by Stephanie Nebehay
GENEVA - Last year tied for the hottest year on record, confirming a long-term warming trend, the World Meteorological Organization (WMO) said on Thursday, and future warming depended on action to cut greenhouse gas emissions.
The first ten years of the millennium proved to be the hottest decade since records began in the 19th century, it said.
"The main signal is that the warming trend continues and is being strengthened year after year," WMO Secretary-General Michel Jarraud told a news conference.
"The trend, unfortunately, will continue for a number of years but the amplitude will depend on the amount of greenhouse gases released," the Frenchman added. "It will depend on action taken to minimise the release of greenhouse gases."
Jarraud said the latest data should convince doubters about the growing evidence for man-made climate change. "If they look at it in an unbiased way, it should convince them, or hopefully a few of them, that the skeptical position is untenable."
2010 was also marked by further melting of Arctic ice and extreme weather events, including Russia's heatwave and devastating floods in Pakistan, the WMO said.
The United Nations panel of climate scientists says human emissions of greenhouse gases are stoking climate change that will bring more floods, droughts and rising sea levels.
"Data received by the WMO show no statistically significant difference between global temperatures in 2010, 2005 and 1998," the United Nations body, which compiles its ranking from data provided by British and U.S. agencies, said in a statement.
Data from British institutes on Wednesday showed last year was the world's second warmest behind 1998, while the other two main groups tracking global warming, based in the United States, said 2010 was tied for the hottest on record.
Over the 10 years from 2001 to 2010, global temperatures have averaged 0.45 degrees Celsius (0.83 degrees Fahrenheit) above the 1961-1990 average and are the highest ever recorded for a 10-year period since climate records began, WMO said.
The difference between the three hottest years was less than the margin of uncertainty in comparing the data, according to WMO, whose assessment is based on climate data from land-based weather and climate stations, ships, buoys and satellites.