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Western medicine isn’t particularly well known for its holistic focus. While there are some exceptions to be sure, they are relatively few and far between. For the most part, physicians address the medical problem in front of them. They don’t have the tools to facilitate access to the things that can help people stay healthy, like fresh food, safe housing, or clean water.

Aaron Bernstein envisions a different medical model. As interim director of the Center for Climate, Health, and the Global Environment at the Harvard T.H. Chan School of Public Health, he’s working to bridge the gap between medicine and public health, such that doctors, hospitals, and insurers might begin to look beyond immediate problems to their root causes, particularly environmental ones. “To continue to have this unfortunately clear line between public health and medicine is a disaster for our health, and is a disaster for the environment,” he says.

Blurring that line, on the other hand, offers win-win solutions to both public health problems and climate change. And in the context of the Covid-19 crisis, which has clear ties to the environmental destruction we’re wreaking on our planet, Bernstein points out it can offer solutions, too.

In an early April phone call, Bernstein told me about the resistance he met when first trying to bring environmental issues into the medical realm, what he sees as some of the best ways to incentivize more environmentally conscious medicine, and why now is the time to “penetrate this delusion that we’re floating above the rest of the web of life on earth.”

As a physician, how did you first become interested and involved in the intersection between health and climate and environment?

I actually learned about climate change for the first time in seventh grade, which in my cohort was, I’m sure, unusual, but I clearly had a very forward thinking and on-top-of-the-science teacher. That was the first time I was interested, but I didn’t think about it very much until I was in college [where] I had some lectures from Stephen Schneider, who was a very well-known climate scientist. And he made it into a really compelling thing to know about.

I decided to go to medical school for a variety of reasons, which included an interest at that point in thinking about how environments matter to people’s health, and [I was] frankly somewhat naïve to the reality that medicine as a profession is pretty disconnected from environmental concerns. When I got to medical school, I realized that there might be an interesting marriage to be had between climate change and health. And when I went to [talk to] some folks from medical school about this, the answer I got was best captured by our Dean who said, Ari, you’re trying to fit a square peg into a round hole. The message was clear. And so I wrote back to some of my college professors and said, Is anyone you know really trying to work on this issue? And that’s how I got to the center that I’m directing today.

How do you think that we can build a more intersectional approach to climate change and public health? How do we get more doctors engaged on the issue?

There’s a pretty, I would say unfortunately, clear line between public health and medicine, in my mind, and I think that reflects the broader world.

People who are engaged in public health are primarily interested in preventing problems. That’s what they do. They work to make sure that people don’t have to see doctors. And doctors, while certainly concerned about things that contribute to ill health, are frankly mostly interested in dealing with problems after they arise. That’s not to say that doctors don’t advise on cigarette smoking, or diets. But you know, physicians learn almost nothing about diet. And they learn even less about environmental determinants of health.

So, the reason for that, of course, is that physicians are paid to treat people after they’re sick. They’re not paid to keep people healthy, really. That’s changing slowly. But, you know, one thing that’s immediately clear from either the $2 trillion-plus we’re spending on Covid, or the $3 trillion we spend every year on healthcare expenses, [is that] we are we are really suffering under an unbearable weight of preventable disease in this country. And so to continue to have this unfortunately clear line between public health and medicine is a disaster for our health, and is a disaster for the environment.

And the crazy part is, we would be so much better off financially and in terms of our health if we essentially incentivized our healthcare system and devised ways to do everything we can to keep people healthy.

Do you have specific ideas around the best kinds of incentives?

For one, if you look at the preventable burden of disease in the United States, there is some share of it that is way upstream of what happens in a clinician’s office. Things like our built environment. The fact we’re sitting in cars for long periods of time is enormously unhealthy. The [low] price of food that is enormously unhealthy for us. A clinician is not going to address those.

But we can start by, for example, educating clinicians about diet. I mean, most medical students in the United States, maybe they have six sessions on nutrition over four years of medical school, if that. And obesity affects a third of adults. It’s a huge driver of disease.

Part of it is also about engagements between healthcare and other sectors of society, and the incentives that are in place to collaborate. A good example is housing. We know that housing is a major determinant of health, whether you have stable housing situation or not, whether the air quality inside your house is good or not, whether there’s a leaky roof or not. And I could go on. And we see children who have housing instability, who have poor environments, and who have much greater medical needs. And those costs right now are essentially being borne by health insurers and people paying health insurance premiums. And doctors make more money when they see kids with asthma exacerbations, because they get paid every time.

Now insurers have gotten wise to this, so they’ve said, well, we’re not going to pay you so much — if the kid keeps coming back, we’ll pay you less. And that sort of puts the onus on providers to somehow figure out how to keep these kids healthy. But there’s no immediate connection between the causes of that childhood asthma —which could be that they living next to a freeway with air pollution, that they have mold in their house, that they have rodents, you know, all these things — and the ability of a healthcare system to actually do anything about them.

There are innovative ways, though, to bridge that [gap]. And a good example of that is in Ohio, where, essentially, there’s an arrangement with insurers and providers such that insurers carve out a certain amount of money for each person that they’re insuring, and give it to a healthcare system. And then the healthcare system essentially makes more money if they’re able to keep people well. Now, a perverse incentive there might be just denying care, and people get sicker and don’t get the care they need. So you have to do this in ways that simply don’t result in people being denied access. Done well, it leads to things like that money being spent to improve home weatherization, which decreases energy bills and decreases fossil fuel emissions, because, of course, homes and buildings contribute a huge amount to how much energy we use. And it improves housing stability.

