Plant wood, not wheat, to reduce C02: report

Harper committed to biofuel; Forests cleared to grow ‘energy crops’
MARGARET MUNRO, CanWest News Service

Restoring and protecting forests would do far more to reduce the carbon load in the atmosphere than dedicating vast tracks of land to “energy crops,” a new report says.

Prime Minister Stephen Harper recently announced a $1.5-billion, nine-year plan to make Canada a leader in biofuel production.

But there is concern in many quarters about the “green” energy boom, which critics say is having a serious environmental impact around the globe as forests are levelled and farm land is set aside to grow biofuel crops.

The report, published today in the journal Science, assesses biofuels – produced by using everything from sugarcane to wheat – and compared carbon emissions associated with their use over the next 30 years.

It concludes growing trees and restoring forests is a far more effective way to reduce emissions linked with global warming and climate change.

“In all cases, forestation of an equivalent area of land would sequester two to nine times more carbon over a 30-year period than the emissions avoided by the use of the biofuel,” says the report by Renton Righelato of the World Land Trust and Dominick Spracklen of the University of Leeds. Taking this into account, “the emissions cost of liquid biofuels exceeds that of fossil fuels.” They note energy crops require an enormous amount of land: to replace just 10 per cent of gasoline and diesel fuel would require an estimated 43 per cent of crop land in the U.S. and 38 per cent of crop land in Europe.

And clearing grasslands and forests to grow energy crops releases carbon stored in existing vegetation and soil and creates large up-front emissions that the report says would “outweigh the avoided emissions.” Only biofuel from woody biomass may be compatible with retention of the carbon now locked in forests, the researchers say.

It might be possible to “sustainably” extract wood from standing forests to produce fuel without destroying the soil carbon stocks that are particularly important in temperate forests, Righelato said via e-mail. Righelato and Spracklen conclude that, where carbon emissions are concerned, it makes most sense to step up the conservation of fossil fuels now in use, and conserve and restore forests while pursuing development of non-carbon fuels for future use.

“If the prime object of policy on biofuels is mitigation of carbon dioxide-driven global warming, policy makers may be better advised in the short term (30 years or so) to focus on increasing the efficiency of fossil fuel use, to conserve the existing forests and savannahs, and to restore natural forests and grassland habitats on crop land that is not needed for food.” In the longer term, they say “carbon-free transport fuel technologies are needed to replace fossil hydrocarbons.”

The Conservative government’s $1.5-billion biofuel initiative aims to replace five per cent of gasoline used in this country with renewable fuels by 2010.
© The Gazette (Montreal) 2007