Abstract: Recent studies assessing plausible futures for agricultural markets and global food security have had contradictory outcomes. To advance our understanding of the sources of the differences, 10 global economic models that produce long-term scenarios were asked to compare a reference scenario with alternate socioeconomic, climate change, and bioenergy scenarios using a common set of key drivers. Several key conclusions emerge from this exercise: First, for a comparison of scenario results to be meaningful, a careful analysis of the interpretation of the relevant model variables is essential. For instance, the use of real world commodity prices differs widely across models, and comparing the prices without accounting for their different meanings can lead to misleading results. Second, results suggest that, once some key assumptions are harmonized, the variability in general trends across models declines but remains important. For example, given the common assumptions of the reference scenario, models show average annual rates of changes of real global producer prices for agricultural products on average ranging between -0.4% and +0.7% between the 2005 base year and 2050. This compares to an average decline of real agricultural prices of 4% p.a. between the 1960s and the 2000s. Several other common trends are shown, for example, relating to key global growth areas for agricultural production and consumption. Third, differences in basic model parameters such as income and price elasticities, sometimes hidden in the way market behavior is modeled, result in significant differences in the details. Fourth, the analysis shows that agro-economic modelers aiming to inform the agricultural and development policy debate require better data and analysis on both economic behavior and biophysical drivers. More interdisciplinary modeling efforts are required to cross-fertilize analyses at different scales.

Abstract: Rather than on crop modelling only, climate change impact assessments in agriculture  need to be based on integrated assessment and farming systems analysis, and account for  adaptation at different levels. With a case study for Flevoland, the Netherlands, we  illustrate that 1) crop models cannot account for all relevant climate change impacts and  adaptation options, and 2) changes in technology, policy and prices have had and are likely  to have larger impacts on farms than climate change. While crop modelling indicates  positive impacts of climate change on yields of major crops in 2050, a semi-quantitative  and participatory method assessing impacts of extreme events shows that there are  nevertheless several climate risks. A range of adaptation measures are, however, available  to reduce possible negative effects at crop level. In addition, at farm level farmers can  change cropping patterns, and adjust inputs and outputs. Also farm structural change will  influence impacts and adaptation. While the 5th IPCC report is more negative regarding  impacts of climate change on agriculture compared to the previous report, also for  temperate regions, our results show that when putting climate change in context of other  drivers, and when explicitly accounting for adaptation at crop and farm level, impacts may  be less negative in some regions and opportunities are revealed. These results refer to a  temperate region, but an integrated assessment may also change perspectives on climate  change for other parts of the world. No Label

Abstract: Rather than on crop modelling only, climate change impact assessments in agriculture need to be based on integrated assessment and farming systems analysis, and account for adaptation at different levels. With a case study for Flevoland, the Netherlands, we illustrate that (1) crop models cannot account for all relevant climate change impacts and adaptation options, and (2) changes in technology, policy and prices have had and are likely to have larger impacts on farms than climate change. While crop modelling indicates positive impacts of climate change on yields of major crops in 2050, a semi-quantitative and participatory method assessing impacts of extreme events shows that there are nevertheless several climate risks. A range of adaptation measures are, however, available to reduce possible negative effects at crop level. In addition, at farm level farmers can change cropping patterns, and adjust inputs and outputs. Also farm structural change will influence impacts and adaptation. While the 5th IPCC report is more negative regarding impacts of climate change on agriculture compared to the previous report, also for temperate regions, our results show that when putting climate change in context of other drivers, and when explicitly accounting for adaptation at crop and farm level, impacts may be less negative in some regions and opportunities are revealed. These results refer to a temperate region, but an integrated assessment may also change perspectives on climate change for other parts of the world.