Global Warming and Agriculture: Impact Estimates by Country, W. Cline 2007
The 2007 Cline food security assessment was based on a global temperature increase of 3.3ºC. We are currently on track for a 3ºC rise by 2050. We are looking at the world that today's children will see.
The climate models used in Cline's study predicted that under the IPCC's scenario A2 scenario (high scenario as the world is on), that global mean temperature would rise by 3.3ºC.
Because of the uncertainty of the potential carbon fertilization benefits to some crops in some regions, Cline gave results for crop yield changes with and without fertilization benefits.
Risk management demands that changes without fertilization would be the basis of food security assessment, but instead the IPCC assessment based on the assumption of large CO2 fertilization benefits based on crop experiments of doubtful validity in the real world.