[timschmidt]

I don't mean to lessen the impact of that statement. I think climate change is a serious problem. But also most of the geologic time that genus Homo has existed, Earth has been in an ice age. Much of which we'd consider a "snowball Earth". The last warm interglacial period, the Eemian, was 120,000 years ago.

[tejohnso]

That's an interesting bit of detail. As you intended, it does not lessen the impact of the statement: "conditions never witnessed by us or our prehistoric relatives". It confirms it, with some additional context.

To me, it seems to make it even more significant. Because as you point out, Homo evolved under ice age conditions over millions of years. Well, here we are about to be thrust into uncharted territory, in an extremely short period of time. With very fragile global interdependencies, an overpopulated planet, and billions of people exposed to the consequences.

[timschmidt]

Right? I would only caution that neither has the ice age been particularly kind to humanity. It seems at least a couple times to have almost gotten us all. There's a genetic bottleneck in genus Homo which seems to date back ~80k years, which aligns suspiciously with the Toba supervolcano eruption. And another around 850k years ago. During each there were likely fewer than 2,000 breeding humans.

Earth has certainly thrived with a warmer climate. No reason we can't too. The problems - for us and other life - stem from the rate of change. Which is easy to see is very very rapid compared to the historical cycles, but still a slow motion trainwreck compared to an asteroid strike, supervolcano, or gamma ray pulse, all of which it seems Earth has experienced. Life and human society will adapt if it has enough time. The quicker the catastrophe the more challenging that is.

I guess what I'm saying is that we're not doing ourselves any favors, but we also shouldn't underestimate mother nature's ability to throw us a curve ball in the 9th inning that makes everything worse. Life has endured an awful lot on this little rock.

[philipwhiuk]

What you just wrote is the same as: 'the entire lifecycle of humanity has no precursor to the conditions' we are about to face.

We aren't facing the ice age that has been the last 120,000 years.

I'm sure the rocky planet will survive just fine, maybe even some extreemophiles, even if we completely screw up the atmosphere. Not 6 billion humans though.

[nkrisc]

The genus Homo dates back nearly 2 million years.

[timschmidt]

Yes. And virtually all of that time has been colder than average: https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...

Sometimes a great deal so. Sometimes less. But nearly always below average. For our whole existence.

That's why the choice of wording struck me.

You can zoom out a bit more and it just gets clearer: https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...

Further out and we're still one of the coldest periods: https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...

We're ice-age dwellers. Always have been.

I can both be alarmed at how quickly the ice age humanity has evolved within is ending, and find that a very funny way of phrasing it. These things don't conflict in me, though it seems triggering to some. People are downvoting me with moral conscience, but I'm just over here laughing at a funny conjunction of paleoclimate and word choice. :) People getting offended by it kinda makes it funnier.

[john_strinlai]

this is the same style comment as "no offense, but <offensive thing>"

if you didnt intend to lessen the impact of that statement, why say something that is specifically meant to lessen the impact of the statement? just say what you want to say without the hedging.