Unintended Environmental Consequences of a Global Biofuels Program

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).Biofuels are being promoted as an important part of the global energy mix to meet the climate change challenge. The environmental costs of biofuels produced with current technologies at small scales have been studied, but little research has been done on the consequences of an aggressive global biofuels program with advanced technologies using cellulosic feedstocks. Here, with simulation modeling, we explore two scenarios for cellulosic biofuels production and find that both could contribute substantially to future global-scale energy needs, but with significant unintended environmental consequences. As the land supply is squeezed to make way for vast areas of biofuels crops, the global landscape is defined by either the clearing of large swathes of natural forest, or the intensification of agricultural operations worldwide. The greenhouse gas implications of land-use conversion differ substantially between the two scenarios, but in both, numerous biodiversity hotspots suffer from serious habitat loss. Cellulosic biofuels may yet serve as a crucial wedge in the solution to the climate change problem, but must be deployed with caution so as not to jeopardize biodiversity, compromise ecosystems services, or undermine climate policy.This study received funding from the MIT Joint Program on the Science and Policy of Global Change, which is supported by a onsortium of government, industry and foundation sponsors

Potential Climatic Impacts and Reliability of Very Large-Scale Wind Farms

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG) emission technologies such as wind energy. The widespread availability of wind power has fueled legitimate interest in this renewable energy source as one of the needed technologies. For very large-scale utilization of this resource, there are however potential environmental impacts, and also problems arising from its inherent intermittency, in addition to the present need to lower unit costs. To explore some of these issues, we use a threedimensional climate model to simulate the potential climate effects associated with installation of wind-powered generators over vast areas of land or coastal ocean. Using windmills to meet 10% or more of global energy demand in 2100, could cause surface warming exceeding 1oC over land installations. In contrast, surface cooling exceeding 1oC is computed over ocean installations, but the validity of simulating the impacts of windmills by simply increasing the ocean surface drag needs further study. Significant warming or cooling remote from both the land and ocean installations, and alterations of the global distributions of rainfall and clouds also occur. These results are influenced by the competing effects of increases in roughness and decreases in wind speed on near-surface turbulent heat fluxes, the differing nature of land and ocean surface friction, and the dimensions of the installations parallel and perpendicular to the prevailing winds. These results are also dependent on the accuracy of the model used, and the realism of the methods applied to simulate windmills. Additional theory and new field observations will be required for their ultimate validation. Intermittency of wind power on daily, monthly and longer time scales as computed in these simulations and inferred from meteorological observations, poses a demand for one or more options to ensure reliability, including backup generation capacity, very long distance power transmission lines, and onsite energy storage, each with specific economic and/or technological challenges.This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors

Toward an Integrated Regional Research Program on Global Change and the Nation\u27s Major Grasslands: Second Annual Report

