Our well-intended attempts at simply and succinctly quantifying the impacts of our food system on climate change through notions such as food miles and carbon foodprints has just gotten more complicated.
It turns out that there are a lot more variables at play, even when just considering the impacts of growing a single food crop, than we generally assume. While the fossil fuels involved in processing and shipping foods gets a lot of airplay, the way food is grown may actually play a more significant role in the overall picture–and may also hold the key to significantly lowering our food system’s climate changing impacts.
Plants both absorb carbon from the atmosphere as they photosynthesize, while also emitting carbon dioxide (along with the microorganisms in the soil–and even the people around them) when they respire.
Once researchers began considering soil carbon “budgets,” they found that vegetables’ ‘carbon footprints’ varied so much from place to place and between different crops that it was almost impossible to make generalizations. Read more…