Significant contribution of industrial agriculture to climate change
While agriculture is acknowledged as a significant source of global greenhouse gas emissions, it is important to understand that not all forms of agriculture have made equivalent contributions to climate change. A recently published review paper compares the differences in greenhouse gas contributions between the management systems of industrial and agro-ecological production systems and finds that industrial agriculture contributes significantly to global warming, representing a large majority of total agriculture-related greenhouse gas emissions.
This is because industrial or conventional agricultural practices make use of high-yielding plant and animal varieties, large-scale monocrops, high stocking densities, decreased or absent fallow periods, high levels of agro-chemicals and high degrees of mechanization. These practices are made possible through the corresponding use of fossil fuels to power the production of synthetic fertilizers and pesticides, agricultural machinery and increased levels of irrigation.
Alternatively, ecologically based methods for agricultural production, predominantly used on small-scale farms, are far less energy-consumptive and release fewer greenhouse gases than industrial agricultural production. Small-scale agro-ecological farms, by maintaining diversity at the farm and landscape levels, by conserving soils and by reducing the inputs of pesticides, fertilizers and fossil fuels, contribute to the maintenance of ecosystem processes, including the mitigation of emissions.
The authors conclude that agro-ecological systems provide management options to reduce the contributions of greenhouse gas emissions from the agricultural sector and provide for management techniques that promote increased carbon sequestration and mitigate emissions from the system. Furthermore, many of the agricultural practices that mitigate emissions, such as soil conservation measures, reduce reliance on inorganic fertilizers and pesticides; and diversification of the farms also increase the resilience of agricultural systems, which will be needed for adaptation to climate change.
With best wishes,
Effects of industrial agriculture on climate change and the mitigation potential of small-scale agro-ecological farms
Brenda B. Lin1, M. Jahi Chappell2, John Vandermeer3, Gerald Smith3, Eileen Quintero4, Rachel Bezner-Kerr5, Daniel M. Griffith6, Stuart Ketcham7, Steven C. Latta8, Philip McMichael9, Krista L. McGuire10, Ron Nigh11, Dianne Rocheleau12, John Soluri13 and Ivette Perfecto14
Address: 1 AAAS Fellow, Global Change Research Program, Environmental Protection Agency, USA. 2 School of Earth and Environmental Sciences and the Center for Social and Environmental Justice, Washington State University Vancouver, Vancouver, WA, U.S.A. 3 Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, U.S.A. 4 Institute for Research on Labor, Employment, and the Economy (IRLEE), University of Michigan, Ann Arbor, MI, U.S.A. 5 Department of Geography, University of Western Ontario, Ontario, Canada. 6 Department of Forestry, University of Cordoba, Cordoba, Spain. 7 College of Science and Mathematics, University of the Virgin Islands, U.S.A. 8 Department of Conservation and Field Research, National Aviary, Pittsburgh, PA, U.S.A. 9 Department of Development Sociology, Cornell University, Ithaca, NY, U.S.A. 10 Department of Biological Sciences, Barnard College, New York, NY, U.S.A. 11 Centro de Investigaciones y Estudios Superiores en Antropologia Social, San Cristobal de Las Casas, Chiapas, Mexico. 12 School of Geography, Clark University, Worcester, MA, U.S.A. 13 Department of History, Carnegie Mellon University, Pittsburgh, PA, U.S.A. 14 School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI, U.S.A.
Received: 11 March 2011
Accepted: 18 May 2011
The electronic version of this article is the definitive one. It is located here: http://www.cabi.org/cabreviews
© CAB International 2011 (Online ISSN 1749-8848)
According to the Intergovernmental Panel on Climate Change (IPCC), agriculture is responsible for 10–12% of total global anthropogenic emissions and almost a quarter of the continuing increase of greenhouse gas (GHG) emissions. Not all forms of agriculture, however, have equivalent impacts on global warming. Industrial agriculture contributes significantly to global warming, representing a large majority of total agriculture-related GHG emissions. Alternatively, ecologically based methods for agricultural production, predominantly used on small-scale farms, are far less energy-consumptive and release fewer GHGs than industrial agricultural production. Besides generating fewer direct emissions, agro-ecological management techniques have the potential to sequester more GHGs than industrial agriculture. Here, we review the literature on the contributions of agriculture to climate change and show the extent of GHG contributions from the industrial agricultural system and the potential of agro-ecological smallholder agriculture to help reduce GHG emissions. These reductions are achieved in three broad areas when compared with the industrial agricultural system: (1) a decrease in materials used and fluxes involved in the release of GHGs based on agricultural crop management choices; (2) a decrease in fluxes involved in livestock production and pasture management; and (3) a reduction in the transportation of agricultural inputs, outputs and products through an increased emphasis on local food systems. Although there are a number of barriers and challenges towards adopting small-scale agro-ecological methods on the large scale, appropriate incentives can lead to incremental steps towards agro-ecological management that may be able to reduce and mitigate GHG emissions from the agricultural sector.
Keywords: Industrial agriculture, Agro-ecology, Small-scale agriculture, Greenhouse gases, Land conversion, Mitigation, Climate change, Global warming, Adaptation