Episodi
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New Tools for Assessing GHG Reduction Policies
As negotiations towards a post-Kyoto agreement on Greenhouse Gas (GHG) emissions intensify, there is a pressing need for flexible, user-friendly analytical tools to quickly yet reliably assess the impacts of the rapidly evolving policy proposals for emissions of greenhouse gases and their impact on the global climate. Such tools would enable negotiators, policymakers and other stakeholders, including the general public, to understand the relationships among proposals for emissions reductions, concentrations of GHGs in the atmosphere, and the resulting changes in climate.
The new Climate-Rapid Overview And Decision Support Simulator (C-ROADS) developed by MIT, the Sustainability Institute, and Ventana Systems, in partnership with the Heinz Center, is just such a tool. C-ROADS is a user-friendly, interactive computer model of the climate system consistent with the best available science, data and observations.
An international scientific review panel, headed by Dr. Robert Watson, former chair of the IPCC, finds that the C-ROADS model “reproduces the response properties of state-of- the-art three dimensional climate models very well” and concludes “Given the model’s capabilities and its close alignment with a range of scenarios published in the Fourth Assessment Report of the IPCC we support its widespread use among policy makers and the general public.”
Biographies
Dr. John D. Sterman is the Jay W. Forrester Professor of Management at the MIT Sloan School of Management, Professor of Engineering Systems and Director of MIT's System Dynamics Group. He is an expert on nonlinear dynamics particularly as applied in economic and socio-technical systems including energy, the environment and climate policy.
Prof. Sterman's research centers on improving managerial decision making in complex systems. He has pioneered the development of "management flight simulators" of economic, environmental, and organizational systems. These flight simulators are now used by corporations and universities around the world. His recent research includes studies assessing public understanding of global climate change, the development of management flight simulators to assist climate policy design, and the development of markets for alternative fuel vehicles that are sustainable not only ecologically but economically.
Dr. Robert W. Corell, Vice President of Programs for The H. John Heinz III Center for Science, Economics, and the Environment’s Global Change Director is also a Council Member for the Global Energy Assessment and a Senior Policy Fellow at the Policy Program of the American Meteorological Society. Dr. Corell also shared in the Nobel Peace Prize Award in 2007 for his extensive work with the IPCC assessments. In 2005, he completed an appointment as a Senior Research Fellow at the Belfer Center for Science and International Affairs of the Kennedy School for Government at Harvard University.
Dr. Corell is actively engaged in research concerned with both the science of global change and with the interface between science and public policy, particularly research activities that are focused on global and regional climate change and related environmental issues. He currently chairs an international initiative, the overall goal of which is to strengthening the negotiating framework intended to prevent dangerous anthropogenic interference with the climate system, central to which is the development and use of analytical tools that employ real-time climate simulations. Dr. Corell also chairs the Arctic Climate Impact Assessment as well as an 18-country international planning effort to outline the major Arctic-region research challenges for the decade or so ahead. He recently led an international strategic planning group that developed strategies and programs designed to merge science, technology and innovation in the service of sustainable development. -
Managing Incoming Solar Radiation
Largely out of concern that society may fall short of taking large and rapid enough measures to effectively contain the problem of global warming, two prominent atmospheric scientists - Paul Crutzen, who won a Nobel Prize in chemistry in 1995, and Tom Wigley, a senior scientist at the National Center for Atmospheric Research - published papers in 2006, suggesting that society might consider using geoengineering schemes to identify a temporarily "fix" to the problem.
The concept of geoengineering - deliberately using technology to modify Earth's environment - has been discussed in the context of climate change since at least 1960. Over the years, proposals have included everything from carbon sequestration through ocean fertilization to damming the oceans. Crutzen and Wigley argued that geoengineering schemes, if done continuously, could reduce global warming enough to buy society time to address mitigation. However, geoengineering schemes may not be the answer. And in fact, such measures have the potential to create more problems than they solve.
In particular, Crutzen and Wigley focused on blocking incoming solar radiation, an idea that has generated much interest in the press and the scientific community. Nature offers an example of how to do this. Volcanic eruptions cool the climate for up to a couple of years by injecting precursors to sulfate aerosol particles into the stratosphere, which has the effect of temporarily blocking incoming sunlight. It is true that volcanic eruptions cool the climate, but their effects are not innocuous, and should serve as a warning to society to be very cautious about deploying such geoengineering “solutions” without careful and considered evaluation beforehand. Among other things, the particles from volcanic eruptions also cause ozone depletion.
