The Case of the Hot Thermometers

Richard H. Timberlake


Mr. Timberlake holds a Ph.D. in Economics from the University of Chicago.  He is also a SAFE member and resides in Bogart, Georgia.


The recent political emphasis on "global warming" has reminded me of a series of "experiments" I carried out one summer when I was in my formative years between boy-emeritus and teen-ager. I was visiting my grandparents who lived in a bucolic village in central Ohio where I had to devise things to do on my own to keep busy.  Since we were living in an age of energy, machinery, and measurement, I had become very interested in dials and gauges and what they measured. I especially liked to watch speedometers climbing above 70 miles per hour, but any gauge that measured anything always caught my attention. I was not old enough to drive and experience a speedometer sweeping across its dial, so I substituted cheap glass thermometers that were common in every household. I located four or five in our house, some in use and others just stored in drawers.

Of course, thermometers do not move unless the temperature they measure is changing, and the daily change was much too slow for what I wanted. So I applied heat by holding matches near the thermometer bulbs, and when the colored column rose past 1000 and 1200, I had my reward. I would then use cold water and even ice cubes to get the column back down into the forties or thirties. Some of the glass bulbs at the base of the thermometers did not like these experiments, and protested by breaking when I applied too much heat or cold too quickly. So I refined my method by using a magnifying glass to concentrate the sun’s heat. That way I had better control for what I wanted.

This summer escapade came back to me recently when I received a copy of a monograph: Is the U.S. Surface Temperature Record Reliable? by Anthony Watts, who has been a professional meteorologist for more than 25 years. Watt's self-imposed task was not to measure temperature, but rather to test the equipment that officially measures surface temperatures. His mission was to find out the "reliability of data used to document temperature trends" in the United States. This data is recorded by a network of 1,221 climate-monitoring stations overseen by the National Weather Service (NWS), which is a bureau of the National Oceanic and Atmospheric Administration (NOAA). Until Watts did his study, no climatologist either in these bureaus or in other institutions had ever done any review of the reliability of temperature measurements coming from these stations. Watts recruited a team of 650 volunteers who visually inspected and photographed more than 860 (about 70 percent) of these temperature stations. Watts notes, "We were shocked by what we found."

They found stations "located next to exhaust fans of air conditioning units, surrounded by asphalt parking lots and roads, or blistering-hot rooftops, and near sidewalks and buildings that absorb and radiate heat." Watts summary thus far (his team is still working on it) is that 89 percent of the stations "fail to meet the NWS's own siting requirements that stations must be at least 10 meters or more away from an artificial heating radiating or reflecting heat source."

The Watts team also found other sources of error--for example, gaps in the data that were filled with data from nearby sites, and sites located on the basis of ready accessibility rather than objective scientific measurement. One department of the NWS in 1979 decided to re-paint the stations using semi-gloss latex paint instead of the traditional whitewash. Watts found through careful testing that just this change brought about a total measurement error of one degree Fahrenheit. The human element at NOAA and NASA also made the biases worse—such things as “adjustments to the data . . . that cause recent temperatures to look even higher.” Possibly, grant applications for studying “global warming” would be positively correlated with such “findings.”

Scientific bias is properly defined as: A systematic tendency to err. In economic measurement, we find it in price indexes, which slightly “inflate” measured prices over time due to product quality improvements that cannot be compensated for or measured. In the measurement of air temperature, the bias has been significant and all in the same direction—that is, it has increased all the actual temperature values over time by a significant degree from what they actually were. Nor is there an offsetting cooling bias. Indeed, the estimated amount of bias in the measuring devices—the temperature error—is greater than the anomaly of temperature—the “global warming”—that the thermometers purport to measure.

Of course, these thermometers were not designed to measure small temperature changes over long periods of time. They would never be acceptable for measuring accurately the insignificant less-than-one-degree change that may have occurred over the last 100 years. Given their probable error, it is very possible that the long-run “warming” these temperature stations have measured is, in fact, a cooling of about one-half of a degree!

Fortunately, true science does not need to rely on these antiquated weather stations any longer. Since 1979 satellite stations orbiting the earth have provided a much more reliable—unbiased—temperature data-set for scientific use. Over that thirty-year period, the satellite stations have recorded virtually NO long-run change, and, in the most recent ten years, a slight cooling.

Maybe the fascination with measuring devices I had as a boy is a general condition that all males experience one way or another. And all that we are witnessing in this day and age with this “global warming” thing is a bunch of grown-up boys heating up thermometers so they can see columns of colored alcohol rise dramatically, and can then imagine the catastrophe that would occur if the gauges measured reality.