The critical role trees play during heatwaves

Mmy two year old is too young to know about climate change. He also doesn’t understand what an “urban heat island” is. All he knows is that his dad keeps saying “No” because it’s too hot to go to our local park in Point Breeze in South Philadelphia, which doesn’t have the shady tree cover found in other neighborhoods. As we walk home, he is completely melted, pointing over my shoulder and repeating “Pah! Pah!” In that plaintive voice that breaks my heart, the father and environmentalist in me cares deeply about the extreme heat and how it will affect my son’s generation.

You may have never heard the term “urban heat island,” but you can probably guess what it means – especially if you live in a city. Modern cities have become concrete jungles with buildings, roads and other infrastructure that absorb and retain heat; When these urban areas “lack nature,” such as trees and green spaces, residents cannot benefit from shade from trees and evapotranspiration, the process by which plants release water vapor that cools the air, lowering temperatures. Extreme heat caused by climate change exacerbates this problem, turning it into a public health crisis.

See more information: The silent work that trees do for the planet

But how much of a difference do trees make? Studies show that the temperature in urban areas can differ 12-18°F between the hottest and coldest neighborhoods– and much of this variation is due to differences in tree cover and green spaces. As heat waves become more frequent and intense, an increase of 18° could be the difference between life and death. Heat-related illnesses, such as heatstroke and dehydration, pose a serious threat to vulnerable populations, such as the elderly and people with underlying health conditions. In 2023 alone, exposure to extreme heat was responsible for more than 2,300 deaths in the US, the highest in half a century.

Dig deeper into this growing public health crisis and you will also find an environmental justice crisis, with the haves and have-nots divided along family lines. Predominantly white and wealthy neighborhoods tend to have more trees, while historically marginalized and underserved communities have more trees. significantly less. This disparity exacerbates inequalities in health outcomes, with worse air quality and greater vulnerability to heat in areas with fewer trees. It also means higher energy costsimposing another financial burden on already cash-strapped communities, as well as higher rates of violent crimeas higher temperatures can increase the incidence of aggression and irritability.

Climate impacts have always disproportionately impacted minority populations, from Black and brown communities that lack sufficient infrastructure and insurance to deal with increasingly frequent and extreme storms, to Indian tribes that depend on fish stocks threatened by ocean acidification. However, extreme heat exposure is one of the most immediate and deadly impacts of climate change, and once again, communities of color are bearing the brunt. In Philadelphia and elsewhere, this 18° difference between neighborhoods may be linked to Red line, which systematically denied services and investment to neighborhoods predominantly inhabited by racial minorities, leaving these areas with inadequate green spaces.

Nature can be our ally in helping people adapt to an increasingly inhospitable climate. We need to rethink the way we develop our cities and the built environment. It’s not just about planting more trees; it’s about integrating nature-based solutions into our urban planning. This includes some obvious steps, like creating more parks and community gardens, but also includes innovative methods like green roofs and walls. These structures, partially or fully covered by vegetation, help filter pollutants, improve insulation, reduce energy costs, absorb rainwater to reduce runoff and increase biodiversity in urban areas.

Local initiatives, such as Philadelphia Beat the Heat Campaign and the Philadelphia Tree Planwhich received US$12 million in federal funding for urban forestry, aim to increase tree cover in areas that need it most. Other cities, such as Miami-Dade, have named Warming Directors implement strategies such as increasing tree canopy, creating cool roofs and developing public awareness campaigns about the dangers of extreme heat. By learning from and scaling up these initiatives, we can create healthier, more resilient and more equitable cities.

We also need to extend protection to people who put their lives at risk in the scorching heat to keep our economy running. Those who work in construction or on farms— two professions disproportionately made up of people of color — are many times more likely to die from heat-related illnesses than the average person. Providing basic improvements like paid rest breaks and more access to water and shade would be a huge benefit to these essential workers, but just a few months ago, Florida Governor Ron DeSantis signed a law which prevents cities and counties from doing just that. My message to our elected leaders is simple: a little more empathy – and a lot more trees – can save lives.

Finally, community involvement in planning and implementation is essential, not only because it is the fairest thing to do, but because it increases the chances that solutions will be effective and stand the test of time. A to study conducted last year by some of my colleagues at the World Wildlife Fund (WWF) found that conservation efforts that incorporate the views and values ​​of local communities result in better outcomes – for people and nature. When we take time to build trust, recognize communities’ personal interest in the issues we are working to address, and leverage their wisdom to ensure these initiatives stand the test of time, we plant the seeds for lasting, large-scale change. change that benefits everyone.

A few nights ago, just before putting my son to bed, we read a children’s book about the life of Wangari Maathai and how she inspired the women of Kenya to plant more than 30 million trees to protect their communities. The first African woman to win the Nobel Peace Prize, Wangari encouraged us to to start planting 10 trees each and getting involved in local initiatives that help our communities. We can address urban heat islands that disproportionately impact people of color. Our neighborhood park doesn’t have to be hotter, dirtier and deadlier than one just a few neighborhoods away.

By investing in green spaces and planting more trees, we help build a future where healthy, happy children, from all walks of life, can enjoy the simple joy of playing in the park.