From: http://www.realclimate.org
“Three years ago, I tried to get a handle on whether UHI [Urban Heat Island] was responsible for the recent warming trend in most of the temperature datasets by comparing the trends for the UAH/MSU 2LT channel and the Jones et al. surface data for some of the world’s “empty places”.
Location/ MSU (deg C per decade) / Jones et al. (deg C per decade)
N Quebec / 0.317 / 0.327
N Ontario / 0.413 / 0.533
N Alb/Sask/Man / 0.424 / 0.470
E Yukon and Nunavut / 0.101 / 0.666
N Alaska / 0.191 / -0.008
SW Alaska / 0.196 / -0.013
Arabian peninsula / 0.021 / 0.328
Sahara / 0.105 / 0.346
W China / 0.335 / 0.328
Outback / 0.007 / -0.057
Amazon Basin / -0.183 / 0.171
Patagonia / -0.013 / 0.049

All trends from the Idso’s web-site world temperature calculator at http://www.co2science.com. The MSU and Jones et al. trends for these empty places are weakly positively correlated with r = 0.426. Notable in this data is how strong the warming in the North is and how different the Southern Hemisphere is.
Comment by Jim Dukelow – 15 Dec 2004 @ 5:08 pm”

NOTE that the correlation between these two data sets is distressingly poor. If r=0.426, then each data set explains only about 17% of the variance of the other data set!

This turns science on its head. The BASE hypothesis for science is always the NULL hypothesis. The null hypothesis states that with respect to the apparent phenomenon in question, there is no phenomenon. It does not exist. The researcher is wrong, and there is not enough evidence to prove the hypothesis that the phenomenon exists. This approach is an irreducible tenet of scientific methodology that is centuries old, and there is no reason to change the history of scientific methodology for the sake of global warming theory.

Therefore, the null hypothesis is that the global temperature of the planet has not changed in the last century. Period. Unless data can be marshalled and organized to disprove the null hypothesis, then we are compelled to accept the null hypothesis. If the existing data can convincingly disprove the null hypothesis, then we accept that the phenomenon exists, with the caveat that new data must always be considered. As scientists, we all know of apparent phenomena which were thought to exist, but were subsequently invalidated by new evidence. That is, the new data made it impossible to disprove the null hypothesis.

THEREFORE, THE BURDEN OF PROOF, ladies and gentlemen, lies on the theory of global warming, not on the null hypothesis. If the surface temperature sensors are faulty, then this is a problem for global warming theorists, not for the null hypothesis.

More specifically, about this UPWARD TREND, others have pointed out that there are flaws in the design and maintenance of common and ubiquitous surface temperature devices. These flaws are prone to produce falsely high temperature readings. The measurement bias continues an upward trend as the device becomes progressively more faulty.

From: http://www.realclimate.org/
“Some considerations regarding the surface temperature record relate to the measurement techniques themselves. The thermometer radiation screens affect the sensor readings. A factory-new Stevenson standard screen still allows solar radiation impact on the temperature measurement of more than one degree. Accumulation of dirt, growth of mould, even flaking of paint, is naturally occurring over the life cycle of some 15 years that the product is used in the field. The radiation error then multiplies…
Comment by Pejk — 27 Dec 2004 @ 5:10 am”

Two other factors could produce upward trends: (1) the Urban Heat Island effect is larger than we once thought, and can be expected to become more extreme as the expanding urban area more fully engulfs the temperature sensor, and (2) as noted by Pejk immediately above, solar radiation is known to contaminate air temperature readings. Impinging solar radiation appears to be increasing on the earth (as discussed in detail by others), and reducing cloud cover. More solar radiation would tend to bias the temperature readings upwards. Note that this would be a solar radiation increase. It would not be a real air temperature increase.

There is another key dictum of science which is being ignored on this is thread. ‘Extraordinary claims must be supported by extraordinary proof.’ Systematic global warming is an extraordinary claim, and the assertion that this is caused by humanity is very extraordinary indeed. I, for one, need to see more clean and credible data.

***REPLY: Some may in fact have a gradually increasing bias. Take for example the Marysville Fire station. It used to be Grass in the rear where the sensor was, then it was changed to concrete, then changes around the station started, such as cell phone towers. Nearby, a new City government building went up, 200 yards away, a strip mall, then a second strip mall on the other side of the street where there was parkland.

