Water kefir is another good option - one you get the grains rehydrated it makes a new batch every 24 hours or so, and you can referment it with fruit juice to make a fizzy probiotic drink. It’s much easier to get started with than kombucha
Farmers can actually become a huge part of solving the climate crisis. Regenerative farming techniques can be applied at scale, in any farming system. There are several third party certifiers such as Regenified and Rodale that farmers can use.