Anticipating impacts of climate change on organic agriculture.

Abstract

Abstract Both conventional agriculture (CA) and organic agriculture (OA) are inextricably linked to climate and will impact and be impacted by climate change (CC). OA, unlike CA, encompasses heterogeneous agricultural management methods and practices, given its multiple origins around the world. Although it represents <1% of the world's agricultural production and about 9% of total agricultural area, OA is a globally growing, low-input, dynamic and knowledge-intensive production system. It provides a larger flow of multiple ecosystems services than, and differs fundamentally from, CA in the conceptual approaches that frame crop, animal and natural resources-management strategies. Organic farmers have fewer means to manage their production systems and they need greater expertise and more time to optimize the management of OA in the face of CC. The diverse OA-based agroecological systems (AESs), compared with CA, provide more regulatory functions that enable OA to adjust to changing environmental conditions; however, OA may experience larger inter-annual variability which is attributed to fewer short-term possibilities for controlling biotic and abiotic stresses. Nevertheless, small-scale organic farmers and communities are seemingly able to cope with weather fluctuations and climate extremes because of the self-regulating ability of OA and the enormous variability in internal adaptation strategies they have developed over time. However, vulnerability of OA to CC will eventually depend on the level of exposure and sensitivity to multiple biotic and abiotic stresses, and on its intrinsic buffering capacity for adaptation and mitigation. Long-term sustainability of OA in the face of CC is intractably linked to ecological sustainability. CC and ecological disturbances may force OA to undergo structural changes or adjustments as to land area; farm size and land tenure; farming complexity, crop-livestock integration, sustainable intensification and specialization; environmental stewardship; and labour intensity. Conventionalization, to the extent that it does not undermine its core principles, may become the only economically viable structural change option to adapt large-scale OA to CC. In order to minimize the impact of CC, OA needs to function within the broader context of multidisciplinary agro-ecological principles, while adopting scientifically based, resource-efficient and semi-closed AESs' approach. The challenge facing OA is to develop measurable and reliable biophysical vulnerability indicators to prioritize adaptation and mitigation efforts at the farm and local levels.