You probably noticed the whirlwind of frantic headlines and social media buzz earlier this month claiming that the Fourth of July had been the world's hottest day on record, hotter than any day in the past 125,000 years! Here's one example, from a retired professor of "geophysical and climate hazards," cited by CNBC:
Wow, scary! Except, somehow all of the stories managed to leave out the fact that "on record" refers to when they first started keeping global records, namely 1979. But it doesn't sound as terrifying to say "the hottest July 4th in forty-four years!" And the 125,000 years bit is especially ridiculous. As Steve Milloy of Junk Science pointed out on Twitter, "the claim that July 3 & 4 were the 'hottest days in at least 125,000 years' are based on biased computer model guesswork & incomplete satellite data. What satellite data is there for 125,000 years ago?"
Milloy poked a few more holes in this narrative in a piece for the Wall Street Journal, in which he argued that "the notion of 'average global temperature' is meaningless." That's because "Earth and its atmosphere is large and diverse, and no place is meaningfully average." It's an unreliable metric, he argues, since "temperatures are higher globally during the Northern Hemisphere’s summer because of more sunlight-trapping land."
Meanwhile, early July was unseasonably warm in the Antarctic, which would have significantly elevated the planetary average. But it is misleading to imply that this is a general upward trend. Surface temperatures today are slightly cooler in early July than they were in April, and this past June wasn't the hottest June on record -- that was June, 1998. Furthermore, he points out that the data that we do have is imprecise:
It has been estimated that 96 percent of U.S. temperature stations produce corrupted data. About 92 percent of them reportedly have a margin of error of a full degree Celsius, or nearly 2 degrees Fahrenheit. The lack of precision of reported temperatures, whether estimated or measured, is not reassuring. Temperature stations also tend to be limited to populated areas. Much of the Earth’s surface isn’t measured at all.
Hence his contention that average global temperature is a "political concept [rather] than a scientific one." It seems to convey more information than it actually does. Which is to say, it doesn't tell us very much about the world. But it does aid environmentalist activists, and their accomplices in the media, as they spin a misleading and hysterical narrative in order to further their anti-civilizational policies. But what else is new?