Climate impacts of feasible food/agriculture/land-use scenarios in a zero-deforestation world in 2050


Präsentation: Michaela C. Theurl, Christian Lauk, Gerald Kalt, Andreas Mayer, Katrin Kaltenegger, Wilfried Winiwarter, Karl-Heinz Erb, Helmut Haberl

 

Zeit/Ort: 14.11.2018, 16:00-18:00, Schottenfeldgasse 29/3

Increasing food demand is a major driver towards increased carbon greenhouse gas (GHG) emissions and the transgression of natural limits. In order to obtain a complete picture of the climate impacts of the complex relationships between increasing demand for land and increased GHG emissions from food production, the emissions from land use change, intensification processes and carbon sequestration on potentially freed up land need to be considered. In the ‘BioBaM model’ we follow a diagnostic approach to characterize the multiple option space of a future food system and assume no deforestation by 2050. We systematically account for GHG emissions from upstream processes (e.g. mineral fertilizer production), agriculture (e.g. manure application), livestock husbandry, and land-use (change). Among 520 scenarios, spanning a wide range of different options for cropland expansion, livestock feeding, crop yields, and human diets, we find 320 ‘feasible’ scenarios with regard to limits of global land availability. GHG emissions of feasible scenarios range from 2.2 to 12.6 Gt CO2e yr-1. When natural succession is assumed to occur on land not required for agricultural production, and carbon uptake of land-use changes as well as emissions from grassland conversion are considered, the range widens to -10.2 to 12.8 Gt CO2e yr-1. We find that many scenarios of calorie-rich and ruminant meat based diets are infeasible in 2050. Highest GHG emissions are found for business-as-usual (BAU) and meat diets on predominantly grain-fed ruminants. Interestingly, BAU diets are feasible under organic, yet globally converging yield estimates with roughage based livestock systems at little cropland expansion (+11%) and with high GHG emissions (10.1 Gt CO2e yr-1). The diagnostic modelling approach of the BioBaM model allows to explore not only the complex relationships of the parameters related to diets, but also to investigate boundaries of the intensity of livestock production.


13.11.2018