Sunday, September 21, 2008

Climate change, human activity and wildfires

Science Daily: Climate has been implicated by a new study as a major driver of wildfires in the last 2,000 years. But human activities, such as land clearance and fire suppression during the industrial era (since 1750) have created large swings in burning, first increasing fires until the late 1800s, and then dramatically reducing burning in the 20th century.

…A 100-year decline in wildfires worldwide -- from 1870 to 1970 -- was recorded despite increasing temperatures and population growth, researchers found. "Based on the charcoal record," Marlon said, "we believe the reduction in the amount of biomass burned during those 100 years can be attributed to a global expansion of agriculture and intensive grazing of livestock that reduced fuels plus general landscape fragmentation and fire-management efforts."

Observations of increased burning associated with global warming and fuel build-up during the past 30 years, however, are not yet included in the sediment record.

Charcoal levels have drawn attention during the past 25 years because these data can track wildfire activity -- both incidence and severity -- over long time periods, providing information when similar data from satellites or fire-scarred trees do not exist. This study is among early efforts to analyze charcoal records for widespread patterns and trends over such a long period.

The 2007 Pine Barrens fire in New Jersey, shot by Thisisbossi, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 2.5

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