Crop biofuels unlikely to halt climate change
The unmet promise that crop-based biofuels can become a carbon-neutral fuel allowing mankind to use as much as we like was shattered earlier this month.
A team led by Dr. Timothy Searchinger of Princeton University concluded that corn-based ethanol nearly doubles greenhouse emissions and switchgrass ethanol — sometimes called cellulosic ethanol — increases emissions by 50 percent. Giving hope for ethanol projects in Hawai‘i, Searchinger said the greenhouse gas impact for ethanol from sugarcane was substantially better, but still not sufficiently quantified.
Natural carbon cycle
Since the start of the industrial revolution, most of mankind’s energy needs have been met by coal and oil, the fossil fuels we now understand are causing a serious climate change problem. Burning fossil fuels releases large amounts of carbon into the atmosphere that had been safely locked underground for millions of years.
Burning fossil fuels interferes with the Earth’s natural carbon cycle in which green plant life absorbs carbon dioxide (CO2) from the air and uses the carbon to build stalks and stems and leaves and tree trunks. At the end of the plant’s life, the carbon breaks down and is returned to the atmosphere as greenhouse gases. Even if the plant is eaten or harvested, the natural carbon cycle isn’t disrupted because eventually the carbon ends up in something that decomposes back into greenhouse gas.
The idea behind biofuels is a simple one: If mining million-year-old carbon disrupts the Earth’s natural carbon cycle, why not stop doing it and take advantage of the natural carbon cycle to grow fuel. The idea of growing fuel is as old as mankind. It was the first fuel used to cook food, stay warm and light the dark night.
The use of biofuels didn’t end before the industrial revolution. Rudolf Diesel, who invented the diesel engine, ran his first models on peanut oil. Henry Ford’s first prototype car ran on corn alcohol. In Europe during World War II, over a million vehicles we converted to run on wood-burning gasifiers because gasoline and diesel were often unavailable to civilians.
Biofuel has advantages, but numbers daunting
It is easy to see why biofuels are hailed as a solution to climate change. The technology to make ethanol and diesel from a variety of crops is well understood and the world has an efficient infrastructure for growing crops.
Biofuels are very compatible with our current energy infrastructure. These bioliquid fuels can be stored, transported and sold just like their fossil fuel counterparts with almost no changes to the vast worldwide energy infrastructure. Even the engine technology developed for more than 100 years to burn fossil fuels can be easily converted to burn crop biofuels.
But our nation’s current appetite for fuel far exceeds our land, making crop biofuels impractical as a simple replacement strategy.
If America turned its entire annual production of corn into ethanol, including the 2.25 billion bushels of corn America exports, it would only replace 12 percent of the gasoline we consume. If America turned its entire annual production of soybeans into biodiesel, including the 400 million bushels exported, it would only replace 6 percent of the diesel we consume.
Food or fuel
The huge amount of cropland required to make biofuels is the heart of the first problem with their large-scale use. What is more important: food or fuel?
While we can make more tractors and even shift labor into agriculture, the foundation of farming is the land itself. And the most productive land is already in cultivation to grow food.
The United Nations first major report on bio-energy released last May concluded that liquid biofuel production could “threaten the availability of adequate food supplies by diverting land and other productive resources away from food crops.”
Dramatic, real impacts of this food versus fuel conflict came to light last year.
Corn tortillas are a staple in the diet of Mexico’s poor, supplying more than 40 percent of their daily protein. But tortilla prices tripled or quadrupled from summer 2006 to winter 2007, increasing hunger and starvation.
Burning and plowing to convert tropical rain forests or temperate pasture grasslands into cropland releases huge amounts of greenhouse gas. Once converted, cropland absorbs far less carbon than the vegetation it replaced. And the effect isn’t minor. Joseph Fargione, a scientist at the Nature Conservancy, calculated clearing grassland releases 93 times the greenhouse gas that could be saved by the biofuel grown annually on that land.
Fargione and Searchinger’s independent work taken together is damming: It doesn’t matter what kind of land is cleared for crop biofuel production, the effect is that greenhouse gas emissions will increase significantly. They both also concluded that the production of crop biofuels almost universally resulted, albeit sometimes indirectly, in new cropland needing to be cleared.
Waste not want not
Although crop-based biofuels will actually accelerate climate change instead of reducing it, there are ways to make fuels from organic sources without crops. Although the quantity of biofuels created will never be enough to completely replace liquid fuels as we use them today, these “clean” biofuels have an important part to play in slowing climate change.
A great deal of organic material is simply treated as garbage. Lumber mills produce bark, sawdust, wood chips and wood scrap as waste. Landfills produce methane gas. And livestock farms create large amounts of animal waste. All this organic waste material creates a huge garbage problem, but could become clean energy.
Gasification of wood waste, like the idea proposed by Green Energy Hawaii’s Eric Knutzen and Hawaiian Mahogany’s Bill Cowern, is already in use around the world to turn garbage problems into an energy solutions. For example, the Tolko plywood mill in Heffley Creek, British Columbia produces tons of green bark wood waste. Instead of treating it like a garbage problem to dispose of, Tolko built a gasification plant that produces 65.3 million kilowatt-hours annually.