Clean Coal Technology and Future Prospects
Clean coal technologies are real, commonly used in commercial industrial gasification and likely essential to reduce CO2 due to the fast growing use of coal worldwide, especially in China. Commercial example of clean coal technology in the USA is the 25 year-old coal to synthetic natural gas (SNG) plant in North Dakota where all of the CO2 is captured and most is geologically storage for use in enhanced oil recovery (EOR) in Canada.
The key issue is expanding clean coal technologies into coal-based electric power generation. This expansion presents additional challenges - more technology options and higher cost of CO2 capture than for industrial gasification. This also requires large-scale demonstration of all three CO2 capture technology options: pre, post and oxygen combustion. In time, the CO2 capture and storage costs will be reduced by both “learning by doing” and developing advanced technologies already moving in to small-scale demonstrations.
Biographies
Dr. Alan Robock is a Distinguished Professor of atmospheric science in the Department of Environmental Sciences at Rutgers University and the associate director of its Center for Environmental Prediction. He also directs the Rutgers Undergraduate Meteorology Program. He graduated from the University of Wisconsin, Madison, in 1970 with a B.A. in Meteorology, and from the Massachusetts Institute of Technology with an S.M. in 1974 and Ph.D. in 1977 in Meteorology. Before graduate school, he served as a Peace Corps Volunteer in the Philippines. He was a professor at the University of Maryland, 1977-1997, and the State Climatologist of Maryland, 1991-1997, before coming to Rutgers.
Dale Simbeck joined SFA Pacific in 1980 as a founding partner. His principal activities involve technical, economic and market assessments of energy and environmental technologies for the major international energy companies. This work includes electric power generation, heavy oil upgrading, emission controls and synthesis gas production plus utilization. -
Episodi mancanti?
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Observed changes in natural systems, largely over the past century, indicate a clear global climate change signal. Even in the face of apparently dominating forces, such as direct, human-driven habitat destruction and alteration, this climate fingerprint implicates global climate change as a new and important driving force on wild plants and animals. Patterns across taxonomic groups are remarkably similar. Large poleward and upward range shifts associated with recent global climate change have been documented in a diversity of species. Likewise, significant trends towards earlier spring events have been documented in plants and animals across North America, Europe and Asia. These changes in species’ distributions and timing have been linked with regional climate warming for many species based on basic research and on long-term historical records. Our recent estimate is that about half of all wild species have responded to regional warming trends of 1-3° C over the past century, with strongest responses over the past 30 years.
In the Third Assessment Report of IPCC (2001), we predicted that species restricted to extreme environments, such as mountaintops, the Arctic and Antarctic, would be most sensitive to small levels of warming and, indeed, these areas are showing the first signs of species declines and extinctions. Range-restricted species, particularly polar and mountaintop species, are showing severe range contractions in response to recent climate change. Tropical coral reefs and sea ice specialists have been most negatively affected, with indications that cloud forest amphibians are also highly vulnerable. New analyses indicate large differences in magnitude of spring advancement between major taxonomic groups, suggesting that normal interactions among species, such as flowers and the insects that pollinate them may become disrupted. Evolutionary adaptations to warmer conditions have occurred at the local, population level, but observed genetic shifts are limited. There is no indication that novel traits are appearing that would allow species to exist under more extreme climatic conditions than they currently live in.
Dr. Parmesan’s early research spanned multiple aspects of the behavior, ecology and evolution of insect/plant interactions in natural systems. Since 1992, however, the focus of her work has been on biological impacts of anthropogenic climate change in natural systems. Her field work has focused on documenting continental-scale range shifts of butterfly species across both North America and Europe. Her more recent research has concentrated on global-scale syntheses of biological responses to climate change across all taxonomic groups. These syntheses have documented the global nature of climate change impacts, spanning all living organisms from microbes to charismatic animals in terrestrial, freshwater and marine systems.
