The Positive Feedback Loop between the Impacts of Climate Change and Agricultural Expansion and Relocation

Climate change and agriculture influence each other. The effects of climate change on agriculture seem to be predominantly negative, although studies show a large variation in impacts between crops and regions. To compensate for these effects, agriculture can either intensify or expand in area; both of these options increase greenhouse gas emissions. It is therefore likely that such negative effects will increase agriculture's contribution to climate change, making this feedback a positive, self-reinforcing one. We have previously used a data-driven model to examine greenhouse gas emissions in 2050 related to agricultural scenarios of increasing demand for food. Here, we extend this approach by introducing the impacts of climate change on agricultural yields. We estimate the additional losses of natural habitats and increases in greenhouse gas emissions resulting from agricultural expansion and relocation induced by the negative effects of climate change. We studied two climate change scenarios and different assumptions about trade. These additional impacts caused by climate change are found to be relatively moderate compared to demand-driven impact, but still significant. They increase greenhouse gas emissions from land use change by an additional 8%-13%. Climate change tends to aggravate the effects of demand drivers in critical regions. Current emission scenarios are underestimates in that they do not include these feedback effects.