From the current issue of Nature magazine (May 28 cover date), Eric Vance’s article “The Man Who Smells Forests” (unfortunately available to subscribers only):
Working at the tops of the trees with ever more sensitive detectors, [Goldstein] has found that forests play a crucial part in the chemistry of aerosol particles and with pollutants such as ozone. His discoveries may help to fill in confounding gaps in atmospheric science, such as how VOCs [volatile organic compounds] from plants affect air quality and how they influence climate. . . . Estimates suggest that the vast majority, perhaps up to 90%, of Earth’s VOC output comes from vegetation, a fact infamously alluded to by US president Ronald Reagan, when he said that forests pollute more than cars.