Could Collapsing Antarctic Glaciers Raise Sea Levels Sooner Than Expected? (salon.com)

"We may be headed for an ice apocalypse which could result in the flooding of coastal cities before the end of this century," writes long-time Slashdot reader whoever57. Grist reports on two of the largest and fastest-melting glaciers in Antarctica which "hold human civilization hostage." There's no doubt this ice will melt as the world warms. The vital question is when... Together, they act as a plug holding back enough ice to pour 11 feet of sea-level rise into the world's oceans -- an amount that would submerge every coastal city on the planet... Each new iceberg that breaks away exposes taller and taller cliffs... In the past few years, scientists have identified marine ice-cliff instability as a feedback loop that could kickstart the disintegration of the entire West Antarctic ice sheet this century -- much more quickly than previously thought. Minute-by-minute, huge skyscraper-sized shards of ice cliffs would crumble into the sea, as tall as the Statue of Liberty and as deep underwater as the height of the Empire State Building. The result: a global catastrophe the likes of which we've never seen... When [land-based ice] falls into the ocean, it adds to the overall volume of liquid in the seas. Thus, sea-level rise.... All this could play out in a mere 20 to 50 years -- much too quickly for humanity to adapt...

A lot of this newfound concern is driven by the research of two climatologists: Rob DeConto at the University of Massachusetts-Amherst and David Pollard at Penn State University. A study they published last year was the first to incorporate the latest understanding of marine ice-cliff instability into a continent-scale model of Antarctica... Instead of a three-foot increase in ocean levels by the end of the century, six feet was more likely, according to DeConto and Pollard's findings. But if carbon emissions continue to track on something resembling a worst-case scenario, the full 11 feet of ice locked in West Antarctica might be freed up, their study showed.
If sea levels rise by six feet, "around 12 million people in the United States would be displaced, and the world's most vulnerable megacities, like Shanghai, Mumbai, and Ho Chi Minh City, could be wiped off the map."

Comments

How Were All of the Last Predictions?

[DatbeDank]

The parable of the boy that cried wolf seems very apt for this story.

Re: How Were All of the Last Predictions?

[ClickOnThis]

Carbon emissions won't continue at their current clip indefinitely, since the green revolution will displace our industrial-revolution based fuel sources.

That won't be enough. Reducing carbon emissions is important, but we also have to reduce the CO2 that is already in the atmosphere.

Also, any amount of terrain we lose will be dwarfed by the terrain gained from Antarctica, no longer covered in 3 miles of ice.

So, rising sea levels will cause devastation to major coastal cities all over the world, but we don't need to worry because we can move to Antarctica??

Then, theres the need to take water off earth. Are we going to colonize the moon, Mars? Thats going to take terraforming on a planetary scale, and 11 meters of ocean-depth seems like a good start.

Okay, I didn't think you could top your Antarctica scheme for silliness. Boy, was I wrong. Do you have any idea how much energy it would take to move eleven metres of our ocean from Earth to Mars? The Earth's ocean surface is about 360 million square kilometres. Multiply that by 11 metres, and you have about 4 trillion cubic metres of water, or 4 trillion metric tonnes = 4 quadrillion kilograms. It takes about 64 megajoules to get 1 kg of mass up to the Earth's escape velocity. So, you'd need 256 sextillion joules of energy, just to get that much water off the planet. That's more than twice the amount of energy the USA consumes in a year. And that doesn't consider the efficiencies involved in the technology you use to move the water, or the effects on climate that would result from doing it. Possible? Perhaps. Practical? No way. Better to find a way to stay where we are, or find water that is on Mars already.

Re:How Were All of the Last Predictions?

[KeensMustard]

The parable of the boy that cried wolf seems very apt for this story.

Yes indeed.

Firstly, the boy cried "It's not warming" - it was.

Then the boy cried "It's the sun!" - it wasn't.

Then the boy cried "It's volcanoes!" - it wasn't.

Then the boy cried "It's a conspiracy!" it wasn't.

By this point, few villagers, if any, were listening to what the boy had to say at all.

The the boy cried "It's stopped warming!" and a lot of people wondered if the boy understood anything at all.

So yes, we are pretty skeptical of what that particular boy (or group of boys) has to say.

Re: How Were All of the Last Predictions?

[Anonymous Coward]

The Jurassic period. O2 in atmosphere was 130% modern levels. CO2 was at 1950ppm, 5-7 times modern levels. The temperature was a whole 3 DEGREES C over modern times! Oh no! The Jurassic DGW, Dinosaurogenic Global Warming, shows that those Dinosaurs - with their Airplanes, SUVs, Coal Fire Plants and Cars and stuff, you know, those Dinosaurs and their DGW destroyed THE WHOLE PLANET!! With their DGW! Look, who wants 26% atmospheric oxygen? More air to breathe? Who wants that? And who wants more CO2 @1950 ppm, you know, to make all those plants and trees convert that CO2 into a higher O2! Who wants that! And we DON'T want the massive biodiversity of the Jurassic, no, we don't want more plants and animals and trees, no.

Any time period the warmunists want to "prove" there is AGW the warmunists just cherry pick ranges. And now I give the warmunists what the need on a silver platter - now they have the perfect example - the Dinosaurs and their horrible DGW (Dinosauric Global Warming) that destroyed the Jurassic... Wait, no, it didn't, it was the best time for life on earth with 1950 ppm atmospheric CO2!

Debt is Wealth. Ignorance is Strength. Freedom is Slavery. War is Peace. Cold is Warm.

Re:How Were All of the Last Predictions?

[Anonymous Coward]

And the point of the story was. THERE WAS A WOLF!

Re: How Were All of the Last Predictions?

[cyberchondriac]

Notice it's always the ACs that come busting out of the gate, name-calling and throwing around ad-hominem attacks like children.
Even for climate change supporters, this article is sensationalist. It just hurts their credibility, really.
Arnold Schwarzenegger has a good approach to the whole issue of fossil fuels vs renewable: even if you don't really believe in anthropomorphic climate change, what happened to the once great concern over air pollution? That's a term I haven't heard much since the '70s, but it used to be a big thing, and rightfully so. Not to mention the fact that fossil fuel is a limited resource that will one day run out. The more calm, rational appeal is more likely to find approval and not fall on deaf ears.

Re: How Were All of the Last Predictions?

[Anonymous Coward]

That's because climate change isn't a race car where you slam on the breaks and you stop, it's more like a cargo ship, where you throw the engines in reverse, toss down an anchor... and you break the anchor and keep moving a few miles anyway.

Or how saving for retirement you don't do everything right away, but if you think about it a little bit, from time to time, then you'll be alright, but if you totally ignore it until it's time to quit your job, you'll be screwed.

Re: How Were All of the Last Predictions?

[david_thornley]

There's one thing in common with almost all the predictions you list: they haven't failed. What we have already done will have effects that last and build up for a long, long time. It may well be that it's too late to avert disaster, even if the disaster is still decades or even centuries away, and that therefore those predictions (not usually by scientists, I note) are correct.

Ask the Dutch how worried we should be

[Anonymous Coward]

The article attempts to spread FUD around "megacities" vanishing, but in reality why do you not think any sea level rise would be engineered around just as the Dutch have done for over a hundred years?

One issue I have though is that it seems like the current estimate of three feet rise over the next 100 years has already taken into account additional ice melt. I am pretty suspicious there is some double-booking going on here, which would be the norm for the climate "science" community.

Another form of double accounting is pretending like we are anywhere near on track for the models that actually predict full ice melt; they are models based on the assumption we'd see runaway exponential warming which is not happening. That's how you know it's truly FUD, when they try to make a case not even viable at this point seem likely.

Re:Ask the Dutch how worried we should be

[mvdwege]

why do you not think any sea level rise would be engineered around just as the Dutch have done for over a hundred years?

1. Make that multiple centuries, for starters.
2. What do you think the cost is for engineering works on that scale? The completion cost of the Delta Works in 1997 was $7 billion.
3. Given the 2 above, how reasonable is it to expect these kinds of works to be ready in time?

Re:Put ice in a glass.

[XXongo]

Fill the glass to the top with water so the ice sticks out the top. Watch what happens when the ice melts. Science. Thanks for playing, morons.

You do know that Antarctica is a continent, and the miles-thick ice sheet under discussion is on land, not floating, right?

Fill a glass to the top with water. Then, melt ice somewhere else, and pour the melted water into the glass. The glass will overflow.

Adapt not Evolve

[Roger W Moore]

All this could play out in a mere 20 to 50 years -- much too quickly for humanity to adapt.

Humanity can adapt to changes on a far more rapid timescale than this. We don't have to hang around until we evolve gills we just move to higher ground and rebuild. This will involve social and economic upheaval and a reduction in the standard of living on a short timescale but that does not mean we cannot adapt to the change.

Re: At the end of the century, who cares

[Nexion]

Agreed, if only they could stop having children in this already over-populated world... THAT would be progress!

Re:I call bullshit on the claims

[gtall]

Miami already has a water problem. They have been battling it for some time now. All it will take is a direct hit from Hurricane Donald at a high tide and we'll be treated to legions of Conservatives saying how the climate has been changing for millenia and that nothing could have been done to save Miami...while they will claim a share of federal disaster aid for their time shares and condos.

Re: At the end of the century, who cares

[Opportunist]

Conservatives make no sense. Contraception is bad, abortion is bad, but at the same time anything and everything to actually help the people they force to exist is bad too.

A conservative is a person that will fight tooth and nail for you to be born, but as soon as you're pumped out you're on your own.