Yet more biofuel doubts


in Economics, Science, The environment

The buzz on all the energy and environment blogs today is a new article in Science raising further doubts about the green credentials of biofuels. Searchinger et al. report that:

Using a worldwide agricultural model to estimate emissions from land use change, we found that corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years. Biofuels from switchgrass, if grown on U.S. corn lands, increase emissions by 50%.

The major contribution made by this study is a quantitative estimate of how land use change in response to biofuel production affects total greenhouse gas emissions. If the displacement of alternative land uses for corn ethanol produces net carbon emission increases, you can bet your life that clearing tropical rainforest to make palm oil is markedly worse.

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{ 4 comments… read them below or add one }

Milan February 8, 2008 at 10:39 am

Studies Deem Biofuels a Greenhouse Threat

Published: February 8, 2008

Almost all biofuels used today cause more greenhouse gas emissions than conventional fuels if the full emissions costs of producing these “green” fuels are taken into account, two studies being published Thursday have concluded.

The benefits of biofuels have come under increasing attack in recent months, as scientists took a closer look at the global environmental cost of their production. These latest studies, published in the prestigious journal Science, are likely to add to the controversy.

These studies for the first time take a detailed, comprehensive look at the emissions effects of the huge amount of natural land that is being converted to cropland globally to support biofuels development.

The destruction of natural ecosystems — whether rain forest in the tropics or grasslands in South America — not only releases greenhouse gases into the atmosphere when they are burned and plowed, but also deprives the planet of natural sponges to absorb carbon emissions. Cropland also absorbs far less carbon than the rain forests or even scrubland that it replaces.

mek February 9, 2008 at 1:59 pm

This isn’t actually news, it’s just news to terribly-informed science writers and politicians that have been willingly deceived by the farm lobby. I’ve been laughing at that “Ethanol: Mother Nature’s Fuel” advertising campaign for awhile; so have corn farmers, laughing all the way to the bank.

Land use is another huge concern and one that tends to go ignored. Demands for biofuel isn’t really creating more agriculture, it’s just switching land use from food production to fuel production, reducing the global food supply and subsequently increasing prices; this is compounding the existing problems caused by global warming into a real disaster.

Milan February 11, 2008 at 10:17 am


If anything, the current biofuels debate shows how scientific literacy is a necessary pre-requisite for sensible decisions about climate change. It’s not enough to have a cabal of experts who pronounce on things, pretty much everyone needs the basic awareness and reasoning skills to know when they are being duped.

. February 11, 2008 at 11:35 am

Biofuels worsen global warming

By salvia on environment

Biofuels worsen global warming, according to two studies published in Science last week. Current US biofuel policies would double carbon emissions over the gasoline alternative. More details: ScienceExpress fulltext pdf of study #1, powerpoint summary of study #1, abstract of study #2, summary of both, policy recommendations pdf (via: 1, 2).
Here’s some context I needed to understand the US study: annually, the US produces ~5 billion gallons of ethanol and uses ~140 billion gallons of gasoline = 145 billion gallons total (sources). US law now calls for 36 billion gallons of biofuel production by 2022. The projections are based on increasing biofuel production to 31 billion gallons by 2015 (or the equivalent of the entire US grain crop from 2004).

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