When Cleophus Sharp was four years old, his parents rushed him to the hospital in Houston because he couldn’t catch his breath, no matter how much he tried. Sharp, who grew up in the historically Black neighborhood of Pleasantville in Houston, Texas, says he almost died because the air in his community was toxic. Sharp spent two weeks in an oxygen tent before returning home. 

Through his organizing work, Sharp later learned air pollution in his neighborhood likely led to him developing asthma. Pleasantville is bisected by several large freeways, and near an international shipping nexus adjacent with frequent truck traffic. “Those industries that were polluting [were] only three miles from us,” Sharp said.

Cordoned off by two major highways, saddled with industrial chemical manufacturing plants and recycling centers, and situated next to two major trade terminals, Pleasantville ranks in the 99th percentile for national climate vulnerability, according to the U.S. Climate Vulnerability Index, a tool developed by the nonprofit Environmental Defense Fund in partnership with Texas A&M University and a range of community groups like Achieving Community Tasks Successfully, the nonprofit where Sharp serves as a board member. The Climate Vulnerability Index is a first-of-its kind mapping tool that allows users to explore social, environmental, economic, and health conditions of every census tract in the U.S. 

Sharp’s health concerns are shared by many. For decades, residents of Pleasantville have been forced to contend with polluted air and soil, disinvestment in public programs and services, and a lack of empirical data to demonstrate what residents know to be true: Pleasantville’s environmental conditions were making far too many of them sick. 

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“Part of the issue is a nonprofit organization has never had access to these types of resources before to prove that point,” Sharp said. “We only can tell you, ‘so many people died from this, and so many people have this issue.’” He says the mapping index will make a “huge difference” for communities like Pleasantville across the country, helping them point to the source of pollutants and help demonstrate to zoning boards and permitting bodies why additional pollution should not be approved in already-overburdened places. 

Grace Tee Lewis, a senior health scientist at Environmental Defense Fund who championed the idea of the mapping tool, said that the index may help community advocates like Sharp illustrate for elected officials and public agencies the connections between innate threats, like weather, and vulnerabilities through social and economic policies over time. 

“I think that some of these intersections — where climate, environment, and existing inequities have been systematically disenfranchising communities — really have to be at the forefront of the policies that we prioritize to try to break the cycle of disadvantage,” Tee Lewis said. 

The inspiration for the index came from other tools that compile environmental and climate data by neighborhood, like the Environmental Protection Agency’s Environmental Justice Screening and Mapping Tool or CalEnviroScreen, California Communities Environmental Health Screening Tool, Tee Lewis says. But few tools take as comprehensive an approach as the new index, which accounts for elements of public funding and policy that impact both how much a community might be impacted by a disaster — and how difficult it will be for them to recover. For instance, no other tool incorporates environmental data with data of the legacies of racist policies, like the intentional segregation of redlining. Without this kind of data, Tee Lewis worried that people were missing out on funding or interventions that actually matched their needs. Because one of the project’s central goals was to support the work of community organizations, Tee Lewis and her team thought it imperative that they partner with under-resourced places to learn which environmental or social factors should be included. 

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Tee Lewis reached out to community leaders like Sharp, who sits on the board of a Pleasantville-based community empowerment organization called Achieving Community Tasks Successfully (ACTS). Feedback from ACTS and other grassroots organizations helped Tee Lewis and the other researchers understand that it was critical to include not only existing sources of pollution, but also what daily factors might be contributing to environmental vulnerability, Tee Lewis said. For instance, the index tracks the percentage of people living with chronic diseases, who can be particularly susceptible to climate and pollution impacts. 

These conversations broadened what the index would later define as ‘vulnerability’ to include metrics of public transit availability and access, the percentage of children taking medication to treat cognitive behavioral differences, rates of homelessness, or even the number of religious and civic organizations within a community. 

After including these factors into their scoring methodology, researchers found that communities with the highest scores are those with “long-standing environmental justice concerns and health disparities, [and] communities that have had a history of inequity,” Tee Lewis said. 

