Improving crop yields may reduce greenhouse gases

摘要

Agriculture produces greenhouse gases from sources such as fertilizers, livestock, and farm machinery. But as the global population continues to grow, agricultural productivity must increase to avoid food shortages. Jennifer Burney et al. (pp. 12052-12057) suggest that investing in agricultural research may constitute a relatively inexpensive global warming mitigation strategy, based on a finding that increasing agricultural output by improving crop yields produces less greenhouse gas emissions than expanding farmlands. The authors estimated agricultural emissions from 1961-2005, a period when technological advances increased crop yields by 135%, and compared the emissions to "alternative world" scenarios in which increased food demands were met by cultivating additional croplands. According to the authors, real-world crop yield improvements may have averted more than 160 gigatons of carbon emissions compared to the theoretical scenarios.