17 Aug 2009 02:08:10
Ancestors may have changed global climate
The agricultural methods of early civilisations may have emitted more carbon dioxide than was previously thought, a study has found.
New research from the University of Virginia and the University of Maryland-Baltimore County has revealed that the burning of forests for farming purposes thousands of years ago could have started climate change.
Writing in the journal Quaternary Science Reviews, experts from the institutions explained that today 90 percent less land per person is used for growing food.
William Ruddiman, lead author, indicated that using slash-and-burn techniques to clear forests for agriculture "may have inadvertently altered the climate".
He commented: "They used more land for farming because they had little incentive to maximise yield from less land, and because there was plenty of forest to burn.
"We suggest in this paper that climate modellers might consider how land use has changed over time, and how this may have affected the climate."
Forests are beginning to be restored in areas such as the US, Europe, Canada and Russia, the researchers said. http://www.elsevier.com/wps/find/journaldescription.cws_h...