I don't think anyone has ever talked about drinking straws or plastic bags as having a meaningful effect on carbon emissions. Reducing their use does reduce the amount of plastic that winds up in landfills and the wilderness, which is the actual point of those proposals.

From some quick data I found, aviation is responsible for 2.5% of carbon emissions. In the US, about 17% of flights are private. Probably a fair number of those are hobbiests, but even if you take that number at face value, you could summarily execute all people who take private jets, and you'd reduce carbon emissions by about 0.425 percent. I'm skeptical that that is going to really make a massive difference in the grand scheme of things.