Global Temperature Data Manipulation
Thousands Of Non-Urban Thermometers Removed
0.3¬∞C Of Pause-Busting Warmth Added Since 1998
0.5¬∞C Of Warming Removed From 1880-1950 Trend
Over the course of the last few decades, overseers of the 3 main 19th century-to-present global temperature data sets — NOAA, NASA, and HadCRUT — have been successfully transforming the temperature record to the shape dictated by climate models.
Namely, there has been a concerted effort to cool down the past — especially the 1920s to 1940s warm period — and to warm up the more recent decades, especially after about 1950. In this way, a trend of steep linear warming emerges that looks similar to the linear shape of anthropogenic CO2 emissions for the 20th and 21st centuries. A better fit between anthropogenic CO2 emissions and surface temperature helps to imply causation, and this ostensible correlation-turned-causation can then be used to justify policy decisions aimed at eliminating fossil fuel energies.
75% Of GHCN Temperature Stations Removed Since 1970s
One of the most unheralded means by which this temperature “shaping” occurs has been the tendentious and wholesale removal of thousands of weather station land thermometers from remote, high altitude, and/or non-urban locations since the 1970s. These are stations which do not show the warming trends predicted by models, as they are not affected by proximity to artificial or non-climatic heat sources (pavements, buildings, machinery, industry, etc.) like urban weather stations are. (As detailed below, locating thermometers near urban heat sources can cause warming biases of between 0.1 and 0.4¬∞C per decade.)
If a highly disproportionate number of non-urban weather stations are removed from the global temperature archive, the urban-based thermometers will be weighted much more heavily than they were before the non-urban stations were removed. And therefore, the temperature record will show (much) more warming — even though the additional warmth is not climatic, but artificial.
And this is exactly what has happened. The Global Historical Climatology Network, or GHCN, is the primary source for temperature data records from all over the world. NOAA, NASA, and HadCRUT heavily rely on GHCN for temperature histories in constructing their global data sets dating back to the 1800s. According to McKitrick (2010), there were still between 5,000 and 6,000 weather stations across the globe contributing to the GHCN temperature archive as recently as the 1970s. Today (or as of 2009), there are only a little over 1,000 left — 75% of the thermometers used in the 1970s have disappeared. There are now fewer weather stations contributing to the GHCN than there were in 1919.
Astonishingly, as many as half (49% as of 2009) of the weather stations across the globe used by the GHCN are now located on the (paved) grounds of airports.