The Problem With Biofuels
Earlier this month, two independent studies in the journal Science dropped a bomb into the already controversial world of biofuels. To cop the New York Times' lede, the studies found that:
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...
Yesterday afternoon, when I finally got around to reading the articles, my chin hit the floor. The NYT was far too gentle: they don't just show that biofuels have worse GHG emissions than gasoline, but drastically worse emissions -- and for virtually every type of biofuel, including cellulosic ethanol (except in some highly specific conditions).
For really the first time, the studies are factoring in the carbon lost from land conversion. The authors argue (persuasively, in my opinion), that it's crooked accounting to simply do a GHG analysis of crops versus petroleum. After all, the crops used for biofuels don't grow in a vacuum. What really happens is that new land -- Indonesian rainforest, Brazilian woodlands, American grassland -- is cleared and ploughed to make way for biofuel feedstock crops. Existing agricultural land, of course, is already in production for food and fiber.
The clearing is a death sentence for wildlife in some of the most biodiverse places on earth. It also releases huge amounts of carbon into the atmosphere -- called the "carbon debt." In fact, the carbon debt run up by land conversion is, in most cases, far more than is saved by subsituting biofuels for petroleum products. (Details on the studies' are below the jump; abstracts are here and here.) It would take decades at best, centuries at worst, to repay the carbon debt. And this when we need steep emissions reductions now.
Look, I'm sure there will be further debate, and maybe even counter-studies. (The biofuels industry appears to be fighting back already.) But in a way, uncertainty could be the real problem for biofuels, as well as for the latest fad in climate policy, low-carbon fuel standards. Either biofuels are a climate catastrophe, as these studies indicate; or we have no idea what biofuels do to the climate because experts don't agree. And that second option is the best case scenario, at least in the near term.
