The U.S. Climate Change Science Program and the Subcommittee on Global Change Research today released a scientific assessment that provides the first comprehensive analysis of observed and projected changes in weather and climate extremes in North America and U.S. territories.

Among the findings reported in this assessment are that droughts, heavy downpours, excessive heat, and intense hurricanes are likely to become more commonplace as humans continue to increase the atmospheric concentrations of heat-trapping greenhouse gases.

Global warming of the past 50 years is due primarily to human-induced increases in heat-trapping gases, according to the report. Many types of extreme weather and climate event changes have been observed during this time period and continued changes are projected for this century. Specific future projections include:

• Abnormally hot days and nights, along with heat waves, are very likely to become more common. Cold nights are very likely to become less common.
• Sea ice extent is expected to continue to decrease and may even disappear in the Arctic Ocean in summer in coming decades.
• Precipitation, on average, is likely to be less frequent but more intense.
• Droughts are likely to become more frequent and severe in some regions.
• Hurricanes will likely have increased precipitation and wind.
• The strongest cold-season storms in the Atlantic and Pacific are likely to produce stronger winds and higher extreme wave heights.

In a letter to Obama supporters Monday afternoon, Al Gore announced he will be supporting Barack Obama for President of the United States. He asked Obama supporters to make a donation in support of the Obama campaign. Siting tremendous headwind Mr. Gore stated: "Over the next four years, we are going to face many difficult challenges -- including bringing our troops home from Iraq, fixing our economy, and solving the climate crisis. Barack Obama is clearly the candidate best able to solve these problems and bring change to America."

Supporters were invited to watch streaming video of Al Gore and Barack Obama live tonight -- 8:30 p.m. EDT at a rally in Detroit, Michigan