Only the seriously stupid or wilfully resistant among us can deny that this planet Earth, our interstellar home, is changing. Even if one were to disregard or dispute the vast array of credible evidence of global warming and environmental degradation we are presented with on an almost daily basis, it would be hard to challenge the notion that, over time, since its very beginning, the planet has evolved from its original state.
Across billions of years—4500 million of them is the best estimate—this third rock from the sun has passed through numerous iterations: the largest of these are defined by science as the Hadean, Proterozoic, and Phanerozoic eons, each of which is further subdivided into eras, periods, epochs, and ages. During the first of these, the hot rock we now call home cooled to the point that water began to form on the surface, enabling the creation of the earliest life forms.
According to the fossil record so far unearthed, human life first appeared during the mid-Pleistocene Epoch, five to seven million years ago, following an environmental cataclysm that destroyed about 75% of all plant and animal species then existing. This demonstrates that for 99.5% of the planet’s existence, humankind did not exist, mainly because the conditions necessary for our survival and propagation were not present—evidence that, over four billion years, the planet evolved from its original state to a stage that supported human existence.
Why, then, should anyone today suppose that the earth has somehow ceased its evolutionary journey? It is ridiculous to think that it has somehow morphed into stasis, an unchanging organism destined to remain for always as we would like it to be.
Of course it is evolving! Of course the climate is changing! As it always has.
During the relatively short period of time human life has existed, the planet has experienced as many as six ice ages, the last of which was about twelve thousand years ago, and four periods of temperature variation warmer than today’s, the last of which was approximately 160,000 years ago. It is worth noting that the temperature variation of the planet today is creeping ever closer to that of the last warm period.
Had we been alive at the end that last ice age, we would have witnessed the retreat of continental-shelf glaciers from what is now Canada and the northern USA as the ice melted during a warming period—just as we see happening in the Antarctic and Arctic regions today. The waters are rising.
Really, the question is not whether the earth is changing, or whether we are truly plunged into a period of global warming. Only the seriously stupid could doubt that. The question is: has this change been exacerbated by the great spewing of carbon-based emissions we have caused? The question is: are we, as self-preoccupied residents of the planet, ensconced in our oft-warring, sovereign nations, able to sacrifice our creature comforts in order to slow down the rate of warming? The question is: are we even willing to do that?
And the critical question is: even if we do decide, globally, to take meaningful action now, not thirty years on, is it already too late?
The humans who walked the planet during the last warm period were not like us today. Humankind has changed mightily since then. It is likely that, if our species is to survive the earth’s latest evolutionary cycle, however long that may last, those remaining will be far different creatures than we are today—perhaps as unrecognizable to us (if we could still be here to see them) as our distant homo erectus progenitors would be (if we had been around to see them).
When I read of the potential devastation to the populations of the planet by the end of this twenty-first century—made worse by our wilful ignoring of humankind’s destructive aggravation of the evolutionary changes naturally occurring—it is of some comfort to me that I shall not be here to suffer through it.
But I wish we could do better.