California bums every year. But among a record-breaking heatwave, 2020 is the worst burning year yet. As of the September 2020, more than 7,600 fires burned over 2.5m acres of land. The season ran for more than several months.
That fits a long-term trend, for California's wild fires are getting steadily worse. Large fires in the 2010s burned 6.8m acres on average, up from 3.3m acres in the 1990s. The fire season in 2020 lasted nearly three months longer than it did in the 1970s. Over the past decade, the state has spent an average of $3.7bn a year fighting fires. Add the cost of rebuilding, treating victims and restoration, and that is perhaps a tenth of the total cost.
The reason is a double blow of climate change and development. More homes are being built next to forests, in what experts call the "wild-land-urban interface" (WUI). A 2018 study estimated that roughly a third of American homes were in the WUL Pricey housing has pushed people in California onto cheaper land close to the wilderness. At the same time, climate change is lengthening the dry season, which stores up fuel for fires. In California, a "huge drought" -- in which dry years become more common and wet ones scarcer (稀少)-- is making matters even worse.
Since neither trend shows much sign of turning around, people on America's west coast will have to learn to co-exist with more and more frequent fires. It's not that different to building on an earthquake active region," says Max Moritz, a wildfire expert at the University of California at Santa Barbara. He suggests that houses should be built near water or open agricultural lands, which can offer a useful barrier.
