Published: 10 January 2022
Nature food
Zhongxiao Sun $^{1,2}$, Laura Scherer $^{1}$, Arnold Tukker $^{1,3}$, Seth A. Spawn-Lee $^{4,5}$, Martin Bruckner $^{6}$, Holly K. Gibbs $^{4,5}$ & Paul Behrens $^{1,7}$

$^{1}$ Institute of Environmental Sciences (CML), Leiden University, Leiden, the Netherlands
$^{2}$ College of Land Science and Technology, China Agricultural University, Beijing, China
$^{3}$ The Netherlands Organisation for Applied Scientific Research TNO, The Hague, the Netherlands
$^{4}$ Department of Geography, University of Wisconsin-Madison, Madison, WI, USA
$^{5}$ Center for Sustainability and the Global Environment (SAGE), Nelson Institute for Environmental Studies, University of Wisconsin-Madison, Madison, WI, USA
$^{6}$ Institute for Ecological Economics, Vienna University of Economics and Business, Vienna, Austria
$^{7}$ Leiden University College The Hague, The Hague, the Netherlands

Table of Contents

Abstract

A dietary shift from animal-based foods to plant-based foods in high-income nations could reduce greenhouse gas emissions from direct agricultural production and increase carbon sequestration if resulting spared land was restored to its antecedent natural vegetation.

Linking land, food, climate and public health policy will be vital to harnessing the opportunities of a double climate dividend.

Introduction

Reverting cropland to its antecedent or ‘potential’ natural vegetation (PNV) can substantially increase aboveground biomass carbon (AGBC), belowground biomass carbon (BGBC) and soil organic carbon (SOC) stocks with additional co-benefits for biodiversity and other ecosystem services.

In addition, information and knowledge nudges could motivate the public’s perception and individual intrinsic identity on sustainable diets, which would facilitate value-driven actions on diet change.

Results

  • Carbon sequestration would be achieved predominately in large countries with large amounts of agricultural production, especially feed crops and pasture.

  • Fig. 1 | Changes in net carbon sequestration and net GHG emissions due to dietary change in high-income countries.

  • Fig. 2 | Potential sequestration and emissions changes due to dietary changes.

  • Fig. 3 | Potential carbon sequestration and emissions changes due to removal of non-EAT–Lancet food items.

Discussion

  • Nevertheless, it would probably be a challenging, long-term and complex process to restore the agricultural land spared by dietary change.

  • In our analysis, we assume a scenario in which all spared land is restored to the potential natural vegetation associated with today’s climate to delineate the maximum potential11. However, this idealized opportunity is probably confounded by more nuanced biophysical and socioeconomic characteristics of various world regions.

  • Competition among end uses inevitably precludes 100% adoption of any one type of land use, and strategies are needed to identify ways in which trade-offs among uses can be optimally balanced.

  • Spared land could also potentially be used for bioenergy cultivation—albeit with different outcomes. Traditionally, bioenergy has been regarded as an economically costly strategy for climate change mitigation with a lower efficacy per unit of land use compared with alternatives.

  • In addition to natural climate solutions that ensue from the sequestration element of the double dividend, other supplementary natural climate solutions address production emissions. These solutions, including improved nutrient management, cover crops and biochar (Supplementary Information), do not require extra land but instead target emissions reductions from remaining cropland.

  • To harness the GHG mitigation potential of dietary change, a holistic social policy that coordinates among food, environment and public health systems will be essential.

  • We aim to isolate the current carbon opportunity due to dietary change in high-income nations alone, assuming all other economic conditions are unchanged. With such a change in diets and production systems, there may be direct and indirect rebound effects which could be modelled in future work.

  • It is very challenging to predict future production structures and trade patterns between economic sectors within and among nations. For example, production structures are heavily determined by technological change and do not evolve linearly. …However, the total opportunity assessed here represents an upper bound of possibilities.

  • While we estimate the magnitude of the potential carbon sequestration benefit due to dietary change in high-income nations, we do not include non-agricultural sectors such as transportation, processing, wholesale, retail, hotel and restaurant food emissions.