In an effort to curb global warming, engineers have created the whitest paint ever made. Coating buildings with this paint may one day cool them off enough to reduce the need for air conditioning, the researchers say. In October, the team created an ultra-white paint that pushed limits on how white paint can be. Now they’ve outdone that. Not only is the new paint whiter, it can also can keep surfaces cooler than the formulation the researchers had previously demonstrated. “If you were to use this paint to cover a roof area of about 1,000 square feet, we estimate that you could get a cooling power of 10 kilowatts. That’s more powerful than the central air conditioners used by most houses,” says Xiulin Ruan, professor of mechanical engineering at Purdue University.