Wildfires in the Southwestern U.S. continued to rage on Wednesday, as the combination of extreme heat and erratic winds fueled the devastation and firefighters warned that blazes near Los Angeles were only about 10 percent contained.
As residents flee and emergency crews attempt to contain the infernos, climate scientists are warning that these deadly fires are climate change in action.
More than 20 fires are also burning in Arizona, Nevada, Utah, Washington state, Colorado, Montana, and New Mexico. Meanwhile, record-breaking heat reached 123°F in Palm Springs and 115°F in Phoenix. Death Valley recorded the country's hottest temperature on Monday at 126°F. At least six deaths have been attributed to the extreme heat.
Michael Mann, a professor of meteorology at Penn State University who was in Phoenix for the Democratic National Platform committee meeting last weekend when the temperatures hit 106°F, told the panel that the extreme weather was "an example of just the sort of extreme heat that is on the increase due to human-caused climate change."
The California cities of Azusa and parts of Duarte were evacuated as twin wildfires burned through the San Gabriel Valley, destroying more than seven square miles combined. Firefighters with the Angeles National Forest service told ABC News that the conditions were the hottest they'd ever encountered.
Mann warned on Tuesday that the worst is yet to come.
"The likelihood of record heat has already doubled in the U.S. due to human-caused warming, and that's just the tip of the proverbial iceberg," he told the Huffington Post.
The high temperatures have stymied emergency workers' efforts to extinguish the fires, which began burning even before the heatwave hit.
Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research, told the HuffPost that there was no question the fires and scorching temperatures were the result of human-caused climate change.
The added heat from rising greenhouse gases equated to "running a small microwave oven over every square foot, at full power for 6 minutes, for every month of drought conditions" in the affected region, Trenberth said. "So what used to be a regular heat wave now has extra oomph, and the danger is not just heat" but also a wildfire risk.
Mann also warned that, absent immediate action to curb climate change, scorching heat in the region could become the new normal by 2050.
"If we continue with business-as-usual burning of fossil fuels, by mid-century what we think of as extreme summer heat today will become a typical summer day," he said.