Al Gore obviously hasn’t read Andrew Dessler’s book:

. . . if you accept the truth of what the scientific community is saying, it gives you a moral imperative to start to rein in the 70 million tons of global warming pollution that human civilization is putting into the atmosphere every day.

This is a fine example of the is-ought problem described by philospoher David Hume. ASU’s Brad Allenby has explained why we should care about the is-ought problem in science:

. . . the elite that has been created by practice of the scientific method uses the concomitant power not just to express the results of particular research initiatives, but to create, support, and implement policy responses affecting many non-scientific communities and intellectual domains in myriad ways. In doing so, they are not exercising expertise in these non-scientific domains, but rather transforming their privilege in the scientific domains into authority in non-scientific domains.