Build more Green Walls: Get cities to plant a crazy number of trees

urban-forestsVerdant greenery captures more than the eye and enhance more than the beautiful scenery around town. Trees are also good for public health because they absorb harmful pollutants, keeping the air we breathe cleaner. By cooling hot urban neighborhoods during the summer and blunting rainwater runoff, trees bring a multitude of benefits for the environment, climate, and family pocketbook as well. On the other side of the world, the planting of a “Great Green Wall” across the African continent is even bringing different nations together on shared priorities like climate change. As Vox summarizes, a new report concludes that the potential gains for local communities are considerable:

The new Nature Conservancy report sifts through all this research and lays out some global scenarios. At the high end, a massive new tree-planting campaign in the world’s 245 largest cities, costing around $3.2 billion in all, could save between 11,000 and 36,000 lives per year worldwide from lower pollution. Those trees would also prevent between 200 and 700 heat-wave deaths per year — with that number presumably going up over time as global warming unfolds.

That’s not all: Because the trees would cool neighborhoods significantly, many households could end up using less energy for air-conditioning — reducing electricity use by between 0.9 and 4.8 percent in some cities and helping slow the pace of global warming. They can also retain storm water, boost real estate values, and may even have important mental-health benefits. Plus, they’d just look nice.

Given these times, the authority of American cities to plant trees without approval from Congress is especially significant. That’s why local governments should go ahead and do just that: initiate an ambitious tree planting campaign as a matter of bolstering our public health infrastructure. For more information, see “Why planting more trees is one of the best things a hot, polluted city can do,” Vox (2016); also see the proposal “2020 Cities By 2020 Leading On Climate Change” (2016).