Why do Al Gore, and many other liberals rant about the environment when leaving a huge carbon footprint?

Because they're scamming the public and trying to install Global Marxism. Every one of their solutions for Global Warming is to tax Westerners very heavily lowering their standard of living and pour that money into the third world. Marxist/Communist governments always have an elite panel of people and Gore is making himself wealthy and powerful with scam as well.