So the people of the 2060s staggered on through the great depression that followed the First Pulse, and of course there was a crowd in that generation, a certain particular one percent of the population, that just by chance rode things out rather well, and considered that it was really an act of creative destruction, as was everything bad that didn’t touch them, and all people needed to do to deal with it was to buckle down in their traces and accept the idea of austerity, meaning more poverty for the poor, and accept a police state with lots of free speech and freaky lifestyles velvetgloving the iron fist, and hey presto! On we go with the show! Humans are so tough!
But pause ever so slightly—and those of you anxious to get back to the narrating of the antics of individual humans can skip to the next chapter, and know that any more expository rants, any more info dumps (on your carpet) from this New Yorker will be printed in red ink to warn you to skip them (not)—pause, broader-minded more intellectually flexible readers, to consider why the First Pulse happened in the first place. Carbon dioxide in the atmosphere traps heat in the atmosphere by way of the well-understood greenhouse effect; it closes a gap in the spectrum where reflected sunlight used to flash back out into space, and converts it to heat instead. It’s like rolling up the windows on your car all the way on a hot day, as opposed to having them partly rolled down. Not really, but close enough to elucidate if you haven’t gotten it yet. So okay, that trapped heat in the atmosphere transfers very easily and naturally to the oceans, warming ocean water. Ocean water circulates and the warmed surface water gets pushed down eventually to lower levels. Not to the bottom, not even close, but lower. The heat itself expands the water of the ocean a bit, raising sea level some, but that’s not the important part. The important part is that those warmer ocean currents circulate all over, including around Antarctica, which sits down at the bottom of the world like a big cake of ice. A really big cake of ice. Melt all that ice and pour it in the ocean (though it pours itself) and sea level would go 270 feet higher than the old Holocene level.
Melting all the ice on Antarctica is a big job, however, and will not happen fast, even in the Anthropocene. But any Antarctic ice that slides into the ocean floats away, leaving room for more to slide. And in the twenty-first century, as during the three million years before that, a lot of Antarctic ice was piled up on basin slopes, meaning giant valleys, which angled down into the ocean. Ice slides downhill just like water, only slower; although if sliding (skimboarding?) on a layer of liquid water, not that much slower. So all that ice hanging over the edge of the ocean was perched there, and not sliding very fast, because there were buttresses of ice right at the waterline or just below it, that were basically stuck in place. This ice at the shoreline lay directly on the ground, stuck there by its own massive weight, thus forming in effect long dams ringing all of Antarctica, dams that somewhat held in place the big basins of ice uphill from them. But these ice buttresses at the ocean ends of these very huge ice basins were mainly held in place by their leading edges, which were grounded underwater slightly offshore—still held to the ground by their own massive weight, but caught underwater on rock shelves offshore that rose up like the low edge of a bowl, the result of earlier ice action in previous epochs. These outermost edges of the ice dams were called by scientists “the buttress of the buttress.” Don’t you love that phrase?
So yeah, the buttresses of the buttresses were there in place, but as the phrase might suggest to you, they were not huge in comparison to the masses of ice they were holding back, nor were they well emplaced; they were just lying there in the shallows of Antarctica, that continent-sized cake of ice, that cake ten thousand feet thick and fifteen hundred miles in diameter. Do the math on that, oh numerate ones among you, and for the rest, the 270-foot rise in ocean level is the answer already given earlier. And lastly, those rapidly warming circumpolar ocean currents already mentioned were circulating mainly about a kilometer or two down, meaning, you guessed it, right at the level where the buttresses of the buttresses were resting. And ice, though it sits on land, and even on land bottoming shallow water when heavy enough, floats on water when water gets under it. As is well known. Consult your cocktail for confirmation of this phenomenon.
So, the first buttress of a buttress to float away was at the mouth of the Cook Glacier, which held back the Wilkes/Victoria basin in eastern Antarctica. That basin contained enough ice all by itself to raise sea level twelve feet, and although not all of it slid out right away, over the next two decades it went faster than expected, until more than half of it was adrift and quickly melting in the briny deep.
Greenland, by the way, a not-inconsiderable player in all this, was also melting faster and faster. Its ice cap was an anomaly, a remnant of the huge north polar ice cap of the last great ice age, located way farther south than could be explained by anything but its fossil status, and in effect overdue for melting by about ten thousand years, but lying in a big bathtub of mountain ranges which kept it somewhat stable and refrigerating itself. So, but its ice was melting on the surface and falling down cracks in the ice to the bottoms of its glaciers, thereby lubricating their descent down big chutelike canyons that cut through the coastal mountain-range-as-leaky-bathtub, and as a result it too was melting, at about the same time the Wilkes/Victoria basin was slumping into the Southern Ocean. That Greenland melt is why when you looked at average temperature maps of the Earth in those years, and even for decades before then, and the whole world was a bright angry red, you still saw one cool blue spot, southeast of Greenland. What could have caused the ocean there to cool, one wondered through those decades, how mysterious, one said, and then got back to burning carbon.
So: the First Pulse was mostly the Wilkes/Victoria basin, also Greenland, also West Antarctica, another less massive but consequential contributor, as its basins lay almost entirely below sea level, such that they were quick to break their buttresses and then float up on the subtruding ocean water and sail away. All this ice, breaking up and slumping into the sea. Years of greatest rise, 2052–2061, and suddenly the ocean was ten feet higher. Oh no! How could it be?