I don't know where you are posting from, but here in the USA one beer with dinner will not put you over the legal limit. Even for a very petite woman, consuming one beer over the course of a dinner will barely get your BAC above 0.03%. The limit in the USA is 0.08%.
Even if you are in a jurisdiction where one beer puts you over the limit, get real. You are talking about operation of machinery that is highly dangerous when operated improperly. Aircraft pilots are in the same situation, and they are prohibited from any alcohol consumption for 8 hours (or more) before flight. How is your situation as a driver essentially different from that of a pilot? Do you want pilots having a beer with their dinner in the cockpit?
What, precisely do 90%+ of scientists working agree on? That AGW exists, and that's all. You won't get 90%+ of scientists to agree on the implications of AGW. In particular, you won't get them to agree that the current computer climate models are Holy Writ, only doubted by the ignorant. The Al-Gore crowd refuses to acknowledge any possibility of error in the climate model forecasts, even though any honest climatologist will admit that the models are imperfect.
Anyone who claims the ability to predict the future behavior of a complex, imperfectly-understood system with 100% accuracy doesn't really understand how the world works.