Greater Mitigation of Climate Change by Organic than Conventional Agriculture: A Review

Abstract

ABSTRACT Organic agriculture is an alternative production system that avoids the use of synthetic pesticides and fertilizers, and relies on biological pest control and on crop rotation, green manure and composts to maintain soil fertility. Although many comparisons have been made between organic and conventional agriculture in terms of crop yields, economic returns and other factors, only a few studies have compared their effects on mitigating climate change. The present review compares the effectiveness of organic and conventional agriculture in mitigating climate change. The review reveals that organic agriculture has a greater potential for mitigating climate change, largely due to its greater ability in reducing emissions of greenhouse gases (GHGs) including carbon dioxide, nitrous oxide (N2O) and methane (CH4). It also increases carbon sequestration in soils compared with that of conventional agriculture. In addition, many farming practices commonly adopted in organic agriculture such as rotation with leguminous crops, minimum or no tillage, and the return of crop residues favour the reduction of GHGs and the enhancement of soil carbon sequestration. The certification of farming practices as required in organic agriculture provides a transparent guarantee of organic principles and standards. This also allows the enforced adoption of new and effective practices aimed at improving the mitigation of climate change. Furthermore, organic agriculture is highly adaptable to climate change compared with conventional agriculture. However, greater recognition of the potential of organic agriculture for mitigating climate change is needed. At present, this recognition depends on the ability of organic yields to out-perform conventional yields, which has been shown to occur in developing countries. More research is needed to improve organic yields in developed countries and to improve the potential of mitigating climate change by organic agriculture. Future strategies for improving the effectiveness of organic agriculture in mitigating climate change are presented and discussed.