Richard Treadgold, does 18 months of cooling pass tests for statistical significance? What length of time for global temperature anomaly data is required to give a statistically sugnificant result?

About 5000 years. Five thousand.

Peter: you need to learn the value of politeness, and the difference between weather and climate.

You of course are polite to Mr Leyland, Professor Carter and others who do not share your nonsensical beliefs.

S2, thanks for the calculations. Those are OLS linear trends? Just out of curiosity, did you account for autocorrelation? As I understand it that leads to increasing the uncertainty even further.

Yes, they are OLS linear trends.

No, I didn’t account for autocorrelation. I am still struggling to come to terms with autocorrelation (but Tamino’s blog helps), and I’m not convinced that it applies here. It might even reduce the uncertainty.

The (+/-) figures that I gave are simply 2*Sigma.

Forget the Environment. The Cold, Hard Facts Point to Another Threat on the Horizon – Climate Change Skeptics

I refer to your article Forget Global Warming. The cold, hard facts point to another threat on the horizon – severe cooling (Business, Nov 10) by Bryan Leyland. It is misinformed and uneducated skeptics of Climate Change that hinder the efforts of those who are instrumental in attempting to abate anthropocentric climate change. The basis for this article (as it clearly stated) was on scientific testing still to be conducted thus constitutes pure speculation. I appreciate his understanding of the importance of carbon dioxide in our atmosphere – but this importance is limited to the need for a steady concentration and balance with other greenhouse gases. In terms of “the moderate increase of carbon dioxide” I’m not sure which side of sanity he leans towards but a 36% increase since the middle of the 19th century is not moderate to most. It was also stated that the major weather (not climate, as stated) events of El Nino and La Nina have failed to be predicted by computer climate models, this is because they are weather events not climatic cycles thus will always be missed by these predictions due to the embryonic understanding and first-hand experiences of such events. It is also illsounded to base an argument on 6 years of “cooling” – 6 years does not represent a trend, 6 years is barely enough to illustrate weather patterns let alone the climate. Lets take the last 6 years of cosmic rays data and base his argument on this. And finally in terms of climate change policy – we are bound to Kyoto through to 2012 and will sustain ratification post-2012 through the full implementation of the New Zealand Emissions Trading Scheme which will do our bit supporting a global movement towards carbon trading.

I note that, as I expected, you evaded:
“One question: how many more years of no warming are needed before you and your friends contemplate the possibility that you are wrong? Is it five years, 10 years, or will you wait until the Thames freezes over – as it did in a little ice age during the “Maunder minimum” of the sunspot cycle. A straight answer please.”
Very much in line with my expectations!

I answered that question in comment #10 in this very thread. But then you obviously don’t worry too much about reading everything…

So, how much are you prepared to wager, in line with the terms I outlined above?

If your advice to your Indian clients extends to climate matters, then I hope they have the good grace to ignore you, because you are well out of your depth.

Regards

I repeat:
“Those who would deny the sceptics the right of free speech are, more than anything else, demonstrating that they believe that their case is weak and will go to any length to avoid admitting that that this so. ”

That is my last word on this. This “crank” is off to India as a member of the “Expert Advisory Group” for the world’s largest tidal power scheme. http://www.kalpasar.gujarat.gov.in/mainpage.htm Perhaps the Indians don’t share your opinion of me. But if you want to be as rude about the judgement of my Indian associates as you are about me, please go ahead. Free speech is still allowed.

AGW, I suspect, will be history very soon. If you want copies of “The Great Global Waring Swindle” and the NIPCC report, I have a few spare ones I can send. It might be a very good exercise in risk management for you and your friends. As they say “when the facts change.. You could start swotting up on global cooling! It was all the rage 30 years ago, so its time it came around again. And who knows, it might be real! Watch those sunspots – or to be correct, the absence of them.

Re: UAH mid-troposphere temps, you said:

I chose it because, if GH gas warming IS occurring, that’s where it will show up most clearly – according to the climate models and, also, the physics of GHG warming. So, in effect, I was choosing the data that should have favoured the man-made global warming hypothesis — if it was true.

This, I am afraid, is nonsense. First, it’s a global figure, so any purely tropical trends will be obscured. Second, the UAH mid troposphere data is “cooled” because it includes influences from the stratosphere, which is cooling (as is predicted to occur with warming caused by greenhouse gases). Note this paragraph from NOAA’s report on the climate of 2007:

These observations show that the global average temperature in the middle troposphere (the layer which is centered at an altitude of 2 to 6 miles, but which includes the lower stratosphere) has increased, though differing analysis techniques have yielded similar but different trends.
In all cases these trends are positive. The analysis performed by RSS reveals a trend of 0.12°C/decade (0.21°F/decade) while the UAH analysis reveals a much lower trend of 0.06°C/decade (0.11°F/decade). When adjusted by University of Washington scientists to remove the stratospheric influences from the RSS and UAH mid-troposphere average, the trends increase to 0.18°C/decade (0.33°F/decade) and 0.13°C (0.24°F/decade), respectively.

Is it a coincidence that the product you chose to feature shows the lowest warming trend of any gobal temperature data series?

Re: cooling since 1998, you said:

The reality is that straight line trends are nonsense because the climate is always changing and it is largely cyclic.

>
I accused you of statistical naiveté, and you prove my point nicely.

Re: sunspots, you said:

Over the last 2000 years there is a close correlation between sunspots and climate.

This is nonsense.
You said:

It is the facts that count.

Indeed, I share that view. It’s a pity that you do not seem to feel so constrained.

As for your complaint about “debate”, I will repeat something that I’ve said here many times – to you, as well, in your last visit here back in April – you are entitled to your own opinion, but not to your own facts. Until you are prepared to face up to the latter, you remain, Bryan, a crank.

Regards

I will respond to your comments in due course (in this case, a main course).