The 2000-2009 decade was the warmest on record, easily surpassing the previous hottest decade — the 1990s — researchers said Tuesday in a report providing fresh evidence that the planet may be warming at a potentially disastrous rate.
In 2009, global surface temperatures were 1.01 degree above average, which tied the year for the fifth warmest year on record, the National Climatic Data Center said.
And that helped push the 2000-2009 decade to 0.96 degree above normal, which the agency said "shattered" the 1990s record value of 0.65 degree above normal.
The warmest year on record was 2005 at 1.11 degrees above normal.
The findings follow years of gradually rising global temperatures which atmospheric scientists attribute to the warming effect of gases released into the air by human activities, including burning fossil fuels.
Political leaders from around the world have been struggling to find a solution to this growing problem, most recently at the climate conference in Copenhagen, Denmark. Reaching agreement has been difficult amid fears of economic effects of any major change.
Concerns about the effects of a warmer climate include rising sea levels and the potential spread of tropical diseases, changes in hurricane patterns, increased drought in some areas, disruption of crop growth and wildlife patterns, and loss of species unable to adapt.
In the United States last year the average temperature was 0.3 degrees above normal. And on average it was moist, with average annual precipitation in 2009 for the 48 contiguous states some 2.33 inches above the long-term average at 31.47 inches. It was the 18th wettest in 115 years of record keeping.
However, dry conditions occurred during much of the year across parts of the Southwest, Upper Mississippi Valley and southern Texas, the agency said. And there was periodic low rain and snowfall in parts of a ring around the country from the northern Rockies, Far West and Southwest to the southern Plains and Southeast, then up along the East Coast and back across the Great Lakes.
Last year's climate milestones included:
- The 10th consecutive summer with above-normal temperatures in the U.S. Northwest.
- Record winter drought in Texas.
- The deadliest February tornado in Oklahoma history.
- The largest wildfire in Los Angeles County history.
- Most active tornado season in a decade in Louisiana and Alabama.
- New seasonal snowfall records for Spokane, Wash., and International Falls, Minn.
- Worst deluge in decades in northern Brazil, affecting 186,000 people.
- Heavy rainfall in northern Argentina, causing a landslide affecting 20,000 people.
- Disastrous floods triggered by heavy rain in Central Europe.
- Britain's heaviest snowstorm since 1991.
- Extratropical storm Klaus (similar to a category 3 hurricane) kills 30 in France and Spain.
- Heaviest snowfall in northern China in 55 years.
- Typhoons batter the Philippines causing fatal flooding.
- More than 600 die in the deadliest typhoon to hit Taiwan in five decades.