The Arctic has experienced the worst fire season on record for the second year in a row, with giant wildfires sending over one third more carbon dioxide into the atmosphere than last year.  Fires raging across the Arctic Circle emitted 244 million tons of carbon dioxide for the first six months of the year, compared to 181 million tons for the whole of 2019, according to Europe’s Copernicus Atmosphere Monitoring Service or CAMS.

The fast warming of the Arctic has manifested this past few months through heat waves that have broken temperature records. At the same time, satellites showed that the sea ice shrank more than during any other July in history. Thinner ice in Arctic waters meant the Northern Sea Route, which is used during the summer months to ship gas, oil and metals from northern Russia to China, opened up earlier than usual this year.

Scientists think so-called “zombie fires” that originated last year may have been smoldering underground during winter months and reignited in spring as a heatwave hit the region. “Once these fires start in that part of the world they can burn for a long period of time,” Parrington said. “I wouldn’t be surprised if we see something similar again next year.” Fires in the western U.S. are still active, and data from CAMS shows that fire intensity in Colorado has so far been well above the 2003-2019 average for most of August. In California, the data shows emissions from fires peaking in the second half of the month— not surprising, given that two of the state’s largest-ever fires started in late Aug