Geoengineering

Harvard Profs Plan Geoengineering Experiment, Igniting Ethics Debate

When Mount Pinatubo erupted in June of 1991, it shot 20 million tons of sulfur dioxide 22 miles into the atmosphere. As the gas spread around the world, it cooled the Earth by about half a degree Celsius. Now two Harvard professors say they are planning to inject calcium carbonate dust into the air over Arizona to see what effect it has on the amount of solar radiation reaching the Earth below. The dust “would reflect away a little bit of sunlight, just the way a very thin cloud reflects away a little bit of sunlight … to offset some of the warming that comes from the slow buildup of carbon dioxide from our industrial activity, David Keith, a professor of applied physics at Harvard, tells WBUR.