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Vol:.(1234567890)Scientific Reports |        (2022) 12:17268  | https://doi.org/10.1038/s41598-022-22228-7
www.nature.com/scientificreports/
that maize yield would decrease severely. For the whole world more mitigation and adaptation actions should 
be taken from now on. Food security would be a significant challenge in this century.
Yield change of maize in main countries. There are huge differences in impacts on maize yield under 
climate change, which would influence the food crisis in different regions. There are 159 countries in the whole 
world which plant maize. The gross yield of maize the top 20 countries accounts for more than 90% of the total 
yield in the 159 countries. So, the changes in the top 20 countries under future scenarios would influence the 
food security of the whole world (Fig. 5). From the results of simulated by CRESE-maize under global warming 
by 1.5 °C, there would be 75 countries facing with yield loss of maize; the mean yield loss rate would become 
33.5%. There would be 84 countries experiencing yield increases. Overall, the global maize yield would slightly 
increase. Under global warming by 2.0 °C, there would be 82 countries facing with yield loss of maize, for which 
the mean yield loss rate is approximate to that under global warming by 1.5 °C. There would be 77 countries 
experiencing yield increase; however, the mean yield increase is apparently smaller than that under global warm-
ing by 1.5 °C. Generally, the global maize yield would decrease. The results show that the adverse effect of warm-
ing up 2.0 °C on global maize production is far greater than warming up 1.5 °C. It is important to take actions to 
develop forward-looking adaptation measures to cope with future climate change.
According to statistics in 2018, the gross maize yield in the top 5 countries is almost 80% of the total maize 
yield of the whole world. The United States accounts for more than 32%; China accounts for about 24%; Brazil, 
Argentina and Mexico account for about 23%. The fluctuation of maize production in these five top countries will 
have a significant impact on the global maize trade. Based on the simulation results, comparing to 1986–2005, 
the maize yield in China, Brazil and Argentina would decrease under global warming by 1.5 °C; the yield loss 
rate would reach more than 20% in Brazil; Argentina would decrease by 14.7%; China would decrease by 3.7%. 
However, there would be increasing trends in the United States and Mexico; the change in the United States 
would not be significant and the maize yield would increase by 0.5%; the yield increasing rate would exceed 50% 
in Mexico. Overall, the gross maize yield in the top 5 countries would decrease by 2% under global warming 
Figure 5.  Yield loss rates on maize in top 20 countries under global warming by 1.5 °C and 2.0 °C.