The mainstream media continue to fall hook, line and sinker for the tempting alarmist bait set by urban heat corruptions. The Guardian said a record was set this year in the U.S. city of Phoenix during a “hellishly hot summer” with the most hot days over 110°F. The BBC’s report on Phoenix took the opportunity to add that heatwaves are becoming more frequent and intense, “because of human-induced climate change”. It is often hellishly hot in the desert state of Arizona, and in fact last summer was the warmest in Phoenix going back to 1933. But strip out the heat created in the ever-expanding concrete and tarmacked metropolis, and it turns out the area was only the 11th warmest on record.
If the record hot summer in Phoenix was due to global warming, as claimed in almost all media, then it would show up at weather stations surrounding the city – “right?” asks Dr. Roy Spencer at the University of Alabama in Huntsville (UAH). As regular readers will recall, Dr. Spencer and his UAH colleague Professor John Christy have been engaged in a recent project to determine the extent of urban heat corruptions in cities. Dr. Spencer took the official surface temperature data for Sky Harbor Phoenix Airport, shown by the red curve in the graph above, and compared it to all rural stations within 10-100 kms of Phoenix. Spencer concludes that the urban heat island effect was the dominant cause of the summer records in Phoenix.
In fact the gap between the red and green lines could be larger since Spencer notes that he used rural data from the U.S. weather service NOAA that had been ‘homogenised’, a controversial process that often leads to rural data being equalised with surrounding areas. According to Spencer, there are unsupportable conclusions being drawn about the supposed role of climate change in the record high temperatures being reported in some U.S. cities. He adds: “Cities are hotter than their rural surroundings, and increasingly so, with or without climate change.” This can lead to extra warmth of up to 10°F, mostly at night, he finds.
The scale of the urban heat corruption is laid out in wider research recently published by Spencer and Christy. They note they are preparing to publish their first paper looking at temperature data across the lower American 48 States with the dramatic conclusion that summer warming between 1895-2023 in U.S. cities has been exaggerated by 100%. Across the United States, much of which is rural, the urban heat effect is placed at a significant 24%. The data investigated are taken from version four of NOAA’s Global Historical Climatology Network, which is an important constituent part of global temperature datasets such as the Met Office’s HadCRUT. The subsequent corruption of the global figures used to promote Net Zero is an issue that seems to be of little interest to most media.
Spencer and Christy calculate the urban heat effect by using satellite maps and data to compute how temperatures change with population density across thousands of closely-spaced pairs of weather stations. Previous ongoing reports on their work have highlight.