Faith is the belief in things for which there is no physical proof. Isn’t that AGW?
Physical proof isn't the only kind of proof. For instance, there is no physical proof of the infinity of primes, though there is mathematical proof. Yet "the infinity of prime numbers" is not an un-scientific or anti-scientific proposition, and certainly not an unreasonable one.
I would argue that a rational faith (for instance, a faith that does not violate the law of non-contradiction) is absolutely different from a scientific fraud. MIchael Mann inflicts scientific fraud.