Biofuels = scam?

I've heard a lot of bad things about biofuels.

Most of the arguments come down to:
1) the whole process is even less efficient/more polluting than our current technologies
2) there's not enough land to produce all this biomass unless we stop growing crops for food

I have also heard frequent references to the 'corn ethanol' lobby with conspiratorial overtones against Coca-Cola, Detroit, and Iowa.

I've generally been sympathetic to the anti-biofuels crowd since it squares more with my experiences and I've heard more numbers from them. I came across something that may change my mind though. As I was trolling for postdoc labs the other day, I stopped by Chris Somerville's lab website. He's a very prominent plant biologist who's specialized in cell wall biology and, at least recently, improving plant structure to optimize biofuel technology. He has a link to a presentation titled "The Future of Biofuels" on his site. I wish I could see his actual presentation, but the slides alone present some significant evidence of the viability of biofuels.

He begins by displaying charts demonstrating that most of our energy comes from fossil fuels, and that these fuels are associated with political/economic instability and climate change. Eight (referenced) graphs lay out a convincing introduction that fossil fuels are a problem that requires an immediate solution. Finally, he runs through the usual suspects of alternative energy with some advantages and limitations of each (nothing new here).

He then begins addressing the different forms of energy conversion that fall under the umbrella of "biomass." There are actually multiple ways to make biomass into energy, and different plants show great differences in efficiency. He lists the three main ways to turn biomass into energy as burning, conversion to syngas, and conversion to ethanol and other fuels. He then shows several slides diagramming the cellulose structure of plant cell walls. There's little writing, but I imagine here he makes the point that cellulose, being I believe the most abundant biological chemical on the planet, has great potential to produce energy if we can develop a way to process it.

One of the reasons why contemporary biomass to ethanol conversion is so terribly inefficient is because we haven't developed technologies that allow us to access cellulose and lignin - the primary (and virtually indestructible) components of the plant "skeleton." I wish there was more text on this part of the presentation, but I infer the overall point as being that advances in technology will radically increase the amount of energy we can get out of biomass. This is completely plausible.

He then addresses the land issue. He first makes the point of reminding us that modern crops are much more productive than their progenitors, and that biotechnology promises greater gains. He then shows how we can get large amounts of biomass from agricultural wastes. His best point, and the one that I find novel and compelling is that many of these biomass crops could be grown on marginal land. Arable land occupies a tiny percentage of the Earth's land surface area (and shrinking thanks to unsustainable practices and suburbs!). Biomass crops, having different profit margins and yield objectives, could be economically harvested from land that doesn't support crops. They generally would receive neither added fertilizer or irrigation. This brings to mind a paper I read on the potential of salt-tolerant plants as crops. We have no shortage of watered, sunny land (e.g. coastal deserts) with too much salt for conventional crops. This could be a great resource for specially bred/engineered biomass crops.

My favorite chart in his presentation is a map of the United States with colors illustrating which biomass crops could be grown most easily in each region. One of the most aesthetically pleasing parts of this chart are the implication that more or less "natural" ecosystems of forests and prairies could be managed for an economic return. For the most part grasses and trees are matched up with regions of the US where they (or close relatives) are native. I love the idea of living in an area that provides economic support for large spaces of nearly-wild prairie and woodland that are managed minimally.

Eco-agriculture, the idea that crops can be managed like a diverse, wild ecosystem (and the foundation of organic agricultural ideals), is worthless in most agricultural settings, but shows some promise in biofuels. You don't need to manage a crop very carefully if your end use is to burn it.

His final conclusions are:
Biomass conversion is capable of providing a very large proportion of our energy needs
Current energy crops have not yet been optimized
Current technologies to process energy crops have not been optimized
"There are no insurmountable problems to achieving cost-effective, carbon-neutral solar energy production from plants."

On the eco-agriculture side, he says that biomass ag will be especially low-impact because:
Fewer chemical inputs are needed
Energy crops could be grown in mixed cultivation (e.g. with native plants) and harvested late to increase biodiversity.

I think I buy it.