Trees Need To Be In Our Future, Too

Look, trees take a very long time to grow. Years, decades, some take centuries to grow to their full height. However, trees planted today might not even reach their full growth because a lot of things are trying to kill them, from lumber companies, to housing projects, to cars belching pollution, and to human waste:

American cities are host to 3.8 billion trees—on sidewalks, in parks, in our front yards and backyards, outside houses of worship and office complexes. They’re crucial for urban life: Most notably, trees cool down cities by creating shade and engaging in transpiration, the process by which they return water vapor into the atmosphere. Together, these effects can lower the temperature of a city street a few degrees (and as much as 10 degrees, as one recent study found). Studies have also found that well-placed trees can reduce air-conditioning costs by about one-third. Trees also remove up to 24 percent of dust; studies show that kids who live near urban trees have lower rates of asthma. Trees can even make pavement last a decade longer.

If cities want to keep those benefits, they’ve got to plan

for a future with a different, more hostile climate. As cities heat up, they effectively become different places, where a species that has persisted for hundreds of years can no longer thrive. By some estimates, the habitable zones for 130 of the country’s tree species could move north by more than 400 miles by the end of the century. New invasive species will arrive. Unless cities continually adapt, these shifts could significantly erode their tree canopies, making urban landscapes uglier—and more unlivable.