The global warming data relied upon by the global warming alarmists is surface temperature data. The satellite and ocean surface data for the latter part of the 20th Century indicated a much milder temperature increase. But, as I have discussed previously here, the surface temperature records kept by the Climate Modeling Unit at East Anglia in the U.K. did not keep the original recorded temperature data and has only kept the much upward shifted data for the period of warming and the downward shifted data from the 1950s until the last warming period began in the 1970s. I have also discussed the tree core data bias Steve McIntyre has found with the temperature record in the Yamal Tree Ring Cores from Siberia used by Briffa. The global warming alarmists have long claimed that the temperature increase in Siberia was especially large and that this is what you would expect given increasing CO2 concentrations in the atmosphere. It turns out that the Yamal data set plays an especially important role in producing a hockey stick upward surge in the surface temperature record, just as the earlier discredited Mann data set still does. In this entry I want to discuss the problems with the "best" weather station system in the world, the extensive U.S. weather station system.
Anthony Watts has examined a large number of U.S. land surface temperature stations and found that 89% have site problems that produce falsely warmer measurements. He says that according to the federal government's own site guidance and maintenance criteria, the stations create a margin of error larger than the entire claimed surface temperature warming of the 20th Century. The IPCC report says that temperatures rose by 0.74 C in the 20th Century. Watt's study of the U.S. stations, using the guidance of the U.S. National Oceanic and Atmospheric Administration (NOAA), found 89% to have a margin of error greater than 1 C, 69% with an error of 2 C, and 11% with an error of 5 C.
NOAA's rules say the temperature sensors should be at least 100 feet away from heat sources and radiative surfaces. Instead, most sensors are very close to buildings for the convenience of the person maintaining the station. This is not a very surprising outcome given human nature, so the policing of the stations would have to be very thorough to prevent it. This policing is non-existent, perhaps because higher temperatures are welcomed by NOAA and the government generally. Buildings are heated in the winter, when the upward trend in temperatures has been the greatest. In the summer, many a building's air conditioning units blow out warmed air extracted from the inside of the building. Buildings and black top areas nearby absorb heat during the day and re-emit it at night. Again, the surface temperature record has increased more at night than during the day. Again this is cited as reason to believe that CO2 in the atmosphere has caused the global warming that explains much of the upward temperature spike in the surface temperature data in the late 20th Century in the U.S.
Similar big increases are found at the weather stations in Siberia and the night time and winter increases are the greatest. If you lived in Siberia and maintained a temperature measurement station, how eager would you be to hike 100 feet from a warm building to read or maintain the station? Nope, as your prosperity increased from decades ago and you came to enjoy a warmer building, your weather station would be given the same warmer pleasure of being closely sited to your warm building. This warming of the Siberia surface temperature record is again often said to be just what would be expected given global warming due to CO2 atmospheric concentration increases.
Watts describes a number of obviously warm biased temperature measurement stations.
- The Forest Grove, OR station is close to a home and directly in the path of the warmed air output of a large window air-conditioning unit, which probably was not around in the 1950s.
- The Redding, CA temperature sensor is under and close to a large light.
- The Tahoe City, CA sensor is 5 feet from a trash burning barrel.
- The Hopkinsville, KY station is shown both now and 30 years ago. It was once 10 feet from a brick house, but at least it was surrounded by grass. Now it is closer to the house and very close to a huge brick fireplace chimney which is very wide and extends well above the roof of the expanded brick home. It is also very near a very wide asphalt driveway. An outdoor grill is also situated close by. Prosperity seems to have come to this home in the last 30 years.
- The Marysville, CA station is beside a large asphalt parking area and the heated air outputs of two very large air-conditioning units. It is also close to a large brick building, with the massive heat capacity of brick buildings.
One would think that the increase in the U.S. population by a factor of three, the increased urbanization, and the increased wealth with accompanying housing improvements would surely cause the temperature stations to record heat island effects and cause a general upward bias in temperatures. Despite this obvious fact, NOAA has generally adjusted the temperature records from these stations upward, not downward! NOAA's upward adjustments alone account for nearly one half of the U.S. surface temperature increase in the 20th Century. This is in addition to the upward bias already present due to the increased urbanization and standard of living.
It is also in addition to another upward bias to the temperature record. In 1979, NOAA specified that white latex paint should replace whitewash for the temperature shelters. This was early in the last warming spurt in the 20th Century. Watts found that the white latex paint adds 0.31 C to the temperature readings. This is about 45% of the claimed warming of the 20th Century. One of the effects of latex paint was a generally thicker and more thermally insulating coating on the stations. This would have the effect of causing the temperature sensor to stay warmer into the night as the housing retained its daytime heat longer. Again, the biggest increase in claimed temperatures was in night time temperatures and this was said to be consistent with the CO2 greenhouse gas effect.
In summary, there appears to be nothing reliable about the surface temperature measurements made at ground stations in the U.S. and similar effects are probably influencing stations throughout much of the world, especially those in Europe, Russia, and China where prosperity increased in the late 20th Century. The much more reliable satellite and ocean surface temperature measurements which cover 70% of the Earth's surface found much less warming in the late 20th Century and are clearly the only reliable temperature records. The ground surface temperature record was biased upward by rising prosperity, increasing population, human nature wanting more comfort, technology changes, more use of asphalt, latex paint, and flatly dishonest upward adjustments. These effects especially would have increased winter and night time temperatures in the record.
The large increases in these ground surface records, added to the historic tree ring upward biases of Mann and Yamal data, were the basis for the UN IPCC claims of a man-made global warming catastrophe due to fossil fuel use and the resulting carbon dioxide emissions. To this was added an exaggerated CO2 lifetime in the atmosphere and a neglect of the primary sources of CO2 in the atmosphere. The IPCC claims are broadly bogus and clearly the result of unmitigated bias. The effect of man's CO2 emissions upon the climate have been very small in actual fact and the climate is still clearly dominated by a number of natural effects, some of which we understand fairly well and some of which we are just beginning to have some understanding.
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