Beer is indisputable proof that Mother Earth loves each and every one of us. However, those who return her love and enjoy her frothy bounty might harbor concerns about the environmental impact of their consumption. Worry no longer: Our resident expert on all things green, the incomparable Umbra, is here to answer your questions about glass versus cans, the plastic widgets (turns out they're really called widgets!) in Guinness cans, and the best way to persuade the beer drinker in your life to recycle those energy-intensive aluminum cans. Ask Umbra -- only on the Grist Magazine website.