“Plenty of scientists,” climate change and the burden of scientific proof.

Friday, I had an interesting debate with a frequent reader of mine about global climate change. She doesn’t happen to subscribe to the theory, herself. And as is usually the case, the majority of the debate centered around the burden of proof for climate change. Namely: that “plenty of scientists” find fault with some or all of the theory. Therefore, the thinking goes, we need to wait for unanimous consensus on the issue before we can accept it as reality.

This brings up a fundamental point about science and the scientific method: all scientists – let alone all studies – do not need to agree for the studies and the overall theory to still be valid within their own purviews. What proves or disproves both a theory and a study is the preponderance of evidence.

In order for a study to be considered valid, it must:

  1. Pose a valid question.
  2. Based on research, formulate a hypothetical answer to that question.
  3. Construct an experiment aimed at testing that hypothesis.
  4. Reach a reasonable conclusion based on the results of that experiment – whether it proves or disproves the hypothesis.
  5. Communicate those findings, in detail, to the wider scientific community in a way that allows others to perform the same test and reach the same conclusion.

That last bit is really critical. That is the portion called “peer review,” and it is the cornerstone of the scientific method. Without it, we could all believe and say whatever we want without proof that any statement in science was valid.

However, it is entirely possible that a given hypothesis may disagree with an over-arching theory while both the theory and hypothesis are correct. The hypothesis may be too narrowly drawn to gain real insight into the theory. Or the hypothesis may reveal a ripple in the overall fabric of our world, while not specifically discounting the larger theory. It may just be an anomaly or an interesting exception.

And scientists, being good scientists, are unwilling to disbelieve their own studies, especially when they’ve received peer reviews. When a scientist discovers something that is peer reviewed as falid, that may lead him to believe that the larger theory is false. It is both noble and necessary for that individual scientist to hang on to and stand by his findings.

But when the preponderance of evidence – all of it as peer reviewed as the dissenting study – points in another direction, logic dictates that we have a high degree of certainty that this other direction is the correct one. Even if or perhaps especially if there are dissenting voices.

This is an important if easily confused point when science enters the political sphere. Fox News or any number of other sources can trot out a “scientist who disagrees with global warming,” but it’s possible neither he nor the theory are incorrect. One guy disagreeing with the group does not disprove a theory. And no matter how much we may all admire individualism, the pioneering spirit without facts that overwhelm conventional thought isn’t a rebel. It isn’t a brave voice of reason. It’s just one more dissenting voice, which valid or not, hasn’t done enough to prove itself. To present these voices as anything grander is just obfuscation for the benefit of a political persuasion. Not real science at all.

Which isn’t to say that real science does not often start from one minority voice, dissenting against common wisdom. But there is a threshold that must be observed.

The hero of the anti-climate science crowd would almost certainly be the Giant Impact Theory of our moon’s creation. As far back as 1898, George Darwin (fifth son of Chuckie) theorized that the moon was actually made of the same material as the Earth. But there had never been a shred of evidence to support it. And without evidence, the theory was mocked as preposterous. Believers of this theory were in a slim minority and dissenters in the scientific community.

In the 1960’s, it was theorized that another planetoid object in the early Solar System which was called Theia struck the Earth and the shattered debris of both the Earth and Theia eventually accreted as the moon. Again without a shred of evidence, most of the community laughed at this theory.

It wasn’t until the Apollo 11 moon rocks could be analyzed that the truth finally came out. Whatever the cause, the moon and Earth absolutely do share an unmistakeable common composition. Down to specific isotopes of oxygen and titanium. Here, finally, was the evidence that long-dead George Darwin needed to have proved his theory. And interestingly, the similarities between moon rocks and Earth materials is so similar and evidence of foreign rock so non-existent that science now believes that the impact theory may still be wrong, if we have not yet come up with a better hypothesis.

All of which means George Darwin may have been right an the Giant Impact Theory may still be wrong. Importantly – and this really is s the critical bit – George was not proven right simply by his absence of belief in prevailing theory. His minority status within the scientific community also did not prove him right. Eventually, had facts on his side.

It may soon turn out that the current theory of climate change is entirely wrong. It may turn out that, once a real question is raised, climate science like classical physics may go the way of the dinosaur. But so far, that is not a position climate science deniers have found themselves in.