Matti Kummu, Matias Heino, Maija Taka, Olli Varis, Daniel Viviroli

Climate change will alter key climatic conditions which human societies directly rely on and which, for example, food production is adjusted to. Here, using Holdridge Life Zones, we define Safe Climatic Space (SCS), a concept that incorporates the decisive climatic characteristics of precipitation, temperature and aridity. This allows us first to define the climatic niche of current food production and then estimate critical areas where food production will face an elevated risk of being pushed outside the SCS by climate change. We show that a rapid and unhalted growth of GHG emissions (SSP5-8.5) could force 31% (25-37% with 5th-95th percentile confidence interval) of global food crop production and 34% (26-43%) of livestock production beyond the SCS by 2081-2100. Our results underpin the importance of committing to a low emission scenario (SSP1-2.6), whereupon the extent of food production facing unprecedented conditions would be a fraction. The most vulnerable areas are the ones at risk of leaving SCS with low resilience to cope with the change, particularly South and Southeast Asia and Africa’s Sudano-Sahelian Zone.