Integrating temperature and CO2-concentration impact on crops into an input–output framework

Abstract

Abstract Environmental Input–Output Analysis (IOA) incorporates feedbacks in coupled economic-environmental systems, driven by an exogenous demand and fixed input–output coefficients with a linearity assumption. For some environmental problems, or over longer time periods, the IO coefficients and exogenous drivers may change. Here, we introduce a climate-feedback into an IO system via the crop sector to illustrate the potential couplings between climate change and material and economic flows. We use existing climate impact ensembles to calibrate climate feedback parameters for crop productivity and implement them in an expanded IO system. We generally find that the same exogenous demand can be met with lower output due to yield improvements, driven by the beneficial effect of CO 2 fertilization which generally dominates the modelled temperature effect on yield, essentially indicating a reduction in land-use intensity driven by CO2 fertilization. However, the temperature effect, which is positive or negative dependent on region, may be underestimated because of the inability of existing process-based models to simulate climate-related agricultural impacts. The overall changes in yield, when exogenous demand is held fixed and annual CO 2 emissions are used as feedback, are of the order of 0.2% when normalized with the regional crop outputs and much smaller when normalized with total output. While the impact of a single year’s emissions is small, climate change is a cumulative problem and becomes significant over decades. Over these time periods, economic structure and demand would be expected to change in response to the climate impacts, requiring a dynamic modelling framework.