> If we're advocating for using paper bags over plastic bags, that means we're advocating for way more CO2 in the atmosphere.

Not exactly. The point is not to use paper bag, but to use durable/persistent bag from any material (even plastic) as long as you can.

For example, I almost never use one-time plastic bags, because I have backpack, so when I go to a grocery store, all the things placed into the backpack.

In such case (from energy perspective) it's easier to peoduce 1 backpack (32l) for several years of daily use instead of paper/plastic/etc ONE-TIME bag.

Unfortunately, that approach doesn't work with other things. For example, it's impossible to buy yogurt not in one-time plastic package and we didn't find a "mass market" solution to that problem. Same goes for any other ONE-TIME package