I DIRECTOR\u27S REPORT: A GPRC Research Framework and Thrusts B FY94 GPRC Grant Competition C Synopsis of Current Projects 1 Thrust 1: Impacts of Climate Change 2 Thrust 2: Measuring and Modeling Net Carbon Exchange 3 Other Projects D Summary and Recommendations of FY94 GPRC PI\u27s Workshop 1 Biogeochemical Cycling Group 2 Climate Scenarios Group 3 Managed and Unmanaged Ecosystem Impacts Group 4 Scaling Group 5 Actions Prompted by the Workshop E Research Integration with ARM-CART: Eco-ARM F Future Directions for the GPRC Appendix I-A: Biogeochemical Cycling Group Workshop Report • Appendix I-B: Climate Change Scenarios Group Workshop Report • Appendix I-C: Managed and Unmanaged Ecosystem Impacts Group Workshop Report • Appendix 1-0: Funded Projects Table • Appendix I-E: Core Research Program Diagram • Appendix I-F: Regional Map II RESEARCH PROGRESS REPORTS (Title, Principal Investigator, Institution): A IMPACTS OF CLIMATE CHANGE 1 Process Studies Effects of Altered Soil Moisture and Temperature on Soil Communities, Primary Producers and Ecological Processes in Grassland Ecosystems · John M Blair, Kansas State University Impacts of global climate change on phytoplankton productivity in lakes along a thermal gradient · Kyle D Hoagland, University of Nebraska-Lincoln Natural Responses of Shallow Lakes and Wetlands for Detecting Climatic/Environmental Change · Donald C Rundquist, University of Nebraska-Lincoln 2 Climate Scenarios for Impact Analysis Space-time Local Hydrology Influenced by Changing Climatology: Disaggregation, Prediction and Comparison · Istvan Bogardi, University of Nebraska-Lincoln Observational and Numerical Study for Interannual and Interdecadel Variabilities of the Atmospheric Circulation · Tsing-Chang Chen, Iowa State University The Effect of Ecosystems on Cloud Microphysics and Aerosol Distribution · Qinghuan Han, South Dakota School of Mines and Technology Development of a Nested Regional Model for the Conterminous United States and Formation of High Resolution Climate Change Scenarios with an Application to Crop Climate Models · Linda Mearns, National Center for Atmospheric Research The detection of Climate Change Using Long Term Daily Climate Records Over Grassland Regions of the Northern Hemisphere · Michael A Palecki, University of Nebraska-Lincoln 3 Modeling Impacts of Climate Change Assessment of Climate Change on a Mixed Agricultural Landscape on the North American Great Plains · James R Brandle, University of Nebraska-Lincoln The Economic and Environmental Impact of Major Shifts in Land Use into Energy Biomass Production for Part of the Great Plains · Paul T Dyke, Texas A&M University Local and Regional Scaling With a Spatially Explicit Ecological Model · George P Malanson, University of Iowa Potential Global Warming Impacts on Vegetation Distribution, Productivity, and Hydrology at Landscape to Regional Scales in the Great Plains Region · Ronald P Neilson, Oregon State University B MEASUREMENT AND MODELING OF NET CARBON EXCHANGE 1 Process Studies Carbon, Water, and Energy Fluxes From a Tallgrass Prairie: A Long-term investigation of Biological, Environmental, and Land Use Factors · Jay M Ham, Kansas State University An Integrated Investigation of Methane and Carbon Dioxide Fluxes in Mid-Latitude Prairie Wetlands: Micrometeorological Measurements, Process-Level Studies and Modeling · Shashi B Verma, University of Nebraska-Lincoln 2 Modeling Studies Regional projections of C Dynamics with Global Change in the Central US Edward T Elliott, Colorado State University Assessment of Climate and Management Induced Directional Changes in Great Plains Vegetation with NDVI and Stable Carbon Isotopes Larry L Tieszen, Augustana College C DETECTION OF CLIMATE CHANGE Climate Change in the Mid-continent of North America William D Gosnold, University of North Dakota 105 Satellite Observation of Lake Ice as a Robust Indicator of Regional Climate Change Thomas M Ullesand, University of Wisconsin-Madison Appendix II-A: Author Index Great Plains Regional Center for Global Environmental Change 20 LW Chase Hall University of Nebraska-Lincoln PO Box 830725 Lincoln, NE 68583-0725 Phone 4021472-7887 Fax 4021472-6614 E-mail agme022@unlvmunledu ACKNOWLEDGEMENT This material is based upon work supported by the US Department of Energy under Cooperative Agreement No DE-FC03-90ER61 01 O Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the US Department of Energ

Global vegetation variability and its response to elevated CO2, global warming, and climate variability – a study using the offline SSiB4/TRIFFID model and satellite data

Abstract. The climate regime shift during the 1980s had a substantial impact on the terrestrial ecosystems and vegetation at different scales. However, the mechanisms driving vegetation changes, before and after the shift, remain unclear. In this study, we used a biophysical-dynamic vegetation model to estimate large-scale trends in terms of carbon fixation, vegetation growth, and expansion during the period 1958–2007, and to attribute these changes to environmental drivers including elevated atmospheric CO2 concentration (hereafter eCO2), global warming, and climate variability (hereafter CV). Simulated Leaf Area Index (LAI) and Gross Primary Product (GPP) were evaluated against observation-based data. Significant spatial correlations are found (correlations > 0.87), along with regionally varying temporal correlations of 0.34–0.80 for LAI and 0.45–0.83 for GPP. More than 40 % of the global land area shows significant trends in LAI and GPP since the 1950s: 11.7 % and 19.3 % of land has consistently positive LAI and GPP trends, respectively; while 17.1 % and 20.1 % of land, saw LAI and GPP trends respectively, reverse during the 1980s. Vegetation fraction cover (FRAC) trends, representing vegetation expansion/shrinking, are found at the edges of semi-arid areas and polar areas. Overall, eCO2 consistently contributes to positive LAI and GPP trends in the tropics. Global warming is shown to mostly affected LAI, with positive effects in high latitudes and negative effects in subtropical semi-arid areas. CV is found to dominate the variability of FRAC, LAI, and GPP in the semi-humid and semi-arid areas. The eCO2 and global warming effects increased after the 1980s, while the CV effect reversed during the 1980s. In addition, plant competition is shown to have played an important role in determining which driver dominated the regional trends. This paper presents a new insight into ecosystem variability and changes in the varying climate since the 1950s