Malaria is spread to humans through the Anopheles mosquito. A new study in the journal Science expects global warming would extend the range of the mosquito and the disease.   View examples of how warmer temperatures could impact humans and wildlife. Study: warmer climate, sicker Earth Cross-species observations see climate/disease connection MSNBC

“WHAT IS MOST surprising is the fact that climate sensitive outbreaks are happening with so many different types of pathogens — viruses, bacteria, fungi, and parasites — as well as in such a wide range of hosts including corals, oysters, terrestrial plants, birds and humans,” lead author Drew Harvell, a Cornell University biologist, said in a statement.
       The researchers said they felt that common traits are likely linked to global warming. “Climate change is disrupting natural ecosystems in a way that is making life better for infectious diseases,” stated Andrew Dobson, a Princeton University epidemiologist. “The accumulation of evidence has us extremely worried. We share diseases with some of these species. The risk for humans is going up.”

CAUSES, CARRIERS TRACKED

The study tracked both causes and carriers of diseases that develop more rapidly with slight rises in temperature. It found that as temperatures increase, carriers are likely to spread into new areas where they could devastate species that have not been previously exposed.
       In the statement accompanying the study, the scientists cited these examples of disease outbreaks tied to climate change:
Expanding range of disease carriers due to temperature. Honeycreepers, forest songbirds that evolved only in Hawaii, are being decimated by malaria from mosquitoes that have been able to range higher in elevation due to warmer temperatures. “Today there are no native birds below 4,500 feet,” said Dobson.
Expanding range of carriers due to moisture. Rift Valley Fever, a deadly viral illness spread by mosquitoes, is strongly linked to heavy rains, which trigger mosquito explosions. “There is clear evidence that Rift Valley Fever outbreaks are linked to El Niño years and we expect an increase in the frequency of El Niños with climate change,” stated coauthor Richard Ostfeld, a researcher at the Institute of Ecosystem Studies in Millbrook, N.Y.
Increased susceptibility to disease. Coral reefs have become susceptible to disease once they are stressed by warmer sea temperatures. The researchers isolated one fungus threatening Caribbean sea fans and found that it grows fastest at exactly the temperature at which many of the corals in the Florida Keys start to bleach, a stress-created condition that turns coral white and can eventually lead to die-offs.
Expanding range of carriers in winter. Warmer winter temperatures can also affect ranges of diseases and carriers. A winter warming trend in the mid-1990s allowed a parasite to spread north to Maine’s oysters, the researchers noted.

MORE STUDIES URGED
The researchers urged other experts to consider that diseases in their specialty might share a common link in global warming.
       “This isn’t just a question of coral bleaching for a few marine ecologists, nor just a question of malaria for a few health officials — the number of similar increases in disease incidence is astonishing,” said Ostfeld. “We don’t want to be alarmist, but we are alarmed.”
The authors said they expect others to question their findings, in part because the issue of climate change and diseases has had very little monitoring and few long-term studies.
       An immediate critic was Sherwood Idso, head of the Center for the Study of Carbon Dioxide and Global Change. He said the Science paper was based largely on speculation and presented “no concrete examples that these things will happen in the real world.”
       The authors urged the scientific community to tackle the issue head on with more research and gathering of statistics.
       “We need to pay better attention to this issue in an increasingly unnatural world,” stated Dobson.
       
       MSNBC.com’s Miguel Llanos and The Associated Press contributed to this report.