Biofuel crops may worsen global warming: study

Biofuel crops may worsen global warming: study

Updated Sat. Feb. 9 2008 9:04 AM ET

Philip Stavrou, CTV.ca News

Converting land for biofuel crops results in major carbon emissions and actually worsens the problem of global warming instead of mitigating it, says a new study.

 

The study by Nature Conservancy, an organization working to protect ecologically important lands and waters, will be published in Science magazine later this month.

 

"Our study found that any biofuel that causes clearing of natural ecosystems will increase global warming," Joe Fargione, a scientist for The Nature Conservancy, told CTV.ca.

 

"This is the first study to fully account for the effects of land clearing."

 

Fargione said the carbon lost by converting forests, grasslands and peatlands outweighs the carbons saved by using the resulting biofuels instead of fossil fuels.

 

"Most people don't realize that there's three times as much carbon in the plants' soil of the earth as there is in the air," said Fargione.

 

He said converting natural areas into croplands results in tons of carbon being emitted into the atmosphere -- a carbon 'debt' that outweighs any benefits.

 

For example, in the Indonesian peatlands, converting a hectare of land to a palm plantation requires workers to dig a canal and drain the peatlands -- which causes the rich, organic soils to decompose.

 

"So over 50 years that peatland would emit over 3,000 tons of carbon dioxide," said Fargione.

 

"It would take over 420 years to payback that carbon debt."

 

In the U.S., the carbon debt created by the conversion of grasslands to corn crops is 111 tons of CO2 per hectare, said Fargione.

 

He said the payback time for the debt is 93 years.

 

"The reason there's a carbon debt is when you plow (land)... and plant annual crops you increase the decomposition of the soil and that causes tons of carbon to move from the soil through the air as carbon dioxide," said Fargione.

 

Currently, overall land-use change -- mainly attributed to deforestation -- accounts for 25 per cent of global emissions, said Fargione.

 

"If we make our food (such as corn) into biofuels, people are going to cut down more forests to produce more food and that's going to contribute to that 25 per cent," he said.

 

Robin Speer, vice-president of Public Affairs with the Canadian Renewable Fuels Association (CRFA), told CTV.ca that land is not being converted in Canada.

 

'In Canada, ethanol is made from grains such as wheat and corn, and biodiesel is made from canola and soy oil, or animal fats and restaurant grease," said Speer.

 

"There is no land being converted, and much of these grains are surplus, so we are just giving farmers a new market and creating thousands of new jobs in rural Canada."

 

Alternatives

 

In the U.S., energy legislation signed in December mandates a six-fold increase in ethanol use as a fuel -- 36 billion gallons a year by 2022.

 

Dr. Donald L. Smith, Chair of the Department of Plant Science at McGill University, told CTV.ca that the U.S. is more concerned about energy security than it is about the environmental impacts of creating biofuels.

 

Still, Smith said there are ways to make converting land for biofuel crops a viable option for both the economy and the environment.

 

"It depends on the biofuel crop and how you produce it," he said. "With biofuels in the long run, if we do the right crops with the right production methods it could be very beneficial.

 

"But I think the approach that's being taken right now is probably not the right one."

 

Smith said planting fast-growing grasses (switchgrass, miscanthus, etc.) instead of corn could be an alternative method.

 

Smith said corn probably produces more biofuels per hectare than fast growing grasses, but when comparing net increases -- fossil fuels in versus biofuels out -- switchgrass is much better.

 

The fast-growing grasses may also provide a solution to the overall problem of using food crops for purposes other than food, said Smith.

 

Still, he admits that the research into conversion of biofuel crops like switchgrass is relatively new in comparison to the progress made on corn.

 

The Nature Conservancy study also predicts that switchgrass, if it replaces croplands and other carbon-absorbing lands, will still result in 50 per cent more greenhouse gas emissions -- when compared to using gasoline over a 30-year period.

 

Researchers say the focus needs to shift to creating biofuels from waste products, such as garbage.

 

The CRFA agrees that these "next-generation biofuels" will help Canada grow beyond oil.

 

"Next-generation biofuels, including cellulosic ethanol, will be made from many different sources of organic biomass such as municipal solid waste, forestry and wood waste, and agricultural residues (like wheat straw, corn cobs, etc.)," said Speer.

 

"Biodiesel will also be made from fast-growing non-edible plants like algae. The technology is developing rapidly and the story keeps improving - more clean-burning fuels for a better renewable future, with cleaner air and better prices at the pumps for all consumers."

 

In Canada, the Conservative government is pushing for an average of 5 per cent renewable fuel content in Canadian gasoline by 2010.