Main Crops’ Yield Risks of the Belt and Road Terrestrial Countries Under 1.5°C and 2°C Global Warming Scenarios

Abstract According to the Fifth IPCC Assessment Report, climate change poses severe risks to the Belt and Road region. To promote regional food security, this study examined yield risks in four staple crops (rice, wheat, maize, and soybeans) under 1.5°C and 2°C global warming scenarios. Yield data was derived from simulations of multiple climate-crop model ensembles from the Inter-Sectoral Impact Model Intercomparison Project. A threshold was defined as the 10th percentile of the reference period distribution (1986–2005) of crop yields. Then, adverse consequences on yield were assumed to arise once future crop yields were lower than the threshold. To quantify the likelihood of crop yield loss, the agreement of model combinations at which the threshold was crossed was calculated for each crop on a grid scale. Conclusions about crop loss and its risks were as follows: (1) Impacts of warming on yields differ between crop types and regions. The likelihood of yield loss in low-latitude regions was higher than that in mid-latitude regions for maize, rice, and soybeans. (2) Under a higher warming scenario, the mean yield loss likelihood would increase 0.16%–3.06% at low-latitude subregions but dropped by no more than 2% for subregions with higher latitudes. (3) Under 1.5°C global warming, the “risk zone” accounted for 37%, 35%, 25%, and 13% of growing areas for maize, wheat, rice, and soybeans, respectively. (4) The higher the warming, the larger the “risk zone”. When warming increased from 1.5°C to 2°C, the four crops’ calculated “newly added risk zones” would increase by 1.8%–3.5%. This study revealed patterns of yield loss risks for major crops in the Belt and Road in different warming scenarios and subregions and could provide some references for regional responses or adaptions to climate change in the agricultural system.