The greenhouse gas impacts of converting food production in England and Wales to organic methods

Agriculture is a major contributor to global greenhouse gas (GHG) emissions and must feature in efforts to reduce emissions. Organic farming might contribute to this through decreased use of farm inputs and increased soil carbon sequestration, but it might also exacerbate emissions through greater food production elsewhere to make up for lower organic yields. To date there has been no rigorous assessment of this potential at national scales. Here we assess the consequences for net GHG emissions of a 100% shift to organic food production in England and Wales using life-cycle assessment. We predict major shortfalls in production of most agricultural products against a conventional baseline. Direct GHG emissions are reduced with organic farming, but when increased overseas land use to compensate for shortfalls in domestic supply are factored in, net emissions are greater. Enhanced soil carbon sequestration could offset only a small part of the higher overseas emissions. The greenhouse gas (GHG) mitigation potential of organic methods is poorly understood. Here, the authors assess the GHG impact of a 100% shift to organic food production in England and Wales and find that direct GHG emissions are reduced with organic farming, but when increased land use abroad to allow for production shortfalls is factored in, GHG emissions are elevated well-above the baseline.