Data Displaced

When natural hazards destroy homes and livelihoods, where do people go? Clark Gray searches for them using data.

Clark Gray
Clark Gray is a population and human-environment geographer who studies human migration when natural disasters strike. (photo by Megan Mendenhall)
August 17th, 2023

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In 2006, Clark Gray was hiking through the Andes mountains, trudging along washed-out roads during Ecuador’s rainy season. After arriving at a small rural community, he found its leader and requested a list of households in the village. Then, he went door-to-door to ask questions and was often answered with an invitation to stay and chat — or even a plate of warm tamales.

At the time, he was a PhD student in UNC-Chapel Hill’s Department of Geography and was conducting his dissertation research on the relationship between environmental changes and rural livelihoods in developing countries — work that has been foundational to his career as a population and human-environment geographer.

In those days, the idea of climate-driven migration was just emerging in the field of  geography. But, over time, as the impacts of climate change have spread across the globe, Gray has dug deeper into this idea.

Climate-driven migration is human movement caused by environmental factors such as droughts, floods, wildfires, or sea-level rise. World Bank’s 2021 Groundswell report details that climate change could cause up to 216 million people to move within or between countries by 2025. Conditions like water scarcity, low crop yields, heat stress, and extreme weather events are likely to displace an increasing number of people from rural and coastal areas to urban areas, according to the report.

This type of migration happens everywhere, including the United States. But people living in the Global South near the equator are disproportionately affected by climate-related migration. That’s where Gray’s focus lies.

Today, most of Gray’s research takes place at a desk, on a computer. It may not sound as exciting as trekking through the Amazon or rural Uganda, but for Gray, the opportunities on the data science side of geography are plentiful — and just as thrilling for his math-oriented brain. He uses massive online databases to address critical topics about the implications of climate change for human life. When people want to know how their health, food supply, or livelihoods might be affected, Gray can point to the data.

“I have these really cool data and tools that allow me to answer big questions people are asking,” he says.

Forging connections

Through his work, Gray has discovered that there are many misconceptions about how climate affects human movement and migration. He has observed a general fear of mass displacement of people from low- to high-income countries, but his findings are not consistent with this concern. In fact, most people move domestically — if at all. These migrants are up against huge economic and legal barriers, so expensive international moves are often unfeasible.

“I worry more about the people who are stuck,” Clark admits.

Additionally, Clark finds it difficult — if not impossible — to separate climate migrants and refugees from the rest of the migrant population because everyone is affected by climate change. One group might flee an area because of extreme heat while another leaves for economic reasons.

It’s all connected, according to Gray. In fact, he and his colleagues avoid the terms “climate migrant” or “climate refugee.” Both groups are part of the same flow of people, following routes that have been carved by generations of migrants before them.

Gray’s research has shown that events like prolonged drought, heavy flooding, sea-level rise, and intensification of natural disasters have all contributed to human displacements. For example, a farmer working in an area that has become subject to drought might move to a bigger city within their country to seek other economic opportunities.

Although the story of climate-driven migration is more nuanced than it appears, Gray’s work is helping to unpack some of the complexities associated with it.

Molding the data

Upon completing field work for his PhD in rural Ecuador, Gray received opportunities to continue his research, including a project in Uganda studying soil degradation and rural livelihoods, and another in Bangladesh investigating population mobility and natural disasters. His research interest was so new that no matter the job, Gray had to collect his own data — or politely ask another researcher for theirs — often working with relatively limited data sets as a result.

But this has changed in the last decade, and Gray can now access publicly available data collected by other researchers.

“It’s possible to do a lot more now than we ever could before,” he says.

Organizations like the U.S. Agency for International Development, the World Bank, and national statistical agencies all have accessible databases that include household surveys and structured interviews. Participants have often reported on income, health, governmental aid, environmental changes, and a host of other human- and geography-related topics.

Gray’s day-to-day work involves managing and analyzing public data by writing thousands of lines of code to organize the information for analysis. He then examines different environmental factors and their potential connection to outcomes like human migration.

Gray’s goal? To draw cause-and-effect relationships by combining survey and environmental data — work that is largely collaborative and involves other researchers from a variety of disciplines.

“It’s like fresh human knowledge just waiting to be unlocked,” he says. “It’s a bit like exploring the wilderness: We can choose where to go, and we don’t know what we’re going to find.”

Data science research like Gray’s is critical for addressing climate change. People want to know how they will be impacted. While the nuances are hard to convey, Gray hopes he can provide clarity and push policy change — work made easier thanks to the incredible support and resources at UNC-Chapel Hill.

He has been a true Tar Heel since the day he was born at UNC Hospitals. Even though he studies human movement, he has found a permanent home on campus and never strayed through his undergraduate years, PhD, and now as a professor in the Department of Geography.

“At UNC, I have always been able to find like-minded scholars who care deeply about the drivers and consequences of environmental change and also about supporting each other,” Gray shares. “It is working with these folks that is the most fun and exciting part of being a faculty member.”

Clark Gray is a professor in the Department of Geography within the UNC College of Arts and Sciences and a fellow within the Carolina Population Center.