First of all, these are the data that I used in my first post, not the data you referred me to in your links, and not the data reflected in the graphs I posted above.  

You said that the data for the three graphs had these uncertainty factors, they don't, it's not the same data, it's the GISTemp data that you referred me to because you were unhappy with my use of the data you just now linked to.

Secondly, the uncertainty for the 1850's is 8 standard errors (two standard errors X 4)
One or two Standard Errors is generally considered reliable. Eight standard errors is ridiculously unreliable, almost to the point of uselessness.
A good graphical representation of this is presented in the paper linked on the HadCRUT page that you linked to.
On Page 21 of P. Brohan, J. J. Kennedy, I. Harris, S. F. B. Tett & P.D. Jones. Uncertainty estimates in regional and
global observed temperature changes: a new dataset from 1850.  You see a graph showing the true uncertainties in the
data.

Figure 12: Global average of land and marine components of HadCRUT3. (C); Land (top),
Sea (middle) and difference (Land-Sea, bottom). The solid black line is the best estimate value,
the red band gives the 95% uncertainty range caused by station, sampling and measurement
errors; the green band adds the 95% error range due to limited coverage; and the blue band
adds the 95% error range due to bias errors.

Even so, these uncertainty estimates have no bearing on my argument.
Their measurements of standard deviations and standard error are based on a mean global average that is presumed accurate.  Unfortunately, for the years in which they lack sufficient station data to produce a reliable mean (which is the whole point of my argument) - they simply made it up.

From: P. Brohan, J. J. Kennedy, I. Harris, S. F. B. Tett & P.D. Jones. Uncertainty estimates in regional and global
observed temperature changes: a new dataset from 1850
Page 17

     If the gridded data had complete coverage of the globe or the region to be averaged, then making a time series would be a simple process of averaging the gridded data and making allowances for the relative sizes of the grid boxes and the known uncertainties in the data. However, global coverage is not complete even in the years with the most observations, and it is very incomplete early in the record. In general, global and regional area-averages will have an additional source of uncertainty caused by missing data.
     To estimate the uncertainty of a largescale average owing to missing data the effect of sub-sampling on a known, complete dataset is used. The NCEP/NCAR reanalysis dataset [Kalnay et al., 1996] provides complete
monthly gridded surface air temperature values for more than 50 years. To estimate the missing data uncertainty of the HadCRUT3 mean for a particular month, the reanalysis data for that calendar month in each of the 50+
years is sub-sampled to have the same coverage as HadCRUT3, and the difference between the complete average and the sub-sampled average anomaly is calculated in each of the 50+ cases. The 2.5% and 97.5% values forming the error range of the HadCRUT3 mean for that month in the record are then estimated from
the standard deviation of the 50+ differences, assuming that the differences are normally distributed.

(emphasis mine)

From the textbook: Subsampling, Politis, Romano and Wolf (1999),:

In general, subsampling distribution gives a relatively low accuracy approximation to the true sampling distribution of an estimator.

If you want more info on Subsampling, buy a book.

The idea is basically that where they had no data, they invented new data to generate a mean.  
You cannot get a global average temperature from data covering less than 16% of the globe, any more than you can get the mean of a sheet of graph paper with 100 squares from data for 16 of those squares.  So what do you do?  Subsampling.   You plug in numbers into the remaining 84 squares.  Numbers which may or may not have any connection to the actual temperature in those 84 squares.

This is only one of several problems with the Global Temperature data used by IPCC.


I've tried to make this argument as simple as possible.  You didn't like the fact that I used the IPCC data.  You provided links to other data.  I posted a graph from those other links, and your response was to claim that uncertainties in the IPCC data applied to the graphs I posted.  Now I'm back to explaining the problem with the data that I (fairly succinctly) described in the very first post in this 5 page thread.


Somebody on this forum must understand my argument.  If you still don't get it, I can't help you.

Eyas wrote:
You cannot get a global average temperature from data covering less than 16% of the globe, any more than you can get the mean of a sheet of graph paper with 100 squares from data for 16 of those squares.

This, it seems to me, is the core of your argument.

However, it simply isn't correct. According to some experts, it takes no more than a hundred strategically placed or so surface stations around the world to get a decent first cut at a global temperature reading. Everything beyond that simply refines and sculps the estimate. It's important, to be sure, but it's nothing that changes the overall estimate. Thus, while the spatial coverage in the late nineteenth century wasn't very good, it was certainly sufficient to get a decent estimate of global temperature.

I have another question for you as well. Even if you doubt the instrumental record, what about the satellite record? Proxy records such as borehole and tree ring analysis? Model reconstructions? All of these methods are in very good agreement, and all show the same trend of 20th century warming.

