The Climate Report

"February 2 may be the day when the question mark was removed from behind the debate about whether human acitivity was linked to climate change," declared Achim Steiner, director of the United Nations Environment Program (UNEP) at the launch in Paris of the Intergovernmental Panel on Climate Change (IPCC) report.

The IPCC was set up in 1988 by the World Meteorological Organization and the UNEP to guide policymakers on the impact of climate change on our world. It issues a report every six years; this report, entitled "Climate Change 2007: The Physical Science Basis," involved 2,500 scientists from all over the world. Some highlights of the report:

The Cause

Global warming is "very likely" caused by man—the strongest conclusion to date. Concentrations of heat-trapping greenhouse gases in the planet’s atmosphere "have increased markedly as a result of human activities since 1750," mainly from the use of fossil fuels like oil, gas and coal, and because of agriculture.

The Outlook

Hotter temperatures and rises in sea level "would continue for centuries" no matter how much humans control their pollution. It is "very likely" that heat waves, hot weather, and heavy rainfalls could become more frequent. Toward the end of the century, sea ice in the Arctic may disappear "almost entirely" in summer.

Temperature Change

Predicted temperature rises of 2-11.5 degrees Fahrenheit by the year 2100. That was a wider range than in the 2001 report.

However, the panel also said its best estimate was for temperature rises of 3.2-7.1 degrees Fahrenheit. In 2001, all the panel gave was a range of 2.5-10.4 degrees Fahrenheit.

Sea Levels

>Projects rises of 7-23 inches by the end of the century. An additional 3.9-7.8 inches are possible if recent, surprising melting of polar ice sheets continues.

Hurricanes

An increase in hurricane and tropical cyclone strength since 1970 "more likely than not" can be attributed to man-made global warming. Scientists said global warming’s connection varies with storms in different parts of the world, but that it influences the storms that strike the Americas.

Man-made factors have "likely" contributed to changes in wind patterns. It also is "likely" that typhoons and hurricanes will become more intense, with stronger winds and heavier rains. — AP