Are all biofuels equal in terms of their capacity to reduce greenhouse
gas emissions relative to the use of gasoline? If not, what factors
determine which biofuels have greater capacity to reduce greenhouse gas
emissions? What is the most reliable method of measuring a biofuel’s
effectiveness for reducing greenhouse gas emissions? What role does land
conversion make in determining the effectiveness of biofuels in reducing
greenhouse gas emissions? Which biofuels of the future are likely to
result in maximal reductions in greenhouse gas emissions? How close are
we to that future?
Moderator:
- Dr. Anthony Socci, Senior Science Fellow, American Meteorological
Society
Speakers:
- Dr. Joseph E. Fargione, Regional Science Director, The Nature
Conservancy, Central US Region, Minneapolis, MN
- Timothy Searchinger, Visiting Scholar and Lecturer in Public and
International Affairs, Princeton University, Woodrow Wilson School,
Princeton, NJ
- Dr. Daniel M. Kammen, Class of 1935 Distinguished Professor of Energy,
Professor in the Energy and Resources Group Energy and Resources Group
(ERG) , Professor of Public Policy in the Goldman School of Public
Policy, Professor of Nuclear Engineering in the Department of Nuclear
Engineering, and Co-Director, Berkeley Institute of the Environment,
and Founding Director of the Renewable and Appropriate Energy
Laboratory (RAEL), University of California, Berkeley, CA
- Dr. G. David Tilman, Regents’ Professor and McKnight Presidential
Chair in Ecology, University of Minnesota, St. Paul, MN
Program Summary
Biofuels: Threats and Opportunities
- It is possible to make biofuels that reduce carbon emissions, but only
if we ensure that they do not lead to additional land clearing.
- When land is cleared for agriculture, carbon that is locked up in the
plants and soil is released through burning and decomposition. The
carbon is released as carbon dioxide, which is an important greenhouse
gas, and causes further global warming.
- Converting rainforests, peatlands, savannas, or grasslands to produce
food crop–based biofuels in Brazil, Southeast Asia, and the United
States creates a “biofuel carbon debt” by releasing 17 to 420 times
more carbon dioxide than the annual greenhouse gas reductions that
these biofuels would provide by displacing fossil fuels.
- Depending on future biofuel production, the effects of this clearing
could be significant for climate change: globally, there is almost
three times as much carbon locked up in the plants and soils of the
Earth as there is in the air and 20% of global carbon dioxide
emissions come from land use change.
- Global demand for food is expected to double in the next 50 years and
is unlikely to be met entirely from yield increases, thus requiring
significant land clearing. If existing cropland is insufficient to
meet imminent food demands, then any dedicated biofuel crop production
will necessarily create demand for additional cropland to be cleared.
- Several forms of biofuels do not cause land clearing, including
biofuels made from algae, from waste biomass, or from biomass grown on
degraded and abandoned agricultural lands planted with perennials.
Present Generation of Biofuels: Reducing or Enhancing Greenhouse Gas
Emissions?
Previous studies have found that substituting biofuels for gasoline will
reduce greenhouse gasses because growing the crops for biofuels
sequesters takes carbon out of the air that burning only puts back,
while gasoline takes carbon out of the ground and puts it into the air.
These analyses have typically not taken into consideration carbon
emissions that result from farmers worldwide converting forest or
grassland to produce biofuels, or that result from farmers worldwide
responding to higher prices and converting forest and grassland into new
cropland to replace the grain (or cropland) diverted to biofuels. Our
revised analysis suggests that greenhouse gas emissions from the land
use changes described above, for most biofuels that use productive land,
are likely to substantially increase over the next 30 years. Even
advanced biofuels from biomass, if produced on good cropland, could have
adverse greenhouse gas effects. At the same time, diverting productive
land raises crop prices and reduces consumption among the 2.8 billion
people who live on less than $2 per day.
Simply avoiding biofuels produced from new land conversion – as proposed
by a draft European Union law – does not avoid these global warming
emissions because the world’s farmers will replace existing crops or
cropland used for biofuels by expanding into other lands. The key to
avoiding greenhouse gas emissions and hunger from land use change is to
use feedstocks that do not divert the existing productive capacity of
land – whether that production stores carbon (as in forest and
grassland) or generates food or wood products. Waste products, including
municipal and slash forest waste from private lands, agricultural
residues and cover crops provide promising opportunities. There may also
be opportunities to use highly unproductive grasslands where biomass
crops can be grown productively, but those opportunities must be
explored carefully.
