Monday, January 18, 2010

Just because it looks like a "trend line" doesn't mean...

I've been critical of trend lines before.

The ones used by the ABS have particular problems.

But try this one on for size:

Note that the "trend line" ends the series going down.

But squint and look at just the purple line and it is apparent the series is broadly going up.

Possum says it is an "utterly ridiculous 4th degree polynomial curve".

Useful for Andrew Bolt who published it here to make it look as if global temperatures were not increasing.

He is up to other tricks as well and Possum is on to him.

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Anonymous said...

Given the rate at which the global warming panic is falling apart, and the IPCC's credibility is collapsing (see, eg today's "Australian"), I'd say the degree of the polynomial used to fit the data is the last thing the warmist alarmists and credulists should be fretting about.

Andos said...

Citing 'The Australian' to back up your arguments doesn't carry as much weight as you seem to think.

David Stern said...

That's probably not enough data to determine a trend over the full 1979-2009 period in that data. If you can determine anything with that it's that it was cooler in the 1980s and early 1990s and warmer in the late 90s and 2000's. There is no way to say the trend is going down now. Far too little data.

Wil said...

"Anonymous", I await any scientific rebuttal of the broad ACC hypothesis. Public opinion may be moving against it, but the science, already very solid, just steadily builds in its favour (more's the pity).

Adam S said...

What the UAH charts appear to suggest is not that warming isn't happening, just that it's not happening at an alarming rate.

Any thoughts on the article on the front page of the Australian this morning about glacier melt?

Anonymous said...

Spencer is onto the problem too.

Peter Martin said...

Hi Adam S,

Here's Quiggin on this morning's Australian front page about the glacier claim.

Adam S said...

John Christy (who works with Spencer) interviewed at the IEEE Spectrum of all places:

I've been a subscriber of Spectrum and an IEEE member and while its a very reputable Sci/Eng organisation, I'm puzzled as to why they are involved in the debate. It's a good interview though.

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