The intensification of global warming as an international issue led Dr. Parmesan into the interface of policy and science. She has given presentations for White House and Congressional representatives, has been involved in several U.S. and international assessments of climate change impacts, and has provided formal testimonies for the US House Select Committee on Energy Independence and Global Warming, as well as the Texas Senate Natural Resources Committee. She has also been active in climate change programs for many international conservation organizations, such as IUCN (the International Union for the Conservation of Nature), the WWF (World Wildlife Fund), and the National Wildlife Federation, and served on the Science Council of the Nature Conservancy. She was a Lead Author and Contributing author of the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report (2001), as well as Reviewer and Co-author of the Uncertainty Guidance Report for the IPCC Fourth Assessment Report (2007). IPCC and its participants were awarded the Nobel Peace Prize in 2007. -
The increase in atmospheric carbon dioxide (CO2) is the single largest human perturbation of the climate system. Its rate of change reflects the balance between human-driven carbon emissions and the dynamics of a number of terrestrial and ocean processes that remove or emit CO2. It is the long term evolution of this balance that will determine to a large extent the speed and magnitude of climate change and the mitigation requirements to stabilize atmospheric CO2 concentrations at any given level. Dr. Canadell will present the most recent trends in global carbon sources and sinks, updated for the first time to the year 2007, with particularly focus on major shifts occurring since 2000. Dr. Canadell’s research indicates that the underlying drivers of changes in atmospheric CO2 growth include: i) increased human-induced carbon emissions, ii) stagnation of the carbon intensity of the global economy, and iii) decreased efficiency of natural carbon sinks.
New Estimates of Carbon Storage in Arctic Soils and Implications in a Changing Environment
The Arctic represents approximately 13% of the total land area of the Earth, and arctic tundra occupies roughly 5 million square kilometers. Arctic tundra soils represent a major storage pool for dead organic carbon, largely due to cold temperatures and saturated soils in many locations that prevent its decomposition. Prior estimates of carbon stored in tundra soils range from 20-29 kg of soil organic carbon (SOC) per square meter. These estimates however, were based on data collected from only the top 20-40 cm of soil, and were sometimes extrapolated to 100 cm. It is our understanding that large quantities of SOC are stored at greater depths, through the annual freezing and thawing motion of the soils (cryoturbation), and potentially frozen in the permafrost.
Recent detailed analysis of Arctic soils by Dr. Epstein and his colleagues found that soil organic carbon values averaged 34.8 kg per square meter, representing an increase of approximately 40% over the prior estimates. Additionally, 38% of the total soil organic carbon was found in the permafrost.
Past, Present and Future Changes in Permafrost and Implications for a Changing Carbon Budget
Presence of permafrost is one of the major factors that turn northern ecosystems into an efficient natural carbon sink. Moreover, a significant amount of carbon is sequestered in the upper several meters to several tens of meters of permafrost. Because of that, the appearance and disappearance of permafrost within the northern landscapes have a direct impact on the efficiency of northern ecosystems to sequester carbon in soil, both near the ground surface and in deeper soil layers. Recent changes in permafrost may potentially transform the northern ecosystems from an effective carbon sink to a significant source of carbon for the Earth’s atmosphere. Additional emissions of carbon from thawing permafrost may be in the form of CO2 or methane depending upon specific local conditions.
Dr. Romanovsky will present information on changes in terrestrial and subsea permafrost in the past during the last glacial-interglacial cycle and on the most recent trends in permafrost in the Northern Hemisphere. He will further discuss the potential impact of these changes in permafrost (including a short discussion on potential changes in methane gas clathrates) on the global carbon cycle. Dr. Romanovsky’s research suggests that permafrost in North America and Northern Eurasia shows a substantial warming during the last 20 to 30 years. The magnitude of warming varied with location, but was typically from 0.5 to 2°C at 15 meters depth. Thawing of the Little Ice Age permafrost is on-going at many locations. There are some indications that the late-Holocene permafrost started to thaw at some specific undisturbed locations in the European Northeast, in the Northwest and East Siberia, and in Alaska. -
Herman Daly, Ph.D., delivers the keynote address the recent AMS workshop on Federal Climate Policy. He explores the distinction between economic growth —a quantitative increase in size that is constrained by the physical limits of the Earth system—and economic development—a qualitative improvement in our state of being. In so doing, he helps identify design principles for climate policy that can enhance environmental protection, benefit the economy, and promote political feasibility.