Biofuels and a Low-Carbon Economy
The low-carbon fuel standard is a concept and legal requirement in
California and an expanding number of states that targets the amount of
greenhouse gases produced per unit of energy delivered to the vehicle,
or carbon intensity. In January 2007, California Gov. Arnold
Schwarzenegger signed Executive Order
S-1-07, which called for a
10-percent reduction in the carbon intensity of his state’s
transportation fuels by 2020. A research team in which Dr. Kammen
participated developed a technical
analysis
of low-carbon fuels that could be used to meet that mandate. That
analysis employs a life-cycle, “cradle to grave” analysis of different
fuel types, taking into consideration the ecological footprint of all
activities included in the production, transport, storage, and use of
the fuel.
Under a low-carbon fuel standard, fuel providers would track the “global
warming intensity” (GWI) of their products and express it as a
standardized unit of measure—the amount of carbon dioxide equivalent per
amount of fuel delivered to the vehicle (gCO2e/MJ). This value measures
vehicle emissions as well as other trade-offs, such as land-use changes
that may result from biofuel production. For example, an analysis of
ethanol shows that not all biofuels are created equal. While ethanol
derived from corn but distilled in a coal-powered refinery is in fact
worse on average than gasoline, some cellulosic-based biofuels – largely
those with little or no impact on agricultural or pristine lands have
the potential for a dramatically lower GWI.
Equipped with detailed measurements that relate directly to the
objectives of a low-carbon fuel standard, policy makers are in a
position to set standards for a state or nation, and then regulate the
value down over time. The standard applies to the mix of fuels sold in a
region, so aggressively pursuing cleaner fuels permits some percentage
of more traditional, dirtier fuels to remain, a flexibility that can
enhance the ability to introduce and enforce a new standard.
The most important conclusions from this analysis are that biofuels can
play a role in sustainable energy future, but the opportunities for
truly low-carbon biofuels may be far more limited than initially
thought. Second, a low-carbon economy requires a holistic approach to
energy sources – both clean supply options and demand management – where
consistent metrics for actual carbon emissions and impacts are utilized
to evaluate options. Third, land-use impacts of biofuel choices have
global, not just local, impact, and a wider range of options, including,
plug-in hybrid vehicles, dramatically improved land-use practices
including sprawl management and curtailment, and greatly increased and
improved public transport all have major roles to play.
Biofuels and Greenhouse Gas Emissions: A Better Path Forward
The recent controversy over biofuels notwithstanding, the US has the
potential to meet the legislated 21 billion gallon biofuel goal with
biofuels that, on average, exceed the targeted reduction in greenhouse
gas release, but only if feedstocks are produced properly and biofuel
facilities meet their energy demands with biomass.
A diversity of alternative feedstocks can offer great
GHG benefits. The largest
GHG benefits will come from dedicated
perennial crops grown with low inputs of fertilizer on degraded lands,
and especially from those crops that increase carbon storage in soil
(e.g., switchgrass, mixed species prairie, and Miscanthus). These may
offer 100% or perhaps greater reductions in
GHG relative to gasoline. Agricultural and
forestry residues, and dedicated woody crops, including hybrid poplar
and traditional pulp-like operations, should achieve 50%
GHG reductions.
In contrast, if biofuel production leads to direct or indirect land
clearing, the resultant carbon debt can negate for decades or longer any
greenhouse gas benefits a biofuel could otherwise provide. Current
legislation, which is outcome based, has anticipated this problem by
mandating GHG standards for current and next
generation biofuels.
Biographies
Dr. Joseph E. Fargione is the Regional Science Director for The
Nature Conservancy’s Central US Region. He received his doctorate in
Ecology from the University of Minnesota in 2004. Prior to the joining
The Nature Conservancy, he held positions as Assistant Research Faculty
at the University of New Mexico (Biology Department), Assistant
Professor at Purdue University (Departments of Biology and Forestry and
Natural Resources), and Research Associate at the University of
Minnesota (Departments of Applied Economics and Ecology, Evolution, and
Behavior).
His work has focused on the benefits of biodiversity and the causes and
consequences of its loss. Most recently, he has studied the effect of
increasing demand for biofuels on land use, wildlife, and carbon
emissions. He has authored 18 papers published in leading scientific
journals, including Science, Proceedings of the National Academy of
Sciences, Proceedings of the Royal Society, Ecology, and Ecology
Letters, and he was a coordinating lead author for the Millennium
Ecosystem Assessment chapter titled “Biodiversity and the regulation of
ecosystem services.” His recent paper in Science, “Land clearing and the
biofuel carbon debt” was covered in many national media outlets,
including the New York Times, Washington Post, Wall Street Journal,
National Public Radio, NBC Nightly News, and
Time Magazine.
