JAZMIN CASTELLÓN STANDS on Congress Street in Chelsea overlooking a new park, with a pavilion and scattered chairs, beside a flat open area where more trees could potentially be planted. It’s a park she has spent years helping to shape, and when it opens to the public this summer, it will provide shade and relief from the heat for local residents. Along its edges, young trees line the sidewalks every few feet, many just four- or five-years-old. Castellón is the climate justice organizer at GreenRoots, a community-based advocacy group, and in her eyes, those trees are crucial infrastructure: a frontline defense against extreme heat.

This type of work is especially urgent in Chelsea, which is one of the hottest cities in Massachusetts. Densely populated, it’s home to many low-income and immigrant residents who face disproportionate exposure to extreme heat. Blocks of triple-deckers and apartment buildings leave little room for trees. Pavement, asphalt, and rooftops absorb sunlight during the day and release it slowly at night, trapping heat long after sunset.

Many of the trees in Bear Park were planted thanks to the TreeKeeper program, an initiative Castellón has helped build since 2024. The program trains local residents to care for and expand Chelsea’s urban tree canopy, and has grown into a network of about 80 volunteers maintaining over 200 trees. In neighborhoods where shade is scarce and heat accumulates quickly, the effort has become a critical tool for cooling streets block by block.

The TreeKeeper program was funded, in part, by a $500,000 Environmental Justice Collaborative Problem-Solving grant through the EPA that was rescinded after President Trump took office in 2025 and federal agencies slashed funding for programs targeting vulnerable populations. As a result, the broader TreeKeeper program had to scale back by roughly half, significantly reducing its staffing, maintenance, and long-term tree care capacity. The cuts suspended a planned expansion into Everett and Malden alongside core local tree-planting, heat resilience, and community education in Chelsea.

The state recently awarded GreenRoots a $25,000 Environmental Justice Fund grant, part of which will support the organization’s TreeKeeper stewardship program. But the program’s future beyond next spring remains uncertain. “We are currently working with the city to figure out how to keep the 200-plus trees that we planted in the last year alive,” Castellón said.

The loss of a single grant rarely affects just one project.

In Chelsea and neighboring communities along the Mystic River, advocates say federal funding cuts ripple outward, slowing climate resilience work and straining the network of grassroots organizations working to protect residents from flooding and extreme heat. Other work mapping heat hotspots, expanding the tree canopy in other areas, installing shade structures, and improving access to cooling resources through other programs have also been suspended.

The funding cuts are significant for residents most vulnerable to extreme heat: older adults, young children, and people with chronic health conditions, many of whom have limited access to cooling resources.

The loss of funds has disrupted a broader network of heat-related initiatives across Massachusetts, many supported through EPA environmental justice grants. Across Chelsea, Everett, Malden, and Boston, these cuts have halted heat resilience planning, urban forestry expansion, indoor heat safety outreach, and multilingual education programs, and cooling interventions such as shaded bus stop shelters, neighborhood water fountain installations, and residential upgrades that include installing light-colored “cool roofs” that can significantly reduce heat absorption.

Asked for comment, an EPA spokesperson did not respond specifically to questions about the TreeKeeper program, but said in an email that “we fully understand that ensuring clean land, air, and water for all Americans requires us to spend precious taxpayer dollars wisely.” The email also criticized the Biden administration for implementing a “radical agenda of wasteful DEI programs and ‘environmental justice’ priorities on the EPA’s core mission.”

For Castellón and GreenRoots, this is not the first time federal policy shifts have disrupted heat-related work.

During the first Trump administration, the EPA rolled back environmental justice funding and froze several existing grants, forcing GreenRoots to pause a planned citywide tree-planting and heat relief outreach campaign that had been years in the making. That instability prompted the organization to diversify their funding streams. They accept donations from individuals, apply for foundation grants, and advocate for state money in addition to relying on federal funding. That has helped sustain core operations and allowed GreenRoots to continue its heat resilience efforts.

“The funding loss doesn’t just stop one program. It disrupts the whole network of collaboration we’re building for heat resilience and environmental justice.”

Jazmin Castellón, climate justice organizer at Greenroots

Rafael Enamorado has watched the summers grow hotter and the tree-lined streets go bare in his 45 years as a resident of Chelsea. At home, a window air conditioning unit offers some relief, but it is outside where the change in climate is most felt. The loss of trees troubles him. “We need trees around for the environment, for the oxygen,” he said.

