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This analysis quantifies changes in global agricultural markets for maize, rice, soybeans, and wheat due to yield changes triggered by climate change. The scenarios include four representative concentration pathways (RCP), five global climate models, three shared socioeconomic pathways (SSPs) capturing differences in population levels and economic growth, and enhanced CO2-fertilization. Yield projections incorporate the influence of SSPs on nitrogen application and agricultural technology. Depending on the SSP and comparing the RCP8.5 ensemble yields (with CO2-fertilization) to a no climate change scenario in 2050, price increases for maize (61.3%-80.9%), soybeans (36.7%-51.7%), and wheat (5.4%-11.1%) are observed. Large wheat producers in temperate regions expand wheat production under climate change. Rice benefits from CO2 fertilization resulting in a relatively uniform price decrease across scenarios of 19.5%-19.9%. Cropland expansion between 2015 and 2050 is lowest for the high economic growth scenario. Depending on the crop and region, there are significant reductions in production especially for maize. Absolute changes in trade patterns are most pronounced for wheat and least for rice. Using trade as a means to dampen the negative welfare effects of climate change will be important and so is economic growth. [ABSTRACT FROM AUTHOR]

• Carbon tax on energy inputs reduces land allocated to crops in the United States. • U.S. carbon tax on energy inputs shifts some cropland to other countries. • Small carbon leakage from shifting agricultural production. • Increase in carbon emissions offset by overall emission reduction. There is increased interest in a carbon tax in the United States (U.S.) and policy makers, farmers, and other stakeholders need to understand the various economic and environmental aspects of such a policy on agriculture. A global agricultural simulation model assesses changes in production, commodity prices, and trade resulting from a U.S. carbon tax. In addition, greenhouse gas (GHG) emissions from land-use change are quantified to evaluate the possible unintended consequence of increasing emissions in the rest of the world. Three U.S. carbon tax scenarios are evaluated ranging from $15–$144 per metric ton of carbon dioxide equivalent (t−1 CO 2 -e) and covering a 10-year projection period. The results show that the production cost for corn and soybeans increase by a maximum of 32.6% and 22.4%, respectively at a carbon tax of $144 t−1 CO 2 -e. The production cost increase is compensated in part by an increase in commodity prices. Hence, the decrease in net returns for corn, soybeans, and wheat is 11.4%, 8.7%, and 11.0%, respectively, in the scenario with the highest carbon price. U.S. exports decrease for major commodities such as corn (24.9%), sorghum (20.5%), and wheat (8.7%). Barley, soybeans, and sunflower see an increase in exports of 1.2–8.8%. These changes in trade patterns also result in a re-allocation of land-use in the rest of the world leading to a slight increase in global GHG emissions from land-use change representing 1.8% of total U.S. emissions in 2017. The increase in emissions is small compared to the overall projected reduction from the carbon tax. Policy makers need to be cognizant of leakage in terms of land-use change and that measures must be taken to avoid expansion into carbon rich native vegetation. [ABSTRACT FROM AUTHOR]