A transcript of an interview with Tas van Ommen on the link between Antarctic excess and West Australian deficits of precipitation displays questionable proof of anthropogenic global warming.
A natural circulation pattern surrounding Antarctica has three lobes because of the three continents and three ocean basins in the Southern Hemisphere. Tas claims in the past 30 to 40 years the strength of that three-lobe pattern has increased, bringing moisture and warmth into Antarctica and dry air back up to Western Australia.
He claims that a natural explanation has a 1:1000 probability.
Well, it is a real smoking gun I guess. It could be that we have just happened to find something that is really one in actual fact, thousands flukey event to get such a large snowfall. The more natural interpretation is that there is something been going on in the last 30 to 40 years and we know what that something is. It is the human impact on the atmosphere.
This was reported as ‘proof of climate change‘. But he admits it is an assumption.
TAS VAN OMMEN: The basic conclusion is that if this is being driven by human impact then you would expect it to continue but as climate change continues to change, the current situation changes too.
The evidence that the putative change in circulation is due to AGW, and not due to natural variation, comes from ‘some’ climate models.
“This pattern has strengthened in the past 30 years and some of the computer models that reproduce this are showing that it looks like it has happened because of greenhouse gases – carbon dioxide – and also ozone (being depleted).
“We wouldn’t claim on the strength of this that it is proven in black and white, but it’s another piece of evidence.
One can always find some model to confirm an hypothesis.