Comments on: Comparing Global Temperatures

By: David Norrish

David Norrish — Sat, 10 Oct 2009 01:29:46 +0000

Paralysis by analysis. Why not simply confuse the issue with some facts.
It was globally warmer in the past, particularly around 1000 and 2000 years ago. Populations living and farming in Greenland is particularly relevant.
There have been cold periods in the past with glaciers growing and the Thames freezing over.
These climatic events correspond with variations in solar activity.
AGW was not a factor as each predates greenhouse gas increases.
Sea levels were 60 metres lower some 20000 years ago and have risen since, average 3mm per year. Why has this rate of sea level rising slowed down to present measurements.

Message: For whatever you believe, your argument must stand open scrutiny against historic data going back not less than 2000 years. If it does not, and regrettable most of the AGW comment does not, then best restrain comments until you have done a little research.

By: Jennifer Marohasy » Let’s Stop Averaging Global Temperatures (Part 1)

Jennifer Marohasy » Let’s Stop Averaging Global Temperatures (Part 1) — Thu, 27 Aug 2009 12:59:36 +0000

[...] Tom Quirk comments on how surprisingly similar the calculated mean temperature is: http://jennifermarohasy.com/blog/2009/05/global-temperature-revisited/ [...]

By: Travis

Travis — Fri, 10 Jul 2009 04:33:07 +0000

Well we should know a couple of things right now Polar bear populations are booming, the sea level is not rising, the ice always melts and breaks off in the spring, Glaciers like Gore’s example are leaving because of deforestation and lack of snow fall in that region, the tree ring hockey stick graph is debunked, temperatures world wide are not rising in any significant way, and of course Al Gore and everyone else attached to the green industry is out to make huge money with this propaganda.

Its so funny that the minute a scientist says warming is not happening because of man he is funded by the evil energy companies. But the minute Gore fights for cap and trade and is part of a cooperation making software to track companies carbon emissions for cap and trade that’s OK because he is getting money from the evil green companies one of which he directly profits from.

I am now suspicious of anyone who promotes GREEN anything I want to know where the money is.

Travis

By: Robin Edwards

Robin Edwards — Tue, 09 Jun 2009 19:44:55 +0000

Regarding James’ message of June 5th, if you (correctly) average the sum of squares of the error column in Table 3 and take its square root the answer is 0.139, which rounds very comfortably to the two decimal places quoted. The simple average of the values is 0.1325, which rounds to 0.13. Not really a big deal with these remarkably similar “error” values, as one would expect. I accept the table Jennifer provides without reservation as being statistically correct.

Robin

By: Jennifer Marohasy » Sea Ice Extent Now Normal in Arctic

Jennifer Marohasy » Sea Ice Extent Now Normal in Arctic — Mon, 08 Jun 2009 03:59:28 +0000

[...] Global surface temperatures aren’t increasing: http://jennifermarohasy.com/blog/2009/05/global-temperature-revisited/ [...]

By: James

James — Fri, 05 Jun 2009 12:57:38 +0000

The third table has an incorrect analysis. You cannot average errors or uncertainties as is done in the table. The common method is to take the square root of the sum of the squares. This is basic data analysis. To find such a basic and simple error, really makes me wonder if the rest of blog has anything in it that is worth considering.

By: tom quirk

tom quirk — Wed, 20 May 2009 13:13:14 +0000

Dear Christopher

I took the monthly data as it was readily available from the four sources and I had a similar sample from a year ago.

The data is accumulated in different ways by the land and satellite groups. From memory, the mean monthly land based temperatures (possibly means, highs and lows) are submitted each month to the National Climate Data Center and perhaps directly to some of the analysis centres from the many Met stations around the globe.

This sets the form of the data.

The satellites are surveying bands that move over the atmosphere as they orbit the earth that rotates below them. So there is all manner of time, distance and angular processing.

The choice of time intervals is probably not quite arbitrary as by inspection of the data there is a high degree of commonality and the El Nino La Nina features are present. At larger time intervals these features will be lost as you look for the long term trend. Going to shorter intervals increases the noise but some people like noise and you should still find the signal!

I guess you might run a moving correlation window (like a moving average) through the data to see what the ideal time interval should be. That would be an interesting exercise.

I don’t believe there is a critical point here as the interesting features of GISS and Hadley – not learning from each other and the sensitivity to a 2 degree rise in temperature over 100 years will not be enhanced by finer detail.

kind regards

Tom

By: Comparing the Four Global Temperature Data Sets « Watts Up With That?

Comparing the Four Global Temperature Data Sets « Watts Up With That? — Wed, 20 May 2009 05:36:31 +0000

[...] Reposted from Jennifer Marohasy’s website. [...]

By: cohenite

cohenite — Tue, 19 May 2009 13:41:12 +0000

A comparison between the ground and satellites is here;

http://www.woodfortrees.org/notes

The last 3 graphs are instructive; the 3rd last demonstrates just one of the many defects with the anomaly method of comparing temperature trends between the 4 collectors; GISS has an artificially high temp trend base simply because of its base period with almost 0.5C difference between it and the satellites; the 2nd last graph shows that when the base period is standardised there still is 0.2C difference; the final graph shows the deficiencies of temp records and the fatuity of saying the trend is similar between all 4 indices. Pure luck.

By: SJT

SJT — Tue, 19 May 2009 11:43:52 +0000

“This is my beef with all this warmening business, the change is barely within the range of instrument, and on top of all that, there are the differences of measured data by the various agencies.”

The average is the result of many measurements that are higher and lower than the average, the instruments don’t measure the average directly. That four independent sources, one officially approved by sceptics, all agree to a large degree, seems to be a good validation of the measurements.