Lake Michigan’s Left Coast reveals Paleozoic limestone and dolomite dating to the Devonian Period (420–350 million years ago). Abundant in rocks from the Paleozoic are fossilized brachiopods, marine animals with upper and lower hard shells hinged at the rear. Though they first appear in rocks dating to the early Cambrian Period (540–485 million years ago), brachiopods reached their highest diversity in the Devonian.
Brachiopods were decimated during the Permian–Triassic extinction 250 million years ago. Of Earth’s five mass extinction events, this “Great Dying” was the most major. More than 90 percent of all living species were wiped out. Because Earth’s crust is constantly regenerating, hard evidence documenting causes of the Great Dying disappeared long ago. But it’s thought to have happened in phases, as a chain of events.
At that time, Earth was not as we know it today. Though the Permian period produced creepy amphibians and fearsome reptiles, mammals had not yet crawled from the vast oceans. The atmosphere was a thin wisp regularly bombarded by meteors, which, combined with frequently erupting volcanoes, created a dust that obscured the Sun.
Plant life died and rotted, turning air into poisonous methane (natural) gas. Carbon dioxide levels were high; volcanoes ignited fires in coal and petroleum deposits laid in the Carboniferous Period (358.9–298.9 million years ago).
Methane and CO2 are powerful greenhouse gases that caused temperatures to rise in what scientists call the runaway greenhouse effect. With greenhouse effects and oceans starved of oxygen, Earth’s young life forms suffocated.
Humans created organized societies only 10,000 years ago. Australopithecus afarensis, the first hominid creature, walked on two legs a mere 3.2 million years ago. If the Earth’s history were packed into one 24-hour day, that hominid would have walked at 11:58 PM. By Earth’s time clock, it was just seconds ago that Lucy (the celebrity Australopithecus) and her pals in East Africa lifted their heads, stood upright, and scanned the horizon for trouble.
Ever since, Homo sapiens has been monkeying with Earth’s bounty and delicate systems. In the 21st Century, we are proud of our civilization.
We have created deadly plagues by manufacturing “food” that serves up carcinogens and artery-clogging sludge instead of nutrition. We go to alleged healers who dupe us into health problems we don’t have, drugs we don’t want, surgeries we don’t need. We recover in hospitals that give us untreatable infections. We know how to pillage aquifers that supply our fresh water, kill pollinators that make plants grow, and cause earthquakes where none previously shook the ground.
In the United States, we elected as president a misogynist fraudster, a uneducated narcissistic who remarks, [Being the US president] “is more work than my previous life. I thought it would be easier.” The eastern United States has been hit repeatedly by massive hurricanes, yet our leaders deny climate change, claiming it is a hoax. We know about the runaway greenhouse effect—the series of events leading to Earth’s greatest mass extinction—yet we do not alter our ways.
The physicist Stephen Hawking is one of many scientists who has raised concerns about the future of our species. He recently said “our fragile planet will not support us forever” and gives us another 1,000 years on Earth. Hawking says we need to move to another planet to survive, thereby implying that goal is within our reach. Really? Hawking must be a glass-half-full kind of guy.
Even if humankind were able to colonize another planet, only those who could afford the airfare would escape. As they cavort elsewhere in the Universe, Earth’s wealthy will need help: computers to handle the load of recreating Planet Eden, and humans to handle the computers. Not to mention the manual labor of creating a planetwide Mar El Lago.
The wealthy few will look to the massive underclass. Perhaps they will capture loads of sturdy young men and pretty young women, chain them to the bottom of a space vessel, and use them for manual labor and a diversified gene pool. Most of us will be stuck here on Earth, becoming the first species to cause its own extinction.