Wildfires across California have burned over 4 million acres of land so far this year, a record-breaking statistic. 

In 2020, over 8,300 wildfires in California have killed 31 people. The blazes have also destroyed more than 8,600 buildings, according to the California Department of Forestry and Fire Protection (Cal Fire). The 4,040,935 acres of land burned is over double the previous record. In 2018, 1.67 million acres of land burned in California.

Because of the severity of these blazes, even those living far away from the fires were affected by the smoke from the flames, which created unhealthy air quality. The smoke was so dense that it sometimes blotted out the sun in California, according to the Associated Press. In September, a heatwave swept the state, and it helped fuel the fires. There was so much air pollution that stores across California sold out of air purifiers, according to AP. 

There is no clear answer to how the fires started, but according to the National Weather Service, most fires start from lightning, especially where the ground is dry and easily ignited. 

Mike Flannigan, director of the Canadian Partnership for Wildland Fire Science at Canada’s University of Alberta, said the escalation of fires in California and the U.S. is largely because of human-caused climate change. Scientists have said that climate change has made California significantly drier, thus making trees and plants more flammable. 

There is some hope that the fires may decrease because powerful winds that were expected to spread flames have not materialized. Also, clearer skies in some areas allowed air tankers to spread retardant, which many hope will diminish the fires, according to AP.

Cal Fire officials said the Glass Fire, a wildfire in Napa and Sonoma counties that started Sept. 27, is their top priority. The blaze is currently 30% contained. 

“We are seeing some relief in the weather, but it’s going to be three or four days before it really makes a difference on the fire,” Cal Fire meteorologist Tom Bird said at a news briefing about the Glass Fire. “The one good thing going forward, we’re not expecting any wind events to push into the fire.”