Clouds are the largest source of uncertainty in climate predictions.

In a paper published this month in Science Advances, Dada’s team establishes a new heavy hitter in cloud creation: a kind of chemical released by trees.

The role of trees in seeding clouds is important, because it suggests what the sky above some regions might be like if governments manage to tamp down sulfur emissions.

In a world with less pollution, plants and trees will become more dominant drivers of cloud formation, an echo of the premodern world.

While anthropogenic emissions dominate cloud formation in populated areas, plant volatiles dominate over more pristine land elsewhere.