Go write to Consumer’s Checkbook about their criteria if you’d like to see it changed. The report is at https://www.checkbook.org/boston-area/supermarkets/ (paywall)

In regards to global warming specifically, my understanding is that what one chooses to eat is much more important than where it came from. That is, locally sourced beef emissions >>> imported produce emissions. Here’s an explainer: https://youtu.be/F1Hq8eVOMHs?t=226. I mention this only to highlight that this aspect of sustainability is complicated and occasionally counterintuitive.