Feb. 25, 2009 -- Two of the most destructive consequences of climate change -- drought and wildfires -- may have an upside. Over the course of many centuries, they conspire to suck greenhouse gases out of the atmosphere, according to a new study. Wildfires scorch portions of the United States every year, from the lodgepole pines of Colorado to the dry, sunbaked brush of southern California. They spew huge amounts of carbon dioxide into the atmosphere, equivalent to as much as 4 percent of the country's total industrial emissions. If western United States becomes increasingly parched due to climate change, as climate models predict, the risk of wildfire will become ever greater. In the long run, that may not be such a bad thing. An analysis of 2,000 years of sediment deposits from the bottom of the Chesapeake Bay reveals that droughts coincide with more wildfire activity. They also produce tons of carbon-rich soot and charcoal that gets buried in soil or underwater sediments. Related Content:
The connection between drought and wildfire is strongest over the last millennium, starting with a stretch of planet-wide warming called the Medieval Warm Period, around 700-1100 A.D. Eastern North America dried out during this time, and black carbon deposits spike dramatically in the Chesapeake Bay sediments. "We're not sure how big the fires were," Siddhartha Mitra of East Carolina University, the lead author of the study said. "But the amount of black carbon we see suggests they were pretty darn large." Though the team hasn't made a formal calculation, Mitra said that as much as 30 percent of all the carbon locked up in trees, grasses and other plant matter that burns may be sequestered. The finding could have implications for climate policy in the future. There may be a way to burn large swaths of forest or grassland as a means of carbon sequestration. "There's a trade-off, a balance between the net loss of carbon to the atmosphere versus the net gain in carbon from sequestration," Mitra said. "When do you get to the break even point? Does burning benefit us to some extent that we haven't thought of before? These are the kinds of questions we need to be asking." Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
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