It is fire season in Siberia, which means vast tracts of boreal forests are ablaze. As occurred in 2015, smoke is turning skies a bright orange across eastern Russia, China and other downwind areas.

The past few years have seen huge conflagrations in this region, due to a combination of forest management practices, firefighting policies, human-caused global warming and shorter-term weather fluctuations.

NASA satellite imagery taken Monday, July 18, shows dozens of fires pouring smoke into the skies above sparsely populated areas of Siberia.

Zoomed-in view of some of the smoke plumes flowing from the Siberian forest fires. Image: NASA

These fires are a significant contributor to climate change, since when these forests burn they release planet-warming greenhouse gases into the atmosphere.

They are also a potential accelerant of the Arctic sea ice's rapid melt, since soot from forest fires that far north can be transported northeastward and deposited on sea ice in the Arctic.

Once soot lands on ice, it turns the surface dark, thereby causing it to absorb more sunlight and melt faster.

This year's forest fires are close to becoming one of the most devastating in recent Russian history

It's unclear exactly how large an area is on fire right now in this region, with environmental groups criticizing Russian government figures as too low.

A report released in early June by the environmental group Greenpeace found that forest fires in eastern Russia had already burned more than 3.5 million hectares, or 13,513 square miles. This is an area larger than the state of Maryland.

Russia's government says that as of July 18, only 11,776 hectares are actively burning, and the federal forestry agency has reportedly said the total amount of acres burned so far this year is just 669,000 heactares.

"This year's forest fires are close to becoming one of the most devastating in recent Russian history," the Greenpeace report stated. According to the environmental group, the average Russian wildfire season burns up to 6 million hectares, or about 23,000 square miles.

Temperature anomaly visualization for April 2016, showing extremely mild conditions compared to normal in eastern Russia. Image: NASA GISS

This year is almost certainly going to be the hottest on record for the globe, and one of the most unusually warm regions-to-date, compared to average, has been Siberia.

Siberia's forest is mainly comprised of an ecosystem known as boreal forest, which circles the top of the globe throughout Canada, Scandinavia and Alaska. The world's largest ecosystem, these forests are essentially massive savings accounts for carbon dioxide.

When they burn, these long-stored gases are released into the atmosphere, thereby accelerating global warming.