The World Meteorological Organization announced today that a spot in the California desert now holds the world's record for hottest-ever recorded air temperatures. But that's not due to our ever-heating climate, at least not yet. This record was set almost a century ago, and it was long considered a second-place ranking because of a clerical error made 90 years ago today.
Generations of elementary school students around the world have memoriozed the former putative record: 136°F, recorded on September 13, 1922 in El Azizia, Libya. This measurement knocked the previous all-time high temperature out of first place: a paltry 134°F measured July 10, 1913 at "Greenland Ranch," near Furnace Creek in Death Valley. But meteorological researchers have long suspected the El Azizia record may not have been accurately recorded. There were a few reasons for the suspicion. El Azizia isn't a particularly hot place compared to the rest of North Africa, and that 1922 record hasn't even been approached since. The person who recorded that 136° temperature was new on the job, and the equipment he was using was on the verge of obsolescence and hard to read besides.
The record may have come from an error as simple as reading the wrong part of the temperature indicator on the thermometer. The El Azizia recording was made on an Italian army post during that country's colonial period in North Africa, and the thermometer used was a "Six-Bellini." Six-Bellinis had indicators that marked each day's high and low temperatures, and the user read those highs and lows by noting where the bottom of that indicator rested. The team of meteorologists decided that the inexperienced technician probably took the reading off the top of the pointer instead. This would have added 7° Celsius to the actual temperature, approximately a 12°F difference. The El Azizia temperature would have been just under 124 degrees, which Death Valley beats frequently.
The World Meteorological Association's inquest into the El Azizia record started in 2010, though it got shelved for a little while. One of the meteorologists who made the determination, Khalid El Fadli, is director of the climate section of the Libyan National Meteorological Center. Today's announcement might have come sooner had El Fadli not had to go underground for a time during the Libyan Revolution. Delay or no, the clincher came when researchers found the original El Azizia log book, and determined that the tech had taken similarly erroneous measurements in the same period.
But if your Californian patriotism is stirred by Death Valley's regaining the title as Most Unbearably Hot Place On Earth, don't pop open that overheated bubbly just yet. The records we're talking about here are just part of the picture. We have air temperature records only from those places where we've managed to install and maintain weather stations, and there's a very high likelihood that the real record-holder is out there going uncelebrated. Just down the road from official record-holder Furnace Creek, Badwater -- the lowest dry-land point in the Western hemisphere -- is usually a few degrees hotter at mid-day than Furnace Creek, and might well have topped the old record back in 1913 were anyone there to record it.
And parts of the world are even more remote and forbidding, and it's unlikely we'll ever establish weather stations there. Satellites can measure the Earth's surface temperature even in the remotest places, and so far the hottest surface temperature ever recorded was 159.3°F in Iran's Lut Desert in 2005, with second-place (156.7°F) going to a spot in the bush in Queensland, Australia.
Surface temperature -- referred to by the meteorologists as "Land Skin Temperature" (LST) -- is not the same as air temperature, which is what was recorded that June day 99 years ago in Death Valley. LST can be as much as 50°F higher than air temperature, as anyone who walks barefoot on pavement in the summer will know all too well. And the differential between LST and air temperature can vary widely, depending on prevailing winds, vegetation, humidity and a number of other factors. So we won't get an easy correlation between LST in the Lut Desert and air temperature in the Mojave any time soon.
Which may not matter. The thing that makes the Lut Desert break records is its unrelenting sunlight, the generally high temperatures in the region, lack of vegetation, and the Lut's gravelly surface, which is predominantly made up of dark volcanic rock. As it turns out, human cities do a really good job of imitating all of those conditions, through the "Urban Heat Island" effect -- in which we get rid of vegetation, build shiny metal and glass buildings and rock walls, and pave the ground with asphalt. As our temperature rises, it may turn out that the world's highest-ever Land Skin Temperature will be recorded someplace like a parking lot in El Centro -- and we'll have plenty of thermometers on hand to record the air temperature, and probably plenty of complaining Tweets as well, and Instagram photos of eggs frying on sidewalks.
But for now, Death Valley, take a sweaty bow. Your rightful title has been restored, even though it has a couple of asterisks attached. We always thought that El Azizia record was pretty bogus ourselves.
Chris Clarke is an environmental writer of two decades standing. Director of Desert Biodiversity, he writes from Joshua Tree regularly at his acclaimed blog Coyote Crossing and comments on desert issues on KCET weekly. Read his recent posts here.