Biofuels in the Future
Using the world's best farmland to grow biomass for fuel can lead to indirect land-use changes that accelerate global warming and increase competition for food worldwide-but that's only part of the story, said three experts at the International Biomass '08 Conference & Trade Show held in April in Minneapolis.
The contending needs for energy, food, sustainability and carbon reduction is an intensifying worldwide dilemma. The world's population is growing and arable land is not, Tilman said. "Our population is at 6.3 billion people and heading toward 9 to 9.5 billion people," he said. "We're on a steep population growth curve. People around the world are consuming more of everything-not just food-and in the next 50 years the population will grow by another 3 billion more people."
Rising incomes in developing parts of the world are allowing millions of people to transition from subsistence diets consisting of mainly grains to those including beef. This dietary shift is accelerating the demand for grain around the world at a rate that is "much greater than the world's farms can produce," and that is contributing to higher grain, land and food prices. Similar forces are driving energy prices higher. "Global energy consumption has doubled in the past 50 years, paralleling demand for food," Tilman said, explaining that it will double again in the next 40 years.
As this global competition for land materializes, there is a growing belief that producing fuel from traditional food crops is leading to corn, soybean oil and wheat being priced at the "energy equivalent" of $100-per-barrel oil. "There's a fear that the food and energy sectors are becoming less independent and more joined," the ecologist said.
In spite of these new pressures, Tilman said there is still enormous potential for next-generation biofuels if they can attain irrefutable low-carbon status. In addition to sharply cutting the fossil energy used to make biofuels-a would-be boon to biomass power-future producers must look to waste, agricultural residues and perennial energy crops grown on marginal, degraded or abandoned land to achieve conclusive low-carbon status, he said.
Tilman's critics say those constrictions greatly diminish the role of biofuels in an increasingly carbon constrained world. In fact, Tilman admits that only 15 percent of the world's current petroleum use could be offset by biofuels made from the environmentally friendly feedstocks he endorses.
Tilman is best known in the biofuels industry for his groundbreaking work with mixed prairie grasses for ethanol production. The Cedar Creek Biodiversity Experiment in Minnesota showed that the best yields of biomass energy per acre came from planting a combination of six perennial grass species together on unproductive land. Biofuels made from such high-diversity prairie grasses are carbon negative, in theory yielding 140 percent less greenhouse gases than gasoline, he said.
In the near future, Tilman said, it's likely that the high price of food and food crops will make it increasingly less likely that farmers will dedicate grain to biofuels. "Economics and ethics will likely mean that our best land will go to food production with ag residue and dedicated energy crops like mixed prairie grasses grown on degraded land going to biofuels," he said.
The Emergence of ‘New Agriculture'
Lynd, a leading biomass expert and co-founder of Mascoma Corp., asserted that land conversion theory is new, fragmented and still not wholly accepted by the scientific community. He said it's decidedly premature to conclude that biofuels have no potential because of their superficially inherent connection to land-use change. "The space has been so incompletely explored," he said, adding that the hope of "new agriculture" will provide previously unforeseen pathways around the land conversion dilemma.
New uses and new combinations for existing crops, as well as new crops and new crop systems will lead to exponential gains in productivity and biomass yields, Lynd said. "This new agriculture has only scant investigation worldwide."
Looking at the broad issue of land use and resource consumption, Lynd said the world will not be able to produce its way out of the dilemma it now faces. He said it will require systemic redesign and radical changes in the way we use and produce energy. Ultimately, Lynd said, the continued investigation and development of biomass-based fuels, coupled with the limitless potential of new agriculture, hold great potential for dramatic land-use reductions while increasing the amount of land used for food, feed and fuel globally. "Even the most challenging cellulosic ethanol land conversion scenarios can achieve large carbon reductions given the motivation to achieve [that] outcome."
Lynd said theories put forth by scientists such as Princeton's Tim Searchinger do not embody the multiple systemic changes that are characteristic of sustainable transition paths. Translation: They lack hope and underestimate human ingenuity.
Advances in agriculture and biofuels production technology won't be enough, however. Lynd said a host of factors must coalesce to bring about the changes that are now widely accepted as necessary. Vehicle efficiency (fuel economy), for example, will have to improve by a multiple of 2.5, as will biomass crop yields. Someday, he said, it might be possible to meet all of the world's food and mobility needs using 10 percent less land than we use today.
Volume Requirements Versus Performance
Greene said the biofuels industry should not casually dismiss land-use-change and food-versus-fuel theories, as Iowa Sen. Charles Grassley, R-Iowa, did last week calling the recent criticism of ethanol by foreign officials "a big joke," according to The New York Times. Rather, he said, it's vital to acknowledge the role biofuels play-negligible or not-in land-use-related issues.
There are, however, many other factors at play, Greene said.
"If you step back a little bit, it's easier to see the complexity of this issue," he said, explaining that the world's growing population, rising incomes, changing diets, and increased energy demand, as well as a growing demand for biofuels from food crops, are putting increased pressure on land and food prices. "All of these things are attributed to increased grain prices," he said. "Increased grain prices are leading to higher prices for land. As grain goes up, so does land. We've already seen land prices go up substantially in the United States and that's going to trickle throughout the rest of the world. It also puts more pressure on farmers to increase yield, and there are a variety of ways they can do that but driving the land harder is going to be among them. Higher land prices and higher pressure for increased yields are going to lead, in an unconstrained world, to increased clearing of land, more fertilizer and more tillage."
Building on the assertions made by Tilman and Lynd, Greene said the key to making biofuels work is exploring paths to increase both food and biomass production while steering clear of land conversion drivers. "We can get more food and more biomass off of our land, fighting global hunger and global warming at the same time," he asserted.
Farmers need an incentive to change, however, and the fastest, most effective way to provide that incentive is through public policy, Green said. "We need to avoid extremes, embrace change and pay for performance, he said. "We need to put dollars on the table for the things we want as a society."
Referring to the corn ethanol industry's vital function as a bridge to next-generation biofuels, Greene said, "We can't expect an industry to accept change that victimizes or cannibalizes its current existence."
On the other hand, it's time to start making performance-based policy choices that favor low-carbon biofuels. "Feedstocks that use very little land or are outside of land-use competition should not be penalized," he said. "Feedstocks that are grown on flat, black, prime arable land-those that cause the most land-use competition-should have the highest penalty."
Greene said the new 36-billion-gallon renewable fuels standard moves the United States in the right direction with its land-use safeguards, aggressive production targets and bold greenhouse gas emissions reduction floors. However, the NRDC would eventually prefer to see a more fundamental low-carbon fuel standard with performance-based incentives that go beyond carbon to water and land-use-change sustainability checks.
"We need to move away from these simple, blunt volume requirements that just pay for more and more production, and start paying for performance," he said. "We should also move away from technology picking. Let's let the market and the innovation of industry and farmers figure out, through [low-carbon policy drivers], what we as a society need."
Tom Bryan is editorial director of Biomass Magazine. Reach him at firstname.lastname@example.org or (701) 738-4962.