The link between racist housing policies of the past and the climate risks of today

For decades beginning in the 1930s, the federal government encouraged mortgage lenders to deny housing loans to people living in predominantly Black neighborhoods. These practices and policies, collectively known as redlining, reinforced segregation and worsened inequality.

Groundwork USA, a network of environmental justice organizations, is exploring the connection between formerly redlined neighborhoods and the climate crisis today. As part of its Climate Safe Neighborhoods initiative, Groundwork overlaid historic redlining maps from nine U.S. cities with data about tree cover, heat, and impervious surfaces such as asphalt and concrete.

Fewer trees and more paved surfaces put communities at higher risk from heat waves and extreme storms, which are growing more frequent with climate change. Neighborhoods with few trees and vast stretches of pavement are hotter, research shows. And with less vegetation to soak up water and more paved surfaces, these neighborhoods are more likely to flood.

Yale Climate Connections spoke with Cate Mingoya, director of capacity building at Groundwork USA, about what the mapping data reveals and how the group is helping local residents respond.

This interview has been edited and condensed for clarity.

Yale Climate Connections: How have redlining and other racist housing policies affected climate risk?

Cate Mingoya: Redlining, while it did not create segregation, codified practices of segregation and created economic disincentives for people to invest in those neighborhoods that were formerly redlined.

That means that a city, which relies heavily on property taxes, is not going to be funneling resources – things like parks, things like trees, things like improved sewer infrastructure – into those neighborhoods that are considered “declined” or “declining,” which was the designation of those redlined neighborhoods. And so now, 90-plus years later, we’re still seeing that those areas that were formerly redlined are hotter, are wetter, and have poorer air quality.

Research by Jeremy Hoffman and Vivek Shandas shows the degree to which that’s the case – that on average, it’s about 4.7 degrees Fahrenheit hotter in the same city, on the same day, between neighborhoods that are redlined and [non-redlined areas]. But that can be as an extreme as [almost] 20 degrees Fahrenheit. That’s the difference between turning on your air conditioner and not. That’s the difference between a $150 bill and a $250 bill at the end of July for your electricity. And that’s the difference between spending some time hanging out on the front porch with your family in the summer and ending up in the hospital for heat stroke, or for an exacerbated condition, like asthma, for example.

YCC: What’s it like for residents to see this on the mapping tool? What are the responses?

Cate Mingoya: One of the things that has been really surprising to me is how much these maps can be used as a neutral platform for conversations about equity. For example, in Richmond, Virginia, we’ll chat with residents and they say, “Yeah, we knew this neighborhood was redlined. We know from our lived experience that this neighborhood is a lot hotter.” But they appreciate getting to have these concrete tools to sit down with their local government, with elected officials, with leaders in their community and say, “You need to explain why this is still the case. And you need to explain what you’re going to do to make things look a little bit different.”

And we also find that it is a really great platform for conversations with people who are skeptical about the climate crisis, who say, “Well, I don’t know if that’s a concern in our community.” But when they sit down and see a 15-degree disparity between one neighborhood and another, it helps them to think “Gosh, my lived experience in my neighborhood – it might be a lot different from someone who was formerly redlined.”

Once you see these maps, you can’t unsee them. Once you see the historical damage, you can’t unsee it. So these maps serve as a great platform for conversations about equity in a way that I did not expect.

YCC: With this knowledge and information, how are you working to reduce these disparities?

Cate Mingoya: In all of the nine cities that are part of our Climate Safe Neighborhoods partnership, we are looking at short-term mitigation measures – so things like getting trees installed and getting air conditioning to residents who maybe don’t have it and are suffering from the urban heat island effect.

But really importantly, we’re also working on building resident capacity so that they can self-advocate. That’s doing things like figuring out, “How does our governance structure work? What is the master planning process, and what’s the opportunity for me as a resident to intervene with my needs? How is the money that the city collects and redistributes for things like parks and trees and green spaces – how does that get distributed?”

One of the things that you can’t do to reduce these disparities is think you can plop a bunch of trees in, or plop some green infrastructure in, and call it a day. Our neighborhoods don’t look like this by accident, so they’re not going to change by accident. And one of the most important things that we can do is not just make interventions to cool and dry our neighborhoods, but also make sure that residents have a built capacity to intervene in the way that these resources are distributed so that they can be more equitably distributed.

We’ve worked really closely with the residents to identify the exact street corners and what type of green infrastructure they’d like to see in those places. So sometimes it’s trees, sometimes it’s the installation of rain barrels. In some cases, it’s asking for small parklets. In some cases, it’s asking to rip up pavement on underutilized properties and have the ability of that water to sink into the ground instead of just pooling and flooding out into the street. In some cases, it’s downspout planters. But it’s really specific to what the community members and what the neighborhood wants to see. And that’s really important in creating long-term stewardship. And then again in righting that long-term harm, having residents be in the driver’s seat around decision-making in their community when so often residents are completely left out of the car.

One of my favorite examples comes from the Globeville neighborhood in Denver, which is a Superfund site and used to be the home of a lead-smelting plant. The residents from the Globeville neighborhood were sitting with a mapping portal and were looking at tree canopy cover. And one of the residents noticed that the tree canopy cover in their neighborhood was 1%. But if you were to take a bus ride [to another area just across the river], the tree canopy cover there was over 23%. That’s a huge difference – 1% tree canopy cover to 23%. Imagine what the air quality difference is like, what the shade is like, or even just what the beauty is like of having a really nice dense tree canopy. So that allowed residents to come together with a really concrete ask. They wanted the city to use [tax revenue set aside for climate mitigation measures or creation of green space] to plant trees in the public right of way.

YCC: How can your work be used as a model for other communities?

Cate Mingoya: One of the things that I think works so well about this partnership is that I believe it can be done in almost every city, because the data and the information and the maps are relatively easy to put together with open-source data and serve as a really great platform for conversations about the future. And I think that there’s sort of a three-part structure that communities can take.

One is using the maps to understand a community’s history, because without a really clear understanding of the harms that have happened in the past, you can’t have a vision for the future and for how you’re going to repair that harm.

The next piece is working with residents to understand their priorities and what they would like to see change in their community, because the things that are pointed out on the map might not necessarily be the things that residents prioritize the most and want to see change. So it’s very important to put residents in the driver’s seat, have them lead the conversation, and then act as an organizing force to get their ideas and their priorities into one place.

And then the final piece is to build resident capacity by educating them on how these political processes work. It can be really confusing. Why do you have a mayor and a city council? Whose job is what? When does the budget get decided? And who writes the first draft? What are the opportunities for intervention in the systems and where should residents have a seat at the table where they don’t? And in working to build that resident capacity, residents are not only able to advocate for the implementation of mitigation measures in their community, but they’re able to start applying the same framework to whatever the other challenges are facing their community.

YCC: Looking forward, what do you see looking into the future and the trajectory as this work progresses?

Cate Mingoya: In these neighborhoods that are most vulnerable, we want to see not just a change in the built environment, not just the installation of green infrastructure, but also a real systemic change in how residents are included in decision-making around the issues that matter to them most. Where are there places where there should be seats at the table for residents where there aren’t, and how can we bring a chair to that table and make sure that residents stay? So we’re going to continue to do that work in all of our cities. And then our hope is to create a framework so that other cities that do not have a Groundwork trust, who are interested in this type of capacity building, interested in this type of systems change, can apply the framework and the methods that we’ve put together into their spaces. This is a model that’s worked really well in our communities, and we believe it can work across the country even without the Groundwork presence. So over the next couple years, we’re going to be refining tools and resources so that we can get that into the hands of other community members that want to see change happen where they live.