What the s word really means

This piece was authored by Dr Brett Glencross and first published in the June 2024 edition of International Aquafeed.

The word “sustainability” gets thrown around a lot these days. So much in fact that everyone is adopting its use in some format or other. However, like that famous line from the movie The Incredibles, “when everyone is special, no one is…”, it makes you question if everyone is as sustainable as they claim. So, if everyone is (supposedly) adopting sustainable practices now, how do we tell truth from the greenwashing? The issue is becoming so pervasive that the European Commission is now introducing legislation (Green Claims Directive 2023/0085) to ensure that there is substantiation on the communication of environmental claims going forward.

Much of the problem in this regard comes from the basis by which different sectors claim something is sustainable. Many would have you believe just because something comes from a plant product that this makes it sustainable. Afterall this is much of the claim of the vegan-lobby, in that we should all eat plants and save the world. However, a quick review of some of the literature on the impacts on biodiversity, climate-change potential, water use and so on quickly shows that agriculture has a huge impact. And this is even before we add in the impacts of land clearing and pesticides. Clearly crop production is not without its baggage.

An alternative that many pundits opt for now as a sustainable alternative is insects. While insects sit nice and low in the trophic-system-of-things, they still need to be fed. They are animals after all and still need organic carbon and nitrogen to grow. So, recently I was chasing some life cycle assessment (LCA) data on insects to get some clarity on the topic and came across a good paper on a commercial Dutch insect production system [https://doi.org/10.1016/j.resconrec.2019.01.042] and the environmental impacts of insect meals. I was surprised when I read that it took 32.24kg of feed (spent brewery grains) to produce 6.26kg of outputs of which only 1kg was insect meal. I was even more surprised to read that the carbon footprint (global warming potential) that they reported in that paper was 5300kg CO2-equivalent per tonne of insect meal. Compare that against Peruvian anchoveta meal at 624kg CO2-equivalent per tonne and Brazilian solvent-extracted soybean meal at 4257kg CO2-equivalent per tonne [EF3.1 economic allocation GFLI v2.0 database], and it makes you question things, like what it really means when you say something is sustainable.