@misc{PradhanFischerVelthuizenetal.2015, author = {Pradhan, Prajal and Fischer, G{\"u}nther and Velthuizen, Harrij van and Reusser, Dominik Edwin and Kropp, J{\"u}rgen}, title = {Closing yield gaps}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {491}, issn = {1866-8372}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-408105}, pages = {18}, year = {2015}, abstract = {Global food production needs to be increased by 60-110\% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24\% and 80\% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45-73\%, P2O5-fertilizer by 22-46\%, and K2O-fertilizer by 2-3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way management strategies for closing yield gaps are chosen and implemented.}, language = {en} } @misc{FrielerLevermannElliottetal.2015, author = {Frieler, Katja and Levermann, Anders and Elliott, J. and Heinke, J. and Arneth, A. and Bierkens, M. F. P. and Ciais, Philippe and Clark, D. B. and Deryng, D. and Doell, P. and Falloon, P. and Fekete, B. and Folberth, Christian and Friend, A. D. and Gellhorn, C. and Gosling, S. N. and Haddeland, I. and Khabarov, N. and Lomas, M. and Masaki, Y. and Nishina, K. and Neumann, K. and Oki, T. and Pavlick, R. and Ruane, A. C. and Schmid, E. and Schmitz, C. and Stacke, T. and Stehfest, E. and Tang, Q. and Wisser, D. and Huber, V. and Piontek, Franziska and Warszawski, L. and Schewe, Jacob and Lotze-Campen, Hermann and Schellnhuber, Hans Joachim}, title = {A framework for the cross-sectoral integration of multi-model impact projections}, series = {Earth system dynamics}, journal = {Earth system dynamics}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407968}, pages = {14}, year = {2015}, abstract = {Climate change and its impacts already pose considerable challenges for societies that will further increase with global warming (IPCC, 2014a, b). Uncertainties of the climatic response to greenhouse gas emissions include the potential passing of large-scale tipping points (e.g. Lenton et al., 2008; Levermann et al., 2012; Schellnhuber, 2010) and changes in extreme meteorological events (Field et al., 2012) with complex impacts on societies (Hallegatte et al., 2013). Thus climate change mitigation is considered a necessary societal response for avoiding uncontrollable impacts (Conference of the Parties, 2010). On the other hand, large-scale climate change mitigation itself implies fundamental changes in, for example, the global energy system. The associated challenges come on top of others that derive from equally important ethical imperatives like the fulfilment of increasing food demand that may draw on the same resources. For example, ensuring food security for a growing population may require an expansion of cropland, thereby reducing natural carbon sinks or the area available for bio-energy production. So far, available studies addressing this problem have relied on individual impact models, ignoring uncertainty in crop model and biome model projections. Here, we propose a probabilistic decision framework that allows for an evaluation of agricultural management and mitigation options in a multi-impact-model setting. Based on simulations generated within the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), we outline how cross-sectorally consistent multi-model impact simulations could be used to generate the information required for robust decision making. Using an illustrative future land use pattern, we discuss the trade-off between potential gains in crop production and associated losses in natural carbon sinks in the new multiple crop-and biome-model setting. In addition, crop and water model simulations are combined to explore irrigation increases as one possible measure of agricultural intensification that could limit the expansion of cropland required in response to climate change and growing food demand. This example shows that current impact model uncertainties pose an important challenge to long-term mitigation planning and must not be ignored in long-term strategic decision making.}, language = {en} }