“All the days ordained for me were written in your book before one of them came to be.”
These words written by King David in Psalm 139 declare that God determines the precise date of each person’s entry into the world and implies that there is a specific purpose for the timing of our lives on Earth. New scientific discoveries indicate that what is true for us as individuals also appears to be true of humanity as a whole.
Scientists are recognizing that Earth’s long geological and life history has synergistically worked to open up a brief time window—no more than several thousand years—during which humans can launch and sustain a global, high technology civilization. Researchers also are acknowledging that this time window is unique. It has never happened before and will never occur again. (I describe and document these new scientific findings in a forthcoming book.)
The ice age cycle was a crucial geophysical event in the opening of this unique time window. Ice ages occurred before in Earth’s past, but only in the last 2.58 million years (the Quaternary Period) has the planet experienced an ice age cycle. During the Quaternary Period, Earth has oscillated between 10 percent surface ice coverage and 20–23 percent. (See this white paper for more details on how the ice age cycle made advanced civilization possible.)
Deep ice cores from central and northern Greenland1 and central Antarctica2 and a sediment core from off the coast of New Zealand3 have yielded a comprehensive record of climate change driven by the ice age cycle. However, scientists have longed to learn more about the climate change details that led up to the Quaternary Period. A recent analysis of the Chinese Loess Plateau’s red clay sequence is now filling in those details.4
Details in the Red Clay
The Chinese Loess Plateau sits just northeast of the Tibetan Plateau. Due to the ice age cycle, the Tibetan Plateau alternates between being ice covered and ice free. The melting of the Tibetan Plateau ice causes successive layers of clay to be deposited upon the Chinese Loess Plateau.
Geophysicists have long suspected that the cyclical variations in the eccentricity (ellipticity) and obliquity (tilt) of Earth’s orbit—which drive the ice age cycle—to a much lesser degree, also drove the climate variations before the initiation of the ice age cycle. Analysis of the Chinese Loess Plateau’s red clay sequence confirms that suspicion.
First, the analysis reveals both the 400,000-year and the 100,000-year eccentricity cycles. Second, it shows that both the summer and winter monsoons—which water the great agricultural plains of the Indian subcontinent and Southeast Asia—intensified from 5.2 to 2.6 million years ago. Third, because of the dating accuracy of the analysis, geophysicists can now calibrate red clay deposit data from other regions.
The researchers concluded their paper by mapping out directions for further study. What they have achieved so far already demonstrates the fine-tuning of Earth’s geophysics 5.2 to 2.6 million years ago that made possible the even more remarkable fine-tuning that occurred throughout the Quaternary Period.
Future studies might be able to answer the question of why, in spite of the many cyclical variations in Earth’s orbital and rotational properties, we have enjoyed such exceptional climate stability at such an ideal mean global temperature throughout the past 9,000 years. What is certain is that this extreme climate stability at the most optimal temperature appears fine-tuned to make possible human existence. Before any human’s days came to be, God was already at work with us in mind.