'The Northern Hemisphere Is on Fire'

"Rarely has the continent been covered so extensively with smoke."

Typically, those aren't the sort of opening words you want to read on a website tasked with monitoring the nation's air quality. But it's how Dr. Raymond Hoff, the physicist and professor emeritus at the University of Maryland who helps run the US Air Quality blog, framed his weekend edition.

"Canadian wildfires and fires in the Pacific Northwest have conspired to make much of the northern half of the US a hazy, smoky mess," Hoff writes.

As of the end of last week, here's how much of the continent was covered in smoke plumes—the light grey—and fires themselves, indicated with the red dots.

The fires are now impacting air quality in "most of Canada," Hoff explained in a previous post. This is what the 'hazy, smoky mess' that is our continent looks like from orbit, as per NASA's Earth Observatory satellite:

As you can see, a huge swath of Canada is burning. At one point, the blazes threatened an area the size of Texas, and officials have called them "unprecedented." Wildfires are spreading across the US Pacific Northwest, too. As of yesterday, 250,000 acres had burned Washington state, claiming 80 homes and forcing residents across the region to flee.

That's about the same area that was ablaze in Canada's Northwest Territories, in fact. The NWT government released this photo of the burn:

The fires are producing enough smoke to pose a health hazard to at least three US states: Washington, Oregon, and Idaho. According to US Air Quality, smoke is currently at a 'Code Red'  level in each—the particulates in the pollution eminating from the burn are big enough to be damaging to your lungs when you breathe them in.

Smoke plumes are winding all the way through Nevada, Colorado, and the US Midwest, but not in a concentration that should pose a threat to human health.

"We regularly have large fires in the west," Hoff told me in an email, "but having large fires in Washington, Oregon and Canada bring smoke into the US all at the same time is unusual."

Hoff seems genuinely impressed by the amount of smoke these fires are churning up; he writes eloquently and emphatically about it on the blog, which is somewhat unusual for an atmospheric scientist. Here, in an update on Sunday, he describes the latest satellite imagery of the smoke: "In AQUA MODIS's AOD image from Worldview, the 1920's Impressionists would have been proud of the painting made by the fires in the Northwest and Canada."

This map shows the aerosol optical density (AOD) of the smoke—essentially, how much of the light the plume is blocking out. Which is a lot. Again, most of what you're seeing isn't harmful, it's just lowering visibility and blotting out skylines.

But Hoff notes that North America isn't the only continent that's engulfed in smoke right now; wildfires in Siberia are stamping out sunlight in Asia, too. Over 1.1 million hectares (or 4.5 thousand square miles, or an area a bit smaller than the state of Connecticut) have been torched in Russia this year, yielding yet another fearsome smoke map:

"The Northern Hemisphere is on fire," Hoff writes. And it's pumping out a fairly astonishing amount of smoke in the process.

Climate Central's Brian Kahn explains why all of these forest fires and the emissions they generate bode ill for the future: "The combined boreal forests of Canada, Europe, Russia and Alaska, account for 30 percent of the world’s carbon stored in land, carbon that's taken up to centuries to store," Kahn notes. So, along with the smoke, a tremendous amount of carbon is being released into the air, which of course helps speed global warming.

Meanwhile, Kahn points out that "soot from forest fires can also darken ice in the Arctic and melt it faster. The 2012 fires in Siberia released so much soot that they helped create a shocking melt of Greenland’s ice sheet." It's disturbing, but about what we should expect in an era where major wildfires are the new normal.