Treenuts and groundnuts in the EAT-Lancet reference diet: Concerns regarding sustainable water use

Davy Vanham,Mesfin M Mekonnen,Arjen Y Hoekstra

doi:10.1016/j.gfs.2020.100357

Abstract

The EAT-Lancet universal healthy reference diet recommends an increase in the consumption of healthy foods, among which treenuts and groundnuts. Both are, however, water-intensive products, with a large water footprint (WF) per unit of mass and protein and already today contribute to blue water stress in different parts of the world. The envisaged massive required increase in nut production to feed a global population with this reference diet, needs to occur in a water-sustainable way. In this paper, we identify and quantify where current nut production contributes to local blue water stress and discuss options for water-sustainable nut production. We show that 74% of irrigated nuts are produced under blue water stress (of which 63% under severe water stress), throughout many regions of the world, most notably in India, China, Pakistan, the Middle East, the Mediterranean region and the USA. We critically evaluate which nut types to promote given substantial differences in WFs. We propose sustainable intensification of nut production employing nut-specific WF benchmarks. We also recommend integrated water resources management including maximum sustainable levels of water consumption by setting of WF caps.

Highlights

The proposed transformations in the food system including a universal diet described by Willett et al (2019) include a significant increase in global consumption of treenuts and groundnuts
The regional aspect of blue water stress and the specific contribution of nut production is not addressed. In this perspective paper, we identify and quantify the blue and green water resources required for current treenut and groundnut production, where this production contributes to local blue water stress, and discuss options for water-sustainable nut production
Global treenut production increased from 4.6 million tons in 2000 to 9.3 million tons in 2017, while global groundnut production increased from 24.4 million tons to 33.0 million tons over the same period (FAOSTAT, 2019)(Fig. 1 and SI Table 2)

Summary

Introduction

The proposed transformations in the food system including a universal diet described by Willett et al (2019) include a significant increase in global consumption of treenuts and groundnuts Both are nutrient-dense and contain primarily unsaturated fatty acids, fibre, vitamins, minerals, antioxidants, and phytosterols. Willett et al (2019) acknowledge that for dietary change, blue water use could increase by 1–9% as reductions related to lower consumption of animal products and sugar are overcompensated by increases related to greater consumption of nuts and legumes. They state that staying within the planetary boundary for water can be achieved by combining improvements in water-use efficiency with reductions in food loss and waste. The regional aspect of blue water stress and the specific contribution of nut production is not addressed

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Conclusion