March 28, 2010
Unsettling the Settled Science
Problems with a California temperature monitoring station represent in microcosm why the supposedly settled issue of climate change has become so unsettled in the last few months.
By Steven F. Hayward
If you want to understand why the controversy over global warming won’t go away, forget combing through hundreds of hacked emails or trying to understand the enormously complex computer climate models that spit out predictions of our future doom. Instead, just check out the Marysville, California, temperature monitoring station that NASA and other climate researchers use to track temperature trends. The problems with the Marysville station represent in microcosm why the supposedly “settled” issue of climate change has become so unsettled in the last few months.
The Marysville temperature station is located at the city’s fire department, next to an asphalt parking lot and a cell phone tower, and only a few feet away from two air conditioning compressors that spew out considerable heat. These sources of heat amplification mean that the temperature readings from the Marysville station are useless for determining accurate temperatures for the Marysville area.
Indeed, the Marysville station violates the quality control standards of the National Oceanic and Atmospheric Administration (NOAA). NOAA admits that stations like Marysville, sited close to artificial heat sources such as parking lots, can produce errors as large as 5 degrees Celsius. That is not the only shortcoming of the Marysville data; it turns out that daily data were missing for as many as half the days of any given month. Either the device failed to self-record, or no one recorded the daily data as procedure requires. NASA simply filled in the gaps in the data by “interpolating.”
The Marysville station is only one among the more than 1,200 weather stations scattered throughout the United States from which NASA and NOAA generate data for their climate research, and is one of the key data sources for the claim that the planet has experienced a 0.8 degree Celsius increase in temperature since the beginning of the 20th century. But a survey of more than two-thirds of these stations reveal that the Marysville station is not an anomaly.
To the contrary, 89 percent of the 860 temperature stations surveyed fail to meet the National Weather Service’s site requirements that stations must be located at least 30 feet away from any artificial heat source. Stations seem to have been sited for purposes of convenience rather than accuracy and consistency. Some have been moved over the years with noticeable changes in reported temperature ranges, but NASA reports continuous time series data from these stations without taking note of their relocation.
Who performed this revealing audit of these important data-generating instruments? NASA? NOAA? The Government Accountability Office? The National Academy of Sciences? A congressional committee perhaps? No to all of the above. Meteorologist Anthony Watts used the Internet to recruit an army of 650 volunteers to photograph weather stations around the country and send him the results. Watts posted photos of dozens of the worst offenders on his website, surfacestations.org, and is adding more all the time
The problem of improper instrumentation and inaccurate data is not limited to the United States. Other volunteer cataloguing efforts have revealed similar problems with temperature stations in Australia, New Zealand, England, Canada, South America, China, Africa. . . well, in a word, everywhere. In other words, the entire land-based temperature records have quality control problems.
NASA acknowledges these problems in general, but in its latest defense of itself, released two weeks ago, NASA claims to adjust the raw data from these temperature stations to account for the “urban heat island effect” (the term of art for artificial sources of temperature bias such as heat-absorbing paved surfaces and buildings). What NASA calls its “homogeneity adjustment procedure”—matching up urban data with rural station data—finds the urban heat island effect to be very small, only 0.1 degree Celsius over the last century.
Does NASA inspect each station to see if it is near a heat sink such as a parking lot? No: it delineates weather station locations with nighttime satellite photos. In other words, if a station is near an urban light source as seen from space, it is classified as urban and adjusted accordingly. But many of the rural stations suffer from the defects Watts’s volunteer army has documented, so NASA’s method may not account for station bias properly.
NASA’s latest paper admits this: “Much higher resolution would be needed to check for local problems with the placement of thermometers relative to possible building obstructions.” NASA simply assumes that the errors wash out in both directions, (though in some cases it appears NASA omits stations whose temperature records show no warming or even a declining trend).
We shouldn’t necessarily blame the good folks who sited weather stations over the years. The evolution and deployment of weather stations over the last century and a half was not done with the rigor necessary to answer the kind of precise questions climate science attempts.
It is possible NASA’s climate scientists are right and have adjusted the data more or less correctly, but if a pharmaceutical company came to the Food and Drug Administration with data on a drug trial that was this sloppy and prone to manipulation, the FDA would not be amused. Yet we’re basing multi-trillion-dollar global decisions in part on this work. And it doesn’t help that NASA’s lead scientist in their temperature trend work is the über -alarmist James Hansen, who advocates civil disobedience to shut down coal-fired power plants and crimes-against-humanity trials for climate skeptics. It’s not just the temperature stations that have a serious bias problem.
Steven F. Hayward is the F.K. Weyerhaeuser Fellow at the American Enterprise Institute, and author of the forthcoming Almanac of Environmental Trends.