoengineering to reverse global warming. Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gas emissions. A small number of scientists dispute the consensus on global warming science.

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