The Golden State is in danger of becoming the “Cinder State”. New research reveals that cloud cover is plummeting in southern coastal California, increasing the chances of bigger and more intense wildfires.
Since the 1970s Californian airports have monitored cloud cover, for navigational safety. Park Williams, from Columbia University’s Lamont-Doherty Earth Observatory, and colleagues studied these records and discovered that over the past 40 years low-lying summer clouds have decreased by up to 50% in the greater Los Angeles area. Typically moist ocean air brings stratus cloud along the coast in the morning, and as the heat builds the clouds dissipate. But now the clouds are higher and don’t hang around as long. “Clouds that used to burn off by noon or one o’clock are now gone by 10 or 11am, if they form at all,” said Williams, whose findings are published in Geophysical Research Letters.
A combination of global warming and increasing city sprawl (the urban heat-island effect) are the main drivers behind the reduction in cloud cover. And less cloud cover means drier vegetation and greater chance of fire. To date firefighters have been swift to deal with summer wildfires, but the increasing danger means they will have their work cut out.
