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Global Climate Change - Climate Change In Earth History, Global Warming—the Result Of Human Activity, Effects Of A Warming Climate

Although large changes in climate are a natural part of Earth history, there is little doubt that human activities have caused observed patterns of global warming in the twentieth and twenty-first centuries. Global climate change has large implications for both humans and wildlife. Many threatened and endangered species, which already lead a precarious existence, are likely to suffer further declines. Global warming also threatens populations of species that were once relatively secure, and is likely to result in the endangerment of more species in the future.

A study of habitats comprising 20 percent of the earth's surface suggested that 15 to 37 percent of the world's species may be extinct by 2050 if recent warming trends continue ("Extinction Risk from Climate Change," Nature, no. 427, January 2004.) Summarizing his findings, ecologist Chris D. Thomas said, "The midrange estimate is that 24 percent of plants and animals will be committed to extinction by 2050. We're not talking about the occasional extinction—we're talking about 1.25 million species. It's a massive number."

Additional Topics

Global Climate Change - Climate Change In Earth History

Over hundreds of millions of years, geological and astronomical forces have changed Earth's environment from hot to cold, wet to dry, and back again. Studies have shown that the climate has fluctuated between long periods of cold lasting 50,000 to 80,000 years and shorter periods of warmth lasting about 10,000 years. The Earth is in the midst of one of those warm periods now. These climate …

Global Climate Change - Global Warming—the Result Of Human Activity

Earth's climate is a delicate balance of energy input, chemical and biological processes, and physical phenomena. The Earth's atmosphere plays a critical role in planetary surface temperature. Some gases, such as carbon dioxide (CO2) and methane (CH4), absorb and maintain heat in the same way that glass traps heat in a greenhouse. These greenhouse gases in Earth's atmosphere a…

Global Climate Change - Effects Of A Warming Climate

In 1990 the Intergovernmental Panel on Climate Change (IPCC) noted several early signs of climate FIGURE 3.5 Carbon dioxide sources, 2001 change in Earth's colder habitats. The average warm-season temperature in Alaska had increased three degrees in fifty years. Glaciers had receded and thinned by thirty feet in forty years. There was significantly less sea ice in the Bering Sea than…

Global Climate Change - International Efforts And Global Warming

In order to slow or halt global warming, many industrialized countries are committed to stabilizing or reducing carbon dioxide emissions. The first Bush administration (1989–1992) opposed precise deadlines for carbon dioxide limits, arguing that the extent of the problem was too uncertain to justify painful economic measures. When President Bill Clinton took office in 1993, he joined the E…

SNEFERU'S BENT PYRAMID AT DAHSHUR

In the fifteenth year of King Sneferu?s reign (2610 B.C.E.), he abandoned his building project at the Meidum Pyramid and moved his court 25 miles north to Dahshur. At this point in his reign, the Meidum Pyramid was still a step pyramid, more similar in shape to Djoser?s pyramid at Saqqara than to the true pyramids built later. The move to Dahshur indicates a break with the step-pyramid style in an…

Endangered Plants and Ecosystems - Plants In Decline, The American Landscape, Endangered Forests, Wetlands, Plant Conservation, Ecosystems Approaches To Conservation [next] [back] Working Toward Species Conservation - History Of Species Protection, The Endangered Species Act Of 1973—a Landmark Protection, Federal Lands And Wildlife Protection

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