1998 - 2007 Warmest Decade on Record

The decade just ending will go down on record as the warmest yet globally, according to news from the World Meteorological Organization (WMO).

The WMO also reported that 2007 was a year for many "remarkable" climate events around the globe, including record-breaking warm temperatures in Europe, severe drought in China and the U.S. Southeast, and the first cyclone to strike Iran since 1945. The agency will release its complete "Statement on the Status of the Global Climate" in March 2008.

According to the WMO, the global mean surface temperature for the Earth is now 0.74 degrees Fahrenheit above the annual average of 57.2 degrees Fahrenheit seen between 1961 and 1990. Not only is the globe warming, but the heat-up is accelerating, the WMO added. Average surface temperatures over the past 50 years have increased nearly twice as fast as they did over the past 100 years.

Depending on the weather agency keeping track, 2007 will end up as either the fifth warmest (U.S. National Oceanic and Atmospheric Administration) or seventh warmest (U.K. Meteorological Office/Climate Research Unit) on record.

Among the extreme weather events reported in 2007 were a warmest-ever winter and spring for parts of Europe, high temperatures of up to 113 degrees Fahrenheit in Bulgaria during the summer, and torrential rains and flooding in Mozambique, Sudan, Bolivia and Indonesia. In a three-day period in February, the tropical cyclone Gamède dumped 3,929 millimeters -- 154.7 inches -- of rain on French La Reunion, setting a new world record for rainfall.

The past year was also notable for the record-low extent of sea ice observed in the Arctic. At the end of the Arctic summer in September 2007, the extent of sea ice had shrunk to 1.65 million square miles. That was 39 percent less ice that the average coverage between 1979 and 2000, and 23 percent less than the previous low record set just two years ago. So much sea ice melted this summer that the Canadian Northwest Passage through Arctic waters opened up for the first time in recorded history. The passage remained open for about five weeks, allowing nearly 100 vessels to pass through without the threat of ice.

The WMO said the September extent of Arctic sea ice has been shrinking by about 10 percent per decade since 1979.

As the atmosphere continues to warm, sea levels around the world are also rising due to melting ice caps and glaciers, and ocean water expansion (warmer temperatures cause expansion). The WMO said the average global sea level in 2007 was about 20 centimeters, or 7.87 inches higher, than the average in 1870. Sea level rise is also accelerating; while ocean levels increased by about 1.7 millimeters (0.067 inches) per year during the 20th century, they are now rising by nearly 3 millimeters (0.12 inches) per year.

World Meteorological Organization, "1998-2007 Is Warmest Decade on Record." URL: (http://www.wmo.ch/pages/mediacentre/press_releases/pr_805_en.html)