No matter what happens in the next battles to cap carbon emissions in an attempt to stave off the most catastrophic effects of ongoing climate change, some effects of mankind's industrial rise will remain baked into our future climate. One of those now-unstoppable changes, according to a new National Oceanic and Atmospheric Administration report, is the collapse of our planet's northern ice cap.
The region is now definitively trending toward an ice-free state, the scientists said, with wide-ranging ramifications for ecosystems, national security, and the stability of the global climate system. [...]
In an interview with NPR, marine scientist Jeremy Mathis, director of NOAA’s Arctic Program, went a step further. When it comes to the Arctic, Mathis said “there is no normal” anymore: “The environment is changing so quickly in such a short amount of time that we can’t quite get a handle on what this new state is going to look like.”
One of the most troubling topics that occupied much of our class time, back in the ancient days when young tyke me was studying environmental science, was the notion of local equilibriums. Simplified: Imagine you are pushing a cart along a straight but hilly road. You start somewhere along the road, and spend a certain amount of effort pushing the cart along. When you let go, the cart will want to roll downhill, either forward or backward, until it rests in a valley.
But push a certain amount, and at some point the cart may crest a hill; when you let go, the cart will roll forward to the next valley. If you've changed your mind and now want to push it back to its original position, you can try to push it there using the exact same amount of force that you used in the first place—and it may not work. The hill may be steeper; the valley may be deeper. The new position is now the new normal, and it may require far more effort to move the cart back to where it was than it ever took to slide it to its new position in the first place.
This is, obviously, a gross simplification. You could make a better analogy using chemical processes, but the lesson is the same: if you apply a measured amount of energy to a system, subtracting that same amount of energy later will not necessarily return the system to its original state. Removing a match after a paper is already on fire won't return it to an undamaged state; melt a chocolate bar in the sun and, even after re-solidifying later, it will not look the same.
In the Arctic, the ramifications of "the ice is melting" are myriad, and the implications are far greater than the question of whether or not shipping companies and navies will be able to avail themselves of a new Northwest Passage. Ice is white. Ice, by virtue of its mere color, reflects heat; a specific quantity of the sun's heat is reflected back into space, during the nightless Arctic summers, by the immense Arctic cap. Blue ocean water, on the other hand, more readily captures that heat. Regardless of any future carbon diet we may undertake, an iceless or near-iceless Arctic summer will measurably warm the planet. It will measurably warm the Arctic water, and the Arctic landmasses.
Which leads us to the methane. The permafrost surrounding our great Arctic ice mass has trapped, throughout the millennia, vast stores of organic material. Frozen methane deposits in frigid northern water are immense enough that they, too, are being contemplated as mineable resources; carbon deposits on the frozen tundra are similarly gigantic. And when the ice melts, it is all released. At once. Each ton of carbon we have battled so hard to keep out of the air, and each ton that we have not, now must be measured side-by-side with a new, unstoppable, planetary flood of the stuff that we can do not a single thing about. It will come up from the ocean in large methane burps; it will come up from the tundra in silent, invisible whiffs that span entire continents.
Which leads us, in turn, to more climate change.
Which leads us, in turn, to questions about how the circulation of the oceans will be affected, including the great Atlantic belt that delivers warm water to the British Isles, making European climes considerably more hospitable than they have been during past ages.
And the jet stream, of course. The weather patterns that flow over California, Oregon, and Washington. The rainfall delivered to Kansas. The typhoon and hurricane seasons. The Greenland ice sheets. And so on.
That was always the most alarming proposition, during those 1980s mathematical exercises fiddling with the numbers we knew in order to fathom what might happen to the numbers we didn't. And it is the very principle that causes such teeth gnashing among self-declared skeptics who throw fits as the numbers the top experts arrive at change as new energy sinks and sources get measured, and then remeasured, and refactored into the estimates for what will happen next.
We have some very good guesses for what will happen next—but we also know that, once enough energy is added to the system, there's no pushing that cart back to the last valley. Reduce Arctic sea ice enough, or Antarctic glaciers enough, and the planet's climate will turn radically different no matter how much effort is expended to patch things up in that final hour.
We're now getting hints that, at least in the Arctic, that point of no return has passed. There is no engineering that can fix it; short of carbon sequestration on a scale and of a speed far beyond our current or near-future capabilities, it is done. But we still don't know quite what that means, or how bad it will be, and there is still the hint of possibility that while we cannot prevent the cart from reaching its new valley, we can still stop it from reaching the valley after that, if only we stop pushing.
Science fiction writers and futurists alike have long dreamed of our species being able to terraform entire planets to our liking. It has been considered a pipe dream. It is far too difficult, skeptics point out, requiring too many resources and timespans intolerable to any human society that attempted it. But it turns out that terraforming is, in fact, not that difficult. It can be accomplished in as little as a few hundred years—without even trying. We can, indeed, change the very atmosphere of a planet.
But what we don't yet know how to do—and this is a wee bit important, as it turns out—is terraform it back.