Characterizing Agricultural Land-Use Change in the United States
Cultivation of corn and soybeans in the United States reached record levels following the biofuels boom of the late 2000s. Debate churns about whether expansion of these crops caused conversion of carbon-rich natural ecosystems or instead replaced other crops on existing fields. This project aims to characterize recent changes in agricultural production by identifying crop-specific expansion pathways in the U.S. Results will help inform federal agricultural and biofuels policies and provide valuable data for estimating greenhouse gas emissions from recent land-use change as well as its impacts on ecosystem services.
Mapping Potentially Available Cropland (PAC) in the United States
To meet future demand for agricultural products, it will be necessary to expand cropland area. There is a growing debate about additional land availability in the U.S., with some parties suggesting a nearly endless supply of land for production, while others claim we have already reached “peak land.” To evaluate the extent and location of uncultivated land suitable for crop production in the U.S., we’re creating the first spatially-explicit database of Potentially Available Cropland (PAC) in the United States by fusing satellite-derived land cover data with detailed census and inventory data. Output maps will be used to estimate production potential and associated carbon debt for the U.S. under a range of scenarios, and help identify the economic, social, and physical constraints that limit the practical expansion onto these lands.
Globalization and Emerging Demand-Side Levers for Conservation
Global market demands for soy, oil palm and beef are now major drivers of tropical forest conversion, and most recently the focus of efforts seeking to reconciling forest conservation with food, feed and fuel production. Industry-led stakeholder groups such as the Roundtables for Responsible Soy, Sugar, Palm Oil, Beef and Biofuels are developing production standards aiming to shift business practices to intensify production and avoid forest clearing. Zero-deforestation embargos led by NGO pressure such as the Soy Moratorium and G4 Cattle Agreement are also changing industry practices in Brazil and possibly in Indonesia. We are evaluating these consumer-driven instruments by quantifying and mapping changing patterns of domestic consumption and international trade, stakeholder interviews along value chains and spatial analysis to audit performance of industry standards and zero-deforestation agreements. Our recent results highlight key industry transformation such as increased transparency and traceability, but also clearly point to critical loopholes. Specifically, issues of forest permanence and leakage into other sectors and ecosystems must be addressed. Most importantly, however, shifting trade patterns towards increased exports to China, Russia and India, where purchasing power is less concerned with environmental issues, must be considered as increasing energy is focused on demand-side policy levers.
Supply Chain Mapping & Zero-Deforestation Agreements in the Brazilian Amazon
New-demand side conservation efforts including multi-stakeholder roundtables and zero-deforestation agreements are changing production dynamics in Brazil’s cattle and soy sectors. These policy interventions have been identified as possible drivers of reduced deforestation rates over the last several years, but our understanding of the mechanisms is extremely limited. We are evaluating these demand-side instruments by quantifying and mapping changing patterns of domestic consumption and international trade, stakeholder interviews along supply chains, and spatial analyses to quantify response. We have developed novel methods to map individual cattle and soy suppliers at the property level and trace industry response before and after policy interventions. Our results provide an improved understanding of how the soy and cattle sectors responded to unprecedented consumer-driven pressures and offers insights for improved strategies for zero-deforestation commodity agriculture in the tropics. We are now working to map the full cattle and soy supply chains and document drivers of change over the last decade. Check out our website here, co-created with the National Wildlife Federation, it showcases how supply chain initiatives are supporting effective solutions for verified zero deforestation beef, leather, and tallow production in the Brazilian Amazon.
Drivers, Patterns and Pathways of Tropical Land-Use Change
The causes and drivers of land-use change vary through space and time leading to patchwork of landscapes and the need for varied and responsive policies aiming to address unintended consequences. We use remote-sensing data, statistical models, and household surveys to document and predict land-use change across the tropics. Previous work demonstrated that forests and degraded forests were the land sources for newly expanding agricultural land in the tropics more than 80% of the time in the 1980-2000 (Gibbs et al 2010, PNAS). Now, we are focused on assessing these patterns and drivers for 2000-2010. We are particularly interested in how globalization impacts land-use decisions, and brings new opportunities for conservation.
Mapping the World’s Potentially Available Cropland
We may be facing a growing land scarcity as mounting demands to feed and fuel the world combine with efforts to conserve forests. Many politicians and conservationists alike point to an abundance of degraded land but often fail the realize that these lands often have significant constraints such as low productivity, use by local communities, or could be restored to their natural state to provide key ecosystem services. We are mapping the world’s potentially available cropland, including degraded lands, at the global scale and documenting the challenges and opportunities for use. In addition, we have a case study focused on oil palm on degraded pastures in Brazil and imperata grasslands (alang alang) in Indonesia. GLUE graduate research fellow, Tyler Lark, is also leading a detailed mapping study focused on the United States. He is considering idle lands, cropland pastures, pastures, and grasslands as well as non-traditional sources such as turf grass, lawns and ditches in his search for additional cropland in the U.S. Our results will provide needed inputs to project national and global agricultural production, constrain estimates of direct and indirect land use change, and inform agricultural and energy policy.
Indirect Land Use Change and Global Land Conversions Pathways
Emissions from market-mediated land clearing in response to bioenergy mandates are significant and must be captured by policy to ensure climate benefits. Current estimates of emissions from indirect land use change (ILUC) are plagued with key uncertainties related to land use. Gibbs is tackling these uncertainties by creating the first Global Land Conversion Database (GLCD) by combining remote-sensing analyses on current agricultural expansion pathways with models of forest conversion probability as well as potentially available cropland. The GLCD will revolutionize methods used to estimate ILUC by helping to bring land into focus for global economic models. (Funded by the California Air Resources Board)