Global food production under unprecedented risk of climate change

Global food production is under unprecedented stress due to multifaceted impact of climate change and natural disasters. Here for the first time we estimate the integrated climate risk on natural environment during the historical period by combining the multifaceted impact of hazards, vulnerability, adaptive measures on the exposure metrics e.g. biodiversity, land availability, water availability and quality that are key to the agricultural productivity of a region.To meet the growing food demand, recent decades have witnessed rapid cropland expansions; however, ~48% of them are in the moderate-severe risk areas of South America, equatorial and Southern Africa, South Asia and Southeast Asia. Despite, ~80% of the global landmasses are under low and mild risk, it only accommodates ~35-45% of the harvested areas that are with higher cropping potential for future agricultural expansion. In contrast, ~65-70% of the total agricultural crops grow in ~20% of the croplands that are in the moderate and severe risk areas of Indo-Gangetic plain, Amazon and Parana  basin, Yangtze and Huang He basin Niger basin and Southeast Asia.

By exposing the total and individual crop productivities (crop production and harvested areas) to the integrated risk metric we quantify the fraction of individual crop productions that are under different degrees of risk. At the same time, we assess the risk of extensive agricultural practices on the natural environment e.g. forest cover, grasslands, shrublands, mangroves and protected areas by combining the integrated risk metric with the crop cover.  A newly defined crop climate risk index (CCRI) integrates the climate risk with crop statistics and identifies a higher degree of risk on rainfed crops (~65%) compare to the irrigated crops. The risk is severe on tea, bean, maize, cocoa, roots, coffee, cotton, and onion cultivation. Dependence on low productive, lower potential and high risked forested (40-65%) and grassland (20-60%) ecosystems for cultivation will not fulfill the global food demand in future, while the looming threat on their rapid breakdown is eminent. Diversification of croplands to the low and mild risk alternate destinations is essential to ensure global food security and to protect the fragile ecosystems from degradation.