
What happened last time it was as warm as it’s going to get later this century? - xoa
https://arstechnica.com/science/2018/06/are-past-climates-telling-us-were-missing-something/
======
macinjosh
Global warming is real and humans contribute to it. Just stating that so I am
not called a 'denier' as I have been before.

That being said, the computer models predicting what the consequences of
global warming will be, have greatly over estimated (at least the timeline of)
real world impacts. Since I was a kid I've heard in the news that in the next
5 years or 10 years there will be all these catastrophes linked to global
warming and I have yet to see them come true.

I remember the BBC reporting years ago that the children of today would only
know snow from what they've seen in snow globes, things like that. I think
part of the reason for inaction is due to the news media over simplifying the
problem and reporting (perhaps even exaggerating) the worst long term
predictions.

~~~
Jill_the_Pill
The numerous one-in-a-thousand-year floods don't get you? The super-typhoons
and unprecedented hurricanes? Drought and the human migration motivated by
drought and flood? Species extinction? Wildfires? Loss of islands?

I think it was the photos of disinterred coffins floating through the flooded
streets of New Orleans that first really hit me: it's here.

~~~
danielmg
I don't think you read all of his comment.

Picking a single event like New Orleans isn't great evidence. I lived through
a once in 300 years hurricane in southern England in '87 - that tells us
nothing.

But the increasing frequency of adverse events and once in a x years events is
starting to nod its head in the direction of the impacts of global warming
starting to manifest.

The point he made is a good one - media sensationalism, supported by people
who should know better; it does more harm than good.

The future looks bleak as we, in the west, can go 100% nuke, zero carbon etc
but it's like a fart in a jacuzzi compared to what China will bring as its
economy scales to western per-capita size.

~~~
kojon99
Tough sanctions are the solution to that.

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jseliger
I read an excellent book, _The Ends of the World_ , on just this subject:
[https://jakeseliger.com/2017/09/18/the-ends-of-the-world-
pet...](https://jakeseliger.com/2017/09/18/the-ends-of-the-world-peter-
brannen). But the book gets there through looking at the last five mass
extinction events. It turns out that either every one of them, or every one
except one, hinged on changes in atmospheric carbon levels, which we didn't
realize until relatively recently.

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antognini
This article is about the Mid-Miocene Climate Optimum, which was a period of 5
degrees C of warming about 15 million years ago. Another similar event is the
Paleocene-Eocene Thermal Maximum, which was a period of warming (6 degrees C
in 20,000 years) about 55 million years ago. The PETM was in response to a
massive increase in atmospheric CO2 (several times more than humans have
added), though what caused the injection of CO2 is currently unknown.
Interestingly, although during the PETM the Earth had no polar ice caps to
begin with there was still a rise in sea levels simply due to the thermal
expansion of the ocean. There was a great deep dive into the event on the
podcast In Our Time by three climatologists:
[https://www.bbc.co.uk/programmes/b08hpmmf](https://www.bbc.co.uk/programmes/b08hpmmf)

~~~
throwaway5752
You should note that the PETM CO2 increase was over multiple orders of
magnitude (appr. 20,000 year vs 100) and theoretical rate of emission was 1-2
orders of magnitude less than the current rate.

~~~
antognini
While that's probably true, it's not known for certain what the rate of
emission was. 20,000 years is only an upper bound. It's possible that the
process that led to the CO2 emissions happened over very short timescales
(e.g., a comet impact or volcanic activity). Until we know the process, we
can't constrain the rate.

~~~
throwaway5752
I upvoted you, thank you for replying, but please give me a bit of charity and
understand I was replying with the standard geological uncertainties assumed.
But my understanding is the best fit is volcanic activity by peat or coal beds
over a much longer relative timeframe than current emissions.

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FreeFull
The one big problem I don't see talked about as much for some reason is ocean
acidification. Given more of the surface of the planet is covered in ocean
than in land, and the influence the oceans have on everything, it's pretty
hard not to get worried about it. One consequence that is already happening
(partly due to ocean acidification, and partly due to water getting warmer) is
coral reef die-offs/bleaching.

