Climate change has likely already affected global food production.

Deepak K Ray,Michael Clark,Alexander V Prishchepov,Paul C West,James S Gerber,Snigdhansu Chatterjee,Young Hoon Jung

doi:10.1371/journal.pone.0217148

Abstract

Crop yields are projected to decrease under future climate conditions, and recent research suggests that yields have already been impacted. However, current impacts on a diversity of crops subnationally and implications for food security remains unclear. Here, we constructed linear regression relationships using weather and reported crop data to assess the potential impact of observed climate change on the yields of the top ten global crops–barley, cassava, maize, oil palm, rapeseed, rice, sorghum, soybean, sugarcane and wheat at ~20,000 political units. We find that the impact of global climate change on yields of different crops from climate trends ranged from -13.4% (oil palm) to 3.5% (soybean). Our results show that impacts are mostly negative in Europe, Southern Africa and Australia but generally positive in Latin America. Impacts in Asia and Northern and Central America are mixed. This has likely led to ~1% average reduction (-3.5 X 1013 kcal/year) in consumable food calories in these ten crops. In nearly half of food insecure countries, estimated caloric availability decreased. Our results suggest that climate change has already affected global food production.

Highlights

Previous assessments of climate change impact on crop yields commonly combine future climate scenarios and process-based crop models to project future yields for a limited number of crops for 2050 or later [1,2,3,4]
Recent changes in mean climate occurred across all croplands (S1 Table; S1–S4 Figs), the statistical relationship between weather and crop yields was significant in 54%-88% of harvested areas globally across crops (p < 0.05, Table 1, Fig 1; for model performance see S1–S4 Tables and S7 and S8 Figs)
Within North and Central America recent climate change impact was significant over 89% of maize but 71% of wheat-harvested areas (Table 1)

Summary

Introduction

Previous assessments of climate change impact on crop yields commonly combine future climate scenarios and process-based crop models to project future yields for a limited number of crops for 2050 or later [1,2,3,4]. At higher levels of warming, strong yield losses are predicted in lower latitudes especially for maize and wheat crops [2]. These results provide insights into long-term future changes, there are large uncertainties in both the modeled climate projections [5] and in the crop model parameters [6,7,8].

Methods

Results

Conclusion