Ecosystem Service Effects from Biofuels Production and Use

Transcription

1 Ecosystem Service Effects from Biofuels Production and Use Elizabeth (Betsy) R. Smith US Environmental Protection Agency National Exposure Research Laboratory 1 Research Triangle Park, NC

2 Ecosystem Services EPA defines ecosystem services as the products of ecological functions or processes that directly or indirectly contribute to human well-being, or have the potential to do so in the future. This definition provides a broad interpretation of ecosystem services to characterize services that may or may not be quantifiable. 2

3 Max ECOSYSTEM SERVICES RESEARCH PROGRAM Ecosystem Service quality and potential value of a change varies along the land alteration spectrum Service Quality Birdwatching Hunting 0 Less Altered System Moderately Altered System Highly Altered System 3

4 The Biofuels Supply Chain: Little is known about impacts to ecosystem services beyond the feedstock production phase Feedstock Production Feedstock Logistics Biofuels Production Biofuels Distribution Biofuels End Use Ag Crops Ag Residues Energy Crops Forest Residues Wastes Algae 4 Harvesting & Collecting Storage Pre-Processing Transportation Fuel types Biochemical Conversion Thermochemical Conversion Biological Conversion Chemical Conversion Power & Generators Chemical Feedstocks for Manufacturing Distribution by barge, truck, rail, pipeline Storage in tanks Dispensing Light & heavy duty vehicles & trucks, Off -Road vehicles, Locomotives, Flight technologies, Boats/Ships

5 Ecosystem Services can be impacted along the entire biofuels supply chain Feedstock Production Feedstock Logistics Biofuels Production Biofuels Distribution Biofuels End Use Food and fiber production Human health Climate regulation Wildlife-based recreation Biodiversity existence Soil productivity Water 5 quality Air quality Wildlife-based recreation Biodiversity existence Human health Visibility Sense of place Human health Water Supply Climate regulation Water Quality Wildlife-based recreation Biodiversity existence Human health Visibility Sense of place Water quality Impacts can be positive or negative Climate regulation Human health

6 Many Trade-offs 6 Food and fiber production Food security Climate regulation Carbon sequestration Production of greenhouse gases Wildlife-based recreation Bird watching Hunting Fishing Hiking Biodiversity existence GMOs Invasive exotics Loss of habitat Soil productivity Loss of organic matter, carbon Soil compaction Water quality Nutrient and pesticide runoff Sedimentation Leaking of storage tanks Spills Water supply Irrigation Distillation Air quality Toxic emissions Particulate matter Aesthetics Visibility Rural character Overall impacts depend on relative values of individual services

7 EPA s Regulatory Concerns: Most Common Pollutants 7 Biodiesel Emissions Methanol VOCs HAPs Hexane Wastes Spent Filter Aid (Diatomaceous Earth or Silica) Wastewater Glycerin? Ethanol Emissions PM / PM 10 NO X SO X VOCs Hazardous Air Pollutants Wastes BOD Dissolved Solids Salts?

8 8 ECOSYSTEM SERVICES RESEARCH PROGRAM EPA s Regulatory Concerns: Underground Storage Tanks Ethanol s solubility can cause leaks in noncompatible underground storage tanks affecting groundwater and drinking supply Ethanol s solubility mobilizes BTEX, creating a longer plume Ethanol s high BOD (Biological Oxygen Demand) creates anaerobic conditions, affecting microorganisms and their ability to degrade BTEX Over long-term, ethanol degrades into methane gas, which may lead to vapor intrusion Little is known about fate & transport of other biofuels

9 The Challenge of Sustainability Feedstock type No till? Single cut? Skidder tires? Fertilizers? Cover crop? Native forest? Pasture? Ag field? CRP? Corn? Manure? Water quality? Runoff? Grass? Poplar? Crop Residues? Erosion? Soil carbon? Cold? Wet? Wildlife? Riparian? Near refinery? Adjacent forest? 20% of watershed? 5% of watershed? Patchy? Blocky? Ecosystem Service effects depend on: - What feedstock - When planted/harvested - Where planted - How managed/harvested 9 Environmental Attributes

10 EPA s Future Midwestern Landscapes Study: projections of changes in land management under EISA FML study area with ethanol plant locations Detail for Corn Belt area in Illinois 10 Baseyear (2001) Biofuel targets (2022) Corn/soybean rotation Continuous corn In the Corn Belt, corn/soybean rotation will change to continuous corn, requiring greater chemical inputs and depleting soil productivity

11 Preliminary results of landscape analysis: Base Year compared to Biofuel Targets (under EISA) Percent change to continuous corn by 12-digit HUC between 2001 and 2022 as projected for the Energy Independence and Security Act (EISA) Potential N loadings could increase up to 20% across the Upper Midwest as a result of changes in crop management under EISA. Ohio and South Dakota could see closer to a 30% increase in N loadings 11

12 Clean Water: change in Atrazine loadings projected with shift in cropping practices to reach Biofuel Targets Atrazine is linked to human health, particularly hormonerelated cancers. Combination of atrazine and nitrate has been shown to impact sexual development in amphibians. Change in atrazine loadings may push levels of pesticides in surface water beyond current MCLs 12

13 Ecosystem ECOSYSTEM Service SERVICES value RESEARCH is related PROGRAM to the ability to mitigate or reduce risk Estimated Atrazine application for Base Year landscape Combined index: Atrazine application and population using surface water supplies 13 Potential risk only incomplete endpoint Risk + Exposure a better endpoint 13

14 Switchgrass commonly used as vegetative filter strips and riparian buffers in agricultural watersheds Watershed scale results from many studies: Sediment export reductions of 50 to 95% Nitrogen export reductions of 25 to 90% Phosphorus export reductions of 20 to 85% Retention percentage positively related to buffer width 14 ORNL study at Savannah River Lab is designed to quantify benefits of short rotation woody crops on water quality.

15 Benefits of perennial energy crops are most positive when: Replacing annual crops or pasture, not forests Minimum tillage and cover crop management used Nutrient and chemical applications < annual crops Native or non-invasive species used Harvesting considers bird nesting timing. Used as buffers between annual crops and water ways 15 Sources: McLaughlin and Walsh. (1998). Biomass and Bioenergy. and Wright and Tolbert (several reports)

16 In summary. ECOSYSTEM SERVICES RESEARCH PROGRAM Biofuels effects on Ecosystem Services should be evaluated across the supply chain Trade-offs are spatially explicit and change as values for individual Ecosystem Services change Choices of feedstock, logistics, distribution, etc. should be evaluated in the context of ecosystem resilience and populations served 16