Abstract

The yield potentials of crops were projected by three different methods: (1) The yield potentials of the majority of global crops were projected by the regression analysis of the historical annual crop yield data to be 2 to 3 times of their current yields, (2) The yield potentials of rice, wheat, maize, potato, rapeseed and soybean for China were projected by the AEZ model developed by IIASA and FAO to be 1.2, 2.0, 2.0, 1.8, 2.1 and 1.9 times of its 2010 countrywide average, respectively, and (3) The yield potentials of global rice, wheat, maize, potato, rapeseed and soybean were projected to be 1.4, 2.5, 1.2, 1.8, 1.9 and 2.2 times of its present record yield, respectively, by the maximum light use efficiency (LUE) of plant model. The projected potential crop yields of our study indicate that the carrying capacity of global agro-ecosystem is limited. Thus, in a closed system such as the global ecosystem is not sustainable. Human can only do his best to postpone the inevitable “ending”. Thus, the earlier the human takes action, the better chance is for the humanity to survive.