Climate change is overwhelming. Not only do trees, parks and open space combat it, restoring native habitat and adding to the tree canopy will help cool our communities and clean our air and water.

In late June of 2021, a heat dome over Portland set three days of consecutive record high temperatures: 108, 112 and 116 degrees. In Oregon, 115 people died from the heat, making it one of the deadliest natural disasters in state history.

As we flock to air-conditioned hotel rooms or coastal towns to beat the heat, one recent study indicates we need to get used to it.

The Northwest could see the average number of 105-degree days increase from 0 to 2 in as little as 15 years.      

Without intervention an increase to an average of five days would be reached by late century, while 90-degree days would increase from roughly six days to 37 days each year in that same period.  

The Union of Concerned Scientists predicts that the number of Americans experiencing 30 or more days of 105 degree or warmer will swell from 900,000 more than 90 million by mid-century, according to The Heat Is On. 

“We always have a chance of extreme heat, particularly in the summer,” Katharine Hayhoe, the chief scientist for the Nature Conservancy, told CNN.“But as the world warms, we see that summer heatwaves are coming earlier, lasting longer, and are becoming hotter and more intense.” 

Climate Justice

There is a growing recognition that climate change is a racial justice problem that impacts low-income communities and people of color. Requiring investments in parks and greenways in their (most often) park-deficient communities.

Nationally, parks that serve majority nonwhite populations are on average half as large — 45 acres to 87 acres — and nearly five times as crowded, as parks that serve majority white populations. 

A Trust for Public Land ranking of parkland in majority black cities, only one of the six cities studied exceeded the national median of 15 percent: New Orleans with 26 percent. The other cities fell far short: Baltimore, 10 percent; Atlanta, 6 percent; Detroit, 6 percent; Memphis, 5 percent; and Baton Rouge, 3 percent.

Portland State University and the Science Museum of Virginia’s recent study discovered urban heat islands correlated with previously red-lined neighborhoods. Red lining was the racially motivated practice of refusing home mortgages or insurance to neighborhoods based on the perception that it wouldn’t be a sound investment if people of color lived there.

Researchers studied 108 cities in the United States and discovered that red-lined communities were the hottest neighborhoods in 94 percent of the cities. Why such disproportionate heat exposure? Lack of greenspace and tree canopy, the study concluded. 

With temperatures rising globally, this disparity means minority, multicultural and lower income populations are at higher risk. The Heat Is On documents how these nonwhite populations are disproportionately affected by heat-related illnesses. 

Emergency room visits for heat illnesses in California jumped 35% - 2005 to 2015, but that jump was steeper for minorities. Black residents saw a 67% percent hospitalization increase, 63% of Latinos. Among white Californians such hospitalizations increased just 27%. Urban heat islands and lack of air conditioning are major factors.

The expense of air conditioning is a growing hardship for low-income people. One study of energy use in eight nations: Canada, France, Japan, the Netherlands,  Spain, Sweden and Switzerland, found people spent 35% to 42% more on electricity when they got air conditioning,  resulting in “energy poverty” for some.

The solution: Healthy vibrant trees, parks and greenspaces!

Trees and their shade, or the tree canopy, helps reduce the heat island effect, or the heat absorbed during the day through dark surfaces of roofs, roads and parking lots that is then radiated at night. 

The net heat island effect is cities cool less at night than surrounding suburban areas and stay hotter during the day, all of which is a significant health risk. More people in the United States die of extreme heat than all other weather events combined, according to How Cities Use Parks to Improve Public Health.    

Mature tree canopy reduces air temperature by about 5 to 10 degrees, according to the University of Washington’s Center for Urban Horticulture. The EPA supports that surfaces in shade can be up to 45 degrees cooler than those directly in the sun, as cited in The Heat Is On.

That cooling effect isn’t limited to parks and greenspaces but expands to neighboring communities. Areas ½ mile away, or a 10-minute walk, can be as much as 6 degrees cooler. This evapotranspiration — when trees pull moisture from soil and release it through leaves — cools air directly.

Plus, trees absorb pollution related to traffic, boilers, generators, and other sources, producing billions of dollars in savings from cleaner air, according to Room to Roam.

Parks and natural areas also absorb water. As sea levels are predicted to rise, our coastal and riverfront communities will be impacted. This absorption is an increasingly important function in terms of climate change. 

Natural areas and parks are a less expensive, more efficient way to manage stormwater runoff than concrete sewers and drainage ditches. 

In Philadelphia, the city’s water department has teamed up with its parks and recreation department to create a $4.5 billion, 25-year Green Cities, Clean Waters program. With the addition of 500 acres of parks and green spaces in underserved neighborhoods, their goal is to capture 85 percent of the city’s stormwater runoff.  

The pervious surfaces in parks and natural areas allow rainwater to soak into the ground, which equates to less stormwater to treat. The trees also store water, reducing water flowing to stormwater treatment facilities, according to 

The Benefits of Parks: Why America Needs More City Parks and Open Space.

Greenspace in urban areas can produce measurable wins.  The US Forest Service calculated that over a 50-year lifetime, one tree generates $31,250 worth of oxygen, provides $62,000 worth of air pollution control, recycles $37,500 worth of water, and controls $31,250 worth of soil erosion.

Loss of wildlife due to ecosystem damage is an additional reality. One Smithsonian study reported the loss of 3 billion birds, since 1970. That’s nearly a third of all birdlife in North America. 

Other studies indicate an “insect apocalypse” — half of all insects on the planet being lost because of pesticide use and habitat destruction. “Parks and protected natural areas are becoming even more important in preventing the worst damages of climate change and are vital to education the public on what will be lost if these conditions continue,” reads Top Trends in Parks and Recreation.

    The National Recreation and Park Association predicts:

·     New parks will need to address extreme heat. In Phoenix Arizona, the temperature topped 100 degrees for 20 weeks in 2020 and hit 110 degrees or higher on 34 days.

·     Cities may look to converting empty mall garages and big-box stores into skateparks, farmers markets, community activity spaces and recreation program areas. 

·     Parks could go subterranean: unused tunnels or other below-ground transportation infrastructure could be transformed into cool new park sites.

·     New Park design will be about greater climate resiliency. “Parks will increasingly be seen as multi-benefit landscapes that protect against flooding, clean and filter stormwater, produce shade and prevent heat island effects, and promote not just environmental resiliency but also social resiliency.”