How Climate Change Contributed to This Summer’s Wildfires
The image of the day from NASA’s Earth Observatory shows gusting plumes of smoke veiling the western United States. Two hundred thousand acres are on fire in California, fuelled by strong winds and unrelenting hot, dry conditions. The Carr Fire, in Redding, a hundred and sixty miles north of Sacramento, has incinerated over a thousand structures, most of them people’s homes. Forty thousand people have been evacuated, and six have died. The fire is so large—more than a hundred and ten thousand acres—that it has created its own weather system, making it difficult for firefighters to predict what it will do next.“We have seen extremely explosive fire behavior on this particular fire,” Chris Anthony, a division chief with the California Department of Forestry and Fire Protection, said. “But it’s not unique anymore to what we are seeing on fires in California.” Climate change is slow until it’s terrifyingly fast.
Farther south, in the Ferguson Fire, west of Yosemite Valley, two more people have died, a bulldozer operator and the captain of an élite firefighting squad. More than twelve thousand firefighters are working in California—some have come from as far as Florida—and on Saturday, President Trump declared a state of emergency in order to release federal funds. Ninety-five wildfires are scorching the country from Texas to Oregon, and have burned 4.8 million acres. “This is just July,” Lynne Tolmachoff, a spokeswoman for the California Department of Forestry and Fire Protection, told CBS. “So we’re not even into the worst part of fire season.”
Meanwhile, rains have swamped parts of the East Coast, and tornadoes have swept across the plains. More severe rainstorms and flash floods are expected in the South and the East Coast in the coming days. The jet stream—the freeway of air that circles the Northern Hemisphere—is behaving erratically, meandering like a drunk. “It’s one of these wavy jet-stream patterns that’s causing all the crazy weather,” Jennifer Francis, an atmospheric scientist at Rutgers, said. Francis and others have shown that this type of pattern is linked to the amplified warming in the Arctic. When the hot-to-cold temperature gradient from the mid-latitudes to the Arctic decreases, it can slow or split the jet stream, making it loopier, bringing persistent periods of extreme dry heat to some areas and heavy rainfall to others. In 2010, the Moscow heat wave and wildfires happened at the same time as monsoon rains and flooding in Pakistan. “We’re seeing the same thing this summer,” the Penn State climate scientist Michael Mann told me. “Those regional anomalies aren’t unrelated to each other—they are part of the same larger wave disturbance.” 08-01-18