Earth's
Endless Summer
Causing More Disease
Excerpt
By Amanda Gardner, HealthScoutNews
(HealthScoutNews) -- Perpetual summer is coming to Earth, and
it's not going to be an endless procession of beach parties and
sea breezes. As the world gets warmer, it's also likely to get
sicker -- literally.
A two-year study out of the National Center for Ecological Analysis
and Synthesis (NCEAS) finds climate changes will likely mean an
increase in infectious diseases affecting both plant and animal
systems, possibly threatening the survival of entire species. The
research appears in tomorrow's issue of Science.
"This is a very important paper that brings together the
issues of diseases in plants and wildlife and humans. By looking
at the cross-section, one gets an even stronger picture of the
impact of warming on disease," says Dr. Paul Epstein, associate
director of the Center for Health and the Global Environment at
Harvard Medical School. "One gets a very strong signal that
warming is certainly increasing and contributing to the emergence
and resurgence and redistribution of infectious diseases."
This study is the first to investigate disease epidemics across
entire plant and animal systems.
"We're looking for general patterns across as many diseases
of as many organisms as possible, including oysters, coral, plants
and songbirds, and we're seeing striking similarities in the patterns
of disease spread," says Richard Ostfeld, co-author of the
study and an animal ecologist at the Institute of Ecosystem Studies
in Millbrook, N.Y. "The similarities are striking enough
across the board that we think this has to be taken seriously
now."
The study authors began their research with two known developments:
the warming of the earth's climate and the fact that certain diseases,
such as malaria and Dengue fever, are spreading northward from
the tropics and up into mountains.
The question then became: How are these two linked? And the
answer: Possibly in several different ways.
Pathogens, microorganisms and vectors such as mosquitoes tend
to flourish in higher temperatures. In the Hawaiian Islands, for
example, mosquitoes used to stay below 2,500 feet, where it was
warmer. Now, thanks to global warming, they've moved up in to
the mountains where they are threatening the last populations
of honeycreepers (songbirds unique to Hawaii) with avian malaria.
Reproduction and biting also both tend to increase in hotter
areas. Winter acts as a curb on population growth.
Warmer weather may also make hosts more susceptible to infection.
The spread of disease may not come from the warming per se,
but from changes in rainfall patterns and humidity caused by the
higher temperatures. For example, Rift Valley fever, a virus spread
by mosquitoes, is strongly linked to heavy rains. "One disturbance
sets you up for further disturbances," Epstein says. "Once
the system is disrupted, it's more vulnerable."
Biodiversity is also suffering, as pathogens contribute to declining
numbers of lions, cranes and vultures, to name a few.
"We've underestimated the rate at which climate would change,
the rate at which biological systems would respond to that change,
the cost to our society and to our agriculture, to our forest,
to our health from all of this," Epstein says.
Believe it or not, the news could have a silver lining.
"The good news is that this may serve as a wake-up call,"
he continues. "This can lead us to address how we're developing,
and how we power that development. I don't want to say it's too
late. I like to think that systems can be restabilized."
Earlier this month, the Bush administration reversed course
and acknowledged in a report to the United Nations that human
activity is largely responsible for global warming. However, the
administration still opposes a treaty aimed at cutting greenhouse
gases, and doesn't plan to follow the report's recommendations
aimed at halting the problem.
What To Do
For more information on global warming, check out
Global Warming: Early Warning Signs or the Environmental
Protection Agency.
Reference
Source 101
For more information on how to prevent other diseases, use
PreventDisease.com's "Quick
Prevention Resources".
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