California Wildfires Caused By Global Warming? Not Quite

What caused the rash of brush fires in Southern California? Global warming.

What caused the drought that threatens Atlanta’s water supply? Global warming.

How is it possible that the Boston Red Sox won two World Series within three years? Global warming.

Uh, no, on all three counts.

These days, when fighting global warming enjoys political cachet, it’s tempting for advocates of doing something about the problem to blame any bout of weird weather or natural forces running amok on the changing climate.

As someone who agrees that the U.S. urgently needs to get on the stick with reducing greenhouse gas emissions, I advise resisting the temptation.

Building political support for climate action will depend on persuasion. Information is the currency of persuasion. Let’s not debase the currency by making sloppy, off-hand remarks that global warming caused this or that event.

Events like the California fires or the Southeast drought occur as a consequence of many variables converging. You can no more say that climate change was the sole cause of those events than you can tie a case of lung cancer to one particular cigarette.

The more cigarettes that one smokes, however, the greater the odds that the result will be lung cancer. Likewise, the more greenhouse gases we emit, the greater the odds that the buildup of heat energy in the atmosphere will lead to spin-off consequences -- longer and more extreme droughts, or greater frequency of wildland fires.

We can stress natural systems, but only to a point. Emitting greenhouse gases is one way that we’re taking liberties with nature’s resilience. But it’s not the only way.

The chaparral vegetation that is native to Southern California has burned since time immemorial. Offshore charcoal deposits are evidence that periodic brush fires have been a part of the California experience for centuries.

Today, however, the consequences of those fires are much larger for human society. As subdivisions sprawl into chaparral-filled canyons and valleys that once were sheep ranches or wilderness, odds are greater that people will lose their homes to fire.

California society is playing closer to the edge. The Golden State has some 37 million people today. Its projected population is 60 million by 2050. All those people will have to live somewhere. Which means that more homes will burn when the Santa Ana winds blow.

In the drought-stricken Southeast, Georgia is playing closer to the edge also. Governor Sonny Perdue and other Georgia leaders complain that the Army Corps of Engineers is letting too much water out of dwindling Lake Lanier, which supplies fast-growing Atlanta with much of its water. Perdue says he’s “fed up” with releasing water for endangered mussels when his state’s biggest city is going dry.

His counterparts in Alabama and Florida, whose communities depend on those downstream flows, beg to differ.

Alabama, Florida, and Georgia have been fighting about water for decades. But mussels and interstate rivalries aside, there’s a much bigger issue in play. At some point along the growth curve, water demand will outrace supply -- even in the humid South.

Atlanta has failed to plan ahead for the consequences of growth, Georgia’s neighbors argue. It’s safe to say that Atlanta is not alone in that failure.

Global warming, by itself, didn’t cause the fires or the drought. Making oversimplified statements that it did gives the climate change denial lobby more gunpowder for its medieval tirades about hysterical enviros and scientific hoaxes.

What can be said, however, is that climate change, combined with our increasing demand for resources, is increasing human pressure on natural ecosystems that provide human civilization with essential services.

Nature gives human society only a certain amount of latitude. When we push against nature’s boundaries, nature pushes back. The harder we push, the harder the response. That’s the deeper lesson of California fires and the Southeast drought.