Celeste Hidalgo, 7, (R) and Alana Griego, 5, cool off in the Pacific ocean during a heat wave in Santa Monica, California, June 28, 2013. [Photo/Agencies]

GENEVA - The 2001-2010 decade was the warmest since the start of modern measurements in 1850 and the world experienced unprecedented high-impact climate extremes during the decade, said a report released Wednesday by the World Meteorological Organization (WMO).

The report, The Global Climate 2001-2010, A Decade of Extremes, analyzed global and regional temperatures and precipitation, as well as extreme events such as the heat waves in Europe and Russia, Hurricane Katrina in the United States, and Tropical Cyclone Nargis in Myanmar.

It showed that the average land and ocean-surface temperature for the decade 2001-2010 was estimated to be 14.47 Celsius degree, or 0.47 degree above the 1961-1990 global average and 0.21 degree above the 1991-2000 global average.

Nearly 94 percent of reporting countries had their warmest decade in the first decade of 21st century; some 44 percent of the 127 countries in the survey reported nationwide hottest temperature records in the decade, compared to 24 percent in 1991-2000, said the report.

It found that every year of the decade except 2008 was among the 10 warmest years on record. The warmest year ever recorded was 2010, with a temperature estimated at 0.54 degree above the 14.0 degree long-term average of 1961-1990 base periods, followed closely by 2005.

The decadal rate of increase in the global temperature accelerated between 1971 and 2010.

The global temperature increased at an average estimated rate of 0.17 degree per decade during that period, compared with 0.062 degree per decade for the entire 1880-2010 period, according to the report.

The record warmth was accompanied by a rapid decline in Arctic sea ice, and accelerating loss of net mass from the Greenland and Antarctic ice sheets and from the world's glaciers, said the report.

As a result of this widespread melting and the thermal expansion of sea water, global mean sea levels rose about 3mm per year, about double the observed 20th century trend of 1.6 mm per year. Global sea level averaged over the decade was about 20 cm higher than that of 1880.

The report said most parts of the globe had above-normal precipitation during the decade. The eastern USA, northern and eastern Canada, and many parts of Europe and central Asia were particularly wet. 2010 was the wettest year since the start of instrumental records.

According to the WMO survey, floods were the most frequently experienced extreme events over the decade; droughts affected more people than any other kind of natural disaster owing to their large scale and long-lasting nature; and there were 511 tropical cyclone related disaster events recorded in the ten years.

Over the decade, more than 370,000 people died as a result of extreme weather and climate conditions, including heat, cold, drought, storms and floods, 20 percent higher than 1991-2000.

WMO Secretary-General Michel Jarraud said that a decade is the minimum possible timeframe for meaningful assessments of climate change,

"WMO's report shows that global warming accelerated in the four decades of 1971 to 2010 and that the decadal rate of increase between 1991-2000 and 2001-2010 was unprecedented," he said.

The 100-page report was released to coincide with the first session of the Intergovernmental Board on Climate Services.