Human civilization is maybe 10,000 years old, and for all but 200 of those years, we got most of our energy from plants in the form of firewood. The recent detour into fossil fuels is understandable: Oil and coal were cheap and abundant at first, and there weren't enough trees to power a modern global economy. But with the age of fossil fuels about to end, a case can be made that it's time to return to the old way of doing things, updated with modern technology. Plants, after all, are nature's solar energy storage devices. They convert sunlight into stalks and leaves that can, in theory, be tapped to make electricity or fuel. And since they sequester carbon when they grow, converting them to energy merely puts back what they've taken from the atmosphere. That is, "biofuels" are carbon neutral.
Returning to Our Roots
Biofuels also have other (albeit still theoretical) advantages. As agricultural products, biofuel crops should be less volatile than oil. If prices go up, we just plant more. And because most countries, the United States included, can grow their own biofuel crops and convert them to gasoline substitutes, biofuels would allow today's oil-importing countries to stop sending all their money to OPEC, and instead give it to their own tax-paying, incumbent-voting farmers. The result: energy and food security in one sweetly popular policy initiative.
But wait, there's more. It costs just a few hundred dollars to convert a conventional internal combustion engine to run on some biofuels, and since the infrastructure already exists for handling liquid fuels, replacing gasoline with the right biofuels wouldn't require a lot of new trucks or pipelines. Compared to the $3,000 or so per car cost of hybrids and the who-knows-what it will cost to covert to a full-blown hydrogen economy, biofuels look simple and cheap. Evolutionary rather than revolutionary-a return to our roots, so to speak.
Brazil is a good example of how this might work. It has spent the past decade developing the ability to turn sugarcane into ethanol, which can be used in place of gasoline. The Brazilian transportation system now runs primarily on this locally produced fuel, which is both cheaper than gasoline and immune from Middle East supply disruptions. So how do the rest of us get from here to there? The key is to find plants that
Produce an acceptable amount of energy without unacceptable side effects
Can be "optimized" through the development of new, higher-yielding strains
Then we have to figure out how to extract their energy ever more cheaply and in ever-larger amounts. In other words, the technology has to scale, and "miles per acre" has to soar. We're not there yet, but some of the approaches now being tried offer reason for hope.