Today marks the 50th anniversary of Earth Day, a day traditionally dedicated to protecting the environment.

This year, experts are grappling with a global coronavirus pandemic along with worsening climate change, and some believe the two problems are linked.

Dr. Aaron Bernstein, a pediatrician at Boston Children’s Hospital and interim director of Harvard's C-CHANGE Institute at the T.H. Chan School of Public Health, joined WBUR's All Things Considered to talk about climate change and coronavirus on Earth Day.

As I understand, you started thinking of the link between coronavirus and the effects of climate change while you were treating a child a few months ago?

I was dressed up in my alien suit, as I like to think of it, going into a room of a child who we were concerned might have coronavirus. This was very early on. I couldn't stop thinking about how it was possible that by essentially touching this child, I was connecting myself to a bat somewhere, probably in China.

A bat?

A bat.

Because it's assumed that coronavirus began with somebody ingesting a bat?

Or, you know, some contact with a bat. Yes. And so when it comes to things like COVID but also HIV and SARS and Ebola, many people remember Ebola — that's not so long ago — that three-fourths of these things, these diseases are coming into people from animals.

We have driven, you know, infections and particularly viruses from animals into people. We know that climate change is pushing everything that can move, plant, animal and otherwise to get out of the heat to do so. And that may make opportunities for things to run into each other that wouldn't have run into each other previously. And that can allow for what we call "spillover" of a pathogen from an animal to another animal, or from an animal to a person.

Is there a tighter link? I mean, can we really say that climate change has a direct cause in these viruses?

I think these diseases would be happening regardless of climate change. I think the more important connection is that what we need to do to prevent the emergence of these diseases is in many ways the same things we need to do to combat climate change.

Air pollution from burning fossil fuels, particularly in the United States — people's long term exposure to air pollution over many, many years is damaging their lungs, making them more likely to die and get sicker from COVID. And that's accounting for other things that might make someone more at risk of getting sick with the disease.

How tight do you see this link attacking climate change as we attack other pandemics? I mean, this one, but then we know there will be more to follow.

It's pretty clear that nature is trying to tell us something with COVID. If we're still deforesting the world as we are and we're still having huge amounts of trade in wildlife that may be carriers of diseases for people, you could still wind up with big problems.

When the other pieces of the pandemic puzzle fit together, which are — we have lots of people living in cities, we have lots of people traveling all around the world — and I don't think the solution to the problem is stopping travel or keeping people from living in cities. The link is critically at the most preventative stage, which is also the most cost-effective point. The amount it would cost to do these things is really small in comparison to the trillions of dollars we're paying after the fact. And again, those things we need to do — preventing deforestation, addressing the root causes of climate change and air pollution — have health benefits that go well beyond pandemics.

You're speaking to, I think, many people who are concerned about the environment, but are today wondering how they're going to keep their kids educated at home and from climbing the walls, how they're going to keep everybody healthy, and particularly if they have less income now, how are they going to put food on the table.

So we have coronavirus and we have climate change. But one of them produces deaths that we can directly attribute. One of them produces deaths that are harder to attribute. So how do you get people to see the kind of urgency in this that you see?

You're absolutely right. People want to do what matters to them most right now.

But the other piece is that I take care of children with asthma. We know from the best available science that one in five children in this country has asthma because of exhaust coming out of cars. We know that children with asthma are disproportionately people of color in this country and that that perpetuates inequalities. And so we have an opportunity here as we think about transportation systems and investments in them, and particularly to deal with a major health burden and also at the same time provide for righting historical wrongs.

Also, the evidence is that as we've cleaned the air in this country, our economy does better. And so I think the question in my mind is how we find a path forward that makes sure we put ourselves in the best position to move in a direction that we want to go.

If there is one outgrowth of this that you would like to see take hold, what would it be?

Well, I think it's the recognition that we can do amazing things when our backs are against the wall. I think about my colleagues working in health care and the kind of sacrifices they've made, the way the teachers of the country have essentially transformed education in the span of a few weeks.

We need to figure out the ways that matter, as you put it, so that when people go to vote on Election Day, they see it as Earth Day, and that there is a real understanding that these choices about things that may seem distant or far away are really affecting whether your child has asthma, whether you're gonna have a heart attack when it comes to air pollution and whether an infectious disease may be more able to spread rapidly around the planet.