The less a thing is known, the more fervently it is believed.
In effect a new religion has grown out of secular humanism. Global warming is the central tenet of this new belief system in much the same way that the Resurrection is the central tenet of Christianity. Al Gore has taken a role corresponding to that of St Paul in proselytising the new faith.
There are major differences, however. Whereas it is not possible to call oneself a Christian without entertaining the central belief in the Resurrection, it is certainly possible to be deeply concerned with the order and condition of humanity and so call oneself a humanist without entertaining a corresponding belief in anthropogenic global warming (AGW). Belief in a Resurrection which supposedly occurred some 2000 years ago is a matter of personal faith, whereas AGW is a scientific hypothesis which can and should be tested by observation. Imagine the consequences both to science and to secular humanism should this hypothesis turn out to be untrue and the dire predictions of the climate models fail to materialise.
The quasi-religious nature of AGW is evidenced by the rancour which is generated when people like me express scepticism about the theory. Scepticism is an essential part of science which has, until recently, been a “small-l liberal” pursuit in which the opinions of doubters were respected. Now we sceptics are called “deniers” and, by implication, lumped in with neo-Nazis who question the Holocaust. The accusation that we are somehow in the sway of the oil companies and similar big business interests is commonplace and indeed is the chief argument of non-scientist supporters of the AGW theory. This echoes the “work of the Devil” argument of fundamentalist Christians; it is a mental trick by which the faithful avoid facing the real issues.