Slander or criminal negligence under the flag of a class action suit. The amount of loss to yourself is probably negligble, but the loss to society is huge, so a class action suit would serve to do some serious damage. Look at the global warming issue for instance. One of the biggest propagators of the myth that there is some sort of controversy is Fox News, and the cost for that is at least in the billions (how much did that polar vortex cost us, even)? It would fall under Mens Rea law. Your argument would be, in this case, that because they were willingly ignorant about the truth they have prevented action from being taken, and thus are liable for the damages. Expect a lengthy court battle and a hard time finding a lawyer willing to pit themselves against one of the most powerful media empires in the world.