Global warming will raise the number and scope of health crises, ranging from killer heat waves and famine, to floods and waves of infectious diseases, a latest US study said Sunday.

As world's climate warms, and as people make widespread alterations to the global landscape, human populations will become far more vulnerable to heat-related mortality, air pollution-related illnesses, infectious diseases and malnutrition, according to Jonathan A. Patz, an authority on human health effects of global environmental change.

"We are destined to have some warming," said Patz, a professor at the University of Wisconsin-Madison.

But it won't be a gradually warming world that triggers future health crises, it will be a dramatic increase in severe weather events, major storms, heat waves, flooding, triggered by a shifting global climate that will wreak most of the human health havoc, he said.

Patz unveiled this study at the annual meeting of the American Association for the Advancement of Science in Washington D.C. In a press release, he explained "averages don't kill people -- it is the extremes."

If governments and health officials don't do something to mitigate the potential human health effects of climate change, the world will begin to experience climate-related catastrophe, he warned.

The scientist suggested the world may already be seeing the health consequences of warming, noting the heat wave that struck Europe in the summer of 2004 claimed an estimated 22,000-35,000 lives.

That event was so far out of the normal climate range, Patz said, "what we may see is an increased frequency of these extreme events."

Moreover, as temperature regimes change, weather patterns will be altered and increased rainfall will facilitate the spread of waterborne and food-borne diseases. And increased local rainfall will also make life easier for the insects and animals that carry some human diseases, he said.

One strategy to mitigate future climate-related health problems, according to Patz, would be to develop and use climate forecasts and warning systems to avert disease and adverse health outcomes.

Such events can be predicted with confidence, and if higher risk is forecast, people can prepare by mouse-proofing their homes and taking other measures to minimize contact with the source of a serious disease.

"The key will be early detection, warning and responding to threats," Patz said.

Moreover, necessary steps, such as rooftop gardens and reflective paintings on roof, should be taken in urban areas to mitigate the effects of warmer climate and the "heat island" effect.

Improving deficiencies in such things as watershed protection, infrastructure and drainage systems would ease the risk of water contamination events, Patz suggested.

At present in the United States, where most people have access to treated water, 9 million cases of waterborne disease are estimated to occur each year.

This number is likely to go up with climate change, unless significant steps are taken to minimize probability of sewage overflows and other weather related events that contaminate water supplies, according to the scientist.

Source: Xinhua