Deriving and applying response surface diagrams for evaluating climate change impacts on crop production

This paper presents the method to develop response surface diagrams (RSD) s uitable to evaluate the impacts of climate change on potential crop product ion and crop area. The diagrams depict the response of different agricultur al crops to average long-term changes in ambient temperature and precipitat ion on a country basis. They take into account the spatial and seasonal var iability of climate, and differences in the climate response of important c rops. RSDs for Germany and the Democratic Republic of Congo illustrate that countries and crop types differ greatly in their sensitivity to unit chang es in long-term average climate. In comparing the area-weighted RSDs for Ge rmany and Democratic Republic of Congo, it was found that the potential pro duction in Germany of a weighted aggregation of crops is mainly sensitive t o changes in temperature, whereas the potential crop production in the Demo cratic Republic of Congo mainly responds to changes in precipitation (over the specified ranges of climate variables). The RSDs can provide a visual o verview of these varying sensitivities, and are a convenient and simple-to- understand method to summarize crop responses to climate change in a partic ular country.