Executive Summary/Introduction: Environmental Effects of increased biomass production in the U.S.

Volume 2 evaluates the potential environmental effects of three national biomass production scenarios described in Volume 1.

With the goal of understanding environmental effects of a growing bioeconomy, the U.S. Department of Energy (DOE), national laboratories, and U.S. Forest Service research laboratories, together with academic and industry collaborators, estimated environmental effects of potential biomass production scenarios in the United States, with an emphasis on agricultural and forest biomass. Potential effects investigated included changes in soil organic carbon (SOC), greenhouse gas (GHG) emissions, water quality and quantity, air emissions, and biodiversity. Most analyses in BT16 volume 2 show potential for a substantial increase in biomass production with minimal or negligible environmental effects under the biomass supply constraints assumed in BT16.


Feedstock Assessment Methods and Focal Scenarios

What types of biomass were included in this analysis?

A small subset of the agricultural and forestry assessment scenarios and scenario years from BT16 volume 1 were selected for analysis in BT16 volume 2. The scenarios were selected to include a low- and a high-yield scenario and near-term and long-term biomass supply estimates. Chapter two describes these scenarios and summarizes key assumptions and methods used in volume 1 to quantify the potentially available biomass supplies evaluated in volume 2.

Explore the three biomass production scenarios drawn from volume 1 and how they were quantified.


Land Management: Understanding Land Use Change Implications

How is land use change considered in this report?

This chapter of BT16 volume 2 aims to clarify land-use change (LUC) implications of the select BT16 biomass supply scenarios. The primary type of LUC in BT16 involves changes in agricultural land management practices. The chapter includes a review of LUC studies and concludes that clear definitions of land parameters and effects are essential to improve LUC analyses.

Explore differences in land management under the three scenarios evaluated in subsequent chapters in the report, along with key drivers, assumptions, and implications for environmental indicators.


Fossil Energy Consumption, Greenhouse Gas Emission, and Soil Carbon Effects

What are the greenhouse gas emissions from biomass production in the scenarios?

The greenhouse gas (GHG) emissions and fossil energy consumption associated with producing potential biomass supply in the select BT16 scenarios include emissions and energy consumption from biomass production, harvest/collection, transport, and pre- processing activities to the reactor throat. This analysis illuminates the main contributors and drivers for these emissions, which can inform efforts to reduce the GHG emissions and energy consumption of biomass-derived fuels, products, and power. The chapter also includes illustrative examples of how bioenergy and biobased products can reduce greenhouse gas emissions compared to fossil fuel-based energy and products.

Examine fossil energy consumption and greenhouse gas emissions, including soil carbon effects, of producing agriculture and forestry feedstocks under the three scenarios.


Water Quality Effects on Agricultural Lands

How can future biomass production be managed to protect water quality with minimal decreases to feedstock yield?

This chapter investigates water quality responses to simulated management practices on agricultural lands producing biomass feedstocks in two tributary basins of the Mississippi River. Results from this analysis can be used to identify location-specific management practices that can achieve simultaneous biomass production and water-quality goals.

View the effects of conservation practices on water quality and the tradeoffs among water quality variables (nitrate, total P, total suspended sediment) and productivity.

The visualization for water quality indicators here


Water Quality Effects on Forestlands

How might forest biomass removal effect forest water quality?

Despite decades of research into forest harvest effects on water quality, long-term and consistently collected data to parameterize process-based models of water-quality related to biomass removal in forests are scarce. Therefore, this analysis developed a simple, empirical modeling approach to estimate sediment and nutrient response to the total acres harvested for biomass within a given county.

Review effects of forest biomass harvesting area on water quality indicators.


Water Yield Effects on Forestlands

How might forest biomass removal effect water yield?

Forests play an important role in regulating the quantity, quality, and timing of water yield from watersheds—and, thus, in maintaining the ecosystems that depend on water. This chapter evaluates the potential effects of forest-biomass harvesting on water quantity for select BT16 scenarios.

Regions that are most likely to experience hydrological impacts under the scenarios investigated are identified. The three scenarios modeled all have minor impacts on water quantity at the county level.


Water Consumption Footprint on Agricultural and Forest Lands

What is the water consumption footprint of the scenarios?

