Guest Post by Ira Glickstein.
Time machines are a staple of sci-fi. Someone travels back to the past and changes some momentous historical event, expecting his or her heroic action will improve the present and future, usually with disastrous results! Well, NASA GISS has a different type of time machine that does not actually go back to the past, but simply changes the historical temperature data to make the present Global Warming situation appear worse than it really is, and, by implication, lend credence to their CAGW (Catastrophic Anthropogenic Warming) theories.
This is the second of my Tale of the Global Warming Tiger series where I allocate the supposed 0.8ºC warming since 1880 to: (1) Data Bias, the subject of this posting, (2) Natural Cycles, and (3) AGW, which will be the subjects of subsequent postings. Click Tiger’s Tale (and Tail :^) to see my allocation and read the original story.
This posting is about how the official climate Team has (mis)adjusted past temperature data to exaggerate warming, and how the low quality of measurement stations and their encroachment by urban heat island (UHI) developments have distorted the historical record.
The above blink graphic alternates between two base charts of historical US Annual Mean Temperatures, both publicly posted by NASA GISS, the older one in 1999, and the most recent downloaded from NASA GISS this month (January 2011). The 1999 image is from a blink graphic comparing NASA GISS 1999 and 2008 data originated by a Netherlands website (zapruder.nl). I first discusssed that graphic in 2009.
Please note that both charts are to the same scale and that my annotations are fixed in place so viewers can see how the data has been changed. I have added a handy scale indicating that the large boxes on the NASA GISS charts are 0.5ºC high, along with a ladder showing 0.1ºC increments. The see-saw (with James Hansen juggling the Earth’s temperature data and our economic future :^) indicates the change between a peak in the early 1930’s and a trough in the mid 1990’s. Note how the slope changes between the 1999 version and that for 2011. In the 2011 version, the 1930’s get COOLER and the 1990’s get WARMER. If you add the changes together, you get somewhat more than the 0.3ºC I have allocated for Data Bias, so I am being quite conservative here.
I have used US data for my example because those sources are more under NASA GISS observation and control than most international data, which may be of poorer quaity. In an earlier post on WUWT I included a graphic with a copy of a NASA GISS email released pursuant to a FOIA request that indicates they felt a need to modify historical data seven times over a period of nearly a decade, until they got it right.
That means the previous six times they admit they got it wrong! Keep in mind that their mid-1990’s data has been in hand for over a decade and their mid-1930’s data is old enough to collect Social Security :^), yet they have made that old data work until they got it right, which, in this case, means more in line with their global warming models. CO2 is going up, therefore, temperatures MUST go up, OR ELSE. (Or else they will wiggle and wriggle and jiggle and juggle the data until it does what must be correct according to their theories, which, in turn, must be correct because real climate scientists thought them up and they are -or were- sincerely convinced they are -or were- saving the whole world.)
NASA GISS has been quite blatant in modifying the data even though they are aware that all the older versions exist in electronic archives. They have got away with it because no one in the major media or Congress seems interested in calling them on it. In my free online novel, set several decades in the future when virtually all data is in electronic storage, officials who control the worldwide data servers create what they call a máquina del tiempo (time machine in Inglañol, the then-prevalent version of US English peppered with Spanish words and phrases) that alters historical documents to further their plan for space travel. In the case of weather data, to cover their tracks, they would also have to alter the original hard-copy documents. This isn’t likely to happen since the NCDC keeps these paper records from COOP weather observers secure in a climate controlled vault in Asheville.
MEASUREMENT STATION QUALITY
NASA/NOAA specifies measurement sites in five classes, with the best at least 100 m (over 300 ft) from any source of artificial heating or land development and the worst located right on an occupied building (see my graphic). According to a 2009 survey, as of that year, only about 3% of official sites in the US were at Class 1. About 8% were in Class 2, at least 30 m from a source of artificial heat. About 20% were in Class 3, between 10 and 30 m. The remaining stations were closer than 10 m to an artificial heat source (58%) or right on a heat source (11%).
Thus, only about 3% + 8% = 11% were in the best two classes, reasonably distant from artificial sources of heat, while 58% + 11% = 69% were in the worst two classes, easily affected by nearby heat sources. Thus, over 2/3rds of the official reporting stations in the US were close enough to artificial heating sources to be affected. I do not know if the situation has improved much, or at all, over the past couple of years nor if the situation is better for foreign stations, but it may be even worse!
Of course, the Warmists will remind us, Global Warming has to do with changes in temperature. Thus, if a station has been at the same location for decades, any delta in reported temperature should be consistent with actual trends in that area, right?
Stations in urban areas, even if they have been in the exact same place, have been affected by development and lifestyle changes. This includes installation of air conditioning in buildings that had none fifty years ago, more auto and truck traffic, and construction of nearby buildings. But, many stations have been moved from time to time and thus have not been in the same place all this time, and most have been affected and encroached by civilization and changes in land use.
Why are the stations so close to artificial heat sources? Well, fifty or more years ago, all the readings were taken manually by volunteer observers once a day. Some volunteers were not about to walk the length of a football field to do so. Even as automatic reporting stations were introduced, the stations had to be close to buildings so the data cable could be run to the display. Even though the originally specified maximum cable distance was 1/4 mile, most automated COOP observer MMTS sensors ended up within 10 meters (33 feet) of the building, mostly due to the inability of the NWS to trench under driveways and sidewalks which acted as barriers to putting the temperature sensor in open spaces.
NASA GISS adjusts the data when they know that stations have been affected by local development or if they have been moved. However, the Metadata for this is often incomplete or simply missing. Those corrections are, of course, essential to maintaining the quality and integrity of the temperature data network so comparisons are meaningful over the period from 1880 to the present. No one knows if NASA GISS and their international equivalents have been doing that job as honest brokers or if they are using the wiggle room in their analysis to bias the data in the direction their managers would prefer. What do you think?
It seems to me that my estimate of 0.3ºC for Data Bias and Station Quality is fully justified, but I am open to hearing the opinions of WUWT readers who may think I have over- (or under-) estimated this component of the supposed 0.8ºC rise in global temperatures since 1880.
In my earlier posting in this Tale of the Global Warming Tiger series, I asked for comments on my allocations: to: (1) Data Bias 0.3ºC, (2) Natural Cycles 0.4ºC, and (3) AGW 0.1ºC. Several readers were kind enough to comment, either expressing general agreement or offering their own estimates. A few claim that AGW is ZERO (in other words, rising CO2 and land use changes due to human activities have no effect on temperatures or climate, due to the negative feedback from cloud albedo or other natural processes). I agree clouds have a net negative feedback (most official models assue a net positive feedback) but I do not believe this cancels out all the effects of CO2 on the Earth’s surface absorption of Solar radiation nor of albedo changes due to land use.
What do you think? I have been keeping a spreadsheet record of WUWT reader’s opinions, which I value, along with their screen names, and I plan to report the results later in this series.
This is what you may look forward to:
Normal Seasons of the Sun – How natural processes beyond human control, including Solar Cycles and Ocean Oscillations, are the actual cause of most climate change.
Some People Claim There’s a Human to Blame – Yes, human actions, mainly burning of fossil fuels and changes in land use, are responsible for some small amount of Global Warming.
Is the Global Warming Tiger a Pussy Cat? – If, as many of us expect, natural processes lead to stabilization of global temperatures over the coming decades, and perhaps a bit of cooling, we will realize the whole Global Warming uproar was like the boy who saw a pussy cat and cried tiger.
[UPDATED ~9PM 16 Jan 2011: Some readers don’t like the blinking graphs. We aim to please, Here are non-blinkers.]