Daly is a professor in the School of Public Affairs at the University of Maryland. Previously he served as Senior Economist in the Environment Department at the World Bank, where he helped develop policy guidelines related to sustainable development.
He has received numerous awards including the Honorary Right Livelihood Award, Sweden's alternative to the Nobel Prize. -
According to a February, 18, 2007, press release describing a survey on public perceptions of global warming, a majority of Americans agreed with most scientists that the Earth is getting warmer, but were divided over the seriousness of the problem, predicated on a belief that scientists themselves disagreed about global warming. What, if any, was the role of the news media in fueling that perception? Is that perception still prevalent? And where does the public stand today regarding amelioration strategies? Do people support the policy solutions that are most favored by the Presidential candidates? Is there a relation between what people know about global warming and how concerned they are about it? Is there a divide between Republicans and Democrats on these matters? If so, how might one explain these differences in perceptions about global warming?
Program Summary
With both major Presidential candidates endorsing cap and trade programs to reduce greenhouse gas emissions and Congress increasingly devoting effort to climate change legislation, the American public's views of these matters will become more important in the coming months. Yet survey evidence suggests that cap-and-trade is one of the public's least favorite ways to reduce emissions. Our speaker today, Professor Jon Krosnick, has conducted a new national survey to explore the reasons for this reluctance. Different respondents were randomly assigned to receive different descriptions of cap-and-trade, to see whether some framings increased the policy's appeal. The results identify communication strategies that were and were not successful and thereby point to reasons for the public's reluctance. The survey also experimentally tested the hypothesis that "balanced" news media coverage of climate change has caused the majority of Americans to believe that there is no consensus among scientific experts about the existence of climate change. The survey's evidence highlights unintended consequences of "optimal" journalism and the power of the press.
Biography
For 25 years, Dr. Jon A. Krosnick has conducted research exploring how the American public's political attitudes are formed, change, and shape thinking and action. He is co-principal investigator of the American National Election Study, the nation's preeminent academic project exploring voter decision-making and political campaign effects. A world-renowned expert on questionnaire design and survey research methodology, he has conducted survey studies of Americans' attitudes on environmental issues in collaboration with ABC News, the Washington Post, Time magazine, and New Scientist magazine.
Dr. Krosnick has authored six books and more than 120 peer-reviewed scientific articles. His books include the Handbook of Questionnaire Design (forthcoming), Attitude Strength, Thinking about Politics, and Introduction to Survey Research, Polling, and Data Analysis. Dr. Krosnick teaches courses on survey methodology around the world at universities, for corporations, and for government agencies, testifies regularly as an expert witness in courts in the U.S. and abroad, and has served as an on-air election-night television commentator and exit poll data analyst.
Dr. Krosnick earned an A.B. degree in Psychology (Magna Cum Laude) from Harvard University in 1980; an M.A. degree in Social Psychology (with Honors) from the University of Michigan in 1983, and a Ph.D. in Social Psychology from University of Michigan in 1986. -
Gulf Coast Transportation: Coping with the Future
Climate affects the design, construction, safety, operations, and maintenance of transportation infrastructure and systems. The prospect of a changing climate raises critical questions regarding how alterations in temperature, precipitation, storm events, and other aspects of the climate could affect the nation’s roads, airports, rail, transit systems, pipelines, ports, and waterways in the region of the U.S. central Gulf Coast between Galveston, Texas and Mobile, Alabama. This region contains multimodal transportation infrastructure that is critical to regional and national transportation services. More broadly, what happens in the Gulf region will no doubt, have ripple effects nationwide and internationally, as was evident in the aftermath of hurricane Katrina.
New York City: Preparing for Climate Change
New York City (NYC) represents one of the ïŹrst substantial efforts to undertake climate-change planning for infrastructure changes in a large urban area. Notable characteristics of the NYC system are that it is a mature infrastructure system, that its managers are skilled at dealing with existing hydrologic variability, and that there are many potential adaptations to the risk of climate change in the NYC water supply, sewer, and wastewater treatment systems. Capitalizing on this expertise and experience, the work of the Climate Change Task Force of the NYC Department of Environmental Protection, has focused on the water supply, sewer, and wastewater treatment systems of NYC.
