Reducing negative environmental externalities from agricultural production: Methods, models, and policies

Agricultural lands produce food, feed, fiber and fuel in addition to other benefits for people. Conversion of natural lands and certain management practices have led to a decrease in the benefits that people derive from ecosystems. The losses of these ecosystem services are rarely communicated to the consumer, whether through price or other means. Measuring the social and environmental impacts from agriculture and communicating them to decision-makers has emerged as a priority for researchers and policy-makers. This study contributes to an improved understanding of the functioning of the agroecological system and provides pathways that can improve the environmental performance of agriculture.;Chapter 2 quantified carbon emissions from the production of agricultural goods from a region undergoing rapid agricultural expansion and allocated the responsibility for the emissions between importing and exporting countries. Under current international climate policies, the emissions from goods that are exported are attributed to the exporting country, introducing a potential ethical dilemma. The study required a fusion of techniques, including calculating emissions from deforestation, life-cycle analysis of agricultural systems and allocating emissions between producers and consumers.;Chapter 3 investigated policies to promote anaerobic digesters that use livestock manure and other waste products to generate clean energy and reduce water pollution and greenhouse gas emissions. The MIT Emissions Predication and Policy Analysis (EPPA) model was used to test the effects of a representative U.S. climate stabilization policy on the adoption of anaerobic digesters that sell electricity, generate methane mitigation credits and sell digested manure as a fertilizer replacement. The study found that with a climate policy, anaerobic digesters become a viable energy producer and act to mitigate several sources of pollution.;Chapter 4 synthesized the state of the currently available methods and technologies that monitor the productivity and environmental impacts of agricultural production and present an approach to deploy an improved system. An agroecological sensor web integrates data from remote sensing and ground-based monitoring systems with agronomic, agroecosystem and economic models to provide management-relevant information to decision-makers. Deployment of such a system could have profound food security and environmental benefits.