National Geographic Magazine

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Earth's Changing Climate

Surface temperatures on Earth are warming at a pace that signals a decisive shift in the global climate.

44 487 img/climatetab1.gif img/climatemap1.jpg 753 487 13369344 13369344 img/pollution-287.jpg Land and Sea Climate is changing more rapidly than ever before. Human activity is the main cause. Burning of fossil fuels—oil, gas, coal—has flooded the atmosphere with heat-trapping carbon dioxide, triggering a 1°F (0.6°C) spike in average global temperature in the past century, largely in the past 30 years. Already, impacts include altered precipitation patterns (See Precipitation Fallout map), melting glaciers, intensifying storms, and a rise in sea level. Unless CO2 emissions are slashed, the planet will likely heat up even faster, fundamentally changing the world we live in. Land warms faster than water, one reason the Northern Hemisphere shows greater temperature increase. As oceans warm, their volume swells, contributing to sea-level rise. Photograph by iStockphoto 10 10 1 Land and Sea 0 0 10 Verdana 0 8 0.24 1 0 false 65 112 11 -8 13369344 13369344 img/melting-ice-287.jpg The Warming Earth The Arctic is experiencing the fastest rate of warming as its reflective covering of ice and snow shrinks. In the mid-latitudes there are now fewer cold nights; heat waves are more common. The Indian Ocean and the western Pacific Ocean are warmer than at any point in the past 11,500 years. Against the trend: Pockets of the oceans are cooled by deepwater upwellings. Ozone loss over the South Pole may have cooled parts of Antarctica. Photograph by iStockphoto 10 10 1 The Warming Earth 0 0 10 Verdana 0 8 0.24 1 0 false 285 44 12 -9 13369344 13369344 img/misting-people-287.jpg Heat Wave In 2003, during one of the warmest summers on record in the Northern Hemisphere, as many as 35,000 people died in Europe's heat wave. Photograph by Franck Prevel, AP 10 10 1 Heat Waves 0 0 10 Verdana 0 8 0.24 1 0 false 376 68 11 -8 13369344 13369344 img/mountains-287.jpg Meltdown Glaciers are rapidly retreating, even in Antarctica. Himalayan glaciers, which feed major rivers of South Asia, are receding more than 30 feet a year. Photograph by 123RF 10 10 1 Meltdown 0 0 10 Verdana 0 8 0.24 1 0 false 536 95 12 -8 13369344 13369344 The World Feels the Heat Even a future with dramatic cuts in CO2 emissions will see an additional temperature rise of 2°C (3.6°F) over the next century. Though a few regions such as Russia and northern Europe will benefit from warmer years, most of the world will suffer, particularly the tropics and poorer nations without the funds to adapt. If CO2 emissions are not reduced, temperatures could rise by 5°C (9°F), a likely tipping point altering all ecosystems and causing massive population displacement. 10 10 1 Snapshot: Feeling the Heat 0 0 10 Verdana 0 8 0.24 1 0 false 570 441 12 -8 img/climatetab2.gif img/climatemap2.jpg 753 487 13369344 13369344 img/fire-people-287.jpg Fire Hazards Tinder-dry conditions and high heat in the American West have sparked longer and more destructive wildfires. Photography by iStockphoto 10 10 1 Fire Hazards 0 0 10 Verdana 0 19.4 0.96 0.8 0 false 147 102 13 -2 13369344 13369344 img/boy-by-river-287.jpg Sahel The semiarid Sahel shows an uptick in precipitation compared with earlier decades when practically no rain fell. James L. Stanfield, National Geographic Image Collection 10 10 1 Sahel 0 0 10 Verdana 0 19.2 1 1.2 0 false 343 164 3 -21 13369344 13369344 img/flooding-287.jpg Deluge Heavier and more frequent summer rains in southern China have helped trigger destructive floods, most recently in 2007. Photography by AP/Color China Photo 10 10 1 Deluge 0 0 10 Verdana 0 20 1 0 0 false 552 133 -1 -24