Ongoing Arctic fires this year have been particularly severe in Siberia and Alaska. In Russia, flames engulfed more than 7 million acres in Siberia and beyond in August, forcing President Vladimir Putin to send military transport planes and helicopters across the country to put out the fires.
In Alaska, more than 2.4 million acres have burned over the past three months, inundating nearby cities with smoke and forcing temporary hospitals to open for clean air access.
Now, a cloud of smoke and soot bigger than the European Union is moving from Siberia into the Arctic, according to the World Meteorological Organization. It is forecast to reach Alaska, where fires have scorched an area larger than the wildfire damage in California last year.