On the sidelines of a 189-nation conference to tackle global warming, Bertollini said: "We need to make sure that health becomes the argument to move the agenda on climate change."

Poor nations are the hardest hit by rising average temperatures blamed on heat-trapping emissions caused mostly by human use of fossil fuels. Hotter temperatures can cause widespread crop failure and drought.

But the WHO study presented on Monday shows that Europe only needs to look at recent extreme weather events like the 2003 heat wave that killed 35,000 people to understand the dangers of global warming for the wealthy world.

"We call on those who have the power to take measures and to reduce the potential impact of climate change on our health," said Maria Neira, the WHO director of protection of the human environment.

Human influence on climate could double the risk of death from heat waves in Europe, the WHO said. In the United Kingdom, annual deaths from heat could rise to 3,300 in 2050 from 800 in the last decades.

MORE FLOODS

Floods, the most common natural disaster that causes loss of life and economic damage in Europe, have also been linked to global warming. Europe was hit by 30 major floods in 1995-2004 that killed 1,000 people and affected some 2.5 million people.

There is also evidence that warmer temperatures are spreading tick-borne encephalitis in Europe and may increase the risk of malaria, one of the most deadly diseases in developing countries.

Studies show salmonella infection, often associated with the use of raw eggs in mayonnaise, rises with an increase in average temperatures in Europe.

Allergy sufferers may find their sneezing and wheezing last weeks longer than before as warmer temperatures prolong the pollen-producing season.

"These changes are likely to result from the greenhouse gases. We are pretty certain this is the case," said Bertollini.

Most European countries have vowed under the Kyoto protocol to reduce their greenhouse gas emissions by an average of 5.2 percent from 1990 levels by 2012.

But environmental activists say Europe has to take a tougher approach with more radical mandatory cuts in emissions for after 2012.