Convert your 'green guilt' to action!
This recent interview in Slate with Emma Marris presents a reasonable idea--to not spend too much time feeling guilty about most individual choices, but to use that energy to engage in communal action.
When asked what five easy things each of us could do to make the world a better place, co* recommends, "I’d say No. 1: collective action. No. 2: collective action. No. 3: collective action.
No. 4: eat a little bit less beef. And No. 5: don’t fly if you don’t have to." Read the article--it's a quick, interesting read--and think about how to join in!
(*I use the term "co" for the third person singular non-gendered pronoun.)