Timothy Searchinger is a Visiting Scholar and Lecturer in Public and
International Affairs at Princeton University’s Woodrow Wilson School.
He is also a Transatlantic Fellow of the German Marshall Fund of the
United States, and a Senior Fellow at the Georgetown Environmental Law
and Policy Institute. Trained as a lawyer, Dr. Searchinger now works
primarily on interdisciplinary environmental issues related to
agriculture.
Timothy Searchinger previously worked at the Environmental Defense Fund,
where he co-founded the Center for Conservation Incentives, and
supervised work on agricultural incentive and wetland protection
programs. He was also a deputy General Counsel to Governor Robert P.
Casey of Pennsylvania and a law clerk to Judge Edward R. Becker of the
United States Court of Appeals for the Third Circuit. He is a graduate,
summa cum laude, of Amherst College and holds a J.D. from Yale Law
School where he was Senior Editor of the Yale Law Journal.
Timothy Searchinger first proposed the Conservation Reserve Enhancement
Program to USDA and worked closely with state
officials to develop programs that have now restored one million acres
of riparian buffers and wetlands to protect important rivers and bays.
Searchinger received a National Wetlands Protection Award from the
Environmental Protection Agency in 1992 for a book about the functions
of seasonal wetlands of which he was principal author. His most recent
writings focus on the greenhouse gas emissions from biofuels, and
agricultural conservation strategies to clean-up nutrient runoff. He is
also presently writing a book on the effects of agriculture on the
environment and ways to reduce them.
Dr. Daniel M. Kammen, Class of 1935 Distinguished Professor in the
Energy and Resources Group (ERG), in the Goldman School of Public Policy
and in the Department of Nuclear Engineering at the University of
California, Berkeley. He is also the founding Director of the Renewable
and Appropriate Energy Laboratory (RAEL) and Co-Director of the Berkeley
Institute of the Environment.
Previously in his career, Dr. Kammen was an Assistant Professor of
Public and International Affairs at Princeton University, and also
played a key role in developing the interdisciplinary Science,
Technology, and Environmental Policy (STEP) Program at Princeton as
STEP Chair from 1997 – 1999. In July of 1998
Kammen joined ERG as an Associate Professor of
Energy and Society.
Dr. Kammen received his undergraduate degree in physics from Cornell
University (1984), and his masters and doctorate in physics from Harvard
University (1986 & 1988) for work on theoretical solid state physics and
computational biophysics. First at Caltech and then as a Lecturer in
Physics and in the Kennedy School of Government at Harvard, Dr. Kammen
developed a number of projects focused on renewable energy technologies
and environmental resource management.
Dr. Kammen’s research interests include: the science, engineering, and
policy of renewable energy systems; health and environmental impacts of
energy generation and use; rural resource management, including issues
of gender and ethnicity; international R&D policy, climate change; and
energy forecasting and risk analysis. He is the author of over 200
peer-reviewed journal publications, a book on environmental,
technological, and health risks, and numerous reports on renewable
energy and development. He has also been a lead author for the
Intergovernmental Panel on Climate Change that shared the 2007 Nobel
Peace Prize.
Dr. G. David Tilman is Regents’ Professor and McKnight Presidential
Chair in Ecology at the University of Minnesota. He is an elected member
of the American Academy of Arts and Sciences and the National Academy of
Sciences, and has served on editorial boards of nine scholarly journals,
including Science. He serves on the Advisory Board for the Max Plank
Institute for Biogeochemistry in Jena, Germany. He has received the
Ecological Society of America’s Cooper Award and its MacArthur Award,
the Botanical Society of America’s Centennial Award, the Princeton
Environmental Prize and was named a J. S. Guggenheim Fellow. He has
written two books, edited three books, and published more than 200
papers in the peer-reviewed literature, including more than 30 papers in
Science, Nature and the Proceedings of the National Academy of Sciences
USA. The Institute for Scientific Information
recently designated him as the world’s most highly cited environmental
scientist of the decade.
Dr. Tilman’s recent research explores how managed and natural ecosystems
can sustainably meet human needs for food, energy and ecosystem
services. A long-term focus of his research is on the causes,
consequence and conservation of biological diversity, including using
biodiversity as a tool for biofuel production and climate stabilization
through carbon sequestration. His work on renewable energy examines the
full environmental, energetic and economic costs and benefits of
alternative biofuels and modes of their production.
American Meteorological Society
2325 Rayburn
25/04/2008 at 12:00PM