Who is committing fraud here?

Richard Treadgold, whose blog Climate Conversations appears to be the sole active NZ blog devoted entirely to climate change denial, is rehashing an old argument (See Well, where’s your evidence, Renowden?). He claims:

“Global warming has not happened for about 15 years, unless you take a micrometer to the thermometer. And if you have to do that just to detect warming, then it’s hardly dangerous, is it?”

Of course this has been explained to him and his mates many times. Either his brain is just not capable of comprehending the simple story – or he continues to raise it despite the fact it has been well refuted. After all, if your real purpose is political, to manufacture doubt, honesty is your last concern. That’s why he claims climate scientists are committing “fraud” on this question (and others).

I dealt with the issue in my post “What, me worry?” – distorting climate change data. It is simply the issue of how to detect a relatively small trend in temperature against a background of relatively large natural variations which don’t contribute to the underlying trend. A common problem is sciences of all sorts.

It’s a question of observation period. We know, for example, that organic carbon builds up in soils under pasture. But try measuring the carbon levels over one season or one year and you just won’t see it. It’s buried in the inevitable noise of the variation in carbon levels over short times. But collect the data over 10 or more years and you will start to see the trend.

Its the same with global temperatures. The overall trend is not obvious, can’t be extracted from the data, over relatively short terms, because of the relatively large natural variations. When someone bases their claims on such a short perod you have to wonder about their honesty because its simple enough to produce any result you desire by chossing your time period. This is clear from The Escalator produced by Skeptical science.

Its a classic example of the activity that goes on in the climate change denier echo chamber (of which Treadgold is a part).

Here’s another give away. Why is Treadgold talking about 15 years – these guys used to use 10 years? Well the reason is their desire to preserve 1998 data. Global temperatures that year were exceptionally high so that data point has an over-riding effect on determining trends over a short term. If Treadgold has stuck to 10 or 12 years he was in danger of actually finding a statistically significant trend. That is the last thing he wants.

Statistical confidence in the observed increase in global temperatures comes from data collected over a long period. Selectively cherry-picking the data in the way Treadgold and his mates does is a no -no in science.

But of course science is the last thing they are interested in. Their purposes are political – and the manufacture of doubt.

Its obvious who is committing the fraud here.