John R. Balmes, MD, is a professor of Environmental Health Sciences at the School of Public Health at the University of California, Berkeley. He has studied the respiratory health effects of air pollution for the past 18 years. We spoke with him about how climate change is affecting health, as well as his role with The Lancet Countdown on Health and Climate Change, an international collaboration of researchers and clinicians tracking the global progress on health and climate change from 2016 to 2030. The Lancet Countdown will produce an annual report, the first of which was released Oct. 31, 2017. The following day, UC Berkeley held a panel discussion, "Climate Change: The Defining Health Challenge and Opportunity of the 21st Century: A Lancet Countdown Event," at which Dr. Balmes and other speakers discussed the implications of the report and California’s role as the U.S. leader in climate change mitigation policy.
Can you discuss your role with The Lancet Countdown?
The leadership of The Lancet Countdown reached out to me to set up a “launch event,” which would generate publicity for The Lancet Countdown report to increase awareness of the public-health impacts of climate change. They reached out to me because a) I’m a physician and they wanted to reach a health care audience as well as the general public, and b) because I’m in California, and California has leadership with regard to climate change mitigation policies in the U.S., especially now that the Trump administration is pulling out of the Paris Climate Accord. And I’m a physician member of the California Resources Board, so I’m both a physician and a climate change mitigation policy maker. There are relatively few Americans involved in The Lancet Countdown collaborative team. And they wanted more Americans to be aware of what they were doing and to potentially collaborate with them in the future because this report is going to come out on a regular basis.
How are you going to get the word out?
We’re staging an evening event on Nov. 1, 2017, the day after the first Lancet Countdown report of nation-specific indicator data is published. We put together four or five speakers to give short presentations on the main themes of The Lancet Countdown. And all the people who are speaking have prominent positions with regard to climate change and public health or climate change mitigation policy. This will be a public event, held at the Brower Center at UC Berkeley, which is a LEED (Leadership in Energy and Environmental Design) building and is named after David Brower, the first Executive Director of the Sierra Club.
People know about drowning in floods or becoming electrocuted, not having fresh water or food because of a hurricane and loss of electricity, and so forth. But how else can climate change affect health?
Extreme heat directly affects health: Whenever there are multiple days in a row of extreme heat, people actually die of heat-related illness. In California in 2006, there was a major heat wave where it was 100°F for a week and many people died. You’d think it would be in the Central Valley where it gets the hottest, but it was along the coast. People in the Central Valley, even poor people, have adapted to the heat in the summer and have air conditioners. But along the coast, including San Francisco, most people don’t have air conditioning because you don’t need it. So, when you have one of these heat waves, people, especially elderly people who have pre-existing heart and lung disease, will die if they can’t get to a cooling center.
This was well documented in Chicago years ago: There was a big heat wave in the mid-‘90s in which many people died. And they determined it was mostly socially isolated older people with pre-existing disease. And they implemented policies where even the garbage collectors going through the alleys would identify who was an older person living alone who wasn’t able to get to a cooling center. There was a system to get people to cooling centers and there were a lot fewer deaths the next time they had a heat wave. And in Europe a little over a decade ago there was a heatwave that killed thousands of people in France and Italy and, again, it was socially isolated older people. And it happened in August when the young people were on vacation, leaving grandma alone at home. It was a combination of heat and air pollution. (With extreme heat over multiple days, there’s also usually a lot of ozone and other pollutants because of more energy consumption.)
Can you discuss how climate change is impacting air pollution and health?
Air pollution will get worse with climate change. California is noted for having very strict air quality regulations, the strictest in the country. And those are designed to lower our air pollution health burden. But the warming of the climate works against those regulations. And specifically ozone, which is a major constituent of our smog here in California, goes up almost linearly with temperature. We have good data to show that. So there will be more ozone. And, as I said, during extreme heat events, there’s more energy consumption, which generates more nitrogen oxides and fine particulate matter.