Biographies
Michael J. Savonis has 25 years of experience in transportation policy, with extensive expertise in air quality and emerging environmental issues. He has served as Air Quality Team Leader at the Federal Highway Administration (FHWA), since 1996. For the past 16 years, Mr. Savonis has overseen the Congestion Mitigation and Air Quality Improvement Program which invests more than $1.5 billion annually to improve air quality. He directs FHWA’s transportation / air quality policy development, research program, and public education. He received DOT’s Silver Medal in 1997 and FHWA’s Superior Achievement Award in 2004.
Dr. Cynthia Rosenzweig is a Senior Research Scientist at the Goddard Institute for Space Studies at Columbia University. Her primary research involves the development of interdisciplinary methodologies by which to assess the potential impacts of and adaptations to global environmental change. She has joined impact models with global and regional climate models to predict future outcomes of both land-based and urban systems under altered climate conditions. Advances include the development of climate change scenarios for impact and adaptation analysis, and the application of impact models at relevant spatial and temporal scales for regional and national assessments. Recognizing that the complex interactions engendered by global environmental change can best be understood by coordinated teams of experts, Dr. Rosenzweig has organized and led large-scale interdisciplinary, national, and international studies of climate change impacts and adaptation. She co-led the Metropolitan East Coast Regional Assessment of the U.S. National Assessment of the Potential Consequences of Climate Variability and Change, sponsored by the U.S. Global Change Research Program, and was the lead scientist on the New York City Department of Environmental Protection Climate Change Task Force. -
Separating Solar and Anthropogenic (Greenhouse Gas-Related) Climate Impacts
During the past three decades a suite of space-based instruments has monitored the Sun’s brightness as well as the Earth’s surface and atmospheric temperatures. These datasets enable the separation of climate’s responses to solar activity from other sources of climate variability (anthropogenic greenhouse gases, El Niño Southern Oscillation, volcanic aerosols). The empirical evidence indicates that the solar irradiance 11-year cycle increase of 0.1% produces a global surface temperature increase of about 0.1 K with larger increases at higher altitudes. Historical solar brightness changes are estimated by modeling the contemporary irradiance changes in terms of their solar magnetic sources (dark sunspots and bright faculae) in conjunction with simulated long-term evolution of solar magnetism. In this way, the solar irradiance increase since the seventeenth century Maunder Minimum is estimated to be slightly larger than the increase in recent solar activity cycles, and smaller than early estimates that were based on variations in Sun-like stars and cosmogenic isotopes. Ongoing studies are beginning to decipher the empirical Sun- climate connections as a combination of responses to direct solar heating of the surface and lower atmosphere, and indirect heating via solar UV irradiance impacts on the ozone layer and middle atmosphere, with subsequent communication to the surface and climate. The associated physical pathways appear to involve the modulation of existing dynamical and circulation atmosphere-ocean couplings, including the El Nino Southern Oscillation (El Nino/La Nina cycles) and the Quasi-Biennial Oscillation.
The Sun's Role in Past, Current and Future Climate Change
Correlations of instrumental or reconstructed climate time series with indices of solar activity are often being used to suggest that the climate system is tightly coupled to the sun. Yet correlations have to be used with caution because they are not necessarily synonymous with cause-and-effect relationships. Therefore, it is critical to understand the physical mechanisms that are responsible for the signals. Independent tests can then be applied to validate or reject a hypothesized link. Spatial structures that are related to the processes that translate the solar influence into a climatic response can serve as such a test. A particularly powerful example is obtained by looking at the vertical extent of the solar signal in the atmosphere.
Biographies
Dr. Judith Lean is Senior Scientist for Sun-Earth System Research in the Space Science Division of the Naval Research Laboratory in Washington, DC. She has served on a variety of NASA, NSF, NOAA and NRC advisory committees, including as Chair of the National Research Council (NRC) Working Group on Solar Influences on Global Change and, most recently, the NRC Committee on a Strategy to Mitigate the Impact of Sensor De-scopes and De-manifests on the NPOESS and GOES-R Spacecraft. A member of the AGU, IAGA, AAS/SPD and AMS, she was inducted as a Fellow of the American Geophysical Union in 2002 and a member of US National Academy of Sciences in 2003.
