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How do global warming alarmists divert attention away from the fact that temperatures have risen much more slowly than their computer models have predicted? In last week’s column we saw how alarmists claim we should trust their computer models even after the models have been proven inaccurate when measured against real-world data. As shocking as that assertion is, it pales in comparison to another common tactic employed by global warming alarmists: doctoring the real-world temperature data.
NASA satellite instruments have been measuring temperatures in the earth’s atmosphere since 1979. The satellite instruments are highly valuable because they can collect and report temperature data from the earth’s lower atmosphere that are not corrupted by urban heat island effects or local land-use changes that impact local temperature readings.
When the satellite instruments first began collecting and reporting temperature data, scientists expected the satellite readings would report more warming than actually occurs at the earth’s surface. The reason for this is carbon dioxide traps heat disproportionately in the earth’s lower atmosphere rather than at the ground. Accordingly, global warming theory postulates that the earth’s lower atmosphere will warm more quickly and to a greater degree than the earth’s surface.
The scientists who oversee the collection of temperature data at surface temperature stations have long assured us that they effectively filter out urban heat island effects and local land-use changes. Therefore, if they have indeed properly filtered out these sources of heat bias, the surface temperature reports should show less warming than the satellite-collected data.
For more than 30 years now satellite data and surface station data have been available for analysis. Surprisingly, the scientists who oversee the collection of surface temperature data report more warming than the satellite data report. This tells us either that sources of artificial warming have not been properly filtered from the surface temperature data, or the warming of the past 33 years is not due to increases in atmospheric carbon dioxide.
Interestingly, the raw temperature data collected by surface stations are fairly compatible with the temperature data reported by satellites. Neither shows much warming. In an attempt to draw the public’s attention away from such inconvenient facts, alarmists doctor the raw data and actually add more warming to the raw data, while disingenuously claiming they are filtering out urban heat island effects and other heat biases.
Climate scientist Roy Spencer, who oversees the NASA satellite instruments measuring global temperatures, reports that virtually all of the warming claimed by the overseers of U.S. surface temperature stations is the result of adjustments government-employed scientists make to the raw data. The objective, unaltered temperature readings show essentially no warming since 1973.
Similarly, the government-employed scientists who report surface-based U.S. temperature data continually revise old temperature records to make earlier years seem colder than reported in the raw data, and more recent years warmer than reported in the raw data. For example, the federal government’s Goddard Institute reported in 1999 that the 1930s were far and away the warmest decade in the U.S. instrumental record, and that U.S. temperatures had not risen between the 1920s and the end of the twentieth century. Now, however, after a decade of retroactively adjusting prior temperature data, the Goddard Institute claims 1990s temperatures rivaled the 1930s and that substantial warming occurred in the United States between the 1920s and the end of the twentieth century.
The reason these retroactive adjustments occur and always inflate the raw data to give the appearance of increased global warming is because partisans like James Hansen are assigned by the federal government to oversee, adjust, and then report on the surface temperature data. Specifically how do such biases show up in the data? Partisans adjust the raw data to make it seem like there was a greater urban heat island effect in New York City 100 years ago, when the city held only 5 million people and industrialization was in its infancy, than there is today when the city holds 8 million people and gasoline and electric-powered machinery creates still more artificial warming.
The raw New York City data show less than 2 degrees warming since 1910. Common sense tells us much of that warming is likely due to the increase in population and heat-producing machinery and activities. The global warming partisans who oversee and report the data, however, have adjusted the New York City data upward, rather than downward, to claim the city has warmed nearly 3 degrees since 1910.
So long as the foxes continue guarding the hen house, we will always receive doctored temperature data that misrepresents the very modest warming reported by objective, raw temperature data.