Climate change mitigation and air quality go hand in hand. I’m a pulmonary physician treating asthma, and many people with asthma have allergies. We’re expecting more problems with allergies related to climate change because the growing season is changing. As a result, there’s a major release of pollen that people are allergic to several weeks earlier than there used to be in California. Ragweed, which is a major allergen, used to not be in California. People used to move from the Midwest and East Coast to California to get away from ragweed. Now we’re expecting the area that ragweed covers to increase with climate change. And when there’s more carbon dioxide in the atmosphere, it has been shown experimentally that ragweed grows better and produces more pollen. So there’s a well-documented concern that there will be increases in allergies and asthma attacks related to climate change. We also expect that there will be a greater health burden on other respiratory diseases because our regulatory policies are being somewhat defeated by climate change.
In what other ways is heat affecting public health?
There are also vector-borne diseases. Vectors, such as mosquitoes and ticks, will thrive in new habitats that they currently don’t thrive in. We’ve already seen this in California with West Nile virus, which historically wasn’t a problem in Northern California but has gradually worked its way north. Part of that is thought to be due to a temperature rise. Around the world, malaria is the big disease related to the mosquito vector. There was a good study on Mt. Kilimanjaro. Right now, the only areas affected by malaria are down at the base. But with the temperature rising, they expect the malaria-prone areas to gradually go up nearer the top of the mountain. Dengue fever is another one that’s extending—we don’t have dengue in the U.S. But there’s a lot of concern that the Southeast U.S. will have dengue fever if the climate change prediction models are right, which I think they are.
How can differences in seasonal temperatures impact individuals’ ability to work or exercise outdoors?
Things are changing pretty quickly here in California. Right now in the Central Valley there are a few days of extreme heat, where it’s over 105°F, per year. By mid-century, it’s expected to be at least 50 days a year, if not more. So for almost two months of the year, it would be over 105°F. And people who do work outdoors, like farm workers and construction workers, are going to either not work those days or wear air-conditioned space suits to be adequately prevented from developing heat exhaustion. And we’re already experiencing more days of extreme heat than we did several decades ago. San Francisco had the hottest day on record the Friday before the Labor Day weekend. It was 106°F.
From year to year the difference in temperatures is small. But when you look at a decade or two, it’s a big difference. I co-authored a paper about the Summer Olympics to highlight how people exerting themselves outdoors in extreme heat are at risk, including of dying. And we showed that if the climate change predictions are correct, only a few cities in the world by mid-century will be able to hold the Summer Olympics because the marathon—one of the oldest Olympic events, going back to Greek history—is also the one in which participants are most prone to heat stress. People start having heat stroke and dying after the temperature gets into the 80s with high humidity. Helsinki, Finland, will be one of the few cities in the Northern Hemisphere that could hold the Summer Olympics, because it will be too hot elsewhere.
Can you address whether climate change has a role in the raging wildfires we’re seeing in Northern California?
These are multiple fires. You can’t blame any one fire or any one hurricane on climate change, but there’s an arc or a trajectory. Catastrophic wildfires throughout the West have been on the increase for several decades. There are multiple factors, but climate change—hotter, drier weather—is definitely a contributor. In California, we consider climate change mitigation the No. 1 way to try to prevent these catastrophic wildfires.
Similarly, we’re having more and more severe hurricanes. Houston is a perfect example. They don’t have a Hurricane Harvey every year. But they’ve had three 500-year floods in a row and the last one was a 1,000-year flood; three years in a row they’ve had these bad floods. That is more than just a one-off. Again, it’s the trajectory. We have always had hurricanes, but now there are more hurricanes and more severe hurricanes.
How does climate change impact mental health and well-being?
The psychological stress of extreme heat events is an important consideration. Going back to the Labor Day weekend when it was unseasonably hot here in the Bay Area, people were visibly upset. Most of us couldn’t get cool because we don’t have air conditioning, and even ceiling fans (which I put in years ago after experiencing a 100°F day and not being able to sleep) didn’t really do the trick. And, if your livelihood is at risk because you can’t work outside, that will also be an issue. And globally there’s concern about mass migration. At the end of this century, Bangladesh is expected to be two-thirds under water. Florida is expected to have major changes in the amount of habitable land. Where will all these people go? The U.S. is a rich country, so people in Florida can figure out a way to move in time. But Bangladesh is a poor country; where are they going to go? To Myanmar or India? Drought is already a problem in multiple places in the world, as it was in California. But certainly in much of Africa, it’s a huge problem. With more drought because of climate change, where will those people go? The stress on multiple levels, physical and emotional, from climate change is a major public health issue globally.
Also see Floods, Heat, and Infectious Diseases.