Abstract

As a baseline guide for indicating the urgency of today’s climate change situation for protecting food security, we estimate the total unavoidable global warming by including all unavoidable sources of warming; in particular, for policy relevance, we start with the time to atmospheric greenhouse gas stabilization. We rely of the IPCC assessments and the National Research Council’s 2011 Climate Stabilization Targets. Having made this estimate by a simple calculation, we link the unavoidable global warming to unavoidable crop yield changes from climate crop model projections. From the climate science, we identify the following unavoidable warming sources that contribute to unavoidable future warming: 1.Duration of global warming; 2.Today’s global emissions scenario; 3.Time from the fastest emergency reduction of emissions to atmospheric greenhouse gas stabilization. 4.Delayed warming from the ocean heat lag; 5.Deferred warming from unmasking of committed warming due to fossil fuel air pollution aerosol cooling. 6. Additional warming from positive climate system feedbacks resulting from the above.