In landfills like ours at Kekaha, organic garbage rots and releases methane gas. The Environmental Protection Agency reports that by 2004, more than 375 operational landfill energy projects in 38 states supplied 9 billion kilowatt hours of electricity, and 74 billion cubic feet of methane to end users, the equivalent of 150 million barrels of oil.
Organic waste from livestock farmers can be efficiently converted to fuel. The federal AgStar program, run jointly by EPA, DOE and the U.S. Department of Agriculture, works with livestock farmers to capture biogas from animal waste for on-farm energy. At a larger scale, a $200 million, 55-megawatt power plant is under construction that will be powered completely by manure from Minnesota’s numerous turkey farms.
The focus on biofuels and climate change has resulted in a great deal of research on growing algae as a biofuel. Although the research has not yet resulted in anything beyond small prototypes, scientists hope to create an idea fuel source. Algae could be grown with little land use impact; it could avoid the food vs. fuel dilemma, and, in fact, could even be used to scrub CO2 directly from power plant emissions. If all that sounds too good to be true, it is probably because it isn’t true yet today, and like many scientific efforts may not yield results for many years, if ever.
Ethanol made from Kaua‘i sugarcane
Gay & Robinson, in partnership with Pacific West Energy, is planning a 12 million-gallon-per-year ethanol plant and a bagasse-fired boiler and turbine to generate electricity to sell to the Kaua‘i Island Utility Cooperative. The project, on the drawing board for years, has been delayed repeatedly for a variety of reasons: federal and state subsidies had to be firmed up, financing was an issue as the cost of the project grew, the price of ethanol has varied from $4 to $1.50 to $2.30 today, and multiple federal and state permits are required. The last round of delays occurred as the plant was redesigned to reduce costs necessary to be competitive in a market with failing ethanol prices.
The project’s developers point out key benefits, including economic development on Kaua‘i Westside and reducing our dependence on imported foreign oil. The benefit important to reduce climate change is a possible net reduction in greenhouse gas when some of Hawai‘i’s gasoline appetite is replaced with 12 million gallons of ethanol from the plant each year.
Brazilian studies estimated greenhouse gas reductions of 86 percent when ethanol from sugarcane replaces the use of gasoline. These savings require that waste bagasse be used to produce electricity, further displacing fossil fuel emissions, as is planed for the Kaua‘i project. However, the Brazilian estimates do not include greenhouse gas emissions resulting from land use changes, the issue identified in studies early this month by Searchinger and Fargione.
The sugar used to make ethanol on Kaua‘i must be offset by increased production of sugar for food somewhere else in the world.
Searchinger calculates the greenhouse gas emissions from putting rainforest acreage into sugar production somewhere else in the world will result in a greenhouse gas payback period for sugarcane ethanol of 46 years. Worse yet, if the replacement sugarcane is grown in wetlands, common on the Mainland, the emissions could be significantly greater and the payback period much longer. While diverting Kaua‘i’s sugar production into ethanol may have local benefits, it will increase greenhouse gas emissions and speed climate change.
However, ethanol production on Kaua‘i may not deserve the negative greenhouse gas credit for this land-use effect. Unable to compete with sugar grown more cheaply elsewhere, the profitability of sugar production on Kaua‘i is steadily declining.
A&B closed its McBryde Sugar Co. in September 1996. Amfac stopped growing sugar in 2000.
If Kauai’s sugar land would eventually become fallow, then no indirect conversion of land anywhere else can be attributed to local ethanol production. In this case Searchinger estimates a four-year greenhouse gas payback period.
Growing sugarcane on Kaua‘i to make ethanol, if the alternative is to let the land go uncultivated, may be one of the few biofuel crops with a practical chance of reducing greenhouse gas emissions.
To reduce greenhouse gas emissions and fight climate change we must stop encouraging crop biofuels. Tad Patzek, an engineering professor at the University of California and co-author of a recent report on ethanol, says we should channel the billions of dollars spent on corn crop ethanol into fuel-efficient cars and solar cells. This point of view has become almost universal across academics, economists, and renewable energy scientists.
Another place to direct our priorities is to capture practical waste biomass for energy.
Of course, using energy more efficiently and conserving energy should remain a top priority to reduce greenhouse gas and slow climate change. Eberhard Jochem, professor of economics and energy economics at the Swiss Federal Institute of Technology, explained in Scientific American, “The huge potential of energy efficiency measures for mitigating the release of greenhouse gases into the atmosphere attracts little attention when placed alongside the more glamorous alternatives of nuclear, hydrogen or renewable energies. But developing a comprehensive efficiency strategy is the fastest and cheapest thing we can do to reduce carbon emissions. Wasting less energy is the quickest, least expensive way to stem carbon emissions.”
• Walt Barnes, a Wailua resident, is a scientist and writes a series of columns about the man-made causes of global warming for The Garden Island. He can be reached at email@example.com