Blog about UN Climate Change Conference in Bali 3-14 December 2007 and other related issues

Thursday, October 18, 2007

Effects of Climate Change

About 100 years ago, people worldwide began burning more coal and oil for homes, factories, and transportation. Burning these fossil fuels releases carbon dioxide and other greenhouse gases into the atmosphere. These added greenhouses gasses have caused eartah to warm more quickly than it has in the past.
How much warming has happened? Scientists from around the world tell us that during the past 100 years, the average global air temperature has risen more than 0.6°C (1.0 °F). This may not sound like very much change, but even one degree can affect the Earth. Below are some effects of climate change that we see happening now.
Sea level is rising. During the 20th century, sea level rose 10-20 cm (4-8 inches) due to melting glacier ice and expansion of warmer seawater. In the next 100 years, sea level may rise as much as 85 cm (33 inches). This is a threat to people living near the coast, wetlands, and coral reefs.
Arctic sea ice is melting. The summer thickness of Arctic icebergs is about half of what it was 50 years ago. This melting ice may someday cause changes in the world’s ocean currents.
Sea-surface temperatures are warming. Some animals, such as corals, cannot live in warmer seas. Over the past few decades, about a quarter of the world’s coral reefs have died.
Heavier rainfall causes flooding in many regions as warmer temperatures speed up the water cycle. In the last ten years, floods have caused more damage than in the previous 30 years.
There have been changes in where we can farm: As climates warm, some mid-latitude places, like Europe, are getting a longer growing season, while some tropical places are becoming too hot and dry to grow crops.
The amount of drought may be increasing. Higher temperatures lead to a high rate of evaporation and very dry conditions in some areas of the world. Researchers are not sure if drought has increased as a result of current warming.
Ecosystems are changing. As temperatures warm, species may migrate to cooler places or die. Species that are in particularly danger include endangered species, coral reefs, and polar animals such as penguins, polar bears and seals.
Severe weather events may be more common and stronger. Some researchers say that the number and strength of hurricanes, tornadoes, and other events has increased over the last 15–20 years. However, scientists are still looking into this.

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