It did not happen overnight, but the changes would make the most horrific post-apocalyptic films seem mild by comparison. Obviously, around 252 million years ago, well before the advent of human beings, the relevant apocalypse was caused by natural events: volcanic eruptions that set off a sequence of events that ultimately extinguished most life on Earth. Sealife dropped by 95%; those on land by 70%. Mammals, reptiles, fish, birds, plants… everything was impacted. Those species that that survived the rising global temperatures recreated the planet that we know today. It was logged in biohistory as the End-Permian Extinction, or the Great Dying.
Back then: “Average global temperatures likely rose 6 to 12 degrees Celsius (about 11 to 22 degrees Fahrenheit) near Earth’s equator and 10 to 14 degrees C (18 to 25 degrees F) near the poles. (For reference, climate scientists have cautioned that a 2-degree Celsius rise in average global temperatures today could kill 99% of the planet’s coral reefs and risk the collapse of the polar ice sheets.)
“In this hotter, drier climate, fire frequency increased faster than plants could adapt. They were no longer able to ensure the forests’ sustainability, and a crucial source of carbon storage disappeared… Life rebounded after the Great Dying, of course. A study of fossils in south China found that marine species able to burrow into the sea floor were among the first to recover after the long silence of the End-Permian Extinction. A paper published last week in Science Advances adds to the evidence that animals able to escape underground were best equipped to ride out the chaos.
“‘By studying the Great Dying, we find that it affected everything, as you might imagine,’ said David Bottjer, a paleoecologist at USC who worked on the study of the sea floor. ‘Of course, we do get to see how it recovers. But this recovery is over a long time, like a million years or more.’… The human-caused warming Earth faces in the foreseeable future isn’t yet as extreme as the temperature swings of the Permian period. But these anthropogenic [man-caused]-fueled changes happen faster than those brought about by nature alone.” Who cares? It happened so long ago, and it was clearly something beyond anyone’s control, not to mention that there were no humans back then.
Ah, but here is where it gets interesting… in the era of human existence. Floating molecules of carbon-base gasses stabilized at approximately 280 parts per million until the late 1700s, when after thousands of years, according to Earth.org, those carbon-based gasses (mostly CO2) quickly rose until they hit the present day 420 PPM. What those little PPMs do is reflect heat back down to the planet’s surface. Scientists are researching what happens with global temperature rise, particularly when it begins accelerating and hitting a point-of-no-return tipping point, after which the most dedicated efforts at stemming manmade contributions to greenhouse gases will no longer work. While experts are looking at the past, they are very concerned about the present.
Today, we already have vicious cycles of climatic events, triggered by excess greenhouse gases, increasingly clicking into a feedback loop that threatens to continue without end. Soon. Here’s a simple example. As permafrost (tundra) melts, it releases masses amount of methane (23 times denser, hence heat-capturing, than CO2), which rises into the atmosphere and in turn causes more permafrost to melt, etc. Vicious cycle. Knowing that darker matter absorbs and retains heat – as opposed to lighter colors that reflect heat away – when white ice melts (e.g., polar ice, glaciers, etc.), it reveals the darker substructure below. Earth and ocean water. That in turn causes more heat to be retained, and another destructive heat cycle begins. As you can surmise, when these cycles feed massively on themselves, that nasty tipping point becomes unstoppable. We are perilously close. Back to understanding the past.
So, let’s move forward from that End-Permian Extinction into the time when life was restored. “The Quaternary Period is the third and last of the three periods of the Cenozoic Era. You and I are living in this period, which began only 2.58 million years ago. This is less than 0.1% of all of geologic time!” Quaternary Period—2.58 MYA to Today, US National Park Service report. But the parts that are most interesting occurred about 10,000 to 15,000 years ago.
“Many of the large mammals and some of the large birds of North America, South America, and Australia became extinct at the end of the Pleistocene Epoch. This was a rather modest extinction compared to the other ‘mass extinctions’ discussed [the End-Permian Extinction above]. Nevertheless, this extinction was distinctive in that most of its victims were large, land-dwelling mammals weighing more than 90 pounds (40 kg). In North America 33 of 45 large genera (73%) died out. In South America 46 of 58 genera (80%) went extinct. In Australia 15 of its 16 large genera (94%) were lost. By contrast, Europe lost 7 of 23 large genera (30%), and only 2 of 44 (4%) died in Africa south of the Sahara. Clearly, extinctions were much more severe in the Americas and Australia.
“The cause of the extinction; the reason it was restricted mostly to large, land-dwelling mammals; and why it took place primarily in the Americas and Australia have been the subjects of heated scientific debate. According to one hypothesis, these animals died out because they could not adapt to rapid climatic changes at the end of the Pleistocene. A competing hypothesis, known as ‘prehistoric overkill,’ holds that human hunters killed off these large animals. Further study may show that the extinction resulted from a combination of many different factors. Populations that were already under stress from climatic changes were perhaps more vulnerable to hunting when humans began to occupy new areas…” Park Service.
What is particularly stunning about the contemporary aspect of climate change, and mankind’s profound reliance on fossil fuel-powered machines and transportation, is the stunning speed with which these changes are occurring, evidenced by the rising, post-industrial era PPM numbers above. “‘We’re warming up the world on the scale of hundreds of years, and there’s a good chance that when you increase temperatures and change the environment at such a rapid pace, that’s when ecosystems break down,’ [Chris Mays , a paleontologist at University College Cork] said. ‘The pace of change is actually really important. And that’s where we actually see quite a concerning pattern today.’” LA Times.
The operative word in the above is “today.” We keep speaking about what the turn of the century will look like if we don’t sufficiently address climate change soon. We speak about aridification and desertification by using the word “drought.” Drought is part of a cycle. Cycles end. Aridification and desertification are long-term/permanent. We do not need to pretend that the horribles simply a problem that only future generations will endure. Every story of wildfires, agricultural disaster from farmland that is no longer productive (land that is turning to dust), the most intense tropic storms in recorded history, increasing numbers of powerful tornados, storm surges invading and destroying coastal areas, massive flooding, the spread of insect-borne diseases from bugs having to move, water wars, people fleeing their desiccated farms causing unsustainable migration and spreading death… it’s all climate change related. It’s happening now.
I’m Peter Dekom, and nature simply does not care if every animal and plant on earth dies; she’s been here before!
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