It is a slam-dunk certainty that American mainstream media will seize upon a recent story in the Los Angeles Times, “Southern California sets all-time heat records amid broiling conditions,” as justification for its continuing support of the contested theory of man-caused global warming. It has already happened with a Yahoo News story claiming that the new temperature records world-wide prove man causes climate change.
But there are problems in pursuing that path.
First, days that reach and exceed 117-degree temperatures have been known to happen for a very long time in the interior basin of southern California, sometimes referred to as “Death Valley” (though not to be confused with the literal Death Valley). There, temperatures rise above 120 degrees regularly nearly every summer.
The United States’ official all-time record high of 134 degrees F was set July 10, 1913, in California’s real Death Valley. A meteorologist quoted in the L.A. Times article intimates that is where the recent hot air originated, having been pushed westward (advected) over into the Los Angeles basin from an area of strong high pressure (anticyclone) centered farther inland.
Second, by 2018 (into the 21st century) a burgeoning urban heat island (one that now encompasses Los Angeles City proper, Los Angeles County, and the surrounding suburbs) has grown enough to produce excessively high temperatures to a much greater extent today than in past decades, when the population of California was much smaller.
The Los Angeles urban heat island adds more than four degrees to the daily maximum temperature over and above what it had been when earlier records were set in the 1950s. It was in the nature of things and about time for meteorological conditions to force upward a statistical departure from the accustomed, already hot and dry conditions Angelinos experience every passing summer. Weather records are made to be broken.
Third, a similar outbreak of record high temperatures (during several iconic record-setting heat waves of the past) persisted for weeks across the Upper Midwest and into the Atlantic states some eight decades ago during the 1930s (Dust Bowl). Extreme heat and drought happened in 1934 and again in 1936.
Our Midwestern and Great Plains forebears, who suffered greatly through the Depression years, also suffered through many summers when the daytime temperatures exceeded 100 degrees F and night-time temperatures remained in and above the mid-80s. In July 1936 the City of La Crosse, WI, experienced ten consecutive days when the maximum temperature reached or exceeded 100 degrees. On July 14 of that year, it was 108 in La Crosse, its all-time record. On that same date, the thermometer in Wisconsin Dells topped out at 114, the state’s all-time record high.
Record high temperatures happen, somewhere—in fact, in many somewheres—every day here and there around the world. So do record lows. They’re weather phenomena, not evidence of long-term climate change.
So take a seat Los Angeles, and join the club. Your turn came. Other places have had their turns. Still others will have them in the future. Most will have them repeatedly over centuries. Get used to it. It’s weather, not climate.