There are [also] lots of innovative programs around nutrition, about not just telling people what to eat, but giving them access in, for example, healthcare settings, to farmers markets, to pre-made meals, to learning kitchens, to programs that are designed to … improve people’s lives in ways that don’t increase food bills.

And I might add, in both of these examples, nutrition and home weatherization, these are climate solutions. So, you know, it’s this extraordinarily win-win situation.

Since the Covid-19 pandemic began, you’ve been drawing attention to climate solutions that are also pandemic solutions. Are those similar?

At one level, it’s what I was just talking about. One of the reasons is that Covid-19 is particularly bad for people who have medical problems like heart disease, high blood pressure, existing lung diseases, and diabetes.

A large percentage of all those diseases are preventable. Type Two Diabetes, when I started medical school, was something that physicians didn’t really know anything about. It’s hard to believe in this moment in time, but it was so rare. It never happened. It was obscure. And so we have to recognize that over the last several decades, we have essentially changed our environments, in terms of how people can move around, and our diets, to create a huge burden of disease… And preventing that will mean that when Covid comes, less people are going to die.

[Or look at] air pollution. The evidence that we have suggests that [exposure to] air pollution [increases the] risk of dying from diseases like Covid. That’s not based on direct evidence from Covid. It’s based upon diseases like SARS, which is a coronavirus very similar to Covid, and influenza viruses. And of course, burning fossil fuels contributes the lion’s share of carbon pollution. So a climate solution is a pandemic solution.

But there are other ways as well. We need to recognize that diseases like Covid that are popping out of the woodwork, so to speak, are happening more often. And they’re mostly happening from spillover pathogens from wildlife into people. When you look at what’s causing that, it is overwhelmingly because of habitat destruction, usually deforestation, usually for agricultural purposes. So, one of the solutions to climate change is preventing deforestation. Preventing deforestation is also going to affect our risk of pathogen emergence.

We also know climate change is driving animals to move towards the poles and up mountainsides. That, combined with shrinking habitats, may be increasing the spread of potential pathogens among wild animal populations.

We’ve seen the effects of this in chimpanzees in Africa. People have been able to provide them sanctuaries, but these are a fragment of their original habitat. And Ebola is ravaging chimpanzee populations because they’re in increasingly close quarters. Is that happening with the bats in Asia that are driving emergence of things like SARS and Covid? We don’t really know yet. But, you know, based on first principles, cramming them together in smaller spaces probably isn’t helping. This is one way in which dealing with climate change, may, in fact, help us prevent disease emergence and pandemics.

Here in the US, a vast majority of the population lives in urban areas, largely separated from wildlife and wild places. How do you think that we make can make this connection more tangible?

Frankly, with Covid, nature is really trying to tell us something. It’s trying to remind us that our lives are inseparable from the lives of the other organisms we share the planet with. And I think that affords an opportunity to penetrate this delusion that we’re floating above the rest of the web of life on Earth, that we’re somehow separate from it.

I think there are other ways too. I think it’s particularly important in primary education to make sure that our children are learning about the connections between people and other life forms. I’m a big fan of schoolyard gardens for that reason, so students grasp and grapple with the reality that growing food is not the same as getting outputs from a 3D printer. There are forces that we don’t immediately control that can really affect the likelihood of the food that’s planted actually giving us something to eat.

I’m a big proponent of access to green spaces in cities where children are living, particularly children living in most disadvantaged parts of our cities.

Do you think there’s a way that we can build on the Covid-19 response in terms of taking action on climate change at this time?

We have to be talking about climate change, and for that matter, the biosphere, right now, in the same way as if you had a heart attack, and are in the process of recovering, you know, that’s exactly the time that we talk about diet and smoking and exercise and all the things that prevent further heart attacks. This is exactly the time we want to be in conversation.

Again, we’re spending $2-plus trillion on the economy. Shouldn’t we be spending those dollars in ways that will provide us a path forward rather than a path backward? And by a path backward I mean, you know, doubling down on technologies and infrastructure and energy sources that have gotten us into the mess we’re in right now.

Are you hopeful about that, given the current administration?

I think people overestimate the current administration’s influence, or for that matter, any administration’s influence on this. If you look at the states with the highest penetration of renewables in terms of their overall electricity production, it’s not the states people would think. It’s places like Kansas, and Iowa, and Nebraska.

And that’s because renewables are abundant there, particularly wind, and they’re cheap. If there’s any reason to be optimistic, it’s because of renewables in the heart of the country, or the automotive industry pushing, despite whatever the administration is doing, for greater fuel economy, or the recognition by everybody that cars that have electric motors are better performing cars, and don’t put out air pollution that’s going to make your kids sick with asthma… There’s also the reality that people are eating less red meat in this country than they’ve ever eaten. You know, we’re seeing this.

Would it help if we had a coordinated national action on this, of course it would. But I think it’s important to bear in mind that the federal government has really never led on environmental concerns.

I think there’s lots of reasons to be optimistic, and I think the actions that states are taking are going to push on the federal government to really do more, because otherwise, you’re going to have places like California having one set of standards and other states or regions having another set of standards, and the private sector is not going to be able to deal successfully with those alternate realities. I do think it’s critical that we work in our cities and states to really advance

This interview has been edited for clarity and length.