Ask an Expert: Noah Scovronick on Climate Change, Extreme Heat, and Its Impact on Health

August 1, 2023
Noah Scovronick

By Karina Antenucci

It’s not just you. It has been hotter than usual this summer… much hotter. July 2023 was the world’s hottest month on record, with some sources claiming this has been the hottest month on Earth in 120,000 years. Recently, U.N. secretary general António Guterres referred to this new era as one of “global boiling.”

As global temperatures continue to rise due to the effects of climate change, researchers are broadening their scope of study to understand the impact of increased heat on everything from disease to violence to help protect people now and in the future.

In this installment in our Ask an Expert series, we speak with Noah Scovronick, assistant professor in the Gangarosa Department of Environmental Health, director of Emory’s MPH Certificate in Climate and Health, and director of Emory’s Climate & Health Research Incubator, to discuss his research around heat and its impact on health, violence, and snakebite.

You’ve done several studies about temperature and violence. Why did you decide to focus on that topic?

Violence is something that we all worry about to some extent and, anecdotally, people assume there is more violence when it’s hot outside. But there have only been a few recent studies that have actually quantified that. We realized we had the opportunity to begin to answer some questions about the environmental determinants of violence. And the other reason we decided to pursue some of these projects is that violence research is something that captures student imagination and gets them interested in the relationship between climate change and human health.

What effect does temperature have on violence?

There are three different avenues of violence research in my work: the link between temperature and suicide, temperature and homicide, and, more recently, I started a project on temperature and police violence.

The work on temperature and suicide has been in collaboration with researchers around the world. We have put together a lot of data to see how these relationships may be similar or different across countries. We have found there is an association not only with the season and suicide but also with changes in day-to-day temperature.

The study on temperature and homicide I worked on focused on South Africa, which has one of the highest homicide rates in the world. We found that on hotter days there are clear increases in homicides.

We are also currently using publicly available data to determine whether or not fatal police shootings in the U.S. are associated with temperature. This work is currently in peer review, and we should have results to share this fall.

The general finding that there tends to be increasing violence as it gets warmer is interesting, but also concerning within the context of climate change.

What is the reason for more aggressive behavior on hotter days?

There are two leading theories. One is that when it is warmer, people are outside more and there is more opportunity for conflict and for a perpetrator and victim to interact. The other theory is more physiological, that there are changes in the nervous system that creates more aggressive behavior.

What research findings can you share related to the impact of heat on human physiology?

Rollins colleagues and me are part of the ENVISION Research Group that is primarily focused on heat and air pollution. Stefanie Ebelt, professor of environmental health and epidemiology; Howard Chang, professor of biostatistics and bioinformatics and environmental health; and I have a number of projects looking at how day-to-day changes in heat are affecting people’s health. Several of those projects are funded by the National Institutes of Health.

One large study led by Stefanie is looking at the relationship between heat and acute kidney injury, a common health outcome that can be very serious and very costly to the health care system and to the individual. Kidneys are vulnerable to the effects of heat because of their role in hydration, thermoregulation, and other processes related to heat. This project is trying to pin down who is vulnerable to acute kidney injury using Emory’s hospital data, which gives us a lot of detailed information not only on basic demographics, but also what comorbidities they have, laboratory test results, and what medications they are taking.

Another project that I’m leading is using administratively collected data to understand who is vulnerable to heat. Some hospitals have begun to code social determinants of health in patients’ medical records, including things like housing quality or if they are an unhoused person, education level, if they live alone versus in an institution, and more. These things are all relevant when it comes to a person’s vulnerability to heat. We’re hoping we can use that information to help design interventions to reduce the health burdens of outdoor heat.

Please elaborate on the work you are doing around snakes and heat.

A recent project looked at whether snake bites are more likely to occur on days when it’s hotter in Georgia. We used a dataset from all over Georgia, which told us when and where patients went to the hospital for a snake bite. We also did the same thing for envenomation from other types of creatures, like from spiders or scorpions. We found that short-term temperature changes had a strong effect on both groups (snakes and non-snakes) but more for snakes. The odds of a snake bite increased about 6% for every 1 degree Celsius increase in outdoor temperature. That told us that it may not just be that people are more likely to be outside during warmer weather, but there may be something about snake behavior that is also driving the association.

Why is research on heat and climate change important to public health?

One reason is simply to understand what the threats of climate change areto health. If you’re the health department or working in other domains of public health and trying to protect people, you need to understand what those impacts are, who is most vulnerable, and how important the effects are likely to be. That will let you know how to prioritize your public health action.

What should policymakers be doing to protect the environment and human health?

They should be proactive about understanding the likely impacts of climate change locally and how to protect their people from those impacts. Also, they need to be thinking specifically about  the intersection between climate change and equity because the effects are likely to fall disproportionately on underserved populations. If you’re not thoughtful or careful on how you design your interventions, you may actually worsen health disparities rather than close them.

I am currently involved in an EPA-funded environmental justice project related to climate change called REACH-Atlanta (Resilience, Equity, and Adaptation for Climate and Health) which is a partnership with Environmental Community Action. This community-engaged project is about making climate change information more available to people on the west and south sides of Atlanta who are impacted by climate exposures, such as heat, air pollution, and flooding, as well as to gain insight into the community members’ knowledge, experiences, health risks, and concerns.

What about the general public? What should we all be doing?

Everyone has a role in reducing carbon and greenhouse gas emissions, as well as advocacy and preparation for the health impacts of climate change. People can be proactive about understanding and preparing for the likely impacts they may face where they live. For example, how to protect yourself during a period of extreme heat or having a plan in case of a disaster like a flood or hurricane. And we all should advocate for policies that reduce emissions; invest in a low-emission, climate-resilient infrastructure; and create programs that can protect us and our communities from the effects of climate change.

Noah Scovronick’s work focuses on the links between climate change and human health. His research includes epidemiological studies on the relationship of climate-sensitive exposures with adverse health outcomes and investigations of the health implications of reducing greenhouse gas emissions, and to identify policies capable of producing large health “co-benefits.”