January 22, 2006

This year’s report of the Worldwatch Institute focuses on China and India, as these two nations join the United States and Europe as major consumers of resources and polluters of local and global ecosystems. The report explains the critical need for both countries to “leapfrog” the technologies, policies, and even the cultures that now prevail in many western countries for the sake of global sustainability


Suzanne C. Hunt, Janet L. Sawin and Peter Stair discuss renewable alternatives to oil

“The fuel of the future is going to come from fruit like that sumac out by the road, or from apples, weeds, sawdust — almost anything,” the CEO of the Ford Motor Company told a reporter for the New York Times. “There is fuel in every bit of vegetable matter that can be fermented.”

Those words, which perfectly capture the sense of excitement and potential surrounding biofuels today, were actually spoken in 1925 by Henry Ford. Some of the earliest motor vehicles developed by Ford and others ran on biofuels — on mixtures of ethanol and gasoline for the early spark ignition engines and on peanut and hemp oils in Rudolph Diesel’s earliest compression engines.

Today, following an eight-decade detour in the petroleum age, biofuels are back — fueled by a powerful combination of advancing technologies, rising environmental concerns, farmer support, and soaring oil prices.

Biofuels are made from plant matter — from sugarcane, for instance, or soybeans — and other renewable feedstocks. The most widely used transport biofuels are ethanol and biodiesel, with ethanol currently accounting for more than 90 per cent of global biofuel production. About one quarter of world ethanol production goes into alcoholic beverages or is used for industrial purposes (as a solvent, disinfectant, or chemical feedstock); the rest becomes transport fuel for motor vehicles.

Biodiesel, on the other hand, is made from plant oils that are modified into a fuel very similar to diesel. Most of the world’s biodiesel is used for transportation fuel, but some is used for home heating and other applications.

Global production of ethanol has more than doubled since 2000, while production of biodiesel, starting from a much smaller base, has expanded nearly threefold. In contrast, oil production has increased by only seven per cent since 2000. The two biofuels provided just two per cent of global transportation fuels in 2004. Brazil, which has led the way in biofuels development since 1980 and which produces 37 per cent of ethanol worldwide, has demonstrated the large scale viability of this fuel source — ethanol from sugarcane accounted for roughly 40 per cent of Brazil’s non-diesel motor fuel in 2004.

The increase in petroleum prices since 2004 has raised interest in biofuels and prompted other nations to follow Brazil’s lead. Delegations from China, India, Peru, the Philippines, and Thailand have travelled to Brazil, hoping to replicate that nation’s success or to line up ethanol imports. Interest in biofuels is growing rapidly, generating a seemingly constant stream of new initiatives.

Farmers, energy companies, and consumers the world over are discovering that biofuels are not as fanciful or as far in the future as they thought. Many energy experts believe that biofuels have the potential to displace a significant amount of petroleum around the world over the next few decades. And the next generation of biofuels holds even more promise. “Cellulosic ethanol” and “designer diesel fuels” can be made from a wide range of materials, including corn stalks, wheat straw, paper, sewage, and municipal wastes — and potentially with far lower economic and environmental costs than the current generation of biofuels.

The wide range of potential benefits from the large-scale use of biofuels is creating unusual coalitions of political support among groups often at odds: farmers who are seeking new markets, oil executives who want to remain in the energy business for the long term, environmentalists opposed to the polluting impacts of fossil fuels, and pacifists and military hawks who fear that dependence on unreliable sources of oil is undermining national security.

Dramatic growth in biofuels is virtually certain in the years ahead. While the potential economic and environmental benefits could be significant, some crucial questions remain to be answered: Can biofuels grow rapidly enough to offset a significant proportion of world oil use? Will production of crops for fuel crowd out food crops and wildlife habitat? Will it deplete soils? How will a transition to biofuels affect the global climate? How can farmers continue to reap the economic benefits of biofuels as multinational companies step up their investments in all segments of the production chain? And what mix of policies is most likely to steer the biofuels bandwagon in a direction that is economically and environmentally sustainable?

