The Planting Healthy Air report documents which cities stand to benefit most from tree plantings, in terms of both heat and PM reduction, and how much investment would be required to achieve meaningful benefits.
The analysis found that investing just US$4 per resident in each of these cities in tree planting efforts could improve the health of millions of people, and that trees are as cost-effective as many other common solutions.
Most of the cooling and filtering effects created by trees are fairly localized, so densely populated cities—as well as those with higher overall pollution levels—tend to see the highest overall return on investment (ROI) from tree plantings.
The localized nature of trees’ effects, however, means that particular neighborhoods in virtually any city could benefit from plantings. City planners can even target plantings to protect areas with especially vulnerable populations—such as near schools and hospitals—or use trees as a screen against PM coming from highways and industrial areas.
While trees alone can't solve the entirety of cities' air and heat problems, they are a critical piece of the puzzle. The report shows that even a conservative global investment in urban trees can save tens of thousands of lives.
Download the Planting Healthy Air report above.
You can also download the executive summary here, as well in Spanish, French, German, Portuguese, Italian, and Simplified and Traditional Mandarin.