Why is Colorado on fire? Climate effects aren't always as obvious as the weather…

Colorado’s massive High Park fire has jumped the Poudre River and is beginning to menace Fort Collins in earnest. This is very bad news. Some experts fear the blaze won’t be contained before fall and if you live anywhere to the east of it you’re probably quite worried, and for good reason. You might well be concerned if you live south or west, too.

Back in March, Tom Yulsman of the University of Colorado’s Center for Environmental Journalism warned us that this could happen.

On March 1, snowpack in most of the mountainous parts of the state was between 70 and 89 percent of average. By the third week of the month, a dramatic melt-off was underway. Now, snowpack in the state stands at just 58 percent of normal. That’s only a bit higher than in March of 2002, a year that brought drought of historic proportions to Colorado and the West. By mid-June, 19 U.S. wildfires were burning, most in California, Utah, Colorado, New Mexico, Wyoming and Alaska. (The worst March conditions on record in Colorado were in 1977, when snowpack stood at just 46 percent of average.)

Almost all of the state is abnormally dry, with about half in moderate to severe drought,according to the U.S. Drought Monitor. (For Boulder, it was the driest March on record, with just a trace of precipitation.) Drought extends all the way across much of the rest of the West as well, including California, Nevada, Utah, Arizona and New Mexico. The odds are not good for relief in the next few months, with higher than average chances of dry conditions continuing at least through June, according to the Climate Prediction Center.

I piled on, wondering will 2012 be the summer when Colorado finally burns to the ground?

There are plenty of variables in play, but I think the conclusion that a lot of us are drawing focus on the combination of “millions of acres of dead trees” and “extreme drought.” A couple summers ago I was up in the high country and even then was thinking sweet hell, all it would take is a typical little dry spell, followed by one ill-placed lightning strike and the ensuing Coloradopocalypse would have them choking on the smoke in Philadelphia.

At the risk of sounding all, you know, hysterical – because that’s what people who talk about climate disruption are, right? – it’s probably worthwhile to look at the variables closely. Tom did a nice job on snowpack already (and Brian Angliss has been relentless on these kinds of issues here at S&R over the past few years), so I want to take a moment to looks at the other major one.

That’s a pine beetle. This little guy and his friends have been responsible for decimating millions of acres of forest in the Colorado mountains, and this includes lots of the forest being destroyed by the High Park fire.

A 2008 USDA Research Forum paper by Jacques Régnière and Barbara Bentz of the Canadian Forst Service lays out the details, but the short and sweet goes like this:

  • Pine beetles thrive when winter temperatures are warmer – cold winter temps are the main thing that kills them.
  • Drought is a huge problem because it hampers trees’ ability to fight off infestations.

The drought issue has already been addressed, as noted above. But what about temperatures? This graph seems instructive:

Of course, we’re not just talking about Colorado – it’s the entire US and Canadian West. For instance, here’s Yellowstone:

And here’s Canada:

In other words, we’re getting warmer. Which is good for pine beetles. Which turns forests into kindling. Especially during drought cycles.

Which leads us to this:

That’s yesterday, and obviously the situation (unlike the weather) is … fluid.

So there are some facts. Do what you will with them.

6 replies »

  1. Sam

    This is a really good post. Sometimes I think climate arguments go for good science instead of clear communication. This makes the point beautifully. While denialists can still claim it’s not man-made and merely cyclical, it’s getting harder and harder for them to claim it’s not happening.

    • Thanks – I appreciate it. I think, at some level, the key for me is that I have stopped bothering with those who cannot be helped. Focusing on those who are interested in facts and implications at this point….