Wide Swings of Warming and Cooling

Geological Survey of Arctic Ocean Borderland tells of extreme cooling and warming during last 3 million years

By JOHN LEAKE

The climactic scene in the The Great Gatsby occurs during a terrible heat wave from which there is, in 1920s New York, no escape. The unrelenting heat oppresses and confuses everyone. As the narrator remarks:

The next day was broiling, certainly the warmest, of the summer...The straw seats of the car hovered on the edge of combustion; the woman next to me perspired delicately for a while into her white shirtwaist, and then, as her newspaper dampened under her fingers, lapsed despairingly into deep heat with a desolate cry.

Every summer here in Texas, when everyone starts bellyaching about “the heat,” I am reminded of this scene. At least we have AC now. Lately I’ve heard a lot of chatter about “record heat” in Texas, which is attributed to global warming caused by human activity. This prompted me to do a little research on record thermometer readings in Texas, and I found the following:

The hottest maximum temperature ever recorded in Texas occurred twice: First on August 12, 1936, in Seymour, northwest of Dallas, and again on June 28, 1994, in Monahans, a city near Odessa, according to the National Oceanic and Atmospheric Administration. The recorded high that day was 120.°

The hottest summer in Texas history was 1980. According to NOAA records:

In Dallas/Fort Worth, Texas, high temperatures exceeded 100 °F (38 °C) a total of 69 times, including a record 42 consecutive days from June 23 to August 3,^[of which 28 days were above 105, and five days above 110.

I suspect that none of these hot summers signify much apart from the fact that Texas has had hot summers since people started measuring and recording air temperatures during the latter half of the 19th century. It wasn’t until the year 1880 that weather data was compiled on a truly global scale, which means that the talk of “record temperatures” is in reference to only 143 years of weather records. Prior to the 17th Century, when the first reliable thermometers came into use, humans had no means of precisely measuring air temperature.

Nevertheless, from various natural phenomena such as tree rings, arctic ice core samples, radiocarbon dating of fossilized trees and plants, and the deposition of rocks and sediments from glaciers, scientists have determined that the earth’s has greatly fluctuated over time, with fairly regular periods of glaciation and inter-glaciation, as illustrated on this chart: