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Harvard U. environmental ‘expert’ links coronavirus to ‘climate change’

Q&A: A Harvard Expert on Environment and Health Discusses Possible Ties Between COVID and Climate

Air pollution makes people more vulnerable to respiratory infections; climate change brings people in closer contact with animals that can spread disease.


Doctors and public health researchers are getting an increasingly accurate and nuanced picture of the many ways climate change damages human health.

Now, questions have arisen about whether climate change contributed to the outbreak of COVID-19, whose spread the World Health Organization declared a pandemic on Wednesday. For example, did habitat loss, driven in part by climate change, make it easier for pathogens to spread among wildlife and for the virus to jump to humans? Does air pollution, mainly from the burning of fossil fuels, make some people more vulnerable to contracting the illness?

We spoke to Dr. Aaron Bernstein, a pediatrician and Interim Director of The Center for Climate, Health, and the Global Environment at Harvard’s T.H. Chan School of Public Health (Harvard C-CHANGE), who has seen firsthand how climate change can harm children, mostly through the burning of fossil fuels. We asked him about the ways that climate change might have played a role in the emergence of COVID-19, about any parallels between “virus denial” and climate denial and about how to prepare for the inevitable next pandemic. A lightly-edited version of our conversation follows.

A connection between COVID-19 and climate change doesn’t seem obvious at first glance, at least to lay people, so could you explain the links that you see?

I think the strongest links I see are actually related, first of all, to air pollution, and fossil fuels as a source of air pollution, and fossil fuels, of course, are the major cause of climate change. The other connections I see are that the way we think about the environment as it pertains to health has gotten us into a rut with the emergence of infections like COVID and climate change.

Let me explain a little bit more of what I mean by that. You look at climate change, we have transformed the nature of the Earth. We have fundamentally changed the composition of the atmosphere, and as such, we shouldn’t be surprised that that affects our health. We have, as a species, grown up in partnership with the planet and life we live with. So, when we change the rules of the game, we shouldn’t expect that it wouldn’t affect our health, for better or worse. That’s true of the climate. And the same principle holds for the emergence of infections.

If you look at the emerging infectious diseases that have moved into people from animals or other sources over the last several decades, the vast majority of those are coming from animals. And the majority of those are coming from wild animals. We have transformed life on Earth. We are having a massive effect on how the relationships between all life on Earth operate and also with ourselves. We shouldn’t be surprised that these emerging diseases pop up.

The principle is that we’re really changing how we relate to other species on Earth and that matters to our risk for infections.

I’d like to drill down into the two points that you made. So let’s start with species and climate change. There are a lot of things that lead to habitat loss for species and bring them into closer proximity to human communities. Bulldozing a jungle can do that. But how does climate change play a role in decreasing the distance between wildlife and people?

To be clear, we don’t know with COVID, what role if any the climate effects that we’re already seeing in species around the world may have had on the risk of this disease emerging. We know clearly that it had to do with a market in which animals were commingled, the bats and, potentially, pangolins. But it’s not clear, for instance, whether bat migration patterns, which have been influenced by climate, have played a role.

But we have other examples. We see this extraordinary migration to the poles. We’re watching all kinds of life forms run away from the heat, and that has led to the spread of pathogens, because animals that carry pathogens came in contact with other animals that didn’t carry those pathogens and there was transmission. The constraints upon animal migration because of habitat loss may force animals into closer proximity. The bottom line here is that if you wanted to prevent the spread of pathogens, the emergence of pathogens, as we see not just with people and COVID, but as well with wildlife, you wouldn’t transform the climate. Because that forces species to come into contact with other species that may be vulnerable to infections. There are lots of forces, and habitat loss is a major contributor to it.


Neela Banerjee

Neela Banerjee is a Washington-based reporter for InsideClimate News. She led the investigation into Exxon’s early climate research, which was a finalist for the 2016 Pulitzer Prize for Public Service reporting and the recipient of nearly a dozen other journalism awards. Before joining ICN, she spent four years as the energy and environmental reporter for the Los Angeles Times’ Washington bureau. Banerjee covered global energy, the Iraq War and other issues with The New York Times. She also served as a Moscow correspondent with The Wall Street Journal. Banerjee grew up in southeast Louisiana and graduated from Yale University.

You can reach her by email at [email protected]. For encrypted communication, use [email protected].