Biofuels harm Environment

February 8th 2008.

Biofuels – gasoline substitutes made from plants – can't make much of a dent in climate change and will actually make it worse, say two reports released yesterday.

One study concludes that the current race, propelled by massive government subsidies, to grow biofuel crops on existing agricultural land increases global greenhouse gas emissions because it causes farmers to clear vast tracts of forest and grassland elsewhere, releasing the carbon they store.

The second says the only option that might make sense – planting biofuel crops on land now considered degraded – could replace just a small fraction of the fossil fuels consumed by vehicles.

"Many people imagine that with all the talk about biofuels, they're going to give us all our energy," David Tilman, of the University of Minnesota in St. Paul and co-author of the report on using degraded land, said in an interview. "They're not. ... It's not the miracle" many people believe.

The studies were published in Science magazine on the same day the Helmut Kaiser Consultancy, based in Germany, reported that thanks to government subsidies and targets in Canada and many other places, global biofuel production hit 61 billion litres, at 2,000 refining plants, in 2007 and is forecast to grow by 15 per cent a year until 2025.

But the two scientific studies suggest such supports are bad policy.

"I no longer feel corn ethanol is a wise path," Tilman said.

Biofuels' main advantage is that they store carbon while they grow: That, in theory, offsets the greenhouse gas emissions generated when they're burned. Previous research has shown the gain is greatly reduced by the amount of energy required to grow the crops and convert them to fuel.

Most North American ethanol is produced from corn and wheat. It produces just 20 per cent more energy than it takes to grow and process the crop. That makes the savings in greenhouse gas emissions also about 20 per cent.

Producing fuel from grasses and other non-food crops is more efficient – although still technically difficult – and creates roughly a 50 per cent emissions saving.

But those benefits are wiped out by a consequence of biofuel production, says the first of the new reports by scientists at Princeton and two other U.S. universities and by the Woods Hole Research Centre.

Demand for food continues unabated after agricultural land is turned over to biofuel crops. As well, prices for the crops rise. The result: Farmers expand on to previously undeveloped land, and the carbon stored in the trees, grasses and soil is released into the atmosphere as carbon dioxide, a primary greenhouse gas.

The U.S. would need 43 per cent of its present food-corn land to meet its ethanol projection for 2016.

"Corn-based ethanol, instead of producing a 20 per cent savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years," the study says. The results for non-food crops aren't much better: "Biofuels from switchgrass, if grown on U.S. corn lands, increase emissions by 50 per cent."

The second study, by Tilman and other Minnesota scientists and funded by the Nature Conservancy, offers equally disheartening figures: "Converting rainforests, peat lands, savannahs, or grasslands to produce food-based biofuels in Brazil, Southeast Asia, and the United States creates a `biofuel carbon debt' by releasing 17 to 420 times more carbon dioxide than the annual greenhouse gas reductions these biofuels provide by displacing fossil fuels."

It says planting grasses for biofuel on the half-billion hectares of degraded land around the world would, for many years, have a double climate-change benefit. The crop could be harvested to make "green" fuel and its roots and the gradually improving soil would store more carbon.

But even if all that land were converted to biofuel crops – an unlikely event – they'd still meet, at best, only 20 per cent of the global demand for transportation fuels, Tilman said.

Michael Bryan, who heads the industry group BBI Biofuels Canada, said ethanol from corn, and even the "better" version from non-food plants and waste matter, isn't perfect, but is helping in the move away from a fossil fuel economy.

What the world needs is a clean alternative to burning ethanol. Whether we are burning oil-based ethanol or biofuel, it still amounts to the burning of carbon.