Trapped ice reveals changing trends of biomass burning over 650 yrs

WASHINGTON - A new study has shown that carbon monoxide trapped in a column of Antarctic ice spanning 650 years reveals fluctuations in biomass burning-the consumption of wood, peat and other materials in wildfires, cooking fires and communal fires-in the Southern Hemisphere.

“Combined with concentration measurements of CO, this record allows us to constrain the relative strength of biomass burning activity over the 650-year period in the Southern Hemisphere,” said co-author and research lead John Mak, a geoscientist at SUNY Stony Brook.

“What we find is that the amount of biomass burning has changed significantly over that time period,” Mak added, “and that biomass burning was in fact a significant source of CO during pre-industrial times.”

The researchers found that biomass burning appears to have been more prevalent 100 to 150 years ago than it was during the 20th century.

The biomass burning trends indicated by the CO largely agree with Southern Hemisphere records tracking charcoal particles in sediments and with measurements of methane from trapped ice.

“While this is consistent with previous findings, there is still a common mis-perception that biomass burning rates are much higher today than in the past. This is significant since many researchers assume that human-induced biomass burning is much greater than ‘naturally’ occurring biomass burning,” Mark said.

“While this may still be the case-there were people around in the 18th century-the fact that today’s rates of [Southern Hemisphere] biomass burning seem to be lower than one to two centuries ago calls for a re-evaluation of sources,” he added.

The research appears online in Science Express on Dec. 2, 2010. (ANI)