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).

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.

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. http://www.financialpost.com/story.html?id=213343

By ELISABETH ROSENTHAL
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.