In our previous blog post, Air Travel Science, we mentioned traveling by air over the Ohio River. Its course has been altered substantially by the retreat of the Wisconsin ice sheet during the last installment of the Ice Age which began in the last 120,000 years. We remain in the last stage of the Wisconsin glacial event. The retreat of the last continental glacier was but one of many manifestations of major glacial advances and retreats during the Pleistocene epoch—firmly dated by the scientific community as extending from 2.588 million years ago to 11,700 years ago.
For a majority of the 2.588 million years, brief episodes of warmth interrupted the otherwise icy conditions. These episodes were termed “interglacials” and occurred every 41,000 years. Just over 800,000 years ago, there was a major shift in the cycle. Instead of an interglacial every 41,000 years, there was a shift to a 100,000 year cycle. Sudden, short-lived spikes in global temperature of about 10,000 years were followed by slower temperature declines of approximately 90,000 years. The impact of glacial cycles are of enormous benefit to humanity. If they do not occur, modern human life would be impossible to sustain.
A brilliant Serbian mathematician, astronomer, and climatologist, Milutin Milankovic (1879-1958), proposed that Earth’s glacial cycles were connected to three Earth motions. Obliquity, the axial tilt of Planet Earth which varies between 22.1º and 24.5º over a period of 41,000 years, results in more extreme seasons.This effect is variable, affecting the distribution of heat at crucial intervals. Obliquity is stabilized by lunar gravity. Eccentricity, the shape of the Earth’s orbit, is affected by gravitation from larger planets Jupiter and Saturn. It results in changes in the degree of solar radiation and occurs at 100,000 and 400,000 year intervals. Finally, axial precession occurs on a cycle of 19,000 to 23,000 years from solar and lunar tidal forces and causes variation in northern hemisphere irradiation.
There are many other factors which relate to glacial cycles. We quote from a research group called FosterLab whose web site effectively deals with the Mid-Pleistocene Transition—the marvelous beneficial change to humanity’s welfare when the ice age cycle transitioned from 41,000 years to 100,000 years: “The Earth system is incredibly complex however and a cascade of feedbacks, some of which are poorly known, amplify the orbital forcing to enact global climate change.” One important amplifier researched by FosterLab is how CO2 is partitioned between the atmosphere and the ocean on these timescales. The ocean holds around 60 times the CO2 of the atmosphere…..On geological timescales the ocean therefore drives atmospheric CO2 change.” Such information may illustrate the logical fallacy of “oversimplified cause” for our contemporary population of global warming enthusiasts obsessed with consumption of fossil fuels producing the “pollutant” CO2. Plant life could not survive without CO2. Natural fluctuations in CO2 have occurred for literally billions of years.
Dr. Hugh Ross of Reasons to Believe has skillfully outlined many possibilities inherent in benefits of the ice ages for humanity in Chapter 15 of his 2016 volume Improbable Planet and in his web series “Miracles of the MId-Pleistocene Transition” parts 1-3. Clearly outlined is the startling transition of the ice age cycle from 41,000 to 100,000 years beginning 800,000 years ago. Ross reviews researchers’ proposals of interplanetary dust, mineral dust, export of organic carbon from oceans, and tectonic events. He adds his own citations of the benefits of the current solar optimum: “We currently enjoy unusual stability in our climate.” We are in the warm phase following an ice age. And yet, we are not too warm. Ross also highlights the apparently supernatural benefits of a remarkable recent paucity of harmful supernovae closer than 5000 light years. Ross states, “Our protection from nearby supernova events appears exceptional.” And how do we explain the “long cool summer” we now experience? The Sun became exceptionally stable in luminosity about 50,000 years ago and seems likely to remain so for the next 50,000 years. “This era of exceptional stability in solar luminosity helped make possible humanity’s launch and development of global, technologically advanced civilization,” writes Ross. World population has ballooned from one billion to 7.5 billion since 1800.
We recommend the above-mentioned resources as a brief introduction for those interested in understanding the meticulous preparation of our unique planetary home by the Creator. The Pleistocene epoch has been termed an Ice Age. It is one of five major ice ages to be identified on Earth. The previous one persisted 100 million years from 360 to 260 million years ago. The Pleistocene Ice Age and the current Holocene epoch of exceptional climatic stability is more significant in terms of contemporary planetary life. In particular, we are aware of the profound impact of the last several glacial epochs since the Mid-Pleistocene, especially the recent Wisconsin glaciation. We observe its effects as evidenced by formation of lakes, new river drainage patterns, erosion, deposition, and many other impressive glacial features. Perhaps most startling is evidence of sea level reductions of up to 400´during the cold periods in the last several tens of thousands of years.
Geologic events such as those we have described may be characterized as miraculous. The degree of fine tuning is virtually impossible to attribute to naturalistic chance. The best examples are solar and cosmic events occurring in concert with the Mid-Pleistocene Transition as well as the many events on Earth which have produced multiple mineral resources since our planet formed 4.5 billion years ago. God is not constrained by time as is humanity. His timeless miracles have been ongoing since the initial creative miracle—the beginning of time, space, matter, and energy 13.8 billion years ago as humans reckon time. That stupendous creative event was the first of many ongoing miracles in the universe we call home in preparation for modern man created “in the image of God.” Full humanity has been present on Earth only 0.00002% of the time since the beginning of Earth’s planetary history. Sustaining miracles for the benefit of humanity still occur.