Focus on health
June 14, 2011
The climate has an immediate effect on human health and has always been closely tied to the survival of world populations. Factors such as temperature, wind and sun determine the availability of clean water, food and clean air.
Now that climate conditions are changing, experts have observed a negative impact on the health of populations in vulnerable parts of the world.
Dire statistics
According to the World Health Organization (WHO) climate change is responsible for up to 140,000 deaths a year, most of which occur in developing nations.
It cites diarrhea caused by contaminated water as one of the main killers, but singles out water shortages, heatwaves and failed harvests as further factors. All too often the health systems in these countries are in no position to adapt to the new challenges posed by global warming.
The WHO also points to malaria and dengue fever as increasing threats in developing countries. Pathogens are carried by mosquitos that thrive in damp, warm regions.
Tropical threat
But these days, these insects also breed in moderate climates. Tiger and bush mosquitoes are native to Asia but the past couple of decades have seen these species invade many countries throughout the world through the transport of goods and increasing international travel, explains Egbert Tannich from the Bernhard Nocht Institute for Tropical Medicine.
Even Europe now offers them the conditions they need to thrive. "Warm temperatures and breeding opportunities facilitate their development and spread," says Tannich. "And the more mosquitos there are, the greater the likelihood of being stung."
But for the time being, the threat is relatively low. "So far there is no indication that anyone in Germany has been infected with pathogens carried by Asian mosquitos," he stresses. Nevertheless, he sees the Asian tiger mosquito that transmits dengue fever as a serious potential threat.
Lethal heat
A meteorologist with the German Meteorological Service (DWD), Christina Koppe predicts that extremely hot summers will have become the norm in Europe by the late 21st century.
"There's more to climate change than a few hot summers but temperatures in Germany are obviously rising," she says.
She says it's hard to put an accurate figure to the number of fatalities caused by high temperature because its effect is often non-specific.
"An impaired cardiovascular system is one of the main reasons heat kills pople," she says. In the unusually hot summer of 2003, for example, between 35,000 and 50,000 people died as a result of the heat. The statistics don't bode well: According to NASA, the past decade was the warmest since weather records began in 1880.
Meanwhile, the summer of 2010 saw the people of Moscow badly affected by widespread forest and peat fires outside the city which blanketed it in a fog of acrid smoke.
According to the Russian Economics Ministry, the smog and heatwave claimed thousands of lives.
"14,300 more people died in July and 41,300 in August than in the same period in the previous year as a result of the abnormal heat, the forest fires and the smog," it stated in a report.
Temperature threat
Rising temperatures cause many problems that do not necessarily entail excessive heat. In northern Russia, for example, melting permafrost results in swamp-like conditions that provide an ideal habitat for dangerous pathogens. Moreover, the ground is left unpassable, jeopardizing transport of food and medicine to remote regions.
But although the WHO maintains that the overall effects of climate change are negative, it also concedes that in some parts of the world it brings certain benefits too. Milder winters boost food production, for example.
But more research is needed to identify the full impact on human health of global warming. For a variety of reasons health systems all over the world are already under review. They will face even more challenges in the coming years.
Author: Kerstin Schnatz (jp)
Editor: Sonia Phalnikar