His home, like most in the region, was built to withstand difficult winters and prevent freezing but not overheating. State codes require landlords to maintain minimum indoor temperatures during winter months. No comparable standard exists for dangerously high indoor temperatures in summer. As climate change makes heat waves longer and more frequent, that gap leaves many renters exposed to conditions that public health researchers increasingly describe as life-threatening.

“People feel heat,” explained Nasser Brahim, the director of Climate Resilience at the Mystic River Watershed Association. “The challenge is that our infrastructure and policies were built for a cold climate, not a hot one.” Extreme heat is one of the leading weather-related causes of death in the United States, according to the Centers for Disease Control and Prevention.

Yet, heat risk is not evenly distributed. Older buildings without insulation, top-floor apartments beneath dark roofs, and densely paved neighborhoods can trap heat and raise inside temperatures to dangerous levels. For households already struggling with energy costs, running an air conditioner can mean sacrificing other essentials.

“People who are low-income … and people of color are more likely to be impacted by extreme heat and have the least access to resources to adapt.”

Nasser Brahim, director of Climate Resilience at the Mystic River Watershed Association

Research shows that in urban environments tree canopy can reduce neighborhood temperatures by several degrees, while reflective surfaces and shaded infrastructure lower ambient heat and reduce energy demand.

For Castellón, the intersection of environmental hazards and extreme heat is not theoretical — it’s borne out in places like the neighborhood near the Tobin Bridge where residents have been warned not to open their windows because the aging structure is shedding toxic lead paint dust. That leaves families with few options on sweltering summer days. Keeping windows shut traps heat indoors; opening them risks exposure to contaminated air.

“They’ve been told that they shouldn’t open their windows for the next four years. But how are you going to ask people to do that when it’s going to be super hot outside?” Castellón said.

A 40-point gap in shade coverage

Chelsea sits in the Mystic River Watershed, where white neighborhoods have up to 14 times more tree canopy than BIPOC neighborhoods, a disparity rooted in decades of disinvestment that still shapes who gets shade.

That 40-point gap means BIPOC neighborhoods run nearly 4°F hotter on average, with far greater health risk during heat waves.

Source: Wicked Hot Mystic Research, Mystic River Watershed Association (2022)

That’s why, she said, GreenRoots’s work has to continue even without federal funding and local advocates are rethinking how to sustain it in the long-run.

GreenRoots host community meetings, typically drawing 50 to 60 residents, and distribute surveys to gather input from residents to understand what programs they value and what gaps remain. This helps the organization decide where to focus its limited resources. Even as federal funding shrinks, the goal remains the same: to continue channeling whatever funding they can secure, whether from foundations or smaller grants, into programs that reflect what residents actually need.

“The people who live here are the experts,” Castellón said. “They know what works in their daily lives.”

At the same time, the Mystic River Watershed Association continues to work on building cooling infrastructure. Brahim and his colleagues spent the winter months walking Chelsea’s streets with municipal tree wardens, noting empty sidewalk pits and corners where trees once stood. Back in the office, they layered heat maps with demographic data, tracing the overlap between the hottest streets and the residents most vulnerable to extreme heat.

“We think about where a tree would make the biggest difference,” Brahim explained, “where shade might fall over a grandparent watching a game, a parent pushing a stroller, or a teenager resting after practice.”

Once the community plans are set, the work will move from paper to the street. Crews will still cut into sidewalks – though at a slower pace because of the budget cuts – to create space for tree roots, while volunteers go door to door, talking with residents about how trees cool neighborhoods and cut energy use. The mission won’t change: plant trees, help them survive, and turn exposed, hot sidewalks into shaded, livable streets. But without the federal grant, the projects will move slower and reach fewer neighborhoods. For now, every bus stop shade structure and every newly planted tree still matters, but Nasser says these small wins are no substitute for the large-scale investment vulnerable communities desperately need.

As summers grow hotter, the policy landscape is shifting. The question is no longer whether heat poses a risk, but how quickly cities built for winter can adapt to a hotter reality. How a city prepares for protection may determine who stays safe, but as of now, the heat will arrive whether systems are ready or not.

“These federal cuts have been devastating for our ability to do this work at the scale needed, devastating for our community-based partners, devastating for municipalities, and devastating for the residents and workers who would benefit from these investments,” Brahim said. “Every project matters — but it’s nowhere near what these communities truly need.”

This was a multimedia reporting project of the Media Innovation Studio at Northeastern University’s School of Journalism. The reporting team for this story was Lin Chen, Jeta Perjuci, and Yaron Porat-Gibsh, working with journalism professor Dan Zedek.