Fanning the Flames

Peter Spotts has a very informative and intriguing article in the Christian Science Monitor on the country's growing wildfire risk. While researchers say it's premature to blame the recent So Cal fires on global warming, there is evidence to suggest that climate change has increased the number and longevity of fires (and also the longevity of the fire season) in the West, especially "in forests in the northern Rockies at middle elevations." Far more surprising, however, is this paragraph:

Global warming is expected to increase fire hazards in the western United States under a range of global-warming scenarios. But the greatest increase in risk, some researchers say, is likely to come in the East and Southeast. There, snowmelt and rainfall are unlikely to slake the increasing thirst of trees and shrubs as CO2 spurs their growth during longer, warmer growing seasons. This could leave more of the eastern woodlands drier and more vulnerable to wildfires by summer's end. Meanwhile, some of the most dense mingling of homes and woods – what experts call the wildland-urban interface – can be found in the eastern US.

Not surprisingly, forest fires are a big source of carbon dioxide -- nothing compared to the burning of fossil fuels, mind you, but significant nonetheless. Here's the lead from an article by AP environmental reporter Seth Borenstein:

In one week, Southern California's wildfires spewed the same amount of carbon dioxide - the primary global warming gas - as the state's power plants and vehicles did, scientists figure.

A new study by two Colorado researchers shows that U.S. wildfires pump a significant amount of the greenhouse gas into the air each year, more than the state of Pennsylvania does.

Even more disturbing are indications that, as fires increase, the vast boreal forests, which span northern Canada, Alaska, Siberia, China and Scandinavia, have gone from being a carbon sink to becoming a carbon source. That is to say, the forest, which was expected to sop up excess CO2, may now be contributing to global warming, which in turn is expected to exacerbate wildfires, in what threatens to become a feedback loop. Very troubling.