To beat the heat, cities must enhance forests: study
By collecting data from satellites and sensors placed on trees, the study measured temperatures across different types of urban green spaces in 12 US cities, including New York. It found that air temperature was cooler in forests than in landscaped trees in more than 90 percent of the sites examined.
New data suggests you should head to the trees to beat the summer heat.
A July report by the Natural Areas Conservancy (NAC) found that urban natural areas — which include forests, wetlands and grasslands — represent the most amazing places in cities across the country. New York City has about 20,000 acres of natural areas, or 11.6% of the city’s land cover.
“What this study shows is the real impact of green spaces on people’s comfort levels during the summer,” said Sarah Charlop Powers, executive director of the NAC.
According to a study by the Environmental Protection Agency, extreme heat is the leading cause of weather-related deaths in the United States. As summer temperatures continue to climb in the face of climate change — July 2023 was the hottest month on record — the NAC study underscores why preserving and expanding our spaces is more important than ever.
“I think the importance of this report is just to highlight that nature can be part of the solution to mitigate the effects of heat,” said Clara Brigitzer, deputy director of conservation science at NAC. Green spaces also provide other benefits beyond just cooling, such as biodiversity benefits, recreation benefits, and mental health benefits, Brigitzer added.
To help compile the report, NAC enlisted partners from the Urban Forest Network, which works to promote healthy forested landscapes in cities. By collecting data from satellites and sensors placed on trees, the network of experts measured land surface and air temperatures across different types of urban green spaces in 12 US cities – including New York.
The results showed that air temperature was cooler in forests than in landscaped trees in more than 90 percent of the 40 sites studied. Healthier forests—which have higher rates of canopy cover and native species—usually perform better than degraded forests that tend to lack these characteristics.
In New York City, NAC collaborated with NYC Parks to collect data from Clove Lakes Park on Staten Island, Seton Falls Park in the Bronx, and Forest Park in Queens.
“We are excited to see the results of the Cooling Cities report, which advances our understanding of the importance of natural areas, and highlights the essential work we are doing to protect and expand these areas,” said NYC Parks Deputy Commissioner for Environment and Ecology. Planning by Jennifer Greenfield.
According to one startling finding, on July 21 in Seton Falls Park, the air temperature on the street was 91 degrees compared to 79 degrees in the woods, a difference of 12 degrees.
Shannon Gordy, NAC’s deputy director of communications and external affairs, noted that while forested areas tend to be the coolest, other green spaces play an important role in mitigating climate change.
“The intent of this report is not to pit green space against green space,” she said. “We know we need all the strategies in our tool belt in order to tackle climate change and extreme heat.”
Cities experience higher temperatures on average due to what is called the “urban heat island effect.” According to a 2022 study by the Joint Research Center, cities can be up to 27 degrees Fahrenheit warmer than nearby rural areas. New York City has the third most intense urban heat island effect in the United States, after Newark, NJ and New Orleans, LA.
NAC members say the findings in this report show that urban natural spaces should be integrated into cities’ climate action plans. The nonprofit is calling on New York City to support Int 1065, which would help the city meet its goal of covering 30 percent of trees by 2035. They are also echoing cries from other environmental groups to allocate one percent of New York City’s budget to the parks department.
According to research by NAC, only 0.7 percent of NYC Parks’ expenditure budget is allocated to caring for forested natural areas, even though they make up 24 percent of the parks.
*Editor’s note: This story has been updated to correct the source of the study referenced here.