EnragedParrot wrote:

Eyas wrote:
You cannot get a global average temperature from data covering less than 16% of the globe, any more than you can get the mean of a sheet of graph paper with 100 squares from data for 16 of those squares.

it takes no more than a hundred strategically placed or so surface stations around the world to get a decent first cut at a global temperature reading. Everything beyond that simply refines and sculps the estimate. It's important, to be sure, but it's nothing that changes the overall estimate.

What constitutes an acceptable sample size?  That's the question in this argument.  What level of confidence is generated by using 100 "strategically" placed surface stations and do "strategically" placed stations actually inject an unintended error in what should be a random sampling?

There are ways to measure a level of confidence in a sample size and I'm fairly sure it requires randomness to be accurate......not "strategic" placement.

What constitutes an acceptable sample size?  That's the question in this argument.  What level of confidence is generated by using 100 "strategically" placed surface stations and do "strategically" placed stations actually inject an unintended error in what should be a random sampling?

There are ways to measure a level of confidence in a sample size and I'm fairly sure it requires randomness to be accurate......not "strategic" placement.

Artfive, you're exactly right; which is why I posted the multi-colored graph in my last post.  The GREEN band is the 95% confidence interval of the "supposed" sample.  The Green band show NO warming over the last 150 years; but even this 95% confidence interval is b.s..  It is derived from global average temperatures in the early years that are made up.  They took the 16% of global temperature data that they actually had, and filled in the remaining 85% with "estimates" based on nothing.

This isn't just a matter of the right sample size.  Having a sufficient sample size first depends upon TWO things:
1. A randomly distributed population -- (which temperature is NOT); and,
2. A random sampling -- (which they do NOT use)

This brings up another problem with the Temperature data.  On the GISS site (a link is in one of the prior posts) you can see how, as time goes on, temperatures from new geographic locations are simply added to the population as if they were all randomly selected data from a randomly distributed population.

What I mean is this: let's say that in 1910 you add three sites to your population, all from equatorial Africa -- Hey, guess what? Your "Global" "Average" just shot up by 5 or 10 degrees.  Why? Because the Earth got warmer? NO.  -- Because you just added three temperatures from some of the hottest places on the planet.

I myself am not so shure about the idea of global warming, but I am glad that all of this work to make our planet cleaner is happening, despite shakey facts they base it on.

One very interesting thing about co2 being released into the atmoshere is that the earth could be benifitting from it!!! According to a website icecap.us and according to the new movie "Global Warming or Global Governance", they say that the fact that plants continued to stay green longer this year and the earth's plant life has over all showed much more green foilage than in the past!! they also say that this strange occurance will increase farmland ( Greenland, Deserts etc. and better prodution of excisting farmland!!!

Fotune wrote:I myself am not so shure about the idea of global warming, but I am glad that all of this work to make our planet cleaner is happening, despite shakey facts they base it on.

I'm not sure what you're talking about exactly, but to take any action based on "shakey" facts is wrong.  Wrong, wrong, wrong.

Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Sayshttp://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html

Well, I must disagree with you on the fact that there is "no credible evidence of warming temperatures" over the last 150 years.  In fact, the earth has warmed since around 1850.  The warming is mainly due to the fact that a global cooling period known as "the little ice age" took place from about AD 1100 to AD 1850.  Since the earth was in an ice age and it ended around 1850 then we must have gotten warmer.

Now, there is no credible evidence to support that the earth is getting significantly warmer.  In fact, if there was a warming trend, it appears to have ended in 1998 and the earth has cooled a little since that year.  There is no credible evidence that the earth is about to become a blazing ball of fire.  There is no credible evidence that man is causing or even contributing to any warming that might be happening.  There is no evidence that increased CO2 in the atmosphere is causing temperatures to rise.  In fact, there is more evidence to demonstrate that any warming trend is causing CO2 levels to rise.  

Mars and Earth both seem to be going through a warming period.  The polar ice caps on Mars are melting.  The north polar ice cap on Earth is shrinking.  Where do both Mars and Earth get their heat?  Well, obviously, it is man made carbon emissions!  No, perhaps that is not so obvious in the case of Mars.  But, clearly the common source of heat for both planets is the sun.  And the sun is giving off more heat energy right now than in recent history.  Oddly enough this is causing parts of the earth to get a little warmer.  Even more oddly, the southern hemisphere of the Earth may be getting cooler.  

Well, if the north is warming and the south is cooling, any warming trend cannot said to be global.  So, global warming is mostly an invention of the IPCC and Algore.  Nothing we are going to do is going to make the sun put out less energy.  In time, it will cycle back to producing less energy and temperatures will change again.