Today's libertarian is just some asshat who is too embarrassed to identify themselves a conservative.
So this is apparently why they:
A) Habitually sign "conservative" loyalty oaths
B) Never break from voting the republican line
Nice broad brush made of straw.
Funny since I have never voted for a Republican for president or my congressman.
"Are you asking if I believe the EPA has a duty to fix global warming?"
Basically yes. Wouldn't it be their responsibility?
That is a tough one because it moves into the global sphere. As far as the US goes yes they should be active in making sure the US does it's part but the question then becomes where does the role stop, I don't have a good answer for you sorry.
However making sure that states don't end up underwater, that drought doesn't cause famine etc. would certainly fall under my definition of "provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity"