Thursday, October 08, 2015

Evans, it's another black box

Sackers recently sent me a link about David Evan’s climate theory.

Dr Evans has a theory: solar activity. What he calls “albedo modulation”, the waxing and waning of reflected radiation from the Sun, is the likely cause of global warming.

A summary of his initial work can be found here and later work is here - far too much to summarise in a single blog post. The work is certainly interesting, but as with many climate claims the first issue is whether or not it deserves attention. The second is how much?.

The basic problem is that there is no such thing as climate science and no such tribe as climate scientists even though we use the terms in order to take part in the debate. In reality there are many specialist climate areas and many specialist scientists but unlike more established sciences, climatology hasn’t yet reached a state of overall coherence. There is no climate equivalent of the periodic table.

An alternative to absorbing the minutiae of Dr Evan’s approach is to treat the whole thing as a black box. This in no way implies that the Evans theory is not worth studying for anyone so inclined. The black box approach is merely a practical way to tackle the incoherence problem for those of us with no strong allegiances to any particular theory. Each climate theory is treated as a black box.

It doesn’t matter what is in the box.
It doesn’t matter who built it.
It doesn’t matter who endorses it.
Predictive performance is what matters.

So Dr Evan’s black box passes or fails its first test between 2017 and 2021. Even if cooling occurs on cue, this black box has only passed one simple test. A coin toss could do as much. It doesn’t follow that the Evans box will pass any other tests.

This testing process could go on for decades, but so what? Science is merely a complex way of saying “if you do this you see this”, so that’s how we test assertions about the future. We wait. Scientists may prefer us to admire their lovingly crafted box before it passes any test whatever, but that’s another and much older story - human behaviour.

Having said that, Dr Evans is in my view an interesting chap. I've been following his posts from the beginning because we need such people if we are to make progress. We need to find the climate equivalent of the periodic table because as yet we don't have it. 

Perhaps 2017 will give us our first clue but don't bet on it. 


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Sackerson said...

So could it have predicted previous events from the data that preceded them - do you know?

Kiwiatheist said...

Dr Evans's article has been pretty much debunked by previous work. See here for details

Sackerson said...

Thanks for your comment, KA. Is the debunking correctly done, in your opinion?

A K Haart said...

Sackers - the reply to that should be 'yes' but his theory is a work in progress so I'm not sure what his answer would be.

KA - no doubt Dr Evans would claim otherwise which is why I focus on the predictions.