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(Courageous Discourse) — 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:

A recent article in The Guardian about the fossil record in northern Greenland got me curious about fluctuating temperatures in the northern latitudes, near the Arctic Circle. An old friend used to work as an engineer on an offshore oil platform in Prudhoe Bay on the North Slope of Alaska. The Prudhoe Bay field contains some of the largest hydrocarbon deposits on earth. If petroleum geologists are right, these hydrocarbons were once living algae, plants, and animals that were deposited in successive layers of sediment, under which they were subjected to pressure and heat that converted them into crude oil and natural gas. 

Long ago I started pondering the question: What was the original source of the carbon dioxide that was used by algae and plants to photosynthesize and grow into such an immense biomass? Reviewing the geological history of the Prudhoe Bay field, I saw it was deposited during the Jurassic-Lower Cretaceous. This led to a bit of research on the Jurassic period (between 201-145 million years ago) whose climate is described as follows:

The climate of the Jurassic was generally warmer than that of the present, by around 5 °C to 10 °C, with atmospheric carbon dioxide likely four times higher.

The Jurassic ended 145 million years ago, but what about more recent times? My curiosity prompted me to look at some U.S. Geological Surveys of the North Slope of Alaska, and I came across a document published in 1992. I was immediately impressed by the paper’s abstract. 

Between 3.0 and 0.85 million years ago the Arctic Ocean Borderland experienced two cycles of climatic deterioration, both of which ended in major Northern Hemisphere continental glaciation. The first cooling cycle ended 2.1 million years ago; continental ice extended down the Mississippi River Valley as far south as Iowa. The cooling cycle was followed by a collapse of glaciation and an extremely warm climate that extended to the northernmost land, almost to the North Pole. This warmth at the beginning of the second cooling cycle was greater than that known at the beginning of the first cycle and cooling began again 300,000 years later, during the Olduvai Normalpolarity Subchron and about 1.7 million years ago. The second cooling cycle culminated with the classic Ice Ages, beginning 850,000 years ago. 

At the beginning of the first cooling cycle, forests, dominated by mixed conifers and including minor but moderately diverse deciduous broadleaf trees, bordered a warm-subfrigid Arctic Ocean. Treeline at lat 79’39’ N. indicated an arctic climate remarkably warm by comparison with today’s conditions but not so warm as the climate at the beginning of the second cooling cycle. Two successive terrestrial records in Siberian Beringia, four separate but sequential marginal-marine records in Alaskan Beringia and northern Canada, and core records from the Arctic Ocean indicate that between 3.0 and 2.4 million years ago the Arctic Ocean Borderland progressively changed to a conifer forest-tundra ecosystem, then to fully developed tundra. With these floral changes came the first record of permafrost and a frigid Arctic Ocean.

Especially notable to me are the following:

1). 3 million years is scarcely the blink of an eye in the geologic time scale. 

2). In terms of their effect on the earth’s landscape and life, these are HUGE temperature swings, with glaciers extending as far south as present day Iowa, followed by warm weather extending all the way to the North Pole, and a warm sub-frigid Arctic Ocean bordered by forests at 79’39 N. which runs through northern Greenland. 

3). Though the last Glacial Period ended 11,700 years ago (before any notable human activity), the Arctic is still considerably colder now than it was 2.4 million years ago.

The Arctic Basin

1). What are we to make of these gigantic fluctuations of the earth’s temperature in the last 3 million years as they relate to the issue of purportedly human-induced global warming? 

2). Is there truly sufficient evidence to claim that human activity is now staving off the beginning of the next expected glaciation period?

3). Would it be more desirable to have glaciers begin advancing south, all the way to Iowa, pulverizing and burying everything in their path?

Reprinted with permission from Courageous Discourse.