Geothermal power is a climate moon shot beneath our feet

North Milford Valley, in western Utah, is home to dormant volcanoes, subterranean lava deposits, and smatterings of obsidian—black volcanic glass—that Paiute peoples once collected for arrowheads and jewelry. Scalding groundwater still bubbles to the surface in places. In such a landscape, you remember that the planet’s hard exterior, where we spend our entire lives, is so thin that we call it a crust. Its superheated interior, meanwhile, burns with an estimated forty-four trillion watts of power. Milford was once a lead-, silver-, and gold-mining town, but when I visited the area on a sunny spring morning a scientist named Joseph Moore was prospecting for something else: heat. Heat mined from underground is called geothermal—“earth heat,” in ancient Greek—and can be used to produce steam, spin a turbine, and generate electricity. Until recently, humans have tended to harvest small quantities in the rare places where it surfaces, such as hot springs. Moore’s mission, as a geologist at ... Read full article.