Climate change is 'now understood as a health issue'

Following this year's unprecedented climate shocks, including heat waves around the world, more and more policymakers and practitioners are recognizing climate change as a global health issue.

Dr. Aaron Bernstein has been at the forefront of that movement as the interim director of the Center for Climate, Health, and the Global Environment at Harvard T.H. Chan School of Public Health (Harvard Chan C-CHANGE), whose mission is to put health and equity at the center of climate actions by helping decision-makers understand “the health consequences of our addiction to fossil fuels and shape the policies that help us lead more just, sustainable, and healthy lives."

We spoke with Dr. Bernstein, who is also a pediatrician at Boston Children’s Hospital and an assistant professor of pediatrics at Harvard Medical School, about the threats climate change poses to vulnerable populations and some of the successes he's seen in mitigating climate impacts on health.

It seems that climate change is finally being framed as a global health issue. How did that shift occur?

Dr. Bernstein: I think climate change is now understood as a health issue. However, I'm not sure the folks interested in global health have really understood how the practice of health care, particularly in low- and middle-income countries (LMICs), needs to change in the face of that reality.

We've just gotten to the point where [people realize] climate is about people and not polar bears. When our center was founded in 1996 you could have counted on your hands and toes, and maybe just your hands, how many people saw climate change as a health problem. We've now got a long view on this, and I think a couple of things mattered.

One was reality. This year it's so painfully obvious how much people's health is suffering because of climate change that you'd have to be blind not to recognize it. I think that the tempo of clear health effects has been growing over time. Concerted education is another. Our center from the start, and these days a lot of others, have worked to take the science that underscores how climate matters to health, and bring it to media outlets, policymakers, you name it. Some of my former students are now heads of major climate and health initiatives, and so there are just more people doing this work.

Potentially one of the most powerful messages is how much health stands to benefit when we act on climate, both in mitigation and adaptation. It's now crystallized that fossil fuels, which are driving climate change, are also responsible for huge numbers of deaths, by some estimates as many as one in five deaths, and almost all of those are in LMICs. That's eight million premature deaths a year, and that's just the deaths. The incidence of all kinds of other diseases is huge.

When you move away from [fossil fuels], you can create enormous health and economic gains because people are not sick and they're able to work. We see how climate actions get at the root cause of all kinds of both communicable and non- communicable disease burdens. That makes seeing these issues as health issues both easier and more compelling.

What do you see as the most important current and future health threats climate change poses to vulnerable populations, especially in LMICs

Dr. Bernstein: It's displacement. Population displacement is the final common pathway of climate change effects on health. If you don't have water, you don't have food, or you don't have shelter, then you may be forced to move. It could be displacement from one town to the next. It could be displacement across the world. People who are displaced against their will often have some of the greatest vulnerabilities to health you can find. Nutrition, infectious diseases, and mental health are also affected when you're forced to move.

Short of that, the biggest two areas of concern are food and water. There are huge amounts of water stress, particularly in LMICs. Climate change is making that worse. At the same time, more intense heat, drought and fires conspire to make producing food harder and that means more food insecurity. There’s also a direct effect of carbon dioxide on the nutrition in the food we eat - more carbon dioxide tends to reduce the amount of protein, iron and other nutrients that are already in short supply for too many people, especially in low wealth communities and countries. At last check nearly 1 billion people were already food insecure.

Have you seen any major successes in mitigating climate impacts on health to date and would you have any lessons to share from them?

Dr. Bernstein: Absolutely. I think the first is the United States, which has greatly improved air quality by cleaning up and lessening its use of fossil fuels through innovation and the use of regulations. Hundreds and hundreds of thousands of lives have been saved. There have been all kinds of examples where affected communities have found ways to become more resilient. In Bangladesh, for example, some farmers have moved to brackish-tolerant rice or [cultivating] species that live in brackish waters, such as crabs. There are also farmers around the globe who are likewise relying more heavily on cultivars of crops that can be more drought, salt, and heat resistant.