Dr. Caspar Ammann is a research scientist, in the Climate and Global Dynamics Division of the National Center for Atmospheric Research in Boulder, Colorado. He has a M.S. degree in Geography and Geology from the University of Bern, Switzerland and a Ph.D. in Geosciences from the University of Massachusetts. His primary research is focused on the climate of past centuries and millennia, and how the current changes compare to this natural background. He has reconstructed past climates as well as volcanic forcing from proxy (e.g., ice cores, corals etc..) records and then simulated climate variability and response to forcings in state-of-the-art coupled Atmosphere-Ocean-General Circulation Models. -
Contribution of Black Carbon and Atmospheric Brown Clouds to Climate Warming: Impacts and Opportunities
Black carbon (BC) in soot is the dominant absorber of visible solar radiation in the atmosphere. Anthropogenic sources of black carbon, although distributed globally, are most concentrated in the tropics where solar irradiance is highest. Black carbon is often transported over long distances, mixing with other aerosols along the way. The aerosol mix can form transcontinental plumes of atmospheric brown clouds (ABCs), with vertical extents of 1.8 to 3.1 miles. Because of the combination of high absorption, a regional distribution roughly aligned with solar irradiance, and the capacity to form widespread atmospheric brown clouds in a mixture with other aerosols, emissions of black carbon are the second strongest contribution to current global warming, after carbon dioxide emissions. In the Himalayan region, solar heating from black carbon at high elevations may be just as important as carbon dioxide (CO2) in the melting of snowpacks and glaciers. The interception of solar radiation by atmospheric brown clouds leads to dimming at the Earth’s surface with important implications for the hydrological cycle, and the deposition of black carbon darkens snow and ice surfaces, which can contribute to melting, in particular of Arctic sea ice. Presently, populations on the order of 3 billion people are living under the influence of regional ABC hotspots.
Black carbon (BC) is an important part of the combustion product commonly referred to as soot. BC in indoor environments is largely due to cooking with biofuels such as wood, dung and crop residue. Outdoors, it is due to fossil fuel combustion (diesel and coal), open biomass burning (associated with deforestation and crop residue burning), and cooking with biofuels.
Soot aerosols absorb and scatter solar radiation. BC refers to the absorbing components of soot. Dust, which also absorbs solar radiation, is not included in the definition of BC. Globally, the annual emissions of BC are (for the year 1996) roughly 8.8 tons per year, with about 20% from biofuels, 40% from fossil fuels and 40% from open biomass burning. The uncertainty in the published estimates for BC emissions is a factor of two to five on regional scales and at least ±50% on global scales. High BC emissions occur in both the northern and the Southern Hemisphere, resulting largely from fossil fuel combustion and open burning, respectively.
Atmospheric brown clouds are composed of numerous submicrometer aerosols, including BC, but also sulphates, nitrates, fly ash and others. BC is also internally mixed with other aerosol species such as sulphates, nitrates, organics, dust and sea salt. BC is removed from the atmosphere by rain and snowfall. Removal by precipitation, as well as direct deposition to the surface, limits the atmospheric lifetime of BC to about one (±1) week.
Causal Link between Carbon Dioxide and Air Pollution Mortality
Recent research suggests that carbon dioxide, through its increase in temperatures and water vapor, increases U.S. air pollution deaths. This effect is greatest in locations where air pollution is already high. The causes of the increased death rate are increased respiratory illness, cardiovascular diseases, and complications from asthma due to increases in ozone and particulate matter. Ozone increases with more carbon dioxide because, in urban areas, higher temperatures and water vapor independently increase ozone through enhanced chemical reactions. These effects are not so important in rural areas. However, in rural areas, higher temperatures increase organic gas emissions from vegetation, increasing ozone slightly. Particles increase with more carbon dioxide because carbon dioxide increases air temperatures more than ground temperatures, reducing vertical and horizontal dispersion of pollutants. -
Joint Panel Discussion 8, The Science of Communications: What We Know We Didn't Know but Convinced Ourselves Otherwise (Joint between the Seventh Communications Workshop and the Third Symposium on Policy and Socio-Economic Research).
