In 2009, The Heartland Institute published a study by Watts exploring problems with NWS’s weather monitoring locations. Watts wrote,
The official record of temperatures in the continental United States comes from a network of 1,221 climate-monitoring stations overseen by the National Weather Service, a department of the National Oceanic and Atmospheric Administration (NOAA).
[A (sic) examination of] 860 of these temperature stations … found that 89 percent of the stations—nearly 9 of every 10—fail to meet the National Weather Service’s own siting requirements that stations must be 30 meters (about 100 feet) or more away from an artificial heating or radiating/reflecting heat source.
In other words, 9 of every 10 stations are likely reporting higher or rising temperatures because they are badly sited.
It gets worse. We observed that changes in the technology of temperature stations over time also has caused them to report a false warming trend. We found major gaps in the data record that were filled in with data from nearby sites, a practice that propagates and compounds errors. We found that adjustments to the data by both NOAA and another government agency, NASA, cause recent temperatures to look even higher.
The conclusion is inescapable: The U.S. temperature record is unreliable.
Working with others, Watts continued examining potential sources of bias at NWS climate monitoring sites, concluding in a 2015 presentation to a meeting of the American Geophysical Union, “the 30-year trend of temperatures for the Continental United States (CONUS) since 1979 are [sic] about two thirds as strong as official NOAA temperature trends.”
Watts’ research generated wide media coverage. NOAA felt obligated to respond. By 2012, NOAA researchers had begun an experiment to refute Watts’ claims about the integrity of its weather monitoring system.
The results of NOAA’s experiment are now in, and to the extent it tested Watts’ claims, his concerns were verified. The coauthors of the JAMS paper found “small-scale urban encroachment within 50 meters of a station can have important impacts on daily temperature extrema (maximum and minimum)….”
This extends the area for which temperature recordings by NWS stations are compromised by 66 percent beyond what the agency previously admitted was a problem, leading to the question: How many more monitoring stations’ data are compromised above what Watts previously found?
In particular the JAMS study confirmed what Watts and other researchers have consistently maintained: even relatively modest development near temperature recording devices can skew their measurements, particularly by narrowing the diurnal temperature range—the difference between the daily maximum and minimum temperatures. Anthropogenic heat sources such as motors and exhaust from machinery located near measuring stations, as well as built-up concrete and other types of development, accumulate and store heat during each day’s hottest period and release it only slowly overnight, resulting in higher nighttime lows being recorded, and a smaller diurnal range. Because the vast majority of the much-hyped average global warming of the latter part of the twentieth century stems not from higher high temperatures being recorded but from higher low temperatures usually recorded at night, much of NOAA’s reported temperature rise is likely an artifact of compromised data from poorly sited NWS monitors.
Ground-based temperature measurements, although below those projected by climate models, are still the closest of the three sources of temperature data (ground monitors, satellites, and weather balloons) to matching the models’ projections and trends. Skeptics have long used more accurate satellite and weather balloon data to justify their position that the models’ temperature estimates and projections don’t match real-world measurements. If, as seems to be the case, even the ground-based temperature measurements and trends are lower than NOAA and others have previously claimed, there is little if any reason to trust model projections of temperature. And if this is so, there is even less reason to trust other projections of climate doom spun out by models that are purported to flow from their temperature projections.
The conclusion media pundits, the general public, and politicians alike should draw from this new research is that there is little justification for imposing costly restrictions on fossil fuel use to fight a warming that is, in fact, not severe at all.