A major challenge we face in adaptation is resources, not ideas. With some kinds of climate shocks, like hurricanes, it's hard to know how much should be invested preparing for that versus spending that money on something else. To me, this is a real challenge – how you think about where you put your money, particularly in cities, to get the biggest bang for your buck.

How are health systems in LMICs adapting to climate change?

Dr. Bernstein: I see an enormous leapfrogging opportunity here to not embed those systems with the vulnerabilities that we have baked into our health systems when it comes to climate – everything from supply chains, to how care is delivered, to how health care facilities are built and designed.

I think about Mirebalais Hospital in Haiti which is the largest fully solar-powered hospital in the Western Hemisphere. Mirebalais is in the central plateau of Haiti. It is isolated. This hospital has been fully operational through Haiti's disasters because it's off the grid. That's extraordinary. And in Puerto Rico, after Hurricane Maria, which devastated the island, the island solarized its front-line health clinics. During an island-wide blackout in April, the only businesses that were operating were these health centers, which were also the only sources of water because all the wells are electric.

A lot of hospitals in the United States are on fossil fuel powered micro-grids. They're so energy intensive that they have their own power plants. It makes them more vulnerable, because if one plant goes out, they’re toast.

There's also a strong focus on community health engagement in health system strengthening in LMICs. Rather than make care delivery centralized and have a central nerve center, it is designed to be more distributed. People in the community work through a community health model – 'accompaniment' as Paul Farmer would have described it. I think that's a much more resilient way to provide health care in a world enduring climate change.

You led a task force last year on climate change and pandemic risk, called the Scientific Task Force for Preventing Pandemics at the Source. What were your key recommendations?

Dr. Bernstein: The task force was established because it was becoming clear that major multilateral organizations were providing recommendations to address the pandemic but in many ways, were not acknowledging major scientific findings in this area. The idea was to get some of the science out there so that people in these positions could see it.

What does the science show? It shows, number one, that pandemic risk is foundationally about spillover. That the core problem is the movement of pathogens from animals, typically wild animals, to people, sometimes through livestock. If you read many reports, it's as if the pathogens that cause emerging pandemics are dropped out of the heavens. Another big point was that the pathways to prevent spillover are not only well known, but they are well described in ways that enable intervention. The main interventions are about conservation, bio-security, and surveillance. Better surveillance of pathogens that may spill from animals to people and the wildlife trade can be helpful in preventing spillover . These are pillars of what might be called primary pandemic prevention.

What's stunning to me is that if you listen to and read what many leaders of LMICs are saying, it’s that we need more primary prevention. They are not saying we need more vaccines, tests, and drugs alone - as critical as they are. Why? Because when you don't have, in my view, the influence of industry on what the response should be and the huge amount of profit that is available, you might more readily see that your return on investment from spillover prevention is huge in comparison to putting all of your eggs in post-spillover responses.

How could the global health community play a larger role in addressing climate change?

Dr. Bernstein: In two big ways. One is to recognize that health care globally is a major driver of carbon dioxide emissions and unsustainable use. The waste issue is immense. We simply can't afford from a climate change perspective to build out the health systems in LMICs in the image of the United States.

We need to think carefully about how to sustainably build out health systems. We're talking lesser fossil fuel dependence, greater energy efficiency (and lower electrical bills), and more sustainable water use. These are critical endpoints for those facilities.

The second is that we have to get the global health community to the table when it comes to addressing climate risk. Practitioners in LMICs and global health system strengthening organizations are working their tails off to achieve health gains but it's been hard to get them to focus on climate change. That's changing because the climate shocks are so prevalent now.

One important role of those practitioners and organizations is to call out the funding community to say that you can't just fund HIV, for example, without addressing climate risks. You can't give people antiretrovirals but ignore that people are undernourished, or without water. In parts of the world where natural resources are increasingly threatened by climate risk, whether it's water, or shelter, or food, whatever, we can't be blind to that if we want to protect all of the investments that have been made to date. We have to figure out better ways to make health gains resilient to climate change.