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Comment by saalweachter | Hacker News Reader

So historically in the climate modeling world, +6-8 degrees was considered the "we're all screwed" tipping point; this has led to recent optimism where it now looks like we'll probably level out at +2-3.5 degrees, and only some of us are screwed.

The major tipping points that are estimated at 1.5 degrees are Greenland, the West Antarctic Ice Sheet, and coral reefs dying off.

The former two have an associated sea level rise of about 3.5-4.5 meters all together.

So I think this article isn't changing the "some of us are screwed" narrative substantially; it's more interesting because it pulls out all of the major forecast disasters and gives estimates of when (temperature wise) they'll happen.

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Also from this article, between 1.5 and 2 degrees:

> widespread abrupt permafrost thaw

Which is “fun” because that releases a boatload more carbon into the atmosphere.

(not sure the scale of controversial this is) and anthrax and various other as-yet-unknown bacteria.

And perhaps small pox and other viruses from dead and frozen bodies in permafrost?

And methane.

As the sibling comment mentions methane contains carbon, but yes it’s worth pointing out because the short-term GHG potency of methane is extremely high. There’s potential for some terrible feedback loops here.

https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis

If you have a Clathrate gun in one chapter, it must go off in the next.

Everybody gangsta till the Clathrate gun pops off.

Yes, methane contains carbon.

Methane is, over the span of 20 years, a 84--86 times more potent Greenhouse gas, though.

Are these side effects calculated in the models, or are the models too optimistic?

This article seems to indicate that the current models don’t account for some of it: https://climate.nasa.gov/news/2785/unexpected-future-boost-o...

> The impact on the climate may mean an influx of permafrost-derived methane into the atmosphere in the mid-21st century, which is not currently accounted for in climate projections.

(Note this is an unexpected type of abrupt thaw; the models probably do include the impact of more gradual permafrost thawing. Cold comfort though, and polar ice is melting at a faster rate than predicted overall.)

Historically climate change models have been too optimistic.

The other thing we have to consider is that if the model's range is between "everybody suffers" and "everybody dies" do you want to gamble with that?

Probably not. However, it seems that regardless of what they predict, nothing will happen.

Humanity is like a toddler, only learns when you feel the consequences, rather than learning by being told about it. Also like a stubborn toddler like first needing to experience an almost trauma to change behavior, and apparently we haven't had that trauma yet.

So are there any parts of the world that will benefit from global warming? Canadian and Russian wilderness?

Maybe, but it's not like great trade-off on a global scale.

Extreme latitudes are colder because they receive their sunlight at an angle. The tilt of the Earth and the seasons make things more complicated, but conceptually, if you are at latitude 45, you are also at a 45 degree angle relative to the sun, so sunlight is only 70% as intense as it is at the equator.

With increased global temperatures, northern latitudes may have longer growing seasons, but they'll still have a different, probably inferior climate to what you're losing further south.

So while there may be winners and losers on a global scale, the winners will probably win less than the losers lose.

Antarctica used to be a semi-tropical forest. Perhaps we'll all be living there!

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