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Environmental impacts

Dr. Tara Garnett, Environmental Change Institute, University of Oxford on environmental impacts of food system activities in Southeast Asia
So one way of thinking about the environmental impacts of food systems is to take this supply chain approach, look at the impacts at the agricultural stage, at the processing and the distribution stage, and at the consumption stage. Another way of cutting the cake, as it were, is to think about the different foods that make up a diet and the environmental impacts that arise from the production, distribution, and consumption of those different foods. Some foods have very much higher impacts than other foods.
Increasingly, people are very well aware that animal products carry high environmental costs, and that includes terrestrial livestock products as well as aquatic products, whether harvested from the wild– in the form of fish and seafood– or farmed aquaculture products. So to take terrestrial animal products first– which are growing rapidly in Southeast Asia– livestock contribute to the greatest burden of greenhouse gas emissions of all foods on a global level. It’s been estimated that terrestrial livestock account for about 14% to 15% of global greenhouse gas emissions. But those foods are still eaten– well, they’re eaten in very large quantities in some parts of Southeast Asia, but to much lesser degree in other parts. What’s interesting to note are the trends in consumption.
So particularly in Southeast Asia, poultry and dairy consumption is set to rise rapidly. And that’s a consequence not so much of rising population, but of rising per capita intakes. Another food which carries high environmental costs– because of the method of production– is rice, which, because of the way it’s produced in anaerobic conditions, carries a high methane footprint. And there are things that you can do to reduce that footprint, but that is also an area of concern. And then other foods that have very varying environmental impacts are horticultural products.
They can be foods that are very associated with the overuse of fertilisers and overuse of pesticides, which harms not just the agricultural workers– if those are applied in unsafe working conditions– but also consumers– when there are excessive pesticide residues– and also the local environment. So you get pollution of waterways with contamination with pesticides and also eutrophication arising from excessive nitrogen fertiliser use. When it comes to aquatic products– which are a huge growth area in Southeast Asia, again– it’s really difficult to generalise with aquaculture. So on the one hand, you have marine and wild fish capture, which, again, there are– many of the world’s fish stocks are depleted. And production– wild fish capture is levelling off.
Where the growth is really taking place, particularly in Southeast Asia, is in aquaculture. And here the picture is somewhat nuanced because aquaculture systems are characterised by enormous diversity. So on the one hand, you have highly intensive systems, tightly controlled, heavy use of feed inputs, quite high energy use, often production of carnivorous fish, or shrimp, for example, or salmon-type species. And on the other hand, you have much more extensive systems which may receive a little additional feed input, if any at all, that are often produced for local populations. So it’s very difficult to generalise about the environmental impacts of aquaculture products.
And I think the challenge going forward– as demand rises– is to figure out which systems can feed which people at least environmental cost.
We heard last week of the range of significant environmental impacts that food system activities can have. In this video Dr. Tara Garnett, of the Environmental Change Institute at the University of Oxford, talks through some of the major impacts occurring in Southeast Asia, including greenhouse gas emissions and declining water quality from agricultural practice.


Thinking back to the overview of environmental impacts from Week 1, summarized in the table below:
  • Can you think of other impacts not mentioned by Dr. Garnett here that are being felt in the region?
  • Which food system activities and actors are causing those negative consequences?
  • Environmental impacts of food system activities Environmental impacts of food system activities (UNEP, 2016).


    UNEP (2016). Food Systems and Natural Resources. A Report of the Working Group on Food Systems of the International Resource Panel. Westhoek, H, Ingram J., Van Berkum, S., Özay, L., and Hajer M.
    Image Sources: “Viet Nam, Quảng Nam, Hội An – sprayi” (CC BY 2.0) by garycycles8
    This article is from the free online

    Food and Our Future: Sustainable Food Systems in Southeast Asia

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