How much of a health threat is climate change is the central question many studies informing policy decisions have attempted to answer.
We are of course tempted to answer climate change affects human health. Yet, corroborating data is a difficult task in order to accurately answer the question.
The body of evidence suggesting that climate change and global warming are posing a threat to human health is increasing. Yet, such evidence holds these factors to act as threats only in a complex setting that implies other factors as well.
Let’s take a look at deaths caused by heat. The average global temperature is rising. Yet, so is technology aiming at combating record high temperatures. Air conditioning is present in most of our spaces and heart disease treatments have become more efficient over time.
Also, heat is known to cause hundreds of deaths in developing countries. Of course, the lack of treatments and the not so wide spread of electricity, air conditioning and other technological factors that can weigh in on preventing heat deaths in these parts of the world is one dimension.
In the U.S. a new study looked at heat deaths between 1987 and 2005 and found that the rate of heat-related deaths decreased drastically.
Other reports found that cold-related deaths were more common than heat-related ones. Against this background, it is hard to pinpoint heat and climate change as a health threat. Not one singular climate event can be held accountable for health risks.
Yet, heat and warmer climates in general are hospitable for a variety of insects that carry potentially deadly diseases. Lyme disease, West Nile virus, dengue fever are just a few.
In the U.S., the spread of ticks and consequentially of Lyme disease is linked to the resurgence of forest and therefore the increase of deer population according to federal health experts.
Yet in Canada, Lyme disease spiked in the past 15 years from 40 local cases to 700 on an yearly basis. The areas where the ticks thrived also expanded from 2 to 13. This is pinpointed on climate change and increasingly warmer temperatures that allow the pests to survive from larvae into adulthood.
Both ticks and insects need warm temperatures to breed, feed and sustain a warm body temperature. Otherwise, they lack the mechanism for regulating the temperature of their bodies.
One instance in the U.S. is the Asian tiger mosquito. Since its arrival in the U.S. in the 1980s, the Asian tiger mosquito spread all the way to Connecticut, according to Entomology professor Dina Fonseca of Rutgers University.
Yet another voice coming from the National Center for Atmospheric Research in Colorado, Mary H. Hayden talks about dengue fever, also mosquito-borne:
“I don’t think we can dismiss the role of climate. But can we say there is a direct causal link? No, we can’t. It’s more complex than that”.
It looks like climate change is rather inflicting the increase of factors that lead to certain diseases or health conditions. Ragweed for instance is a wild plant the pollen of which is highly allergenic.
Due to increase in temperatures, ragweed now survives on average three weeks more, prolonging the allergy period all the way through fall in north central U.S. where ragweed became usual.
It is indeed a hard task to link climate change to health risks.
It is indeed hard to link climate change to health risks. Yet, not taking the evidence into consideration is also precarious.
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