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Environmental risks and opportunities

Since 1978, ambient lead concentrations in Sao Paulo, Brazil, have declined dramatically, and people nationwide have been able to breathe cleaner air due, in large part, to Brazil’s ambitious ethanol programme. But while city dwellers have benefited greatly from air with fewer toxic emissions, people in rural areas have endured the rising environmental costs of a large and expanding ethanol industry. The expansion of sugarcane production has replaced pasturelands and small farms of diverse crops with large monocultures.

Preharvest burning of cane fields blanketed local skies with huge clouds of black smoke, while polluted water dumped from ethanol distilleries has harmed rivers and their ecosystems. Over the years, Brazil has developed ways to mitigate these problems, including harvesting methods that do not require burning, waste water treatment methods, and novel ways to use process residues.

The impact of biofuels on the global landscape, atmosphere, and wildlife has been relatively small to date, particularly when compared with the environmental and health costs of extracting, processing, and burning fossil-based fuels. But as production levels rise dramatically and all nations increase their use of biofuels, the environmental tradeoffs seen in Brazil could be experienced on a far larger scale.

Whether blended with conventional fuels or used “neat,” the combustion of biofuels results in far lower emissions of several pollutants, including carbon monoxide, hydrocarbons, sulfur dioxide, and particulate matter, than burning petroleum fuels would. Ethanol can also replace more-polluting additive such as MTBE and tetraethyl lead, as an oxygenating agent in fuel. Thus the use of biofuels can significantly reduce local and regional air and water pollution, acid deposition, and associated health problems such as asthma, heart and lung disease, and cancer.

Biofuels in low-blends can emit greater amounts of nitrogen oxide and hydrocarbons than conventional fuels do. But higher blends of biofuels, fuel additives, and advanced combustion and emissions control technologies that are widely available in new vehicles today can mitigate or eliminate these problems. In general, the air quality benefits of biofuels are greater in developing countries, where vehicle emissions standards are nonexistent or less stringent and where older, more polluting cars are more common.

The potential to significantly reduce carbon emissions and the threat of climate change is one of the greatest advantages offered by biofuels. Unlike fossil fuels — which contain carbon stored for millennia beneath Earth’s surface and which release enormous amounts of greenhouse gases (GHGs) when burned — biofuels have the potential to be “carbon-neutral” over their life cycles. This is true not only because plants absorb carbon dioxide while they grow, but also because some crops sequester carbon in the soil and do not require tilling or the use of fertilizers and other petroleum-based chemicals. Also, some energy feedstocks, like wheat straw and corn stalks, are the byproducts of other crops.

The climate impact of biofuels depends on their fossil energy balance: how much energy is contained in the biofuels versus how much fossil fuel energy was needed to produce them. This in turn depends on the energy intensity of feedstock production — including the type of farming system and inputs used, processing, and transport, as well as the share of emissions associated with co-products. Corn-derived ethanol, for example, may indirectly emit as much fossil carbon into the atmosphere as gasoline does if the corn is grown conventionally with nitrogen fertilizers made from natural gas, harvested and delivered with vehicles run on conventional fuel, and distilled with electricity generated from coal or natural gas. If the corn is fertilized with manure, harvested and delivered with biofuels, and distilled with renewable power, however, associated life-cycle emissions can be dramatically lower than those from gasoline. Petroleum-derived fuels offer no such options, and a litre of gasoline always requires more energy input than it contains.

Even if renewable energy is not used to produce fertilizers, propel tractors, and run the biofuel conversion process, most studies find a significant net energy gain and a decrease in greenhouse gas emissions compared with conventional transport fuels. Estimates of GHG reductions for grain-based ethanol range from 20 to 40 per cent, while cellulosic ethanol could achieve reductions of 70-90 per cent. Where exactly the reductions fall in these ranges depends on which crops are grown and what they replace. For example, the drop in emissions can be far higher if annual crops are replaced with perennial plants than if wild forests are cleared for feedstock.

Today most biofuel crops are grown in intensive monocultures — vast fields of a single plant type that require large amounts of fertilizers, invite pests, deplete the soil, and destroy important plant, bird, and animal habitat. The US Corn Belt, for example, stretches across former beech and maple forests and tall grasslands. In Brazil, new sugarcane plantations are rapidly replacing more varied land uses, while intensified cultivation of palm oil in Southeast Asia is contributing to the rapid destruction of tropical forests.

