It is extremely unusual for the planet to be cold enough to have permanent ice sheets covering both poles simultaneously. So we ARE in an ice age: in fact, a profoundly frigid one.
The Quatenary ("fourth order") Glaciation has so far lasted about 2.5 million years. We don't really know how long it might continue, assuming global level non-interference by humankind. We're pretty sure that of the four known previous great glaciations (yes, now there are four) , the shortest lasted 30 million years, and the longest 350 million. So the Quaternary Glaciation is probably just getting (ha ha) warmed up.
We've finally been shaken out of complacency about the planet's irregular dips into surprisingly long and frigid climate cycles only by the recent realization that humankind has actually had the great advantage of being able to fit the vast majority of its petty hominid business - inventing fire-hardened spears and agriculture and trebuchets and calculus and spaceflight and so on - into a comparatively warm (+5ยบ C), comparatively short (10-15K years) interstitial period between super-frigid glacial maxima. We call this period the Holocene Epoch (basically means "whole, new, notable time" ... which is maybe a little self-referential on our part).
The thing is, virtually every single species of animal, plant, fungus and microbe that exists today has successfully adapted itself to survive in the frigid glacial climate within which all of us have been mutually been surrounded, infused and informed for the last 2+ million years. That is the environment in which life on Earth has ultimately been bred to survive - regardless of a few warmish millennia popping up here and there, like bright maraschinos in a bowl of fruit salad.
And now we're deliberately changing the climate - creating our very own Anthropocene Epoch - without any thought to what its planetary consequences might be, how long it might last, or how we might change it back if it proves to be a problem.
What's worse, we seem intent on proceeding without being able to even vaguely guess how few of the ~9 million species with which we share the planet, might actually be evolutionarily equipped to survive such an artificially-triggered, abrupt, and quite probably catastrophic shift in global climatic conditions.
And that is why, even as we discuss the dawning of the Anthropocene Epoch, we should simultaneously be discussing the Anthropocene Great Extinction.
mischiffmaker on June 1st, 2017 at 23:38 UTC »
Right up there with "If humans came from monkeys, how come there's still monkeys?!? Checkmate, atheist!"
theartfulcodger on June 2nd, 2017 at 01:53 UTC »
It is extremely unusual for the planet to be cold enough to have permanent ice sheets covering both poles simultaneously. So we ARE in an ice age: in fact, a profoundly frigid one.
The Quatenary ("fourth order") Glaciation has so far lasted about 2.5 million years. We don't really know how long it might continue, assuming global level non-interference by humankind. We're pretty sure that of the four known previous great glaciations (yes, now there are four) , the shortest lasted 30 million years, and the longest 350 million. So the Quaternary Glaciation is probably just getting (ha ha) warmed up.
We've finally been shaken out of complacency about the planet's irregular dips into surprisingly long and frigid climate cycles only by the recent realization that humankind has actually had the great advantage of being able to fit the vast majority of its petty hominid business - inventing fire-hardened spears and agriculture and trebuchets and calculus and spaceflight and so on - into a comparatively warm (+5ยบ C), comparatively short (10-15K years) interstitial period between super-frigid glacial maxima. We call this period the Holocene Epoch (basically means "whole, new, notable time" ... which is maybe a little self-referential on our part).
The thing is, virtually every single species of animal, plant, fungus and microbe that exists today has successfully adapted itself to survive in the frigid glacial climate within which all of us have been mutually been surrounded, infused and informed for the last 2+ million years. That is the environment in which life on Earth has ultimately been bred to survive - regardless of a few warmish millennia popping up here and there, like bright maraschinos in a bowl of fruit salad.
And now we're deliberately changing the climate - creating our very own Anthropocene Epoch - without any thought to what its planetary consequences might be, how long it might last, or how we might change it back if it proves to be a problem.
What's worse, we seem intent on proceeding without being able to even vaguely guess how few of the ~9 million species with which we share the planet, might actually be evolutionarily equipped to survive such an artificially-triggered, abrupt, and quite probably catastrophic shift in global climatic conditions.
And that is why, even as we discuss the dawning of the Anthropocene Epoch, we should simultaneously be discussing the Anthropocene Great Extinction.
advocatepurple on June 2nd, 2017 at 04:09 UTC »
"We have had the snowiest winter in twenty years, so the planet cannot be getting warmer"