KIDNEY stones, malaria, Lyme disease, depression and respiratory illness may increase with global warming, researchers at Harvard Medical School say.
Climate change from the burning of fossil fuels will add to risks to public health, said Paul Epstein, associate director of Harvard's Centre for Health and the Global Environment in Boston.
The centre, and groups led by the American Medical Association (AMA), presented data at a briefing in Washington yesterday as part of a call for action to curb emissions.
Global warming causes flooding, heatwaves and wildfires that worsen health, especially for children and the elderly, the Harvard researchers said.
"We expect an increase in hospital admissions for things like pneumonia, chronic lung disease, asthma and other respiratory diseases," said Cecil Wilson, the AMA's president-elect. "Increased heat also increases the risk to people who have other diseases."
The AMA sent a letter to US President Barack Obama last week citing the "significant public health impacts" of climate change. The letter said children, the elderly, people suffering from chronic diseases and the poor would be most affected. Mr Obama has backed climate-change legislation in Congress but he and other leaders at an Asia-Pacific conference last week agreed that a binding global-warming accord is out of reach at next month's climate summit in Copenhagen.
With today's briefing preceding the Copenhagen conference, "we are hopeful that meeting will embody some of the concerns about health", Dr Wilson said.
Climate change is making parts of the United States warmer, raising the risk of kidney stones because of low urine volume linked to heat exposure, according to a study cited by the Harvard centre.
The portion of the US population in high-risk zones for kidney stones will grow from 40 per cent in 2000 to 56 per cent by 2050, and to 70 per cent by 2095, a 2008 study by the University of Texas found.
Costs would increase from $US900 million ($982 million) to $1.3 billion a year, 25 per cent more than current expenditures.
Warmer temperatures in New Mexico are contributing to the proliferation of mountain pine beetles, a pest that has killed 2.6million hectares of trees in the US, setting the stage for wildfires, according to the Harvard findings. Fires release air pollutants and cancer-causing chemicals, raising the risk of respiratory illness and lung disease.
Climate change also increases air pollutants such as ozone and sulphur dioxide, raising the risk of asthma, especially in children, said Jerome Paulson, of the Child Health Advocacy Institute in Washington.
The Harvard centre also found climate change will increase deaths from heatwaves, raise the incidence of waterborne diseases and spread afflictions such as Lyme disease and malaria.
Dislocation and job losses caused by changing climate might contribute to depression and anxiety disorders.