The development of biomass gasification and of technologies that convert cellulosic biomass to ethanol will permit, among other things, the use of native perennial grasses and woody crops that do not require annual tillage. In contrast to corn or soybeans, they require fewer inputs, can sequester more carbon, and provide quality wildlife habitat. The efficiency of energy production for a perennial grass system can exceed that for an annual crop like corn by as much as 15 times while grass crops can sequester 20-30 times as much carbon in the soil.

Several studies indicate that the number and diversity of birds is consistently higher on perennial crop plantations than in row-crop or small-grain fields. For instance, some bird species may benefit directly from habitat created by short-rotation woody crops such as poplar plantations, while grassland species could benefit from switchgrass crops. And if energy crops are harvested in alternating years and rows, they leave behind a more varied ecosystem and can expand the habitat for migratory birds and other wildlife.

Further, strategically planted energy crops can absorb nutrient runoff from more heavily fertilized conventional crops upslope and can catch sediment as it flows toward waterways. One US study showed that a 50-foot buffer at the lower end of a crop field that is planted with native grasses and woody vegetation removed more than 90 per cent of the sediment, total nitrogen, and phosphorus in the runoff.

Rather than compete with higher-valued crops on the best farmland, it is likely that agricultural biomass feedstocks will come increasingly from two less-expensive sources: marginal lands that do not or should not produce high yields of grains or oilseeds, and stover, stems, and other crop residues that are not currently used for anything. As more “waste” products are used to produce biofuels, however, it will be important to determine how much of the residue can be harvested without threatening the year-round land cover and improvement to the soil that this biomass provides.

In the best-case scenario, crops can provide fuel while also reducing soil erosion, slowing or reversing desertification, improving air and water quality, providing wildlife habitat, and reducing GHG emissions. In the worst case, biofuels production and use can increase food prices, add to soil erosion and desertification, further pollute air and water, and destroy ecosystems. To help ensure that the balance is positive, researchers in Europe are laying the groundwork for certification schemes that would encourage sustainable biofuel production practices. Criteria are being developed to assess indicators of sustainability, such as soil fertility, equity of landownership, waste management, and local economic development.

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The future

There is little doubt that biofuels will play a growing role in our energy future. The big question is, how large a role? And how much biofuel can be produced sustainably? It is difficult to make concrete projections, but energy experts agree that biofuels have the potential to satisfy much of the ever-increasing global demand for transportation fuels in the coming decades. The rate at which production will grow and the amount that can ultimately be harvested will depend on many complex, interrelated factors. The most important of these are the price of oil, policy and investment decisions, improvements in agricultural productivity, and advances in conversion technology.

For centuries humans have selectively bred plants for their food values, and with great success. Equally dramatic results are expected as the arsenal of plant breeding techniques is turned on crops for their energy values. Already, crop-breeding programmes have been established in Germany, China, and elsewhere. Genetic engineering techniques are also being used, although they raise a number of contentious issues. A recent joint effort between Monsanto and Cargill has resulted in a type of soybean that the companies claim yields 50 per cent more oil without compromising protein content.

Projections of global biofuels production rise as analysts look further into the future, based on the assumption that advanced conversion technologies will soon be commercialized. Auto manufacturer DaimlerChrysler projects that advanced biodiesel fuels could represent 10 per cent of the European diesel market by 2015. US government agencies have estimated that biodiesel and ethanol could displace between 25 and 50 per cent of US petroleum-derived fuels by 2030. Long-term projections based on the use of agricultural and forestry wastes, and on the use of dedicated energy crops grown on abandoned farmland and marginally productive lands, indicate that the world could theoretically harvest enough biomass to satisfy the total anticipated global demand for transportation fuels by 2050.

The biggest producers — Brazil, the United States, the European Union, and China — all plan to more than double their biofuels production within the next 15 years. Australia, Canada, Colombia, Costa Rica, Kenya, Indonesia, Paraguay, and Thailand are among the many other nations that have deployed or are considering fuel blending mandates, tax credits, or major investments in biofuels research and infrastructure. They are driven by a range of factors, from concerns about regional pollution and global climate change to the desire to help rural communities and to break free from dependence on imported oil.