Elsevier

Food Policy

Volume 37, Issue 4, August 2012, Pages 463-466
Food Policy

Where are the best opportunities for reducing greenhouse gas emissions in the food system (including the food chain)? A comment

https://doi.org/10.1016/j.foodpol.2012.04.006Get rights and content

Abstract

In a recent paper Garnett (2011) examines the greenhouse gas emissions arising from the global food system. This paper builds on Garnett’s contribution by considering how high levels of food waste contribute to the food chain’s greenhouse emissions and how they can be reduced, something Garnett generally overlooks. The emissions that arise from food waste represent the emissions embedded in the production of food that is then wasted and the emissions that arise from the process of waste disposal. Food waste can also be split into pre-consumer and consumer waste. These distinctions give rise to four categories of food waste related emissions: pre-consumer embedded, pre-consumer waste disposal, consumer embedded and consumer waste disposal emissions. The levels of food waste in each category differ between economies, as do the causes of wastage. Policies to address food waste and the associated emissions need to promote a mixture of technological and behavioural change and be tailored to the economic, cultural and technological conditions in each country.

Highlights

► We identify four different categories of emissions arising from food waste. ► The relative importance of these categories differs around the world. ► Reducing food wastage can substantially reduce food system GHG emissions. ► Different waste management techniques can reduce emissions from food waste disposal. ► A range of policy options can reduce waste and waste management emissions.

Introduction

In a recent paper in Food Policy Garnett (2011)1 reviewed greenhouse gas (GHG) emissions arising at different stages in the food system and outlined policy options for reducing emissions. While agreeing with Garnett’s broad conclusion that the major challenge in reducing food system GHG emissions is changing (richer) consumers’ dietary preferences, this comment draws attention to significant potential for reducing food related emissions by reducing food waste, something Garnett largely overlooks.

Despite conflicting data on regional and global levels of food waste (Gustavsson et al., 2011, Godfray et al., 2010, Stuart, 2009; Quested and Johnson, 2009) it is widely acknowledged that food waste is a major problem, with a third or more of global food production lost or wasted (Gustavsson et al., 2011, Godfray et al., 2010). With agriculture responsible for 17–32% of global GHG emissions (Bellarby et al., 2008) reducing food waste should offer substantial opportunities for reducing greenhouse gas emissions (as well as the other negative environmental effects of agriculture and food production). Stuart (2009), for example, estimates that cutting European food waste by half could lead to a saving in total European greenhouse gas emissions of 5%, and Chapagain and James (2011) estimate that avoidable household food waste in the UK is responsible for 20 million tonnes of carbon dioxide-equivalent (CO2e) each year, 3% of the UK’s total emissions.

This comment explores the potential for reducing food waste related emissions by distinguishing between waste arising at two different stages in the food system: pre-consumer waste (from the manufacturing, processing, distribution and retailing of food) and consumer waste (arising in households, after purchase). A distinction is also made between two different types of emission; embedded emissions (generated during the production of food that is wasted) and waste disposal (from the processes of disposing waste food). These distinctions give four categories of food waste emissions: pre-consumer embedded, pre-consumer waste disposal, consumer embedded and consumer waste disposal emissions.

It is argued that Garnett underestimates the potential for savings in each of these emissions categories, and therefore overlooks some important policy options for reducing food system GHG emissions – options that differ between low, middle and high income economies. Embedded and waste disposal emissions from pre-consumer waste are considered first, and then the two emission types from consumer waste. When considering embedded emissions the scale of each type of waste is examined as these emissions are reduced by reducing waste (with given production, processing and transport systems). Waste disposal emissions, however, can also be reduced by adopting lower GHG emission waste disposal systems.

Section snippets

Pre-consumer embedded emissions

Levels of per capita pre-consumer waste, from production through to retailing, are relatively similar across the different regions of the world, varying between 150 and 200 kg/year in nearly all regions apart from South and Southeast Asia where they are 110 kg/year (Gustavsson et al., 2011). This outweighs consumer food waste by a factor of 2 in Europe and North America, a factor that is higher in less developed regions, rising to over 25 in Sub-Saharan Africa, where consumer waste is very low (

Consumer embedded emissions

Garnett focuses on consumer embedded emissions in her discussion of food waste. As discussed earlier, wastage of food by consumers is a problem generally restricted to developed economies, but even in these countries is about half pre-consumer wastage (Gustavsson et al., 2011): in the UK consumers waste 8.3 million tonnes of food a year (22% of the total bought), two thirds of which is avoidable waste (Quested and Johnson, 2009) while in the US consumers are reported to waste as much as 40% of

Conclusions

This comment has only brushed the surface of the numerous issues surrounding food waste around the world. However, with over 30% of food around the world wasted and large quantities of CH4 given off by landfill sites, food waste is an important contributor to the global food chain’s GHG emissions. Food waste is also a problem that without proper policy interventions is likely to get worse as countries around the world develop. There is very little data on historical food wastage. However, Hall

Acknowledgement

The author would like to thank Andrew Dorward as well as the editor and an anonymous reviewer for for comments on an earlier draft of the paper.

References (27)

  • DEFRA, 2006. Carbon Balances and Energy Impacts of the Management of UK Wastes....
  • EPA, 2006. Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks. United States...
  • Food and Agriculture Organisation

    The State of Food Insecurity in the World

    (2009)
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