"Colonizers escaped (to mountainous areas) to avoid the swamps that bred malaria. Those areas are no longer safe," Epstein told reporters upon presenting the study, noting that malaria cases have quadrupled in the past 10 years and kill 3,000 African babies a day.

Epstein, of the Harvard Medical School, wrote the report in collaboration with reinsurer Swiss Re and the United Nations Development Program.

The report warned that "malaria could suddenly swell in developed nations, especially in those areas now bordering the margins of current transmission."

Scientists believe greenhouse gases, such as carbon dioxide (CO2) released by cars and utilities burning fossil fuels, lead to climate change by trapping the sun's heat in the atmosphere. That can lead to rising seas that may cause flooding and stronger storms.

Rising temperatures increase the range of the mosquitoes and ticks that carry maladies like malaria, West Nile virus and Lyme disease, the study said.

Cases of asthma, which is worsened by particulates in the air, can increase from greater amounts of CO2, the report said. Plants high in pollen and some soil fungi grow better with higher levels of the gas.

WICKED WINDS

In addition, climate change's stronger winds increase the amount of dust in the air from expanding deserts, which compound the effects of air pollutants and smog from the burning of fossil fuels as well as the risks to asthma sufferers, it said.

That could increase the $18 billion that asthma and allergies cost the US health care system each year, according to the report, which lists suggestions large companies could take to reduce their liabilities from greenhouse gas emissions.

Last month, a federal judge dismissed a lawsuit from eight states and New York City against five of the largest US utilities claiming that their emissions were a public nuisance and would cause property harm. The case is on appeal.

The authors of the study hope to bring their findings to corporate boards to reduce climate risks and liabilities.

Companies can lessen risks by joining markets that trade greenhouse gases and by broadening their energy palate from coal and oil to alternatives such as wind and solar power, and possibly, nuclear and hydrogen power, Epstein said.

US President George W. Bush dropped out of Kyoto Protocol on climate change early in his first term.

The agreement created a carbon dioxide market in Europe that allows companies that chose not to cut their greenhouse gases to buy credits from companies that have.