Max Jordan Nguemeni Tiako is a resident physician at Brigham and Women’s Hospital in Boston. Eugenia C. South is a physician-scientist at the Perelman School of Medicine at the University of Pennsylvania, where she is the faculty director of the Urban Health Lab.

As physician-scientists who conduct research on the impact of urban environments on health and safety, we are troubled by the casual disparagement of the Biden administration’s proposal to plant trees in communities that lack them. The overall mocking tone of some criticisms of “tree equity” would be easy to ignore if our surroundings, generally, and trees, specifically, did not have a profound influence on our physical, mental and social health. But they indisputably do.

Equally indisputable is the fact that trees are not evenly distributed across communities. Formerly redlined Black neighborhoods have the least amount of green space today, while predominantly White neighborhoods have seen an increase in tree canopy cover.

We all have a right to benefit from trees, and numerous studies have demonstrated their value in addressing health disparities across the country.

Take, for example, the leading cause of death in the United States — heart disease. Living in a green neighborhood is associated with lower rates of heart attacks, high blood pressure and diabetes in older adults. A 2015 study estimated that living on a city block with at least 11 trees decreased the risk of heart-related conditions in ways similar to increasing an individual’s income by $20,000 or being 1.4 years younger. Our own research this year showed that lack of tree canopy cover in urban neighborhoods is associated with higher risk of hypertensive disorders of pregnancy, a leading cause of maternal morbidity and mortality.

Trees also help people feel happier, enhance well-being and improve mental health. In a randomized controlled trial, our team found that people living near newly greened spaces reported feeling less depressed than those who did not. Other studies show that people walking in green spaces show a decrease in blood flow to the part of the brain that fuels negative thoughts. People even write happier social media postings after spending time in a park.

Many may view nature as having primarily a decorative, beautifying role. But this beautification itself, the visual experience of nature, directly influences our body chemistry. One example of this is the experience of stress, which can be a toxic antecedent to many health problems. Our team found that people who walked by a recently greened lot with new trees had a significant drop in their heart rate compared with people walking past vacant spaces, a marker of real-time stress reduction. We’ve also demonstrated a decrease in prenatal stress among pregnant people with depression and anxiety based on the number of trees near their house. And trees help people feel more connected to one another, which is an underappreciated boon to health.

Public safety is also impacted by trees. Well-controlled studies have found that drivers pay closer attention and are less stressed when driving on highways with trees compared with barren landscapes. In Philadelphia, our lab’s work has shown that greening leads to reductions in violent crime and improvements in how safe people feel. Also in Philadelphia, research has found a correlation between more trees and fewer incidents of gun assaults among adolescents.

Trees are well known for filtering pollutants and thus improving air quality, which is linked to a range of health benefits. In hotter months, their shade significantly reduces ambient temperature; a study of 108 U.S. cities found that the difference in temperature between the hottest and the coolest neighborhoods was as great as 13 degrees Fahrenheit, much of it attributable to uneven distribution in the tree canopy. Extreme heat not only sends people to the emergency room for heat stroke — it also exacerbates chronic diseases such as renal disease, with increased rates of acute kidney injury during hotter months.

All these beneficial effects of trees are disproportionately lacking in poorer neighborhoods across the country. Unfortunately, the history of state disinvestment has rendered some residents in neglected neighborhoods skeptical of more recent tree-planting initiatives, seeing them as “disruptive green landscapes” that cities too often use for branding and attracting developers.

Elected officials must address these concerns by implementing policies to prevent disruptive gentrification, while guiding tree-planting to communities with the highest need.

Trees are not nice-to-have amenities, reserved for people and communities that have benefited from long-standing public and private investment. And the $3 billion proposed for tree equity is not a frivolous investment. Rather, trees are a vital part of neighborhood infrastructure. The Build Back Better plan to fund tree planting is an important step that would undoubtedly make us all safer and healthier.