Organic farming’s role in adaptation to and mitigation of climate change : an overview of ecological resilience and a model case study

Sammanfattning: Agriculture is essential for human survival and today it faces many problems related to both climate change and an increasing population. While increased total yields during the 20th century have created the conditions for both global economic and population growth, the agricultural practices utilized have often had detrimental consequences both for ecosystems and people. The agricultural sector is a large emitter of greenhouse gases but it has the potential to mitigate climate change as well. One way that this is possible is by sequestering carbon in soil, which also leads to improved soil quality. With climate change already affecting agriculture, there is an urgent need to increase its resilience. Organic farming is seen by many as both an environmental friendly farming system and as a practice with higher intrinsic resilience against climate change. This thesis aims to investigate in what ways these claims might be true and also how organic farming might be used as a way of sequestering carbon from the atmosphere. Some of the factors determining resilience in agriculture were found to be biodiversity levels and soil organic carbon sequestration rates. By using a model, LPJ-GUESS, organic farming practices were simulated and compared against a field trial in Norway. While indicating similar results for yield, the modelled soil carbon storage trends contradicted those of the field trials indicating that more factors than those used have to be taken into account when modelling organic farming accurately. The main conclusion, based on a review of published literature, is that more focus will have to be put on ecological processes in agriculture in the future in order to create a resilient and sustainable agriculture.