Dear editor:
As a retired geologist, I would like to respond to Terry Hansen's letter which was published in Cowboy State Daily on Sunday, February 23, 2025.
I have no argument with Terry Hansen's statement that the Earth is undergoing "global warming."
In fact the Earth has been warming for the last 12,000 years, since the height of the last period of ice advance in a period of glaciations that began about 2.5 million years ago.
We are currently in an interglacial period. Each cycle of glacial/interglacial periods is about 100,000 years long. According to ice core data from Vostock, Antartica, three of the last four interglacials have been warmer than we are today.
Throughout most of Earth history, the Earth has been much warmer than we are today. Most people view the Earth as unchanging and stable throughout its history.
They base their view of what the Earth should be based on what they observed during their lifetime or that was recorded during the period of written history. The oldest written documents are only about 5,500 years old. This is just a blip in geologic time.
Twelve thousand years ago, sea levels were about 100 meters (330 feet) lower than they are now.
Sea level has been rising constantly since then. Between 85,000 and 125,000 years ago the coastline of the Eastern United States in the vicinity of Cape Hatteras was about 145 kilometers (90 miles) inland from its current location. This is known because of the location of the Suffolk Escarpment, an ancient shoreline.
It is my opinion that the primary reason the Earth is warming is the continuation of the glacial/interglacial cycles. There is likely a human component, but I seriously doubt that the human component is the major one.
Many proponents of human caused global warming cite the abrupt rise in the temperatures over the last 100+ years when compared to the ice core data as their primary supporting evidence.
In a way this is comparing apples to oranges.
For the last 100 years scientists have been recording actual temperatures, weather rather than climate. The ice core data from Antarctica (and Greenland) are averages over hundreds of years.
The ice core data are determined from isotopic composition of air trapped in the the solid ice.
Its isotopic composition is determined by the diffusion of air through the upper levels of snow before the climate models that human caused global warming proponents cite frequently have problems predicting past events.
If they can't reliably predict past climate changes, can they reliably predict future ones?
In the 1990s, there were predictions made that the north polar ice cap would be totally melted by 2020.
It is still there; the last prediction I know of stated it would be gone by 2035.
Some glaciologists believe that the complete melting of the north polar ice cap will be the events that initiate the next glacial cycle by starting a period of snow accumulation and ice build up.
Sincerely,
Ronald Teseneer,
Morganton, North Carolina
