It is always useful to point out that scientific consensus is an agreement amongst scientists in the field about what the evidence implies. So the consensus on climate change means that by far the great majority of climate scientists are persuaded by the evidence that climate change is real and that this real climate change is humanly caused. There is also a theoretical back drop which explains how and why this climate change is occurring, and there is no obvious contradiction or failings in the theory which is leading it to be challenged. Scientists may later modify their positions if the evidence changes. However, it is unlikely they will modify their position to the extent that they argue climate change is not happening, and is not going to produce massive disruption.

We might compare this with the consensus amongst right wing people that free markets are wonderful.

There is no empirical evidence for free market theory – indeed one school of free market theory says no evidence is needed. There is no agreement amongst economists or social theorists that free markets always work or deliver what is promised by their advocates. When applied the theory does not appear to deliver the results promised. It does appear to deliver what cynics say it is meant to deliver (that is more corporate power and more plutocracy). There is no empirical or theoretical consensus. There used to be no political consensus either, Conservatives were well aware that capitalism destroyed all values and traditional social institutions that got in the way of profit. Such real conservatives are no longer common.

Yet the right insist that free markets are the fundamental truth of governance, liberty and prosperity.

Usually the problems with free market theory and its lack of acceptance by independent economists or social theorists is explained away as “left wing bias”, or even “communism” or “conspiracy”. Sometimes it is explained away by saying free market theory is never applied, but in that case we cannot know it will result in goodness when it is applied in full purity. The point is that when it is applied, in the way that it is applied, we get political situations like the present one.

A change in speech away from consensus to persuaded by the evidence, is important because in right wing speak, consensus simply means that people gathered around a table and decided on a position, usually for political reasons as in “there was a consensus amongst Republicans that Obamacare was evil” or “the general consensus amongst evangelical Christians is that the Pope is the anti-Christ” or “the consensus amongst business people is that capitalism is good”. etc.

Persuaded by the evidence takes us back to arguing about the evidence. This is more productive if people are well intentioned, and don’t keep returning to evidence which has been refuted. However in our day, people are being encouraged not to be persuaded by evidence.