Climate Change and Extinction — Taking the Long View
Hope for the Earth
”Cheer up, sad world,” he said, and winked-
”It’s kind of fun to be extinct.”Ogden Nash “Fossils”
The history of the earth is inscribed in death.
Climate change is real. Anthropogenic causes are primary factors. We are creating geologic-level extinctions. We ourselves may be the ultimate extinction. It may be (is probably?) already too late to change course, and even so, very few people seem willing to even consider a course correction. What to do?
Allow me a geologist’s view: Look at it from the billion-year perspective. We cannot destroy the earth, as is so often expounded. We can, however, eliminate the ability of our species, and many others, to survive on earth. But earth itself shall move on.
Long before we could assign numerical ages, the Geologic Time Scale was created. It was based on stratigraphy, the ordering of units and eras throughout the earth’s deep past. It is based on a simple observational principal: given no structural disruption, the Silurian is always above — younger than — the Ordovician, and below — older than — the Devonian.
How did we know where to put the rocks in order, in those places where we could not see the units above and below? What if the rock types varied greatly in different regions (they do)? And how did we know where to mark the boundaries?
In short, through death.
The K-T (Cretaceous-Tertiary) boundary at around 65 million years ago (Mya), that time of the asteroid, massive volcanism, and the end of the dinosaurs, is the most famous extinction event in the public eye. Less known is the Pm-Tr (Permian-Triassic) boundary at around 250 Mya, where close to 95% of marine and 70% of terrestrial species on earth went extinct.
Not to mention the numerous other “minor” to significant extinction events which have helped to define the geologic time scale and set evolution on a tangential course.
In spite of the extinctions, the Pm-Tr event conveniently opened the door for the rise of the dinosaurs, who would dominate for millions of years, until their time in the sun was abruptly cancelled — by the K-T event. In turn, this event allowed for the rise of mammals, including eventually us wee humans.
The difference in our current situation is the dominance of a single species — homo sapiens = us. In contrast, the dinosaurs comprised numerous species, as did the dominant life forms prior to the Pm-Tr event. We are the only ones who seem to have no species-level competition, and those that tried — hello Neanderthals and Denisovans! — long gone.
But given that distinction, we are not even the first species to become the architects of global environmental upheaval. Take the cyanobacteria. From the early days of earth’s history, the atmosphere was anoxic — depleted of oxygen. The only organisms around were archaea, which relied on chemicals for energy.
Then around 2.5 billion years ago, give or take a couple hundred million years, along came cyanobacteria. They utilized photosynthesis, so they prospered in that carbon dioxide-rich atmosphere.
However, the waste product from cyanobacteria was oxygen, whose levels increased over the course of millions of years. As the global oxygen footprint increased, life, other life — especially animals — expanded and diversified.
Downer for the cyanobacteria. Fantastic for evolution and species diversification. In short, the cyanobacteria created their own environmental changes that usurped their place as the alpha organism.
As a geologist, I can attest that yeah, disasters strike. But since the current global situation is a disaster of our own making, if it leads to the demise of homo sapiens, well, we had a dramatic, albeit short, run.
Earth will move on. Some species will survive. Humans are so adaptable, the odds are good that some portion of our global population will also carry on, just like the cyanobacteria are still around and remain an important part of the modern ecosystem. Even the dinosaurs are technically still around, in the wonderful panoply of species that are birds.
Whether or not we remain the alpha species on earth remains to be seen. And if we don’t make it, who knows what the next living advancement (or regression) will be?
“It is a very alluring thing, Mr. President, to do what the world has never done before. No republic has permanently survived. They have flashed, illumined, and advanced the world, and faded or crumbled”
Warren G. Harding
Such thoughts might lead one into nihilistic, possibly fatalistic musings. I for one am not in favor of the “just party on and send us to oblivion” political school of thought. But we need to be aware that the scope and scale of earth processes are so vast that our individual activity does little to steer the ship away from the (rapidly melting) iceberg. If we really want to affect change, we need to force the large corporations and government agencies to right the course. And that is one enormous task.(I have actually held positions in the environmental regulatory field trying to do just such a thing. A rather depressing occupation.)
At the same time, we should never be so arrogant as to proclaim our power and might to destroy — or save — the earth. We should be honest and transparent, and just admit that what we are trying to do is save ourselves. We can never get through to the masses by a moralistic scold about number of species or worldwide climate, but we can hit home with a simple message about the fate of the dinosaurs.
Looking outside of ourselves, there is cause for hope and optimism. The earth will keep on trucking no matter what we do. Remember that the demise of the dinosaurs is what opened the door for us. The future will be, no matter our own fate.
