Emerging Disease Threats in Wildland-Urban Interface

Researchers at YSE found that rapid urbanization could create new opportunities for the spillover of zoonotic diseases, especially in the Global South.

In the next 25 years, the population in urban areas is expected to increase by 2.5 billion, with 90% of that growth predicted in Africa and Asia. 

“The trifecta of urban expansion into wildlands, increased connectivity of people worldwide, and urban growth in places with high pathogens will pose significant disease spillover risks that we are just starting to understand,” says Karen Seto, the Frederick C. Hixon Professor of Geography and Urbanization Science, who co-authored a study published in Global Change Biology.

The study is the first to look at how rapid urbanization in the wildland-urban interface (WUI), areas of land across the globe where wildlife, livestock, and humans closely reside, could influence the likelihood of disease spillover. Yale researchers mapped the distribution of almost 700 mammals associated with more than 100 different diseases across the WUI. These areas, the researchers say, could provide prime habitat for the transmission of zoonotic diseases from their wildlife hosts. The risk is particularly high in the Global South, where a diverse array of potential hosts and rapid, informal growth could leave people especially vulnerable.

“The wildland-urban interface is the perfect place for diseases to emerge because you have people, livestock, and wildlife in these tightly intermixed land use arrangements,” says Rohan Simkin, a PhD candidate who led the study. “But there’s plenty of opportunity as cities grow — and this is particularly true in places like Africa and Asia where cities are going to grow rapidly over the next 20 or 30 years — to design cities that avoid a lot of these impacts.”

Greening the Graphite Supply Chain

Graphite plays a central role in clean energy technologies, from low-carbon steelmaking to energy storage in batteries, but the U.S. has no active graphite mines and is reliant on imports to meet demand. YSE scientists are evaluating the impacts of U.S. production of a climate-friendly alternative — green graphite, which is produced from waste biomass and plastics.

The research team, led by Barbara Reck, senior research scientist at the Center for Industrial Ecology, and Gerald Torres, the Dolores Huerta and Wilma Mankiller Professor of Environmental Justice, is exploring key questions related to the scaling of a domestic green graphite supply chain, including environmental justice issues such as location of production plants. The team is working to develop a set of environmental justice metrics that can serve as a blueprint for other clean energy technologies. The metrics will help identify the best locations for new graphite plants while also providing guidance on maximizing community input and engagement.

The research is funded by the Therese Gonzalez Pilot Projects Fund, which competitively awards grants for interdisciplinary initiatives. The team includes senior lecturer Robert Klee ’99 MES, ’04 JD, ’05 PhD; Yuan Yao, associate professor of industrial ecology and sustainable systems; and Michel Gelobter, executive director of the Yale Center for Environmental Justice.

Mapping Attitudes About Sea-Level Rise

By 2100, sea-level rise will impact millions of people in coastal communities, but a study in Nature Sustainability, co-authored by Yale Program on Climate Change Communication senior research scientist Jennifer Marlon, found that Americans living in coastal regions view rising seas as a problem primarily in other communities. This lack of concern held true even when residents viewed maps projecting their property to be underwater by the end of this century.

The researchers studied residents living in coastal areas projected to flood by 2100: San Francisco Bay Area in California; Palm Beach County, Florida; Norfolk, Virginia; and Ocean County, New Jersey. When residents in these areas were shown maps of flooding projections, it reduced concern about their properties. However, when infrastructure disruptions such as increased commute times were relayed to the coastal residents, it increased their concern about flooding.

“Overall, our results speak to the critical need to empirically test public climate communication campaigns to ensure that targeted interventions encourage risk perceptions and behavioral intentions in support of climate adaptation policies,” the authors note.

Reducing Uncertainty in Soil Carbon Markets

Natural carbon solutions, which include managing croplands to store more soil carbon, are key to addressing the climate crisis, according to the Intergovernmental Panel on Climate Change (IPCC), but figuring out how best to measure whether these methods are having an impact has been challenging.

Soil organic carbon accounting and crediting primarily uses measure-and-model approaches, relying on predictive models informed by small field trials and limited direct measurement. A study in Environmental Research Letters found that a “measure and remeasure” approach provides hard evidence of carbon storage, boosting confidence in cropland carbon markets.

“If you can address the measurement and verification concerns around how soil carbon stocks are responding, it will help prioritize policies and investments that achieve soil restoration and protection, leading to improved water and nutrient retention in soils and resilience to extreme weather,” says study co-author Mark Bradford, the E.H. Harriman Professor of Soils and Ecosystem Ecology, who was involved in the work through the Yale Applied Science Synthesis Program, an initiative of the Yale Center for Natural Carbon Capture and The Forest School at YSE.

Human Activity Contributes to Half of Methane Emissions From Inland Waters

Although methane persists in the atmosphere for only about a decade, it is 80 times more powerful than carbon dioxide over 20 years, and its concentration is rising faster than any major greenhouse gas. One of the largest sources of methane emissions is inland waters, with half of those emissions stemming from human activities.

Peter Raymond, the Oastler Professor of Biogeochemistry, led a team of international experts in an effort to quantify inland water methane emissions. He says reservoir and farm pond construction and eutrophication due to nutrient pollution are the main anthropogenic sources of methane emissions from waterways.

“That the concentration of methane is going up much faster than it was eight years ago is a surprise to everyone. Obviously, it’s going in the wrong direction,” Raymond says. “But there are a lot of potential ways we can improve processes to reduce emissions.”

Combating eutrophication by decreasing nutrient pollution in freshwater lakes, reservoirs, and rivers can help reduce inland water emissions, he adds.