According to a new study by the National Forest Service, it’s not just the untamed reaches of the U.S. that we need to protect. Because city footprints are expanding at a rapid rate, we need to both plan and protect forests in urban areas, too.
The crux of the study is that U.S. urban footprints are going to almost double over the next 40 years, from 95.5 million acres of land in 2010 to 163 million acres of land in 2060. That would equate to a block of concrete the size of Montana if urban planners aren’t careful about protecting tree-filled green space. And so far, many aren’t: Over the past five years, urban green cover has declined while “impervious” cover (or surfaces that don’t absorb rainwater) have increased.
There are clear, objective reasons cities should protect their trees and plant new ones. Trees are good for air quality and, in turn, good for respiratory health. They reduce urban island heat effects, reduce energy usage, capture water to prevent flooding, improve brain development, and measurably decrease human stress.
The National Forest Service estimates that there are 5.5 billion trees in our urban forests today, and, crucially, the authors of the study provide quantitative numbers on their value. These trees provide huge monetary benefits to society: $18 billion in pollution removal, $5 billion in energy efficiency, $5 billion in carbon sequestration, and almost $3 billion in avoided emissions.
By quantifying the tangible benefits of these trees, the authors of the paper are hoping to make the case for doing more to protect existing green–and set aside space for new forests–as American cities continue to boom. While we tend to think of national parks and national forests as nature worth protecting, we should think of the forests in urban areas as worth fighting for, too. “The urban expansion along with the values associated with urban forests indicate that urbanization and urban forests are likely to be one of the most important forest influences and influential forests of the 21st century,” write the authors David Nowak and Eric Greenfield.
So which areas are most at risk? The areas with the greatest projected increase in city expansion (by percent) are all on the East Coast, led by states including Rhode Island, Delaware, and Connecticut. But in terms of overall land mass, California, Texas, and Florida are likely to hand over the most acreage to urban development–22 million acres between those three states alone.
That’s right. Our lives are in the hands of California, Texas, and Florida. What could possibly go wrong?