Iceless Age

My apocalyptic post on the acidification of the seas, complete with junior home science experiement, turns out to be old news. Earth has been there, done that. Fifty-six million years ago, to be somewhat exact about it. This month’s National Geographic details the PETM: the Paleocene-Eocene Thermal Maximum, in which a huge influx of carbon into the atmosphere raised world temperature radically and killed off life in the seas.

A world without ice. Woaw! Sound familiar?

Scientists don’t know where all the PETM carbon came from. Perhaps it was more than one source, but methane hydrate is a prime suspect. This form of methane is usually, as it is now, contained by cold and high pressure conditions. When it gets hotter, however, the methane breaks loose. And since methane has a much more powerful greenhouse effect than carbon dioxide, it actually speeds up the warming. Then, oxidizing, methane turns into carbon dioxide after a couple of decades, keeping the heat on.

Currently, methane is locked in the tundra and on the deep sea floor. But the tundra is already softening.

Eventually, all that PETM carbon was reabsorbed. But not before some radical changes. Check out the photo of the replica core sample. The dividing line is stark: white below from the calcium creatures kiled off by acidification. The PETM was a tremendous crash of extinction, but also ushered in an evolutionary explosion. Mammals rose from the greenhouse incubator. We might be said to be children of that disaster. How apropos! For the new greenhouse, created by our burning of history, may well smoother the mammals this time around.

Over the geological time scale, the earth abides. Your blogging species, however, well… not so much.