Human Health in a Changing Climate

An Expert Opinion: Jonathan Patz

Polar bears aren’t the only species threatened by climate change. Jonathan Patz, director of the Global Health Institute at the University of Wisconsin, has spent the last two decades studying the ways that a warming world will affect human health. In 2007, he shared the Nobel Prize as a lead author for the United Nations’ Intergovernmental Panel on Climate Change. Patz, who holds degrees in medicine and public health, crisscrosses the globe to spread the word about the far-reaching impacts of climate change on our health and why better urban planning might be the answer.

 When we think about the effects of climate change on our health, most of us probably think about big events like heat waves. Are there other, overlooked implications for public health? 

One of the reasons I think that climate change poses an enormous public health risk is because of the multiple pathways through which the impacts will be experienced. When you have a heat wave, you get worsening of pollution effects. Also higher temperatures promote more ragweed pollen, and then all sorts of infectious diseases. There are so many diseases very sensitive to small shifts in temperature. It’s also extremes of the water cycle. Already we don’t handle heavy rainfall events very well. When it rains really hard, you’re going to find bacteria and viruses in the water.

But I think one of the biggest problems that’s the most difficult to study and document, could be the disruption of big populations: droughts forcing people to move, sea level rise. These are going to cause population-wide disruption, social upheaval. I think this could be a huge burden with mental health, post-traumatic stress, and things like that.

You’ve said that the way climate change is affecting our health is an ethical issue.

Where are today’s most climate-sensitive diseases like malaria, malnutrition, diarrheal disease? They’re mostly in poor countries, especially Africa and India. Then you ask the question, who’s causing global warming? Global warming is primarily from burning fossil fuels -- that’s in the industrialized world. That’s the huge ethical dilemma. Those most vulnerable are the least responsible.

When I was meeting with the Dalai Lama two years ago, I was explaining to him that we didn’t know when we were developing the steam engine and oil- and gas-powered vehicles and powering our electricity with coal, we didn’t know that it was a bad thing. So now we know that. And the Dalai Lama asked me, he said, “Well, wait a minute, now that you know that, why are you still burning fossil fuels? It’s no longer ethical, with that knowledge.” I said to him, “That’s a good question. That’s a very good question.”

It’s easy to feel overwhelmed by the enormity of the problem. Are there concrete things people can do that will mitigate some of the negative effects on our health?

Well, this is the exciting piece of this that I really think is important. With every crisis there’s an opportunity.

The automobile, the dependence on the automobile, is really a very costly design for our health. We actually quantified the economic benefit and the health benefit if you took the 11 largest cities in the upper Midwest and you asked the question, what if short car trips, trips that are two and a half miles, were taken off the road? What would it mean for urban air quality? We found that we would save 500 lives a year, hundreds of thousands in hospitalizations, and about four billion dollars every year in savings from avoided health costs.

Now, what if half of those short car trips become bicycle trips, and only during the summer? That would save another 700 lives per year because of physical fitness. So we’re talking about eight billion dollars, about 1,300 lives saved. So, this is a golden opportunity -- a huge public health dividend -- to be able to design cities and design transportation for active transit, for biking, for walking.

You bike to work, right? Even in the Wisconsin winter?

I have recently bought studded snow tires and I do bike to work, but that’s not actually the message that I want to portray. Because I would say while I bike to work in the winter, I do it for speed and convenience. If I lived further away, I would probably take the bus.

Biking has to become the preferred choice, the easy choice. You can’t ask people to bicycle because they should. This is where the challenge is to urban planning and to the policymakers.

Is that why you’re so committed to advocacy? You spend a lot of time talking to government officials and policymakers.

I do. I’ve spent about 20 years working on climate change health issues. Most of that time has been looking at the hazardous effects, and I think it’s clear that climate change is a big hazard. But I now think that the policies towards smart urban planning, clean energy sources – the potential health benefits of those mitigation policies are huge. I use that cartoon all the time, these climate skeptics saying, “What if climate change is a hoax and we create a healthier and cleaner community for nothing?!”

You were one of the first people in this field. Was there a moment when you realized what huge implications climate change had for public health?

 During one of my medical residencies I rotated at the EPA, and they asked me to review the literature on this issue. And I looked at this 1989 government report where the only health concern was the supplies of underarm deodorant. That was the health concern. And I said, wait a minute…this is a linchpin issue. This is one of those issues that involved population policy, per capita energy and resources, and potential big hazards. This is a huge issue and nobody’s actually doing research. So I started researching it. And now it’s great to see things are really spinning up and people have put climate change health as a top priority.

Back then, did you ever think you’d end up talking to the Dalai Lama about climate change?

No, I didn’t think about that one!