Climate Change Impacts on Agricultural Biodiversity and Food Security

Abstract

Climate change poses an unprecedented threat to agricultural biodiversity, destabilising the genetic resource base
underpinning global food security through range contractions, phenological mismatches, increased pest and pathogen
pressure, and accelerated genetic erosion in traditional farming systems. This study quantifies the projected impacts of
climate change on agricultural biodiversity and food security indicators across three agroecological zones--Nordic
temperate, Central European mixed, and Mediterranean--under SSP2-4.5 and SSP5-8.5 emission scenarios to 2050 and
2100, integrating species distribution modelling (SDM), crop suitability projections, and agricultural biodiversity indices for
847 crop varieties and 62 wild crop relatives monitored at 124 sites in Sweden, Germany, and Spain. Under SSP5-8.5 by
2100, projected habitat suitability loss averaged 38.4% for wild crop relatives (range 14.2-67.8%), with Mediterranean
endemic species facing the highest extinction risk. Crop variety loss from abandonment of traditional farming systems
was projected to accelerate by 2.3-fold relative to baseline under high warming scenarios, with 312 of 847 monitored
varieties at critical risk of genetic erosion. Food security composite scores declined by 18.7% (SSP2-4.5) to 34.2%
(SSP5-8.5) in Mediterranean zones by 2100, primarily driven by reduced crop yield stability rather than mean yield
decline. An integrated in-situ and ex-situ conservation priority matrix identified 47 high-urgency intervention sites
requiring immediate genetic resource collection to prevent irreversible biodiversity loss.