Modeling the potential change in yield and distribution of the earth's crops under a warmed climate

Abstract

The large-scale distnbution of crops is largely d e t e r m n e d by c h a t e We present the results of a clmate-crop prediction model based on the U N Food and Agnculture Ojganizahon crop-su~tability approach, implemented in a GIS (geograph~c information system) environment uslng several global environmental databases The model utihzes dally temperature and soil moisture c o n d ~t ~o n s to determine the properhes of the g r o w n g penod Crops are characterized by the11 vanety-specific m nlmum growing penod requirements and photosynthesis and respiration properties Temperature and rad~ation d u m g the growing penod control the development of each crop The model smulates crop-specif~c geograph~c d~stnbuhons by demarcating the reglon where rain-fed productivity is possible The model takes only non-irngated crop product~vlty into account and the potent~al increase In productivity by techn~cal means IS not cons~dered The model therefore shows no potential yield In a n d , irrigat~on-dependent regions The smulated distributions of crops under current climatic conditions coincide largely with the current agncultural regions Simulations with a n atmospheric general circulation model (AGCM)-denved clunate-change scenano illustrate changes in the agncultural potential There are large regional differences in the response Only high-latitude regions un~forrnly benefit from the climatic change \nth projected longer growing penods and an increased p r o d u c t ~v ~t y Most other reglons, however do not benef~t s~gnlficantly or even lose productivity after such change In most of the latter regions differences in moisture availability control the change The analysis shows that agricultural potential and m p a c t s of c h a t ~c changes can be smulated comprehensively