Two articles appearing today in Science Magazine make the risk of bad biofuels clearer than ever. The first article, "Land Clearing and the Biofuel Carbon Debt," addresses the direct greenhouse gas emissions from growing biofuel feedstocks on land recently converted from natural ecosystems to managed agriculture. This article is by a team from the Nature Conservancy and the University of Minnesota including David Tilman. The second article, "Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change," addresses the emissions from land use change induced by the economic pressures when crops and land are diverted from food, feed, and fiber to fuels. This article is by a team lead by Tim Searchinger now from Princeton, the Woods Hole Research Center, and Iowa State's CARD.
While these two article will no doubt stir a lot of debate about the specific amounts of carbon released from different land types, the amounts of different lands being cleared, and the exact economics driven by growth in biofuels production, three conclusions are crystal clear now: 1) Under business of usual, these two dynamics make it very likely that most biofuels would be responsible for greenhouse gas emissions significantly higher than gasoline or diesel; 2) The fundamental dynamics addressed by these two articles (direct land use emissions and economically induced land use emissions) are undeniable; and 3) Because of these dynamics, the importance of minimum GHG emissions standards and land-use safeguards (see this post) in the recently adopted renewable fuel standard is clearer than ever.
Unfortunately, before EPA has even launched a formal rulemaking, some in Congress appear to be itching to gut the standards and safeguards. Today, the Senate Committee on Energy and Natural Resources held a hearing on the renewable fuel standard and a number of Senators raised questions about the standards and safeguards and the need for "technical fixes." (See this article regarding recent comments by Sen. Thune about his desire to use the Farm Bill to start the gutting around some of the forest protections.)
Let's be clear: the environmental protection provisions in the RFS make it possible for the 36 billion gallon goal to be good for our climate and not destructive of our forests, prairies, and wild places. Obviously, whether it works out this way depending on how well we implement these safeguards. Fortunately, while these articles are just running today, the threats they enumerate shaped the RFS protections. We need to go further; we need to adopt a federal low-carbon fuel standard, but definitely at the head of the class now.
But if we gut these protections, these articles make it clear that the RFS will make global warming worse and lead to greater clearing of rainforests, savannas, and millions of acres of natural ecosystems. Without these protections, it's not that the RFS will be less good--it will be very bad!