Forests are helping reduce global warming, but global warming is killing forests.

Global warming sometimes can seem like a faraway thing in the American West. 

Glaciers?  We really don’t have many.  Except in that national park in Montana.  But those will all be gone in 20-30 years or so.

Polar bears?  Not in our neighborhood. 

Rising sea levels?  Hey, I live at 5,300 feet in elevation.  Even Al Gore isn’t predicting a mile high sea rise any time soon. 

Warmer summers?  Sure, but it’s a dry heat.

But forests.  We’ve got those. 

Although they’ve been healthier.  Vast swathes of lodgepole pine across the West are being devoured by beetles.  Pinyon pines in New Mexico have been damaged by a similar pest.  The outbreak of beetles is natural, and such outbreaks have lasted for years in the past. 

But the intensity and length of the epidemics may be longer because of global warming.  That’s because practically the only thing that can stop such an epidemic is a prolonged period of cold weather – really cold – many degrees below zero – kills off the beetles.  And we’re not seeing that kind of cold winter any more, even in the high country.

The beetles will eat themselves out of food eventually, and the forests will come back over time, just as they do after a fire.

And that’s a good thing.  Because in addition to being a victim of warming, trees are an important brake on warming as well. 

Maybe not all trees – but old growth forest.  In a study released in the past week or so, Canadian scientists have concluded that old growth forests are worth more as carbon sinks than they are as 2 by 4s.

Logging companies are still lusting after big trees in Canada and the US.  And some oil and gas projects – like the HD Mountains drilling project in Colorado – will bulldoze roads through and build wellpads in old growth forests.  That’s a two-fer – destroy the carbon-capturing old growth to put more CO2 in the atmonsphere by burning natural gas.

For the last few decades, conservationists have fought long and hard to protect old growth forest in the US.  Old growth forests in the Northwest, for example, are a treasure trove of biodiversity, providing habitat for rare species found nowhere else in the world (like the Northern spotted owl).  But old growth is rare because prior administrations OKed so much logging, and  old growth on private lands was liquidated for lumber.  The Bush Administration (surprise!) has shown a similar disdain for protecting such forests, lifting protections from over a million acres of old growth.

Not that we need another reason to protect old growth.  But now we do.