Impact of organic farming on global warming - recent scientific knowledge

The review of recent literature on the contribution of organic farming to global warming shows different results. The inhomogeneous results are reasoned in different focuses of the studies looking at different products, system borders or production conditions and production intensities. In summary of the assessed studies can be stated that organic farming emits lower amounts of green house gases (GHG) than comparable conventional systems. Higher area bound GHG emissions in conventional agriculture are mainly reasoned in farm imported feedstuffs that are to a significant amount purchased from overseas. The consumption of products from energy intensive pesticide and fertiliser production is increasing the GHG emissions further. Higher yields per animal or per hectare unit are usually not able to compensate for these negative impacts. Therefore it can be concluded that organic farming is more climate friendly than normal conventional farming, also when product bound GHG loads are calculated. Whereas the emissions of integrated conventional systems are equal to organic systems. In the integrated systems reduced pesticide consumption, use of farm produced resources (e.g. feedstuff, livestock manure) and set asides are advantageous. GHG-balances of organic farming could be improved further by higher area yields or by reduction of energy consumption. Global warming potential of all farming farm systems can be optimised and reduced in future. Renewable energy systems, use of local resources and progress in management skills (increase of input-output relations: feeding, energy-use, nutrients) are usually underdeveloped in practice. Yield increases with moderate increase in mechanisation normally lead to reductions in global warming potential per unit of agricultural product.