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Systematic model inter-comparison helps to narrow discrepancies in the analysis of the future impact of climate change on agricultural production. This paper presents a set of alternative scenarios by five global climate and agro-economic models. Covering integrated assessment (IMAGE), partial equilibrium (CAPRI, GLOBIOM, MAgPIE) and computable general equilibrium (MAGNET) models ensures a good coverage of biophysical and economic agricultural features. These models are harmonized with respect to basic model drivers, to assess the range of potential impacts of climate change on the agricultural sector by 2050. Moreover, they quantify the economic consequences of stringent global emission mitigation efforts, such as non-CO 2 emission taxes and land-based mitigation options, to stabilize global warming at 2 • C by the end of the century under different Shared Socioeconomic Pathways. A key contribution of the paper is a vis-à-vis comparison of climate change impacts relative to the impact of mitigation measures. In addition, our scenario design allows assessing the impact of the residual climate change on the mitigation challenge. From a global perspective, the impact of climate change on agricultural production by mid-century is negative but small. A larger negative effect on agricultural production, most pronounced for ruminant meat production, is observed when emission mitigation measures compliant with a 2 • C target are put in place. Our results indicate that a mitigation strategy that embeds residual climate change effects (RCP2.6) has a negative impact on global agricultural production relative to a no-mitigation strategy with stronger climate impacts (RCP6.0). However, this is partially due to the limited impact of the climate change scenarios by 2050. The magnitude of price changes is different amongst models due to methodological differences. Further research to achieve a better harmonization is needed, especially regarding endogenous food and feed demand, including substitution across individual commodities, and endogenous technological change.

Agricultural methane and nitrous oxide emissions represent around 10-12% of total anthropogenic greenhouse gas emissions and have a key role to play in achieving a 1.5 °C (above pre-industrial) climate stabilization target. Using a multi-model assessment approach, we quantify the potential contribution of agriculture to the 1.5 °C target and decompose the mitigation potential by emission source, region, and mitigation mechanism. Results show that the livestock sector will be vital to achieve emission reductions consistent with the 1.5 °C target mainly through emission-reducing technologies or structural changes. Agriculture may contribute emission reductions of 0.8-1.4 GtCO 2e/yr at just 20 USD/tCO2e in 2050. Combined with dietary changes, emission reductions can be increased to 1.7-1.8 GtCO2e/yr. At carbon prices compatible with the 1.5 °C target, agriculture could even provide on average emission savings of 3.9 GtCO2e/yr in 2050, which represents around 8% of current greenhouse gas emissions. Agriculture is the biggest source of anthropogenic non-CO2 emissions, being responsible for around 40% of total methane (CH4), 60% of nitrous oxide (N2O), and around 10-12% (including CO2 up to 20-35%) of total anthropogenic greenhouse gas (GHG) emissions 1-5. Over the past decades agricultural non-CO2 emission have increased from 4.3 GtCO2e/yr in 1990 to around 5.7 GtCO2e/yr in 2015 according to FAOSTAT (www.fao.org/faostat/en/#data/GT, applying global warming potentials from the IPCC AR4) 3,6,7. This growth is mainly related to increased emissions from synthetic fertilizer and manure application and enteric fermentation from ruminants 2,3,6. However, even though emissions increased by around one third, agricultural production over the same period increased by around 70% according to the FAOSTAT gross production index. Hence agriculture still continues to become more GHG efficient at global scale 6,8 .