Sunday, December 17, 2017

Modern Climate Stability

Most college students were required to enroll in introductory courses such as Western Civilization. More recently these introductory courses have transitioned to World History, sometimes combined with Ancient Civilization. A study of syllabuses of these courses reveals few topics concerning pre-civilization people and cultures. This indicates the paucity of knowledge about the lives of our human ancestors in the day before writing was invented. Yet as we study archaeological evidence produced by these progenitors, we are struck with their robust humanity. Writers of early chapters on human history deduce their hypotheses concerning the experiences of these early human residents. Written accounts from these people do not exist.

Earth scientists have highlighted the monumental effects of glaciers on a planet whose land masses were formerly significantly swathed in ice. Earth was emerging from the Wisconsin Glaciation epoch roughly 12-13,000 years ago. This widespread glaciation left behind thousands of features on Earth. It is difficult to comprehend the  past and present effects of Wisconsin glaciation and how recently this event occurred. In former years I lived in regions where we could climb distinctive neighborhood hills called drumlins, drive upon highways built on eskers in Adirondack State Park, observe kettle holes during walks in the woods, visit unique rocks called erratics in Pyramid Mountain County Park near Morristown, NJ, and hike in the Great Swamp, the “last gasp” of glacial Lake Passaic which covered 300 square miles only 11,000 years ago in the heart of today’s densely populated Northern New Jersey.

In preparing this post I reviewed the impact of the recent glacial conditions in my current home state of Illinois. We reside in extreme northwest Illinois in a region called the Driftless Area. Most of the Driftless area is located in Wisconsin. The region remained curiously unglaciated during the Wisconsin glaciation event. Therefore, the topography has not been smoothed by the effects of ice as have many areas surrounding our region. To our south and east two Illinois state parks including Starved Rock State Park and Kankakee River State Park manifest the mighty impacts of the Kankakee Torrent. Glacial Lake Chicago was breached as huge volumes of Wisconsin ice were melting. The sudden torrent of meltwater cut scenic canyons which remain for us to enjoy today.    

Full humanity existed on this planet about 120,000 years ago. By full humanity we mean “behaviorally and anatomically human.” At that time earth residents were experiencing a relatively brief interglacial following the previous Illinoisan glacial period. The warmest stages may have occurred about 10,000 years prior to the onset of the harsh Wisconsin Ice Age. The prolonged Wisconsin ice age was not a period of physical comfort for humanity. We believe that the earliest behaviorally and anatomically human beings created in the Image of God may date to the Sangamonian interglacial roughly 120,000-130,000 years ago.

The demise of Wisconsin glaciation and the simultaneous climate warming corresponds with the Agricultural Revolution beginning 10,000-12,000 years ago. Agriculture was a boon to the Rise of Civilization in Mesopotamia, India, Egypt, China, Mesoamerica, and South America. Without agriculture it is doubtful that civilization, with its complex society, specialized labor, social hierarchy, and existence of cities, could have formed. Culture is a less formal term to indicate how humans believe, behave, and value. Modern behaviorally and anatomically human beings have possessed cultures for tens of thousands of years. By these standards humans did not produce civilizations prior to about 7,000 years ago.

Let us relate the explosive growth of our civilized human population to the unique Holocene Interglacial period in which we now live. We repeat, once again, two quotes from Dr. Hugh Ross in his recent volume Improbable Planet, Baker Books, 2016: 

“The melting away of the great ice sheets—except those over Antarctica, Greenland, and the North Pole—helped to stabilize global mean temperatures. Until then, climate variability prevented widespread enduring agricultural and manufacturing specialization, trade, and construction of towns, roads, and ships. The climate from 120,000 to 12,000 years ago varied so radically as to render the launch of extensive cultivation and global civilization impossible.

“Then, for reasons still unknown, (emphasis mine) the climate suddenly entered a stable phase shortly after the beginning of the last warm interglacial period. Within a brief period, large scale agriculture emerged, as did sophisticated expressions of human ingenuity and cooperation, for example towns, specialization of industry, and organized trade. These factors, in turn, made possible the exponential expansion of civilization, technology, and human population.”

We live in a time of unusual moderate temperature stability. Global conditions are neither too hot nor too cold. Previous interglacials experienced no such stability. The long term line graph of world temperatures since the end of Wisconsin Glaciation is remarkably close to flat. The Sangamonian (sometimes called Eemian) Interglacial period preceding the Wisconsin Glacial experienced temperatures several degrees Celsius warmer than today—perhaps 3-5ÂșC warmer or even more. This information comes from temperature proxy results since direct readings did not exist. We are thankful for reliable scientific results such as oxygen isotope readings which provide temperature proxy readings up to 800,000 years into past Earth history. The ages of Earth quoted in our posts have been scientifically verified in dozens of different ways, all in agreement with one another.

Our view is that our stable planetary temperature of the past 12,000-14,000 years is but a small dimension of many God-authored transformational miracles to support our current technological society and feed Earth’s 7.5 billion humans. The Creator of all things still watches over Planet Earth and the humans He created to inhabit it, sustaining them from moment to moment.