Global Warming and Disease Vectors

Mount Nebo, along with other mountaintop resorts in Arkansas, began as a place for the well-heeled to escape the summer miasma in the Arkansas River Valley below. By the middle of the nineteenth century steam boats brought folks seeking respite from the mosquitoes which bred in the swamps and transmitted deadly diseases such as malaria and yellow fever. Public health measures have eliminated these diseases in the United States but climate change raises concern for their return.

Malaria endemic countries

Malaria endemic countries

Recently the Intergovernmental Panel on Climate Change released the findings of their fifth report:Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years.

A warming climate means a wider range for disease vectors such as mosquitoes, ticks and flies that carry viruses, bacteria, and protozoa. Examples of diseases born by these pests include malaria, yellow fever, dengue fever, and equine encephalitis to name a few.

current range of Chagas diease

current range of Chagas diease

Most worrisome is Malaria, a parasitic infection of red blood cells for which there is no real cure. Because of the complex life cycle of the parasite their has yet to be an effective vaccine developed. Malaria infects over two hundred million people world wide and kills about a million each year, mostly children.

The mosquito that carries yellow fever for which there is a vaccine also carries dengue fever for which there is no vaccine. The genus Aedes carries both these diseases, is endemic to northern Mexico, and as the climate warms is advancing northward.

These are some of the diseases we know about, but new diseases arise regularly. In the age of jet travel a new disease can move half the way around the world over night and a warmer climate can provide a more accommodating environment.

Every day as a result of burning fossil fuels for cheap energy the planet gets a little warmer, the weather a little more erratic and the oceans a little more acidic. Climate change has far-reaching consequences and touches on all life-support systems. It is a factor that should be placed high on a list of those things that affect human health and survival. The energy with the cheapest up front costs may be more expensive than imagined in the long run.

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