I’m digging through reports and punditry to make sense of health care reform when I realize that while we’ve been debating single-payer systems and high-risk pools, no one’s talking about the most serious health threat: climate change.

I know what global warming is doing to our ecosystems. My Twitter feed is a stream of climate disaster revelations. Given the serious implications droughts, floods, and fires pose to our health, shouldn’t climate change be part of the health care discussions?

Howard Frumkin thinks so. He is a professor of environmental and occupational health sciences at the University of Washington School of Public Health, and, by his measure, climate change is the greatest public health threat of our time.

Here’s his perspective on how climate change fits into the latest governmental health care battles.

Stephen Miller: What’s your sense of where we’re at with the current health care bill?

Howard Frumkin: Obamacare isn’t perfect. It’s a cumbersome system. It was a lot better than the status quo; tens of millions of people who were not insured got insurance. The Republican plan would undo that. It’s grotesquely unjust. If you view health care as a right, then it’s exactly the wrong way to go. We do need to reform Obamacare, we need to reduce costs in the system and enhance quality, and we need to achieve universal access.

Miller: What kind of health care bill is needed in a world with a changing climate?

Frumkin: In general, preparing to protect people from the effects of climate change means we need a robust health system. That means we need strong health departments that have the ability to do epidemiologic surveillance and do disaster preparedness. And do good communication and education. We need a medical care system that is available to everybody.

“To protect people from the effects of climate change means we need a robust health system.”

Climate change as a risk aggravator—or risk multiplier—makes those things all the more necessary. Anything you do to undercut those things in either the public health system or the clinical care system makes us less able to respond to climate change.

So, if you restrict the level of clinical care that’s available to people, and that’s exactly what these proposed Medicaid cuts would do, then all of the adverse health effects of climate change will hit the population. The poor people who will need medical care at that point will be less able to access it. They’ll be sicker, and they’ll die earlier.

Miller: Who is most affected?

Frumkin: The health impacts of climate change for the most part are not new problems, but they’re aggravations or intensifications of existing problems. Poverty is one of the strongest predictors of ill health. Communities of color are disproportionally poorer.

“Health impacts of climate change for the most part are not new problems.”

These are communities with less resiliency. After a disaster, they have less ability to build back. These are communities with higher baseline rates of asthma, so when ozone and pollen levels rise, these are communities that disproportionally suffer. These are communities with less access to health care, so when they develop a case of diarrhea related to climate-induced contamination of water, they may be less able to get that promptly diagnosed and treated.

With almost any hazard you can mention, you’ve got more vulnerability, lower baseline health, and lower resiliency at least in some communities of color.

Miller: We know climate change is affecting global ecosystems. In what specific ways does it threaten people’s health?

Frumkin: I’ll recite for you the Eight Horsemen of the Apocalypse—eight ways climate change threatens health:

Heat

As the world gets warmer, there will be more hot days. Mortality increases during heat waves. Very hot days impair people’s ability to work. They impair peoples’ ability to sleep, which aggravates other health problems. They trigger more violence, and crime rates rise. If there’s too much heat, and your body can’t dissipate the heat, you suffer heat stroke, and that can be fatal.

Severe weather events

These bring about all kinds of health problems, both acutely and chronically. People are injured or killed. People are displaced from their homes, which interrupts medical care and brings about a lot of mental health issues.

Air quality

This is a complicated story. Simply, one of the major air pollutants, ozone, is formed in the air as a secondary pollutant. It doesn’t come out of tailpipes and smoke stacks directly. Ozone is a respiratory toxin that attacks the airways and triggers asthma attacks. The chemical reactions that drive those precursors to become ozone are driven by heat. So, all things being equal, hotter weather means higher levels of ozone.

“This is a complicated story.”

Combustion, which gives us climate change, also gives us particulate matter that kills people. If you dry out a forest and begin to kill off the trees, and infest it with beetles that get a hold because of ecosystem changes, you have a perfect setup for wildfires. These wildfires are relatively short-lived events, but during that time the levels of particulate matter can be so high that they rival air pollution in cities like Beijing and kill substantial numbers of people downwind.

Pollen producers like ragweed grow more robustly under high CO2 and high heat conditions. That means that allergens will become a more common problem. The allergen in poison ivy, called urushiol, actually grows more toxic. Depending on location, the pollen season can be three weeks longer, meaning that allergy suffers have longer to suffer.

Infectious diseases

Ticks, which carry Lyme disease, are a good example. They do better in warmer weather, they become more metabolically active, they feed more—which means they bite us more—and their incubation period is shortened.

