In conclusion, no particular trends stand out as a commonality between all commodities — rather, trend groupings are more apparent at the commodity subgroup level. Notably, rather than inverse relationships suggesting direct trade-offs, we find that for many commodities, there exists a lack of a relationship at all between environmental indicators. This suggests that although optimization towards GHG emissions may not come at the expense of most indicators (in a broad sense), it likewise does not account for all necessary cofactor reductions. Generalizations are difficult to make as each commodity has different inputs, processes, and outputs, but the consensus is that a multifaceted approach to environmental indicator optimization is key.
A broader trend commonly found during our research, however, was the better performance of intensive systems in terms of environmental impact compared to extensive. For animal production, this raises perhaps not a research question but an ethical question of animal welfare — how does one go about defining animal welfare, much less decide the point at which this moral trade-off should occur?
Generally, an important plan of action moving forward is simply gathering more data, as some commodities lack the data points to have strong statistical significance. In particular, the seafood subcategory had a distinct lack of data to analyze, possibly due to its non-terrestrial nature. In addition, data and further analysis in specific parts of the supply chain rather than simply overall is critical, especially for the stages of feed and transportation. With such insight, efforts to streamline the life cycle of all commodities to have the least environmental impact can be utilized in a targeted and efficient way.
Most importantly, we must recognize that environmental action is permeated with nuance — as clearly seen here, a GHG reduction-only approach fails to account for many other crucial factors. In navigating each unique route to preserving the environment, we must keep our eyes on the larger picture of the entire biosphere and its complicated and codependent machinations. We rarely found that reducing GHG emissions resulted in a consistent increase in another impact, but also rarely did it come with a corresponding improvement, suggesting that management moving forward must explicitly consider multiple environmental impacts.