The UN's World Meteorological Organisation (WMO) said in its annual statement on the global climate that rising average temperatures helped generate exceptional drought, floods, hurricanes and typhoons.

"This year was very warm but it was not the warmest ever, very probably it will be in third place among the warmest years," said Michel Jarraud, deputy secretary general of the WMO.

"Temperatures since 1976 have progressed three times more than during the the 20th century, so the rate of increase in temperatures is accelerating," he added.

The global average temperature this year was expected to have risen by 0.45 degrees Celsius by the end of December, WMO said.

The warmest ever year was recorded in 1998, when temperatures rose worldwide by on average 0.55 degrees, capping the warmest century in the millennium, according to the agency, which groups the world's national weather forecasters. The second warmest was 2002.

Average temperatures rose more sharply in the northern hemisphere in 2003 than in the southern hemisphere, with unprecedented highs in western Europe over the summer when a sweltering heatwave blanketed much of the continent, the WMO found.

"In France, Italy, the Netherlands, Portugal, Britain and Spain, there were an estimated 21,000 deaths linked to this heatwave, so it was really something exceptional," Jarraud said.

The heat also melted glaciers in Europe's mountain ranges twice as fast as the record set in 1998, while the extent of the Arctic ice pack in September approached the record low of 5.3 million square kilometres set in 2002, according to WMO.

But Europe's weather was matched by heatwaves in parts of the United States including Alaska, Canada, parts of China, Russia, and Africa as well as unusually intense heat in the Asian subcontinent before the monsoon season.

"Global warming is likely to lead to more frequent extreme events and for some of them to more intense extreme events, but that doesn't mean climate change is an explanation any particular extreme," Jarraud commented.

There were more typhoons, cyclones and hurricanes than average in the Pacific and Atlantic regions, although the pattern matched an increase recorded since the 1990s, WMO said.

The exceptional weather conditions also triggered unusually cold weather in the Gulf state of Oman, parts of Asia around Japan, as well as in Russia, where temperatures plunged to minus 45 degrees Celsius during the winter.

The extreme temperatures helped generate floods and drought in several parts of the world, including the United States and China.

WMO also blamed the heat for triggering massive bushfires in Australia which burnt for 59 days in January and February.

Yet the shifting weather patterns also brought welcome respite from long standing drought for some.

Rain and snowfall ended four years of drought in Afghanistan, filling water reservoirs that had been dry for years, while the Sahel region of the Sahara desert, once the scene of famine, experienced record rainfall.

SPACE.WIRE