Biofuels may be worse for global warming than fossil fuels

Posted by Laura Grant on February 12, 2008
Posted in Transport

maize field : iStockphoto.comBiofuels may help countries reduce their reliance on imported oil, but two new studies published in the Feb 8 issue of the journal Science have cast doubt on the benefits of biofuels as a solution to combat climate change. In fact, using biofuels may produce more greenhouse gas emissions than using conventional fossil fuels in the short term, says one of the studies.

Peviously it was thought that the emissions produced from using biofuels were counterbalanced by the carbon absorbed from the atmosphere by the growing crops. Burning fossil fuels, on the other hand, just released stored carbon into the atmosphere. Hence, biofuels were considered to be more climate friendly than fossil fuels.

But researchers studied the land use changes that occurred when existing crop land is converted to biofuel production. In the United States this is being done on a massive scale to meet government biofuel targets. The US will boost its biofuel production to 36-billion gallons in 2022 from 7.5-billion gallons in 2012. The European Union requires 10 percent of transportation to use biofuels by 2020. And farmers worldwide are responding to the higher crop prices and ploughing up forest and grassland to make new croplands to replace the land that has been diverted to biofuels.

If it’s forest or grassland you’re ploughing up to grow biofuel stock, you get a huge release of carbon – which is carbon that’s been stored over decades, said Timothy Searchinger, the lead author of the study. “According to our calculations, this release of carbon greatly exceeds the carbon benefit you get from using biofuels per year, so you have a long time before you pay off that debt,” he said in an interview on the February 8 Science podcast.

For maize-based ethanol this pay back period could be up to 167 years. The research found that corn-based ethanol nearly doubles greenhouse emissions over 30 years.

It doesn’t matter if the biofuel crop grown is a food crop, such as maize or a non-food crop such as switchgrass. The study found that the land use changes lead to higher not lower greenhouse gas emissions.

The problem is that we need to start reducing our greenhouse gas emissions today.

The key is to avoid using productive land for biofuels, said Searchinger. A better alternative is to make biofuels from waste products that don’t involve converting land.

In South Africa the government’s biofuel strategy released at the end of last year set a biofuels target of 2 percent of the country’s fuel mix, which was lower than the original target of 4.5 percent. Maize, a staple food crop, was excluded in the production of biofuels based on concerns that there would not be sufficient maize for the sustainable supply to the bioethanol industry without affecting food security. Soya beans, canola and sunflower will be used as feed stock for biodiesel, and sugarcane and sugar beet will be used for ethanol.

Via:: Environmental News Service


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