This chapter develops an estimate of water consumption for major potential BT16 production scenarios and presents geospatial analysis to examine the interplay between feedstock mix and water consumption, as well as geospatial patterns of water consumption footprints for different feedstock mixes.

Examine the potential water consumption footprint of producing agriculture and forestry feedstocks.


Air Emissions from Agricultural and Forest Biomass Production.

How could producing and harvesting biomass influence air emissions?

Across the biomass supply chain, multiple operations emit air pollutants; however, the type and source of emissions vary by feedstock. This analysis uses select BT16 scenarios to develop an emissions inventory for emission sources associated with biomass production and supply, which can serve as a foundation for a subsequent air quality modeling and impact analysis, and can inform the development of mitigation options.

Review estimated air emissions associated with potential biomass production and harvesting.


Effects on Avian Biodiversity

How might biomass production affect biodiversity of birds on agricultural lands?

Bird species habitat and species richness in agricultural landscapes were modeled as a way to investigate questions about potential effects to biodiversity resulting from increased energy crop production. This analysis is useful in showing where energy crops could be grown with potential benefits to bird species and where more research is needed to understand the wildlife consequences of adopting particular energy crops and management practices.

Explore possible effects on avian biodiversity in response to biomass production in agricultural landscapes.


Forest Biodiversity Response

How might harvesting of forest biomass impact biodiversity in forests?

Using harvest acres generated in volume 1 of BT16, this analysis assesses and compares implications for biodiversity resulting from potential forest biomass produced in the near term (2017) and long term (2040). Woody-biomass harvest in the examined scenarios would primarily affect biodiversity through changes in forest structure, both at the stand (e.g., loss of canopy cover and residues) and landscape scales (e.g., distribution of stand ages from clearcutting smaller-diameter trees). Case studies of taxonomic groups or single species with life-history traits that rely functionally on dead and downed wood or changing canopy cover are discussed. This information may be used in conjunction with other finer-scaler biodiversity assessments (e.g., state wildlife action plans, county project planning, etc.) to identify species that may be vulnerable to changes.

Explore possible effects of harvesting biomass on vertebrate diversity using a species-based case study approach.


Qualitative Effects of Algae Production

What are the potential environmental effects of algae production?

Algae is another potential biomass feedstock. This chapter begins to address environmental effects of potential algal biomass production for biofuels and bioproducts. The chapter emphasizes greenhouse gas emissions and water consumption, and considers effects of potential algal biomass production on other environmental indicators.

Consider the potential environmental effects of algae production, including water consumption and greenhouse gas emissions.


Climate Sensitivity of Agricultural Energy Crop Productivity

How might climate change affect biomass energy crop productivity and geographic distribution?

This chapter uses 2050 and 2070 scenarios to evaluate the effects of climatic changes on potential future biomass production. The objective of this chapter is to assess the sensitivity of U.S. cellulosic biomass to climate change by presenting initial empirical estimates of the implications of alternative climate-change scenarios for a number of illustrative energy crops. This chapter evaluates the extent to which future changes in climate variables (e.g., temperature and precipitation) are projected to drive significant changes (positive or negative) in the yields of energy crops at the national, regional, or county level. In addition, this chapter addresses the implications of those changes for biomass production. The biomass projections based on particular climate scenarios help in (1) identifying the areas where production of different energy crops is anticipated to benefit or to be harmed in response to climate change and (2) prioritizing future research needs.


Synthesis, Interpretation, and Strategies to Enhance Environmental Outcomes

What are key insights from this report, and how can environmental outcomes of biomass production be enhanced?

Volume 2 of BT16 is a first effort to quantify potential environmental effects associated with illustrative near-term and long-term biomass-production scenarios from BT16 volume 1. Along with results of volume 1, this collection of analyses reveals benefits, opportunities, challenges, and tradeoffs that should be considered as biomass production increases. Estimates of environmental effects for the scenarios considered in this volume can help the research community, industry, and other decision makers in prioritizing research efforts and data collection. Strategies to enhance environmental outcomes from biomass production (e.g., landscape design, precision agriculture, the use of waste, and biomass production in conjunction with wastewater remediation) are discussed.

Explore possibilities for enhancing environmental outcomes of biomass production.