October 20, 2017
How Climate Change Harms Us
Be Well

How Climate Change Harms Us

by John Swartzberg, M.D.  |  

It’s official: 2015 was the world’s hottest year on record, climate scientists say, with green­house gases produced by the burning of fossil fuels largely to blame. Climate change is not just melting glaciers, raising sea levels, and wreaking havoc on our weather pat­terns: Experts predict it will adversely affect human health across the world in profound ways.

We are already witnessing, for example, how climate change (along with globalization) is likely contributing to a resurgence and redistribution of insect-borne diseases such as malaria, yellow fever, and dengue—and ones you probably haven’t heard of yet, like chi­kungunya. In particular, the mosquito-transmitted Zika virus (associ­ated with severe brain damage in fetuses) has been making headlines in recent months, as it continues circling the world. As an infectious disease specialist, I find the spread of such viruses—once restricted to remote ecological niches—especially worrisome. Climate change is also expected to increase or worsen many common chronic illnesses, including heart and respiratory diseases, and it will affect what and how we eat, putting all aspects of food security at risk.

So I was heartened by the landmark climate agreement adopted late last year in Paris by 195 countries, both rich and poor. Though hardly perfect, it could go a long way in reducing greenhouse gases. One hitch is that the accord’s provisions are only voluntary. That doesn’t bode well, considering the current crop of politicians, some of whom still don’t believe climate change is real, not to mention a likely shortage of funds to fully enforce regulations if they are enacted.

In the meantime, I believe the effects of climate change are cer­tainly real—and growing, as evidenced by a mounting number of studies. And I’ve been keeping track of what else is likely in store for us if we don’t change direction. The following examples may not all be as dire as some of those noted above, but they are a reminder that cli­mate change has far-ranging effects indeed.

  • More kidney stones. As temperatures rise, so does the formation of kidney stones, according to a 2014 study in Environmental Health Per­spectives. Hotter days increase dehydration, which increases the concen­tration of minerals in urine that promote kidney stones.
  • More Salmonella infections. Using health department and weather data, researchers at the University of Maryland School of Public Health found an association between extremely hot and rainy days (blamed by many on climate change) and a rise in this foodborne illness.
  • More allergies. A 2014 study from the University of Massachu­setts Amherst in PLOS ONE estimated that grass pollens and allergen exposure will increase up to 200 percent over the next century due to increasing levels of carbon dioxide, a major greenhouse gas.
  • The end of mussels? Sour shrimp? As ocean acidity rises due to increasing carbon dioxide, mussels may form shells that are more brittle and fragile, leaving them more defenseless against predators, according to a 2014 study from the University of Glasgow. Increasing acidity also produces sour-tasting shellfish, as reported in a 2014 study in the Journal of Shellfish Research.
  • A change in tea? Climate change is affecting the quality of tea, according to a 2014 paper in Herbalgram, the journal of the nonprofit American Botanical Council, which analyzed Chinese teas grown under different weather conditions. As the author wrote, “extreme rains, which are becoming more frequent with climate change, serve to dilute tea phytochemicals,” the compounds thought to be respon­sible for tea’s health benefits.

What we can do

The Lancet Commission on Health and Climate Change, a collaboration of academic centers in Europe and China formed in 2015, has called climate change a “medical emergency” that can reverse a half-century of health and nutrition advances. You and I can do our part by transitioning to more sustainable lifestyles, which include driving less (and walking and cycling more) and eating diets that are more plant-based. But perhaps most important is to urge our political representatives to honor the commitment the U.S. made in the Paris Agreement. Here is how to contact your Senator. For more on the Paris Agreement and how to get involved, go to The Paris Climate Agreement.