A Hot Zone for Disease.(researches find correlation between global warming and increase in disease)(Brief Article)(Statistical Data Included)

Fishermen were the first to see the signs. A typical haul of oysters always includes a few empty shells, or "boxes," and usually each one is encrusted with barnacles. But fishermen in Delaware Bay in the summer of 1990 were pulling up boxes that were bone white, as if they'd just been discarded from an oyster dinner; apparently they had died only recently. Many oysters trailed tiny bits of rancid meat. Susan Ford, a marine biologist at Rutgers University, identified the blight as the work of Perkinsus marinus, a deadly waterborne parasite. It had been wiping out stocks up and down the southern U.S. coast for decades but had never come as far north as Delaware Bay. As the parasite settled into its new home, over the next three years oyster hauls plummeted from 500,000 bushels annually to fewer than 20,000, decimating the fishing villages on the Jersey shore. Meanwhile, Perkinsus marinus continued its northward journey another 500 miles to Cape Cod, then another 200 to Maine. "The way the fishing industry operates has had to change markedly," says Ford. "Some managers just closed fisheries. It has been devastating."

Researchers now think such stories will become more and more common. According to a study published late last month in the journal Science, the real culprit behind much of the rise in infectious diseases around the world may be rising temperatures. Drew Harvell, a biologist at Cornell University, and Andy Dobson, an ecologist at Princeton, surveyed new disease outbreaks and correlated them to data on warming trends. Their report catalogs more than 50 outbreaks that coincided with a rise in temperature. It adds up to compelling, albeit circumstantial, evidence that climate change has already begun to trigger the spread of disease. "A warmer world will be a sicker world," says Dobson. "We will see more outbreaks of disease in animals and plants. Unfortunately, those diseases will spill over to humans."

The existence of a link between climate change and disease has been controversial for years, mainly because separating the effects of climate from other causes, such as public-health practices, is ...