The whitest white paint

Scientists at Purdue University have developed a super-white paint that could help cut our reliance on air-conditioning and fight climate change, reports ABCNews.com. Regular commercial white paint reflects about 80 to 90 percent of sunlight. It can keep buildings cooler than if they were painted black but can’t make walls cooler than the ambient temperature. The new paint is made from barium sulfate, a lowcost compound used to whiten photo paper and cosmetics, and reflects up to 98.1 percent of sunlight and does not absorb ultraviolet light. Outdoor tests found that this ultra-white paint kept surfaces 19 degrees Fahrenheit cooler than nearby surfaces at night, and 8 degrees cooler in peak sunlight. The Purdue team estimates that if 1,000 square feet of roof were covered with the paint, it would provide a cooling power of 10 kilowatts—more than the central air-conditioning units used in most houses. Reassuringly, the paint isn’t so bright it’ll hurt people’s eyes. “It just looks bright white,” says lead researcher Xiulin Ruan. “A bit whiter than snow.”

analyzed 20 years of recently declassified images taken by the NASA satellite Terra found that our planet’s 220,000 mountain glaciers have together been losing 328 billion tons of ice and snow a year since 2015. That’s 78 billion more tons than the annual rate from 2000 to 2004. Almost all of the world’s glaciers—including Tibet’s, which used to be stable—are melting, reports the Associated Press. And apart from a few exceptions in Iceland and Scandinavia, melt rates are speeding up everywhere. Alaska’s melt rates are among the fastest in the world, with the Columbia glacier retreating 115 feet a year. “Ten years ago, we were saying that the glaciers are the indicator of climate change,” says World Glacier Monitoring Service Director Michael Zemp, who wasn’t involved in the study. “Now actually they’ve become a memorial of the climate crisis.”