Mankind’s carbon diet could wreck human health as a warming world spreads extreme weather, disease, and malnutrition further around the globe than ever before.
 | Trouble on the HorizonA huge forest fire burns at Parnitha mountain overlooking Athens during a heatwave in 2007. This fire killed two people but many more will die as heatwaves become commonplace in Europe (Photo: Reuters) |
For several hundred years burning fossil fuels has been good for us. Industrial development and urbanization meant economic growth, better nutrition, higher incomes, and improved healthcare. People now live longer and more comfortable lives than before.
Their grandchildren may not be so lucky. Mankind’s fossil fuel binge is the biggest threat to human health this century. Pumping up the carbon economy, like pumping up an athlete with steroids, is a major health hazard in the long run.
This is the awful dilemma faced by emerging nations whose populations are most vulnerable to climate change. They understandably want to improve public health by increasing development. But they may in the process store up health problems for future generations.
Climate change already kills over 300,000 people a year, says the Global Humanitarian Forum (GHF), and the annual toll will rise to half a million by 2030. Even these figures probably underestimate the threat because of the complex interactions between climate, environment, poverty, and health.
Extreme Weather
In the last ten years—the warmest decade on record—there have been on average 350 weather-related disasters every year, reports the Red Cross, compared to about 200 annually in the 1990s.
Rising temperatures mean heatwaves like the 2003 swelter that killed over 30,000 mainly elderly Europeans will be commonplace by mid-century.
Not just aging populations but also increasing urbanization make things worse. The urban heat island effect claimed many victims in 2003 as night temperatures stayed high in French and German cities and elderly bodies could not recover.
Heat stress, cardiovascular, and respiratory problems will claim many more victims as heat and smog levels rise in tandem. It will be even worse for vulnerable people in the hotter, developing world.
 | Picture Gallery (click on the picture to start)See how the climate change balance sheet stacks up. Count the costs of climate change and the costs of protecting the climate. (Graphic: Asian Development Bank) |
A warming planet also means increased frequency and severity of destructive storms and floods. These not only kill and injure people directly but also spread dysentery and cholera as victims are forced to drink contaminated water.
The poor, living in flimsy homes and without access to healthcare, are most vulnerable. Increasing urbanization in the developing world often exposes people to more climate-related health hazards like landslides and floods. Whereas Hurricane Katrina claimed about 1800 victims, Cyclone Nargis in Burma killed about 150,000 people.
Disease Spread
Mosquito-borne diseases like malaria, dengue fever, and West Nile virus could thrive in the warmer, wetter conditions that will spread to some areas due to climate change—to the East African highlands, for example. Hotter air can hold more moisture, helping disease-carriers such as mosquitoes.
"Mosquitoes bite more often at higher temperatures but more importantly increasing temperatures speed up the development of the malarial parasite inside the mosquito," explains Diarmid Campbell-Lendrum of the World Health Organization.
Mosquitoes could die out in areas that become drier with climate change, such as the Sahel. Overall, however, a 2 degrees Celsius rise in temperature will likely lead to 40 to 60 million more people exposed to malaria in Africa, according to the Stern Review.
Waterborne diseases like cholera, dysentery and typhoid could thrive, says Campbell-Lendrum because bacteria replicate faster in warmer temperatures. They may also be more prevalent in areas where water shortages and reduced river flows contribute to algal blooms. If water levels drop, the risk of contaminating rivers and aquifers increases, while flooding can be equally dangerous if contaminants are washed into water sources.
More worrying still, says Anthony Costello, Director of the University College London (UCL) Institute for Global Health, is the possibility that tipping the ecological balance could unleash unknown infections and viruses. “When I qualified as a doctor, if you had told me there was a new sexually transmitted disease coming that would kill 50 million people I wouldn’t have believed you. But we had HIV/AIDS.”
The next deadly pandemic could be the result of our destruction of the ecosystem. That’s because we are extinguishing species and reducing biodiversity. “Some species are ‘competent’ hosts of disease, some are ‘incompetent’ hosts,” explains Costello. “If we lose more incompetent hosts than competent hosts the risk of transmitting new diseases goes up.”
Malnutrition
Disease thrives not just with rising temperatures but also when people are hungry. Malnourished bodies have weaker immune systems and are more susceptible to infections and viruses, while hungry mothers give birth to underweight, weak babies.
Climate change will make it harder to produce enough food to adequately feed a growing world population. Crop yields across the developing world will, on average, decrease as water becomes scarcer. That leads to food insecurity, but not for the obvious reasons.
“Hunger and malnutrition are more related to food prices than food availability, Costello explains. “Quite small changes in yields can push prices up quite steeply. UNICEF reports that hunger is at a 40-year high in south Asia. Food prices have gone up but not come down with oil prices.”
The upshot is that the World Health Organization estimates that almost 60 percent of the 10 million under-5s who die every year have suffered from malnutrition. Climate change could cause up to 250,000 more child deaths annually in South Asia and sub-Saharan Africa, reckons The Stern Review.
For the rich, climate change will make life more unpleasant, uncomfortable, and expensive. For the poor, climate change could make the difference between life and death.
editor: James Tulloch
publishing date: July 13, 2009
Do you have something interesting to add? Write a comment and discuss this topic with other readers. Comments should be on-topic, non-commercial, and not contain abuse of any kind.
Comment Policy
COLLABORATIVE ACTION
I think personaly that it is through collaborative forest management that we can fight adverse effects of climate change,for instance through use of environmental economics,we could...