Earth’s clouds are shrinking, boosting global warming

For more than 20 years, NASA instruments in space have tracked a growing imbalance in Earth’s solar energy budget, with more energy entering than leaving the planet. Much of that imbalance can be pinned on humanity’s greenhouse gases emissions, which trap heat in the atmosphere. But explaining the rest has been a challenge. The loss of reflective ice, exposing darker ground and water that absorb more heat, isn’t enough to explain the deficit, and the decline in light-reflecting hazes as countries clean up or close polluting industry falls short as well. “Nobody can get a number that’s even close,” says George Tselioudis, a climate scientist at NASA’s Goddard Institute for Space Studies.