Panelists: Chris Mooney, Seed Magazine, Washington, DC; Arthur Lupia, Univ. of Michigan, Ann Arbor, MI; Baruch Fischhoff, Carnegie Mellon Univ., Pittsburgh, PA; Molly Bentley, BBC World News.
Moderator: Anthony Socci, AMS Policy Program, Washington, DC. -
Biofuels: Threats and OpportunitiesIt 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 cropâbased biofuels in Brazil, Southeast Asia, and the United States creates a âbiofuel carbon debtâ 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 â as proposed by a draft European Union law -- does not avoid these global warming emissions because the worldâs 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 â 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 EconomyThe 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 (http://gov.ca.gov/executive-order/5172/), which called for a 10-percent reduction in the carbon intensity of his stateâs transportation fuels by 2020. A research team in which Dr. Kammen participated developed a technical analysis (http://www.energy.ca.gov/low_carbon_fuel_standard/UC-1000-2007-002-PT1.PDF) of low-carbon fuels that could be used to meet that mandate. That analysis employs a life-cycle, âcradle to graveâ 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 âglobal warming intensityâ (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 â both clean supply options and demand management â 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 ForwardThe 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.BiographiesDr. Joseph E. Fargione is the Regional Science Director for The Nature Conservancyâs 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 âBiodiversity and the regulation of ecosystem servicesâ. His recent paper in Science, âLand clearing and the biofuel carbon debtâ 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 Universityâs 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 Americaâs Cooper Award and its MacArthur Award, the Botanical Society of Americaâs 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 worldâs most highly cited environmental scientist of the decade.Dr. Tilmanâs 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.
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Adapting to Climate Change – Impacts on Our Transportation Infrastructure
The U.S. transportation system was built for the typical weather and climate experienced locally. Moderate changes in the mean climate have little impact on transportation. However, changes in weather and climate extremes can have considerable impact on transportation. Transportation relevant measures of extremes have been changing over the past several decades and are projected to continue to change in the future. Some of the changes are likely to have a positive impact on transportation and some negative.
As the climate warms, cold temperature extremes are projected to continue to decrease. Milder winter conditions would likely improve the safety record for rail, air and ships. Warm extremes, on the other hand, are projected to increase. This change would likely increase the number of roadbed and railroad track bucklings and adversely impact maintenance work. As the cold season decreases and the warm season increases, northern transportation dependent upon ice roads and permanently frozen soil would be adversely affected while the projected commercial opening of the Northwest Passage would result in clear benefits to marine transportation.
The warming would also produce a side benefit of shifting more of the precipitation from snow to rain. But not all precipitation changes are likely to be beneficial. Heavy precipitation events are projected to increase, which can cause local flooding. At the same time, summer drying in the interior of the continent is likely to contribute to low water levels in inland waterways. Strong mid-latitude storms are likely to become more frequent and hurricane rainfall and wind speeds are also likely increase in response to human-induced warming. Coastal transportation infrastructure is vulnerable to the combined effects of storm surge and global sea-level rise.
Transportation planning operates on several different time scales. Road planners typically look out 25 years. Railroad planners consider 50 years. And bridges and underpasses are generally designed with 100 years in mind. In all cases, planning that takes likely changes into consideration will be important. -
The Mauna Loa CO2 Record: From the Era of Discovery to the Era of Consequences
2008 marks the 50th anniversary of the Mauna Loa and South Pole CO2 records, which are the longest continuous time series of atmospheric CO2 levels. These records have played a critical role in advancing research on global warming by establishing the reality of increasing CO2 and providing a quantitative basis to assess the impact of human activities on atmospheric CO2. From 1958 to 2008, the CO2 levels at Mauna Loa increased from 315 to 385 part-per-million. The records establish that an amount of CO2 equivalent to 56% of the global emissions of fossil-fuel burning over this period has been retained in the air. The remaining 44% has therefore been absorbed by the oceans and land plants. Our ability to predict the impact of future emissions on the CO2 loading of the atmosphere and hence future climate hinges critically not only on future CO2 emissions, but also on the behavior of these land and ocean sinks.
