Journal Article N762921K75 Nitrogen Research Support, Non-U.S. Gov't climate change impact food security model intercomparison uncertainty 1.5°C warming 142M471B3J Carbon Dioxide Fertilizers Grain Proteins Research Support, U.S. Gov't, Non-P.H.S. climate change climate change adaptation crop models crop simulation model ecophysiological model ensemble mean ensemble median ensemble modeling ensemble modelling extreme low yields grain protein model ensemble multimodel ensemble prediction process-based model smallholder farming systems