My point is…humans have built up around what used to be rural weather stations, and while some effects can be accounted for, and mathematically adjusted based on population growth, others, like the fireman’s BBQ, and the close by parking, and the a/c units from the cell phone towers exhausting hot air are random occurrences that researchers don’t know about nor have adjusted for.

There is a difference between cherry picking and cherry pruning. If someone was motivated to make a case by purposefully selecting outliers he would be guilty of cherry picking – a form of deceit. But if someone examines outliers for purposes of quality control, that is cherry pruning and is a positive contribution to the state of science.

His quote referred to explaining “SOME” global warming as attributable to these biases, not MOST, and certainly not ALL.

Exactly why did you leap to the extreme when reading/representing the quote in question?

You’ve downloaded the GISS model – perhaps you’d like to show me where these station data are used? You won’t be able to because they aren’t.

Observational data at large scale (not individual stations) are used to evaluate the models after they’ve been run – but again generally only at the continental scale and above. The evaluation is not just with trends but with patterns of variability (El Nino responses, NAO etc.) and obviously, the better the data the more reliable the evaluation.

Note that the climate model hindcasts for this area are around 0.5 over the 20th Century – significantly less than this individual station. Should this record therefore be shown to contaminated, it would actually improve our confidence in the models, not lessen it!

MODERATOR NOTE: see my reply in this new thread here

http://www.norcalblogs.com/watts/2007/06/a_note_from_a_nasa_climate_res.html

Somehow I have a hard time believing that the air conditioners, automobile parking, asphalt, etc. that is suggested as contaminating said data has been around that long.

If these sources are measurably influencing temperature at the compromised locations, I would expect to see a step function increase that could be tied to the point in time when the site became compromised.

*** REPLY: Perhaps, but in some sites, many things around the site are changing too, such as building up around it, Chnages in trees, grass, asphalt etc in neaby areas, so sometimes it gets masked. The point is, these weather stations are out of spec by NOAA’s own published standards.

It seems somewhat misleading to use temperature measurements from from a variety of locales that have all been “adjusted for error”, when nobody knows what the error sources are.

Lon

Fundamentalists do not like to accept evidence that the earth is older than the Bible would seem to indicate, either.

As their faith is supposedly scientifically-based, Global Warmists should be prepared to accept that non-conformists are going evaluate their claims and the means used to arrive at these claims, as well as the extrapolations drawn from these claims.

I find it interesting that “Doubters” have taken on the role of Galileo, whilst Al Gore & Heidi Cullen play the Vatican hierarchy.

Frank

Great work! I’ve known about this problem of bad measurement for over ten years now, and it has been hard to get people to take notice. You are doing a valuable service. (Would love to compare notes sometime.) Keep up the great work.

I’m only trying to illustrate that some sites (and certainly not all of them because some are in good working order) are contributing to the data set indicating that there is a warming trend, which may be interpreted as global warming. The surface data record is only part of the entire global warming equation. There is satellite data, sea surface temperture data, and radiosonde (weather balloon) data.

When the good surface sites and the bad ones are tagged, then analyzed again, there may be no net difference at all. We don’t know yet and won’t until the survey is finished.

But right now a statistically significant numnber of the total stations surveyed thus far seem to have issues that have not been dealt with. That percentage may not hold as the survey progresses or it may get larger. Again we won’t know until we do them all.

But don’t you think it s a good idea to flag the obviously bad sites that don’t meet the NOAA standards for temperature measurement? By doing so, they can be removed or adjusted in the data set so that whatever conclusions are drawn are not based on faulty data.

Flagging sites that have car radiators six feet from the sensor or air conditioners blowing on them seems like an obvious step that is just basic science.

There are lots of sites that don’t have such problems that show a cooling trend. They’ll all be available when the surfacestations.org website comes back up, thanks for your patience.

While I can agree that there are multiple sources of error in various temperature records, the cherry picking of sites and the misleading presentation of data on this blog does little to advance the argument the global climate is not warming. In reality, the various temperature graphs presented, which all show warming despite the various biases and errors in the data, probably do more to confirm the global warming argument than disprove it.