In some cases, the pathogens themselves do better under warmer conditions. There’s a reason that tropical diseases have always been called tropical diseases. Those diseases exist within specific ecological niches. As those niches expand their ranges, you expect the diseases to expand their ranges too. Dengue and Lyme disease are spreading in the U.S.

Food- and water-borne diseases

The water-borne diarrheal diseases, gastrointestinal diseases, surge during warm weather and severe rainfall. Concentrated rain flow tends to concentrate disease-carrying insects in drinking water supplies—both surface water and ground water.

We’re also learning that some of the organisms like the bacterium that causes cholera that actually thrive under warm weather conditions like coastal areas are taking up residences in other areas and thriving more than anyone knew. We expect those to be worsening problems as well.

Food

For my money, this is one of the biggest and most worrisome sets of threats. Many people in the world are hungry. Even in this country about 15 percent of people are food insecure, according to the Department of Agriculture. When food availability goes down, prices go up, and people who are food insecure have more difficulty buying food. One of the ways people cope is by buying calorie-dense, nutrient-poor inexpensive foods. That is one of the drivers of the obesity epidemic. It stands to reason that something we need to worry about is that food-insecure people facing higher food prices will suffer diminished dietary quality and diminished nutrition.

Our ancestors took early wild versions of various crops and bred them all under the Holocene climate conditions. Now that we’re moving out of the Holocene, it turns out that most of the crops don’t do as well. Add to that: The biochemistry of most crops changes with warmer weather and high CO2 levels. You get a lower content of protein, of zinc, of a number of the micronutrients.

Mental health

People’s lives are upended when they witness or are victims of the violence disasters can do. After Katrina, for example, probably the biggest public health impact was on mental health, when hundreds of thousands of people were misplaced. We saw rising rates of domestic violence, substance, abuse, depression, anxiety, and so on.

In warm weather, people with severe mental illness have especially high mortality rates. It may be a function of illness, such as schizophrenia or manic-depression. It may be that the medications that those patients take impair their ability to dissipate heat. Maybe the illness itself limits a person’s ability to judge danger and take protective action.

Armed conflict and mass migration

There’s a very good argument that the Syrian conflict originated with climate-related drought that hit Syria for several years before the Arab Spring occurred. The displacement of millions in Syria, the deaths of hundreds of thousands had a terrible public health impact.

There’s a very good argument that the Syrian conflict originated with climate-related drought.

What happens if Miami or New Orleans or Los Angeles or Phoenix have to decant their populations because of sea levels, heat, or fresh water supplies? Where will they go? What provisions will we make for continuity of medical care? What will we do about housing and employment, which are necessary for good health? Seattle may be a receiving area, but we haven’t planned for that. We don’t even have enough housing for the people who are here.

Miller: So what do we do? How do we adapt?

Frumkin: It turns out, the things we have to do to tackle climate change are in many ways very good public health strategies.

We need to wean ourselves from internal combustion, single-occupancy motor vehicles, and move more toward walking biking and transit. That’s good as a climate mitigation strategy—the transportation sector accounts for about a third of greenhouse gas emissions. It’s also a great strategy to fight the obesity epidemic. And it’s a great strategy for cleaning up air in urban air sheds that are otherwise polluted. It’s also a great strategy for reducing one of the major causes of death for young people in this country, which is car crashes.

Livestock production has the heaviest carbon footprint of any of the parts of our food chain. If we eat less livestock, eat lower on the food chain, it substantially reduces cardiovascular and cancer risks.

Miller: Can you point to any adaptation examples already in action?

Frumkin: Portland has put curb extensions on the streets. These are rounded areas of curb that make the sidewalk protrude into the street. Excavating them down to 20 or 30 feet, filling them with gravel and then covering them with native plantings. This is a traffic calming device. It helps to create the infrastructure that encourages people to bicycle. It’s also a stormwater management strategy. These things are situated strategically so that they catch runoff during severe rainfall events and sequester the runoff in these retention pits and then slowly release it into groundwater, which helps protect water quality and prevent flooding.

Miller: I’ve seen other projects like that across the country. Some impacts, I imagine, are easier to address than others.

Frumkin: Maybe the most widely spread impact is the way it makes you feel to have a conversation like the one we’re having. The way it feels for children to grow up under the shadow of possible apocalyptic scenarios. The way it feels for adults to see their familiar beloved places being changed. Depression and anxiety are natural responses to those changes. Maintaining hope and optimism and good cheer become more difficult.