When people first started talking about biofuels—especially bioethanol, which is made from plant material—they had grand plans. Biofuels were supposed to reduce our dependence on foreign oil, help fight climate change by producing fewer carbon emissions than fossil fuels, and reduce poverty in the developing world by providing employment for farmers. Unfortunately, a few decades into the biofuel revolution, many experts are saying that plant-based fuels aren’t living up to their promise. In fact there’s a growing body of evidence to suggest that they’re actually making things worse. Here are just a few examples:
- Biofuels are taxing the world’s water resources by using massive amounts of water for irrigation. In many places (particularly in the Midwestern United States) that water is being taken from nonrenewable aquifers. The process of turning plants into fuel is also very water intensive.
- Because biofuels were billed as the magic cure-all for the world’s problems, land that previously had been used to provide food for humans is being diverted to biofuel production. With less land available for growing human food, there’s less of it available. That has driven up the price of food—particularly in developing countries. As a result, people who were already poor are being pushed further and further into poverty.
- It turns out that instead of reducing greenhouse gasses, biofuels pump just as much pollution into the air as oil and gas. In other words, the carbon footprint of biofuels is just as massive as that of fossil fuels.
That’s not a terribly optimistic scenario, is it? It's true that corn and other crops aren’t working out as sources of cheap energy, but we shouldn't give up on biofuels just yet. There’s one plant that may be able to live up to biofuel’s original hype—without falling into any of the traps we just discussed: prickly pear cactus. Sounds a little crazy, but here’s how it works.
First, cacti primarily grow on land where rainfall is unpredictable. Since food crops generally require regular rainfall, cacti won’t be competing with food crops. Currently about 18 percent of the world's land could support cactus production but is not suitable for hardly any other crop.
Second, because cactus farming would use currently unusable land, it would provide income-producing agriculture jobs in many parts of the developing world where all the available arable land is already occupied. Aside from being able to thrive in the desert where it’s unbearably hot, prickly pear cactus also has the amazing ability to survive in below-freezing temperatures (as low as –15 degrees C/5 degrees F). That opens up even more unused land for possible cactus harvesting.
Third, cacti are different from most plants in the way they carry out photosynthesis. By hoarding water during the day, cacti need only about one-fifth of the water that traditional plants do. And to produce one unit of dry biomass (using that measure we can compare apples to apples, or more accurately, cactus to corn), cactus takes only one-tenth of the water that the usual plant-based biofuels do.
The next time someone offers you a great deal on some landlocked desert property, think twice before you turn it down. You might just miss out on the next big thing.