Over the past decade, our understanding of these sinks has improved, based in part on observations of trends in atmospheric O2 concentration. Our knowledge of these sinks establishes securely that large reductions in fossil-fuel CO2 emissions will be required over the next few decades to stabilize CO2 below “dangerous” levels. Recent work has also raised concerns that the sinks may be weakening due to effects of global warming on the stores of carbon in land ecosystems or in the oceans. This subject remains clouded in uncertainty, however. Even larger and more immediate emissions reductions may be necessary if such “positive feedbacks” turn out to be important.
Carbon Dioxide in Historical Context: Implications for Policy
The uptake of fossil fuel into the biosphere is limited, both in how fast the carbon will be taken up, and in the total amount of CO2 that will be absorbed, by the ways in which the carbon cycle on Earth works. The carbon cycle today is taking up fossil fuel CO2, slowing considerably the rate of CO2 rise and warming. But CO2 concentration measurements from ice cores from the past 800,000 years suggest that ultimately the carbon cycle may act as an amplifier of climate change, releasing carbon during times of warmer climate.
The biosphere on land is currently in net balance, with natural uptake in some areas compensating for deforestation in other areas. The land biosphere could act as either a source or a sink in the coming century, but ultimately would be swamped by the amount of fossil fuel carbon available.
About three quarters of of the carbon we release will dissolve in the oceans on a time scale of a few centuries. Uptake into the oceans will slow as the rising CO2 concentration exhausts the buffer chemistry of seawater, its ability to dissolve more CO2. CO2 is also less soluble in warmer water than cold, so that CO2 uptake will decline further with climate warming. There is recent evidence that CO2 uptake in the Southern Ocean, the main invasion route into the deep sea, has been slowing even more quickly than expected based on those two reasons alone, suggesting that CO2 uptake into the ocean is also slowing because of changes in ocean circulation. The ocean might take up CO2 more slowly if its overturning circulation stagnates in a warmer world.
Carbon cycle models agree that even after the ocean and land have taken their fill of fossil fuel CO2, between 15 and 30%, will remain in the atmosphere for thousands of years. Many of the most profound changes in Earth's climate will take place on these long time scales, such as the melting of ice sheets, permafrost soils, and methane hydrates in the ocean. Sea level in the past has changed by 5 to 20 meters for each degree C change in Earth's temperature. These results imply that the long-term change in sea level from fossil fuels could be 100 times worse than the forecast for the year 2100. -
Does the current framing and scaling of the
climate/energy issue adequately capture the
challenge posed? If not, what might be a
more appropriate frame and scale?
The Union of Energy and Climate
The issues of global energy demand and climate response are, at one level, complex and contentious. However, they are linked by simple but compelling considerations. First, we know that energy demand is driven by the product of population, per capita yearly income, and the amount of energy required for each dollar of economic production. The product of these three quantities sets the rate of current (2007) world energy consumption at approximately 0.5 billion trillion joules of energy each year. With the projected increase in population and average per capita income, this number will reach approximately 1.5 billion trillion joules each year by 2050. That increase is equivalent to the construction of 1000 large coal burning power plants per year for the next four decades. The scale, the size, of this increased demand for energy must be recognized in any analysis of the global climate issue because approximately 80 percent of current energy generation is from fossil fuels that release carbon dioxide when combusted.
While the flow of energy is obviously important to the global economic infrastructure, the flow of energy within the Earth’s climate system reveals simple but compelling conclusions. The Earth’s climate system receives approximately 4000 billion trillion joules of energy each year from the sun in the visible region of the spectrum. The Earth radiates approximately 4000 billion trillion joules of energy back into the blackness of space each year in the infrared. But the energy flow within the climate system is such that some 5500 billion trillion joules cycle per year between the Earth’s surface and the atmosphere that contains water vapor, clouds, and carbon dioxide, etc. The amount of energy cycled back to the Earth’s surface from the overlying atmosphere increases with increasing carbon dioxide and water vapor. Why is this important to the issue of climate change? Small changes in globally averaged land surface or ocean temperatures are often cited and debated, or their significance casually dismissed. That is the global warming debate. That discussion misses the crucial point. It is the net flow of heat, not globally averaged temperatures, that guides the course of future events. Net heat flow carries with it a fundamentally different message from the implications of global warming. An analysis of the climate issue from this point of view will be topic discussed at this AMS Science Series.
