Generally it is more interesting and important to point out problems with the orthodoxy on climate change than its opponents, because it is orthodoxy that gets put into policy, not heterodoxy.
But as the climate debate fractures in the face of evidence, a wider range of views becomes significant.
Climate skeptics have recently been excited by research suggesting that the world has been warming for the last 10,000 years in a way that leaves little room for the CO2 mechanism.
Was the Earth in a period of global warming or cooling before the 20th century?
Attempting to answer this question has thrown up a conundrum for scientists, with some studies showing a warming trend, while others suggesting it cooled until humans intervened.
Now a new study hopes to settle the issue by arguing that data points to the fact that Earth’s climate has been warming over the past 10,000 years – long before human activity is thought to have changed the climate.
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With their current knowledge, Professor Liu and colleagues don’t believe any physical forces over the last 10,000 years could have been strong enough to overwhelm the warming.
The study does not, the authors emphasise, change the evidence of human impact on global climate beginning in the 20th century.
But contradicting the orthodoxy is not in itself sufficient reason to get excited about a study.
The graph accompanying the story shows some of the competing views.
The blue line most closely represents the orthodoxy, reproducing Mann’s Hockey Stick at the end of it. Professor Liu and colleagues come to the conclusion represented by the green and black lines.
So what is different between the various methods?
The reconstructions showing cooling during the last 10,000 years are based on “biological thermometers” – temperature reconstructions generated from analysing ice core samples and the like.
Professor Liu shuns these, because they could be wrong, in favour of a computer model.
Whoops.
Most of the debate in climate actually boils down to just how good models are.
Rather than breaking with orthodoxy, Liu appears to be using its tools to try to erase the temperature record that exists from actual data.
His model might not conform to the hockey stick paradigm, but then that has more or less been jettisoned as being an artefact of statistical manipulation.
But it does conform to the orthodox paradigm that this is the hottest time in recorded history – you’ll notice his reconstruction erases the Roman and Medieval climate optima.
And it follows established form in thinking that the imaginary world of models trumps the real world of data.
And just as other climate models appear to have a warming bias, what is to say that is not the cause of this model showing an increase in temperature over the last 10,000 years when data show the opposite?
Just because something appears to buck the orthodox doesn’t make it right. Sometimes there’s a little too much of that thinking on the skeptic side.
In this case that appears to lead to welcoming a new version of the orthodox paradigm in the mistake that it is somehow different, and therefore supportive of your case.
Models never trump data.