Climate Change and Human Health
By Joshua Blanco
When we hear about the disastrous effects of climate change and its toll on both the planet and society, the spread of disease is often given little to no consideration as a real and dangerous threat. But now that a virus has been named our biggest enemy, it’s time to understand how climate change impacts viral transmission and what that means for the future of public health.
A steady increase in global temperatures, for example, has led to an extension in both the range and season of insects prone to carrying diseases capable of infecting humans. Such is the case with mosquitoes and ticks, which have been able to live longer in a larger territory throughout the warmer months, leading to a greater potential for human illnesses resulting from Zika virus and Lyme disease. The WNC region is a primary example. “Lyme disease is a big problem in our area,” says Dr. Maggie Sugg, medical geographer and assistant professor in the Department of Geography and Planning at Appalachian State University. “We’re seeing a spread of the tick habitat due to warmer temperatures…and cases of Lyme disease have increased more than 300 percent.”
What’s more, the increase in humidity and rainfall creates an environment that is both warm and moist, essentially providing a mass breeding ground for disease-carrying insects like the A. aegypti mosquito, the World Health Organization reports. This mosquito in particular has led to the spread of both dengue and yellow fevers.
But insects aren’t the only members of the animal kingdom worthy of our concern. Climate change has also led to a shift in habitat and migration for a number of animal species, bringing them in close contact with humans. The recent outbreak of COVID-19 provides a good illustration of how this works. With an approximated 30,000 plus coronaviruses estimated to exist in nature, it becomes reasonable to suspect animal contact as a likely source of future outbreaks. According to a study published in Nature, the majority of infectious diseases witnessed in humans are transmitted from animals.
Understanding the connections between climate change, ecosystems and adaptation is a complicated process, and the funding required for researching these relationships is still lacking. “The combination of public health and climate change research are areas that have not had much funding the last few years,” Sugg said.
“We know science can be political,” says Dr. Jennifer Runkle, an environmental epidemiologist at the North Carolina Institute for Climate Studies at North Carolina State University. In partnership with the WNC Health Network, Runkle conducted a ten-year study focusing on social determinants of health in the region. “We found that poverty and race…were two important drivers of health disparities,” Runkle says. “That’s important because COVID-19 is especially pernicious among those medically vulnerable groups.”
People need to be aware that what is bad for one virus may be ideal for another. By reducing emissions and improving our environmental awareness, we might be able to prevent a future pandemic, or at least mitigate its effects.
For more information on the intersection of climate change and human health visit cdc.gov or read the Fifth Assessment Report by the Intergovernmental Panel on Climate Change at ipcc.ch.