Greenland Ice Swells Ocean Rise

BBC ^ | 2-16-2006 | Paul Ricon

[blam]

Greenland ice swells ocean rise

By Paul Rincon
BBC News science reporter, St Louis

Kangerdlussuaq Glacier "drains" about 4% of the ice sheet

Greenland's glaciers are sliding towards the sea much faster than previously believed, scientists have told a conference in St Louis, US.

It was thought the entire Greenland ice sheet could melt in about 1,000 years, but the latest evidence suggests that could happen much sooner.

It implies that sea levels will rise a great deal faster as well.

Details of the study, by Nasa and University of Kansas researchers, are also reported in the journal Science.

The comprehensive analysis found that the amount of ice dumped into the Atlantic Ocean has doubled in the last five years.

If the Greenland ice sheet melted completely, it would raise global sea levels by about 7m.

Greenland's contribution to global sea level rise today is two to three times greater than it was in 1996.

Sleeping giant

"We are concerned because we know that sea levels have been able to rise much faster in the past - 10 times faster. This is a big gorilla. If sea level rise is multiplied by 10 or more, I'm not sure we can deal with that," co-author Eric Rignot, from the US space agency's (Nasa) Jet Propulsion Laboratory in California, told the BBC News website.

Previous estimates suggested it would take many hundreds of years for the Greenland ice sheet to melt completely. The new data will cut this timescale, but by how much is uncertain.

It takes a long time to build and melt an ice sheet, but glaciers can react quickly to temperature changes

Dr Eric Rignot, Nasa "It depends on how fast the glaciers can go and how sustainable the acceleration can be," said Dr Rignot.

He added: "It takes a long time to build and melt an ice sheet, but glaciers can react quickly to temperature changes."

In 1996, Greenland was losing about 100 cubic km per year in mass from its ice sheet. In 2005, this had increased to about 220 cubic km. By comparison, the city of Los Angeles uses about one cubic km of water per year.

Rising surface air-temperatures seem to be behind the increases in glacier speed in the southern half of Greenland since 1996; but the northward spread of warmer temperatures may be responsible for a rapid increase in glacier speed further north after 2000.

Satellite monitoring

Over the past 20 years, the air temperature in south-east Greenland has risen by 3C.

Warmer temperatures cause more surface melt water to reach the base of the ice sheet where it meets the rock. This is thought to serve as a lubricant, easing the glaciers' march to the sea.

Helheim Glacier loses the equivalent of about half a football field a day

The study's results come from satellites that monitor glacier movement from space.

Rignot and colleague Pannir Kanagaratnam, from the University of Kansas, built up a glacier speed map from the data for 2000 and then used measurements from 1996-2005 to determine how glacier velocity had changed in the last decade.

The researchers plan to continue their monitoring of the Greenland glaciers using satellite data.

The Greenland ice sheet covers 1.7 million sq km and is up to 3km thick.

The scientists described their results at the annual meeting of the American Association for the Advancement of Science.

[RobbyS]

An unanticipated cold snap could change things before this happens.

[blam]

"You are probably familiar with the viking farm that was buried when the ice advanced, that has in recent years been uncovered thanks in part to the withdrawal of the ice; it is an archaelogical dig site."

Yup. They've even built a replica of Eric's house and the little Christian church that his wife 'cut-him-off' until he built it.

Diamond said the excavations there reveal that they (the Vikings) didn't eat fish or learn from the Inuit how to catch the Ring Nosed seals. He said they probably would have survived if they had. In the last days, they were boiling the hooves of cows for food. The estimate is that there were only 5,000 ever there.

BTW, I read a while back about a DNA study done on the Inuit in the region...It's conclusion was that there was no assimilation of the Vikings into the Inuit line.

[carl in alaska]

Someday we might have to build some huge desalinization plants and create thousands of new man-made lakes and reservoirs in inland areas. If the lakes are deep enough, they could take a lot of water out of the oceans. I hear Las Vegas is running short of water.

