Al Gore has stated that that there is no global warming controversy. He refers to the multitudes of the world's top scientists voicing extreme concern through the UN's Intergovernmental Panel on Climate Change (IPCC) report. He cites a study of a random sample of 928 articles on global warming, none of which were found to express doubt. There is a consensus, he says.

In natural sciences one has to distinguish between:

 A LAW OF NATURE: A definitive scientific generalization based on a sufficiently large number of empirical observations that it is taken as fully verifed;

THEORY: A logical and consistent framework for describing from fundamental principles the behavior of certain natural phenomena;

HYPOTHESIS:  IT has not been proved or disproved, or found false in terms of natures true laws and/or by experiment;

A MODEL: a similar but weaker concept than a theory, describing only certain aspects of natural phenomena typically based on some simplified working hypothesis;

CONSENSUS: a consensus about a hypothesis is a notion which lies outside natural science, since it is completely irrelevant for objective truth of a physical law: Scientific consensus is scientific nonsense.  

Michael Crichton (best known for his novels but also a graduate of Harvard Medical School and a former postdoctoral fellow at the Salk Institute for Biological Studies) warned his audience of the dangers of "consensus science" in a 2003 speech:

"Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you're being had.

"Let's be clear: the work of science has nothing whatever to do with consensus."

"Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus."