Question: Likely effect of the West Antarctic Ice Sheet collapsing?

[TechBear_Seattle]

Again, with the future history stuff. :hi:

Scenario: In 2017, the Ronne and Ross Ice Shelves begin to break apart. As they destablize, the West Antarctic Ice Sheet speeds up as it flows to the ocean. Increase in ocean level almost doubles, from the current rate of about 5mm to 9mm a year.

In 2031, a smallish earthquake in Antarctica (they are rare but do happen: see here) causes a massive slide of the WAIS, causing a vast block of ice the size of Manhattan to crash into the Weddell Sea. This results in an immediately noticeable jump in sea levels (by what, 25cm? 50cm?), not to mention masstive tsunamis that wipe out the southeastern coast of South America and the southwest coast of Africa, with dimished tsunamis continuing through the Atlantic and hitting the eastern US, the Carribbean and western Europe. Sound plausable?

Basically, I am looking for a major disaster between 2030 and 2040 that is directly attributable to global climate change and which will lead to the creation of the first serious planetwide effort to mitigate warming.

[damntexdem]

1. Swine flu?

Or 747s over New York?

[TechBear_Seattle]

2. I have a small meteor impact planned for early in the 22nd century

That is going to provide the impetus for a global effort to find and colonize other planets and to get various "arks" offworld. :hi:

[Systematic Chaos]

3. I'm surprised it hasn't happened already.

I've never claimed to be a psychic or a prophet by ANY stretch, but I had a nightmare involving that same kind of scenario about 2 years ago. Basically the way it played out was that I was with my wife in the break room of the job we both worked at back then, and suddenly the television set went to a massive breaking news story of approaching tsunamis and an instant one-foot sea level rise due to a huge chunk of ice (few hundred square miles) sliding off of Greenland. The nightmare ended long before I could see reports of countless millions dying in huge floods, but it was so damn vivid I've never forgotten it and never will.

It's coming soon. I don't know how soon, but soon. And don't worry because at that stage it will be way beyond too late. :(

[phantom power]

4. It would have to be larger than Manhattan to raise sea levels appreciably.

[TechBear_Seattle]

9. Would Rhode Island do it?

I think it was last year than an oceanic ice shelf split off one of the biggest bergs ever recorded; news stories about it described it as the size of Rhode Island.

[Warpy]

5. Ice sheets over water don't raise ocean levels much

It's that Greenland ice sheet we need to be concerned about.

[TechBear_Seattle]

8. The WAIS is continental, not oceanic

And it is currently considered the least stable continental ice sheet, which is why I selected it.

[Warpy]

10. Recent geologic discoveries

have suggested that ocean levels have risen 75 feet above present levels in the past and have done so fairly suddenly.

What they haven't nailed down is the mechanism.

[phantom power]

6. What you need to do is look up the area of the world's oceans.

Then, to compute the volume of your ice block, multiply your desired sea level increase by that area.

it will be large.

[defendandprotect]

7. I'm going with four more years -- 2012 . . . We had 90 degrees in NJ yesterday . . .

And we're in the 80's again today and tomorrow -- its APRIL --!!

The pollution of the planet -- our soil, water, air -- exploitation of animal life --
endless wars -- all point to a suicidal patriarchy.

It's going to be wetter -- both from melting glaciers and from increased hurricane
activity. There will be more cyclones, more tornadoes -- and more earthquakes.

We're headed to 7 billion? US is experiencing another baby boom?

Anyone know where they keep the cyanide tablets?

[HereSince1628]

11. It may block navigation.

As it is mostly free already I'm not sure its absence will allow accelerated glacial movement to take its place.

[caraher]

12. Here's some info

IPCC has a summary of the numbers you need.

If you want to figure sudden rises due to fast melting or rapid discharges of water, the same page estimates the oceans have an area of 3.62 x 10^8 km^2. Take the volume of water you want to add in km^3, divide by the area of the oceans, and convert the result (which will be in km) to your favorite unit.

I suppose you're working from something like this bit about the West Antarctic Ice Sheet: "an ongoing debate focuses on a possible collapse of the grounded interior reservoir, which would result in an eustatic sea-level rise of 5-6 m. Fast moving ice streams drain the interior ice sheet reservoir playing a critical role in a possible instability of the ice sheet. However, the factors controlling the initiation of ice stream onset are a matter of debate."

[TechBear_Seattle]

13. Excellent, thank you!

[TechBear_Seattle]

14. To expand on this a bit

2028: An earthquake causes the unstable WAIS to slip, causing a section of the sheet about 200km long and averaging 200m wide and 140m thick to slip off of the land into the ocean over about 30 minutes time, at around 120 degrees west longitude. The resulting tsunamis hit the North American Pacific Coast hardest, wipe a number of Pacific nations off the globe, and causes massive devastation around the globe. The waves crack the Arctic Ice Cap, exposing the darker water underneath which hastens its melt; the first completely ice-free summer is recorded the following summer.

The reason I want a massive global-warming related disaster is because this prompts 78 nations (including a few that no longer exist, thanks to the disaster) to leave the UN and form the Council of Governments. Over the next four years, more nations do the same; when France and Germany (holders of permanent seats on the Security Council) follow suit, the UN is effectively disbanded. Soon thereafter, the CoG assumes jurisdiction over the treaties of the United Nations, latter on the World Court and, by about 2085, has become the planetary governing body for all intents and purposes.

Sound credible?

[muriel_volestrangler]

15. I think the tsunami is the most credible bit of your scenario

You may want to look for some of the stuff about the Canary Islands and the effects of a landslide into the sea - eg http://news.bbc.co.uk/1/hi/sci/tech/3963563.stm as a starting point.

I don't think 'cracking the Arctic ice cap' is particularly credible, or needed. It's the area of dark water that's important, and existence of a few more cracks won't actually increase that much. But current warming trends can possibly give you an ice-free Arctic summer by 2028 without anything else happening.

The most dubious part may be: how did this ice manage to hold together well enough before the quake to plunge all in one go into the ocean, rather than calving as ice at the edge of continents normally does?

[TechBear_Seattle]

16. In my future history, the WAIS begins to break up about 10 years earlier

I don't have my notes handy, but the time seems about right. Between 2015 and 2020, several of the ice shelves that currently stablize the WAIS start to break apart and the sheet's speed towards the ocean almost doubles. The earthquake is small (and not unprecedented; Antarctica does get them from time to time) but it is enough to break off a vast chunk where the ice was already starting to rot.

I can't imagine that a massive tsunami being funneled through the Bering Strait would not have an affect on the Arctic Ice Cap. By then, the ice cap would have a lot of structural flaws -- call them potential cracks -- which the disturbance would fracture. I would think that as the wave spreads out from the Bering, they would carry away chucks of ice, or at least prompt the broken pieces to drift away.

There is a series (on the Discovery Channel?) called "Mega Disasters," and one of the shows discussed tsunamis. The bit about tsunamis caused by large landslides into the ocean is where I got the idea, which I combined with an old idea of terrorists using rockets to spread black carbon dust over the Antarctic, to hasten its melting. And I wanted a reasonable explanation for how the United Nations, which is inherently undemocratic, was replaced by the democratic Council of Governments.

[muriel_volestrangler]

17. I don't think the tsunami would be funneled through the Bering Strait

I think that rather, it would expend its energy on the shores of the Pacific, causing its damage there rather than transmitting it sideways along them.

[ensho]

18. its going to happen sooner then you think

climate change will and is trumping everything. faster and faster.