Comment by hedora | Hacker News Reader

Comment by hedora | Hacker News Reader

This isn’t too surprising. We already know the global currents are collapsing. That‘ll likely lead to an ice age for Northern Europe within the next 100 years.

Anyway, the graph isn’t too surprising. The northern hemisphere isn’t mixing with the cooler southern hemisphere much as it should, causing the spike.

Next, the northern Atlantic will stop mixing, and then high latitude places like the UK, France and east of there will freeze.

It’s kind of surprising the article doesn’t mention any of this. It made the news rounds again a few weeks ago.

The ice age prediction isn’t new, either: PBS ran a good special on it explaining the issue in the mid 1990’s. They predicted 10-50 years for the to ice age to start once the current started collapsing. We’re on track for a 2050-2090 start of ice age by their estimates, and events are tracking what I remember of their predictions.

Scientists are saying that, if it happens, it’ll be in 2100-2120 now, but I think they are overly-optimistic.

I wish I could find a copy of that program.

Complete thermohaline collapse takes a thousand years, not a hundred years. There will be a slight thermohaline weakening, but no collapse any time soon. Unfortunately journalists have gotten the concepts of complete collapse and weakening totally mixed up, to come to various conclusions that the peer-reviewed literature does not. The other various effects of climate change are much more significant and notable -- and are best documented by the new IPCC synthesis reports rather than one specific documentary film.

The fossil record (as of the 1990’s) has 100 year granularity, and it shows CO2 increases start in step N, then European ice age is underway in step N+1.

Statistics tells us that the expected time between the start of the event and the second sample is 100/2 = 50 years.

Current climate simulations are showing a reasonable chance of this happening over a 150 year span, but then the observed climate changes keep trending to worst case (and closer to fossil record).

Are you thinking of the special with James Burke, “After the Warming”

https://www.youtube.com/watch?v=451xJqNGFqU

Wow you sound very confident in your speculation. Surely predicting the outcome of lotteries is a more lucrative use of your skills?

I thought that the sea caps were all going to melt, the polar bears would have no homes and the sea level was going to rise by like 50 feet.

I was also told that no one had ever predicted a global ice age, that was all conspiracy theory nonsense based on misinformation.

I'm not trying to even be snarky now I'm just wondering where the heck the prediction of an ice age is coming from?

Climate change is driven by increasing atmospheric opacity to infrared. The greenhouse effect: sunlight in, heating of the surface, infrared can't return to space.

This doesn't just warm the world evenly, it disrupts the circulation of winds and currents globally. As a result, some areas now warm will get cold, and vice versa. Some wet areas will dry up, some dry areas will get wetter.

That's the short term, climatologically speaking. Longer term effects are as you say.

There is a reason it is called “climate change”, not “global warming”. We are poking a big system we don’t understand, and are sure something bad will happen, just not exactly what.

In this scenario (which seems to be playing out), the ice caps rapidly melt, dumping cold water into global ocean currents, causing them to stall out for a thousand years or so.

Those currents cool the equator and warm the temperate zones. Without them, the habitable (without indoor heating/cooling) fraction of the planet drops by some large percentage.

_For Northern Europe_.

On average Europe has a much milder climate than Canada, despite being at the same latitudes. That may come to an end.

But that's a local effect, and doesn't change the global long term average story.

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