
Pliocene and Eocene provide best analogs for near-future climates - howard941
https://www.pnas.org/content/115/52/13288
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maxander
> Both the emergence of geologically novel climates and the rapid reversion to
> Eocene-like climates may be outside the range of evolutionary adaptive
> capacity.

A lovely little sentence, elegantly understated and used as a seemingly off-
handed conclusion to the abstract, which essentially means "the world may be
about to end."

Also, NASA is hosting the full article:
[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/201800...](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180008801.pdf)

~~~
grondilu
What is the range of evolutionary adaptive capacity, though? Life has survived
everything that has been thrown at it in several billion years. We just don't
know what it would take to wipe it all. So I don't think the authors were
talking about the complete end of life. They were just saying that we're going
towards a phase of mass extinction, and that is not much controversial.

~~~
dpau
> we are effectively rewinding the climate clock by approximately 50 My,
> reversing a multimillion year cooling trend in less than two centuries.

It’s the unprecedented suddenness of this climate change that makes it
doubtful organisms will be able to adapt. Maybe we shouldn’t be concerned with
whether or not some form of life will still exist, but whether or not _we_
will.

~~~
politician
It's time to start building domes.

~~~
Reelin
Not domes so much as greenhouses. The climate change doesn't kill _you_ , it
kills the crops you depend on to live and then you starve.

~~~
politician
Agreed; I think Sundrop Farms provides a path forward here.

[http://www.sundropfarms.com/](http://www.sundropfarms.com/)

~~~
Reelin
Some other greenhouse examples that are decently large scale, although they
don't necessarily use seawater or generate their own electricity.

[https://bchothouse.com](https://bchothouse.com)

[http://inspiredgreens.ca](http://inspiredgreens.ca)

In case it's of interest to anyone, the more general (and extreme) concept
would be vertical farming.

[https://en.wikipedia.org/wiki/Vertical_farming](https://en.wikipedia.org/wiki/Vertical_farming)

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vivekd
Pliocene like climates by 2040 is easy for me to swallow, after all the
climates then seem similar to modern climates just warmer. Eocene like
climates by 2050 is a bit harder to swallow. It's hard to imagine there being
a tropical environment in the Arctic that can support alligators and Tortoises
in about 30 years time.

Going from Pliocene to Eocene climates in as little as 10 years time makes me
think the model either assumed a huge increase in greenhouse gas production
with India and China becoming superpowers or assumed a runaway greenhouse
effect.

~~~
Abishek_Muthian
> The Mid-Pliocene becomes the best climate analog slightly sooner, by 2030
> CE, but the prevalence of Eocene-like climates accelerates after 2050CE, and
> future climates most commonly resemble the Eocene by 2140 CE

Changes towards Eocene accelerates by 2050 according to the models & doesn't
reflect Eocene until 2140 CE. Still the rate of change is incomprehensible
IMO.

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baking
For anyone interested in finding out more about the last 50-60 million years
of climate history I would strongly recommend this talk:
[https://www.youtube.com/watch?v=Yze1YAz_LYM](https://www.youtube.com/watch?v=Yze1YAz_LYM)

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carboy
I think we passed the tipping point for the climate 25 years ago, we just
didn’t know it, or even today full grasp it.

I was saying 10 years ago they by 2024-2028 we would see runaway climate
changes.

I have friends and relatives that are climate related research scientists. 10,
5, and 3 years ago they thought I was crazy, last year they have all expressed
concerns that I might have underestimated the speed of change. They are very
scared.

I hope I’m wrong, but I don’t think I am.

~~~
KnightOfWords
Depends what you mean by 'runaway climate change'. It takes some time for
climate to stabilize, even if we stopped all carbon emission now it would take
a few decades for the planet to reach equilibrium. We've certainly reached the
point where significant impacts are going to be felt but not necessarily to
the point where, say, the Earth loses all polar ice and remains hot for tens
of thousands of years.

> I was saying 10 years ago they by 2024-2028 we would see runaway climate
> changes.

> 10, 5, and 3 years ago they thought I was crazy, last year they have all
> expressed concerns that I might have underestimated the speed of change.

It's important to recognise that neither you nor I have the expertise to truly
assess this. The climate models are the best we have but there are various
uncertainties. I'm also concerned that they may turn out to be too
conservative but it will take many years to find out.

The most optimistic scenario is that the models break in our favour, serious
action is taken, technology bails us out somewhat and investment in low-carbon
energy and sustainable farming provides employment. The worst case scenario is
that crop yields and fisheries collapse well before the end of the century.

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i_feel_great
Which of our major food-crops can handle Pliocene and Eocene climates?

~~~
throwaway5752
None. Obviously this is suggesting mass human die-off or total extinction.

~~~
i_feel_great
Famine -> law and order breakdown -> mass migrations -> wars and military
conflicts -> population reductions.

Hmmm. I have read this in human history before.

