Study Ties Increase In Forest Fires To Global Warming


Thomas Swetham of the University of Arizona, member of a four-person team that just concluded a study on causes of the increase in intensity and frequency of wildfires, says that climate change in the West has become a reality.

He said, "We are starting to see the effects of that climate change."

The study revealed that during the 16 years period from 1987 to 2003 wildfires burned six and one-half times as much area each year as they did in the prior 16 year period from 1970 and 1986.

In addition, the average length of the fire season grew by 78 days.

As reported in the July 8, 2006 issue of Science News, Swetham and his three colleagues undertook a study to ascertain whether the disastrous increase in forest fires is correlated with global warming.

They examined fire, weather, and snowmelt data between 1970 and 2003.

During the period studied, the average temperature in the Southwest increased by 1.6 degrees Fahrenheit.

More importantly, the Western snow pack typically melted a week to a month earlier than it did previously.

The timing of the snowmelt influences how dry vegetation becomes as the summer season progresses.

For each year, the study showed, the number and total area of major forest fires correlated directly with average spring and summer temperatures and with the date on which the snowmelt peaked.

The conclusion appears inescapable. The force driving the increase in number and intensity of forest fires is global warming rather than past policies of suppressing small fires as previously suspected.

Constance I. Millar of the U.S. Forest Service in Albany, Calif. said, "This trend will not go away unless the trend in temperature turns."

Climate scientists project that average summer temperatures in the Western United States will increase from 3.6 degrees Fahrenheit to 9 degrees Fahrenheit by mid-century, which in turn suggests a doubling of the area covered by wildfires.

Does this mean that there is nothing we can do to mitigate the effects of global warming?

Millar said, "If we can keep the trees [alive], then [they will absorb] carbon dioxide from the atmosphere."

Since the increasing amount of carbon dioxide in the atmosphere is a main factor driving global warming, keeping the forest growing and healthy looks like the best, and perhaps the most doable, option.

New policies which are part of the "Healthy Forest" initiative of the Bush administration point the way.

They emphasize clearing brush as was recently done around Pine and Strawberry. They call for clearing trees and brush, and taking other steps to reduce fuels in vulnerable areas, before fires start.

These are things that can be done, steps we can take to create defensible areas around our homes, and towns, and large stands of precious trees, even in the face of global warming, which appears, for the time being at least, to be unstoppable due to our inability to work out internationally agreed upon pollution standards.

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