Paul Epstein on climate change and our health

How will global warming affect our health? EarthSky spoke with Paul Epstein, a medical doctor trained in tropical public health at Harvard Medical School.

Dr. Epstein, along with Dan Ferber, is the author of Changing Planet, Changing Health: How the Climate Crisis Threatens Our Health and What We Can Do about It, released in April, 2011. The book investigates the risks to human health from climate change. He talked about the main findings of the book:

We look at climate change, particularly, but also in the context of other changes going on in the global environment to try to understand how that affects our health, directly, in terms of specific diseases, and also the larger context of how the environment and ecological systems that underpin us and support us, life support systems, how changes there can affect our health.

One example, he said, is heat waves.

We look at heat waves and the impact of heat waves that are increasing in frequency, duration, and intensity. But it’s also the disproportionate nighttime warming and winter warming over the long-range average that makes heat waves under climate change particularly lethal.

Epstein said that asthma and allergies are on the rise with increasing CO2 emissions from burning fossil fuels. In the U.S., he said, cases of asthma have more than doubled since 1980. He told EarthSky:

A surprising finding is that carbon dioxide levels, when they’re high, increase ragweed production of pollen. They also stimulate early-flowering trees in the spring. So spring and fall allergies, we may be feeling the effect of increased pollen just from CO2. Forget climate change, global warming, for a moment – just higher levels of CO2.

Many elements of fossil fuel combustion may be contributing to this increasing epidemic of asthma, Epstein said. For example, particulate matter from burning fossil fuels helps deliver the allergens, the spores and the pollen, deep into our lungs.

Also on the rise are outbreaks of disease carried by bugs like mosquitoes and ticks which thrive in warm weather. Epstein said:

Lyme disease, for instance, in this country is a vector-borne disease, tick-borne, that in the last decade has moved through New Hampshire and gone up eightfold in New Hampshire, and tenfold in Maine, and is barking at the door of Canada.

But, he said, there is not an even, steady rise in disease impacts. It varies from country to country. It varies over seasons. EarthSky asked Dr. Epstein what people can do to lower the risk to their health from climate change. He said:

There are individual and community-level actions that people can take. No person, no woman, no man is an island. We’re part of families, church, communities, jobs, places of education. And we can be active in all of those spheres.

We need healthy cities programs that really can involve citizens. And here, we’re talking about green buildings, rooftop gardens, tree-lined streets, biking lanes, walking paths, open space, permeable surface, public transport, and smart growth. All of these can reduce the urban heat island effect that magnifies heat waves in the city. So we’d be better adapted. They decrease the air pollution. They provide jobs, stimulate growth and industries, and push these climate-friendly technologies into the global marketplace. So these are places that people and communities can be involved with, changing their communities, planning, city planning, and so on.

In the U.S. and some other developed countries, early warning systems are lowering the deaths from heat waves, Epstein said.

Early warning systems based on climate and weather projections can be helpful in decreasing the health impact of heat waves, for example. This is being done in cities across the U.S. right now. And cities are preparing more facilities for treatment; more air conditioned sites like malls and theaters to house people and even keep them overnight, as we were talking about the warm nights associated with heat waves; and getting transport, getting equipment ready, and so on.

At the heart of Changing Planet, Changing Health, said Epstein, is the idea that the life-support systems nature provides are put at risk from climate change, which ultimately threatens people’s health. He said:

There are two ways to think about public health. One is of public health measures, like vaccination preparedness and so on. But the other is ecological, environmental, and social conditions that underlie our health. And that’s where we’re seeing the greatest threat for health from climate change.