The most recent UN report on climate change predicts that greenhouse gases already in circulation have committed the planet to a warming of 2.5 degrees. “No matter what we do today to reduce emissions, the planet will still heat up,” says Ramanathan. But, through a quirk that Ramanathan has spent 10 years uncovering, the planet actually manifests only ¼ of the warming it should based on these climate models. Air pollution, specifically brown clouds from burning biomass, Ramanathan has learned, act as a global warming mask, reducing sunlight on the ground. “On the one hand, it has protected us, but also prevented us from seeing the full blast of the greenhouse effect,” he says. “One of the dumbest things we can do is to reduce sunlight,” because it reduces ocean evaporation, which cuts down on rainfall, and shifts weather systems everywhere, shrinking harvests and glaciers.