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mkempe
A better and much more recent proxy observation for the effect of a warming
climate is the Eemian [1] aka the last interglacial. Peak temperature 125k
years ago was at least 2 C higher than today, and global sea-level was 8-9 m
higher (of which less than 0.5 m is attributable to thermal expansion of ocean
water). Scandinavia was an island.

[1]
[https://en.wikipedia.org/wiki/Eemian](https://en.wikipedia.org/wiki/Eemian)

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xoa
Does anyone know if there is any party or even organization anywhere right now
pushing proper utilization of the free market to at least internalize the
current cost of CO2 emissions (though that by itself could not solve the
historical lack). It seems like this would actually be one of the few places
where a free market should work extremely well: simply set the price of
emitting a ton of CO2 at the ratcheted price (defined by bid) of industrial
removal (time period of a day or less) a ton plus some assured margin (7%?
exact number could be figured out by experts). The government would serve as
the pivot, emitters would pay in units at the existing price, so a pool of
credits per ton would collect. Anyone who could meet a minimum volume level
(the whole point is massive industrial scale removal) would be able to bid for
those in whatever amounts they could handle per day/week/month. If they
figured out a new scalable way to remove a ton more cheaply, they'd be able to
underbid anyone on a more expensive method and collect the much wider margin
until they used up the pool at that price, while meanwhile the price for
emitters would automatically be adjusted down to the new cost plus minimum
margin. The government might have to get the ball rolling by funding an
initial plant, but after that it should be self sustaining, and would it make
energy prices directly embody the emission cost in a very clean way that would
allow the rest of the economy to locally optimize as necessary.

Obviously there would be many low level implementation details to work
through, but this seems obvious enough that I assume it's been proposed many
times. However I haven't been able to figure out the right search terms to
find any papers developing it further. I've seen plenty of carbon pricing
schemes proposed but all of them seem to use pretty arbitrary rates rather
then simply directly internalizing the goal of zero net emissions and letting
a market on each side sort out how best the meet that goal in any given place.
I'd love it if anyone knows where I could better search, after some recent
work I do have access to college resources again so academic journals would be
fine too. There are also of course plenty of awful schemes by various
political parties pushing various subsidies or "efficiency improvements" or
whatever in a command-control fashion, but that's not great either. Any HNers
who have ideas/sources would be awesome.

~~~
collyw
So far the free market has failed spectacularly at addressing global warming.

~~~
xoa
The free market has never been used to address global warming (it's badly used
in general in fact, possibly in part because few people seem to actually
understand what it is or even internalize that it's a tool at all, not an end,
and like any tool there are applications it is a poor fit for). Amongst the
foundational requirements for a free market to work at all is that the price
should embody all costs. There are some problems of course where this simply
isn't very practical, particularly ones that are heavily non-linear/non-
reversible. But that's not the case for carbon emissions, in fact it's a
pretty good fit. The problem is "release of fossil/long term stored carbon
into the atmosphere", it's easy to measure at various points at the fuel
level, and since it's a gas that will evenly diffuse worldwide and is uniform
removal _from_ the atmosphere can take place anywhere in the world by anyone
using any method. That makes it well suited to abstraction, with a market
system on each side of the equation and government acting as a pivot. Wouldn't
even require global buy-in to make a difference given that the energy market
is primarily globalized anyway, if a few major polities decided to require it
and also made access to their own markets take it into account it'd have a
major effect no matter what anyone else wanted.

~~~
collyw
We got carbon trading a while back. That doesn't seem to have made any
difference whatsoever.

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adrianN
Obligatory xkcd: [https://xkcd.com/1732/](https://xkcd.com/1732/)

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throwaway5752
I thought this was going to be about the Paleocene–Eocene Thermal Maximum
([https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Therm...](https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum))
or (and?) the clathrate gun hypothesis
([https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis](https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis)).
Sobering stuff, particularly heartbreaking for parents of young children.

edit: this is getting downvoted, so perhaps it's a miscommunication. I am most
worried about heat waves and disrupted weather patterns causing more common
crop failures and the geopolitical stress/conflict that will lead to. You can
see the beginnings of this in Syria, Yemen, and various N. African countries
where climate change induced drought was the underlying cause for the civic
unrest. Look at the migrant populations fleeing these areas. I don't mean
anything melodramatic, just that this will be a period of hardship and
suffering greater than what we've become accustomed to in recent history.

