The domestic and international implications of future climate for U.S. agriculture in GCAM

pathways on the results, through a systematic repetition and comparison of this experiment across the SSPs. Additionally, we have focused on the effects of climate change on crops, but applying impacts to livestock agriculture in GCAM and examining the effects of those impacts would be interesting. There is evidence [33] that the integration of livestock impacts may lead to more complex results, as different effects offset or feedback on each other. Similarly, the same framework for analysis could be applied to scenarios with different energy or agricultural policies or different RCPs. Because GCAM includes both energy and agriculture modules, an increased demand for biofuels in the energy sector will bolster prices for several crops in con- junction with climate derived changes in prices. From a more biophysical perspective, this study has explored the impacts of changing trends in agricultural yields. Consideration of extreme events such as droughts, might add a more a more dynamic and varied character to the results from year-to-year. While GCAM includes a reference assumption of increasing yet saturating yields out to 2100 to account for technological development, scenarios explicitly detailing the introduction of more drought- resistant cultivars could provide an additional dimension to this analysis. As the modeling capabilities to analyze such scenarios come online, including dynamic, two-way feedbacks between the Earth system and agriculture, will also push future analyses to provide a fuller

understanding of the interactions of the different sectors of the human-Earth system. Supporting information S1 File. (DOCX) S2 File. (DOCX) S3 File. (DOCX) S1 Fig. (TIFF) S2 Fig. (TIFF) S3 Fig. (TIFF) S4 Fig. (TIFF) S5 Fig. (TIFF) S1 Data. (ZIP) S2 Data. (ZIP) Author Contributions Conceptualization: Leon Clarke, James Edmonds. PLOS ONE The domestic and international implications of future climate for U.S. agriculture in GCAM PLOS ONE | https://doi.org/10.1371/journal.pone.0237918 August 28, 2020 9 / 11