On consensus in science

Nicolaus Copernicus 1473-1543
Nicolaus Copernicus 1473-1543

Consensus is “the first refuge of scoundrels.”

We often hear that the great majority of climate scientists (usually claimed as a 97% consensus of scientists) believe that human carbon dioxide emissions are the major driver of global temperatures. That supposed consensus is often invoked to justify some very stupid political policy.

There have been several papers published over the last several years that claim such a consensus exists. All have been debunked. Now Joseph Bast and Taylor Smith of the Heartland Institute have a new paper that shows exactly how and why these “consensus” papers are wrong. You can read the whole paper here: http://heartland.org/policy-documents/research-commentary-myth-global-warming-consensus.

I am not going into detail on these studies, but rather, I will discuss the concept of consensus itself. The basic theme of this article is that even if a hypothesis is supported by an overwhelming consensus, that consensus provides no evidence that the proposition is correct. Invoking a consensus as an argument for justification is merely an appeal to authority rather than hard evidence; it is almost a matter of religious belief rather than scientific proof.

“Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observation that disagrees with the predictions of the theory.” –Stephen Hawking

Dr. Roy Spencer has shown that climate models based on “consensus” thinking have proven to be spectacularly wrong in predicting global temperatures, see here. And remember, back in the 1970s, the consensus was that we were beginning dangerous global cooling that would soon lead us into another glacial epoch.

“It does not matter who you are, or how smart you are, or what title you have, or how many of you there are, and certainly not how many papers your side has published, if your prediction is wrong then your hypothesis is wrong. Period.” –Richard Feynman

Dr. Judith Curry, Chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, has a long paper on consensus in climate science. She begins by saying: “The manufactured consensus of the IPCC has had the unintended consequences of distorting the science, elevating the voices of scientists that dispute the consensus, and motivating actions by the consensus scientists and their supporters that have diminished the public’s trust in the IPCC.”

She goes on to write: “With genuinely well-established scientific theories, ‘consensus’ is not discussed and the concept of consensus is arguably irrelevant… While a consensus may arise surrounding a specific scientific hypothesis or theory, the existence of a consensus is not itself the evidence.” And she notes: “If the objective of scientific research is to obtain truth and avoid error, how might a consensus seeking process introduce bias into the science and increase the chances for error? ‘Confirmation bias’ is a well-known psychological principle that connotes the seeking or interpreting of evidence in ways that are partial to existing beliefs, expectations, or an existing hypothesis. Confirmation bias usually refers to unwitting selectivity in the acquisition and interpretation of evidence.”

Dr. Roy Spencer is more blunt on confirmation bias:

“As I have always said, if you fund scientists to find evidence of something, they will be happy to find it for you. For over 20 years we have been funding them to find evidence of the human influence on climate. And they dutifully found it everywhere, hiding under every rock, glacier, ocean, and in every cloud, hurricane, tornado, raindrop, and snowflake. So, just tell scientists 20% of their funds will be targeted for studying natural sources of climate change. They will find those, too. It’s not like they will have to look very hard. The 17 year hiatus in warming, which no one predicted, and which the climate models can’t even explain, tells us that Mother Nature is also involved in climate change.”

There are some famous failures of scientific consensus in history. The pre-eminent one was the belief that the Earth was the center of the universe. That was the prevailing consensus 500 years ago. That consensus was shown to be in error, first by Nicolaus Copernicus and later by Galileo, Kepler, and Newton.

At the time of the founding of the United States, the accepted scientific view of combustion held that all matter contained an undefined amount of a nearly weightless substance called phlogiston. Some materials, like metals, were considered rich in phlogiston, while others, like earth, were thought to be poor in it. Phlogiston theory stated that combustion released phlogiston from a material, thereby explaining the corresponding loss of weight in the remaining product.

In 1777, Antoine Laurent Lavoisier produced a paper that earned him the title of the Father of Modern Chemistry. His work demonstrated that phlogiston theory was wrong in every respect. In one sense, carbon dioxide is the phlogiston of the 21st Century.

As late as 1864, it was the consensus view of science that living organisms could spontaneously generate from lifeless matter. Such belief was founded on observation of phenomena in the natural world, such as the emergence of flies from rotting meat. Some scientists had flirted with the idea that a sterile broth would not give rise to bacteria if it was closed off from the air. However, the dominant view of the time was that bacteria, and even higher organisms like mice, bees, and frogs, could be produced by mixing the right objects under the right conditions.

Louis Pasteur, was skeptical of this idea and developed a simple experiment in 1864 that proved spontaneous generation did not occur.

In 1912, Alfred Wegener, building on earlier work by Frank Bursley Taylor, proposed that the continents did not have a permanent spacial relationship to each other, i.e., there was continental drift. Wegener could not, however, provide a reasonable mechanism for his hypothesis, therefore the consensus, for 50 years, was that he was wrong. By the 1960s however, geological research did provide the mechanism and Wegener’s continental drift became part of the larger theory of plate tectonics.

For more documentation on the failure of consensus see here.

Those who credulously invoke the “97% consensus” on global warming as an argument are displaying an ignorance of the facts and of how science works. I refer you to Michael Crichton who wrote:

“I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. 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.”

See also:

Climate and Communism

2014 or 1984?

The Collectivist Mind

IPCC scary stories and a dose of reality

And on my Wryheat blog:

National Climate Assessment = science fiction and politics