By toggling or layering different vulnerability factors on the map, like chronic disease and housing vulnerability, users may be able to tell a story through the data that can help illustrate how this historic harm has systemic present-day impacts. For instance, redlining, the practice of discriminatory mortgage lending policies enacted throughout the mid-20th century, is closely related to the climate impacts communities face today, Tee Lewis says.

Sharp’s childhood home in Pleasantville, for example, was one of the only neighborhoods where Black Houstonians were able to purchase homes in the 1940s with cement foundations. His family moved there in part because they could live safely. “They were able to live a comfortable life, and the people came together to build a close knit neighborhood [where] people looked out for each other,” Sharp said. 

a sign reading "Pleasantville, a historic african-american community" in a grassy field with trees in the background
A Pleasantville sign placed in front of a dredge spoil mound in the community. Annie Mulligan / EDF

But racist zoning and policy decisions threatened the burgeoning community. A “Welcome to Pleasantville” sign once stood atop the Ship Channel’s dredge refuse. In 1957, the area flooded, sending toxic sludge across 40 blocks and displacing the sign.  Two major highways constructed in 1958 and 1974 added significant air pollution. In 1995, a chemical warehouse owned by Houston Distribution Inc. caught fire three times. Legislators recently decided to widen and deepen the Houston Ship Channel. Some local residents are fighting the decision, as it would require the Army Corps of Engineers to excavate potentially toxic bayou sediment that would then be placed in containment zones almost exclusively located in environmental justice communities, like Pleasantville. If this project were approved, the existing dredge pile would double in size.

For too long, it’s been hard for decision-makers to see information about how environmental injustice, racial discrimination, and climate change are interconnected, says risk analysis expert Weihsueh Chiu, a professor at Texas A&M University, who worked with Tee Lewis to develop the index. 

The index can help draw attention to climate risks that might otherwise have gone under the radar, like English fluency, considering that the Federal Emergency Management Agency is notoriously underprepared to assist Spanish-speaking survivors of environmental disasters. “This tool allows you to kind of both zoom in and zoom out,” Chiu said. Some places, like Vermont, for instance, may initially seem to have fewer risks, but the tool may help draw attention to clusters of chronic disease amid an otherwise healthy — or at least perceived to be — state. 

Chiu hopes this is just the first step, and in future the team plans to continue to add to the conditions that users can explore, such as proximity to warehouses. There isn’t a national inventory of warehouse locations, and Chiu has been relying on Google Earth images to locate warehouses in individual communities, such as Will County, Illinois, where warehouses have been springing up like mushrooms due to its location at the intersection of two large interstate highways used for shipping. In some cases, volunteers have driven out to some of these sites to confirm that the warehouses indeed exist. 

Going forward, the team will continue to add to and edit the tool as needed. But already, the index has the opportunity to close the gap between the lived experiences of community members and environmental policy enacted in the legislature. “That was the legwork that we were trying to do as a service to communities, especially disadvantaged communities,” Chiu said. 

In a different way, Sharp hopes that the index will serve as a mirror for residents who are affected by pollution, so that they won’t get caught thinking that health issues are inevitable. “People have lupus, they have upper respiratory problems, and they just think people dying from cancer is normal. They don’t realize that the cancers are from some of the stuff in the air that they’ve been breathing for years.”


One of the world’s leading international nonprofit organizations, Environmental Defense Fund (EDF) creates transformational solutions to the most serious environmental problems. To do so, EDF links science, economics, law, and innovative private-sector partnerships. With more than 3 million members and offices in the United States, China, Mexico, Indonesia, and the European Union, EDF’s scientists, economists, attorneys and policy experts are working in 28 countries to turn solutions into action.


Grist’s editorial team has covered the Climate Vulnerability Index previously. This article is sponsored content from EDF and is not connected to Grist’s previous coverage. Sponsors play no role in Grist’s editorial coverage.