Forest Mitigates Short-Term Health Risk of Air Pollution: Evidence from China.

This study assembles satellite data, individual-level death records, and air quality data to estimate forest greenness impact on air pollution and health outcomes in China. We find that forest greenness improves air quality. A 10 percentage-points increase in the seasonal average normalized difference vegetation index (NDVI) is estimated to increase the overall air quality index (AQI) by 2.6 (3.8% from its mean of 70.8). This NDVI increase predicts decreases in seasonal cardiorespiratory deaths by 1.09% (9.5 people), and in non-cardiorespiratory deaths by 0.87% (7.3 people), ceteris paribus. Also, forest greenness has a mitigating effect of reducing the mortality risk of air pollution as we find that an additional greenness of 10-percentage-point increase in NDVI contributes to a reduction in air pollution-caused mortality by 0.5 people each season. The elderly and especially the elderly males are more likely to benefit from the mitigation by forest greenness possibly because they are more frequently exposed to air pollution and the greenness. A back-of-the-envelope calculation indicates that doubling the greenness of forest would bring about a health benefit that is far beyond an order of magnitude larger than the cost of forest conservation efforts. [ABSTRACT FROM AUTHOR]