Response of crop yield and nitrogen use efficiency for wheat-maize cropping system to future climate change in northern China

•The SPACSYS model can statistically simulate crop yields and nitrogen uptake of wheat and maize.•The SPACSYS model can statistically simulate annual NUE of wheat-maize double cropping system.•Manure led to a higher crop yields and NUE compared with mineral fertilizers under climate change.•Climate change positively impacts on wheat yield (average of +8.5%) but not on maize yield (average of −3.8%).•Climate change reduced annual NUE of wheat and maize by an average of 15% in the north of China.