[Doc Savage]

Do you have any idea how much water you would have to add to the worlds "contiguous Oceans to increase the level even a fraction of an inch????? What BS!

[satchmodog9]

And a total load of crap.

[Salvation]

**It implies that sea levels will rise a great deal faster as well. **

OK if California disappears! LOl!

[djf]

I'm at about 520 feet now, so I'm probably safe.

Keepin my fingers crossed!

[blam]

"How would Greanland continue to warm?"

Yup. I suppose you're correct...takes time though.

[carl in alaska]

From the article: "The Greenland ice sheet covers 1.7 million sq km and is up to 3km thick."

Apparently the ice sheet is up to about 2 miles thick, so if scientists have an accurate esimate of ice thickness then I'm sure their calculation is correct. That would be a massive amount of water, but that ice thickness estimate could be easily estimated too high to make this problem seem bigger than it really is.

[denydenydeny]

"We are concerned because we know that sea levels have been able to rise much faster in the past - 10 times faster."

The whole article dances around the ACTUAL OBSERVED FACT that ocean levels aren't rising at all currently, in spite of the "ravages" of "global warming".

[blam]

"Do you have any idea how much water you would have to add to the worlds "contiguous Oceans to increase the level even a fraction of an inch????? What BS!"

Agreed. The statement suprised me too.

[danamco]

The History Channel did a piece on Greenland that said the same thing; perhaps it was based on that book. The archaeological evidence suggests that the settlers increasingly tried to keep their livestock alive in barns over the ever-harsher winters but eventually had to turn almost exclusively to fish as the climate no longer supported growing enough forage. Turned out they weren't very good at fishing and didn't have enough food.




Here's another "great" well known dooms-sayer of our time a little earlier:

Picture a mutual fund manager whose bad investments have caused his fund to lose value for each of the last 30 years, but who nonetheless has built the reputation of fundmeister Peter Lynch. If you can do so, you can envision Paul Ehrlich.

Ehrlich, a butterfly specialist, began his spectacular doomsaying career back in 1968 with his best-selling book "The Population Bomb." Among his predictions then and since:

* "The battle to feed humanity is over. In the 1970s the world will undergo famines . . . hundreds of millions of people (including Americans) are going to starve to death." (1968)
* "Smog disasters" in 1973 might kill 200,000 people in New York and Los Angeles. (1969)
* "I would take even money that England will not exist in the year 2000." (1969)
* "Before 1985, mankind will enter a genuine age of scarcity . . . in which the accessible supplies of many key minerals will be facing depletion." (1976)

Yet today: 1) Food production is well ahead of population growth and obesity now kills 300,000 Americans a year, 2) the air in New York and L.A. is cleaner than it has been in decades, 3) with two years until 2000, England's odds are looking mighty good, and 4) there are no key minerals facing depletion. Almost all of them, along with raw materials in general, are far cheaper now relative either to the Consumer Price Index or wages.

But have Ehrlich's preposterous predictions hurt his reputation? Far from it - they've made him both celebrated and rich.

In one year - 1990 - he published a sequel to "Bomb" called "The Population Explosion," received the MacArthur Foundation's famous "genius award" with a $345,000 check, and split a Swedish Royal Academy of Science prize worth $120,000.

Last year Erlich slammed his critics (myself included) in a book the very name of which screams chutzpah, "The Betrayal of Science and Reason."

The reason Ehrlich keeps blowing it boils down to a single word: technology. It is Ehrlich's bete noire. So he just ignores its many benefits.

Now Ehrlich is the lead author of an article in The Atlantic Monthly this month, arguing that anybody who still says technology will provide more of such benefits is a liar or a fool.

Among his assertions: We really are running out of oil. That we seem to have such great reserves, he claims, comes from a decision by Arab countries in '87 to simply say they had a lot more oil than they previously had been saying. (Ehrlich claims it was a 250% increase; actually, it was 40%.)

But even if you subtract the new Arab estimate, since "The Population Bomb" came out in '68, world oil reserves are up 448 billion barrels.

Thirty years ago, we had an estimated 30-year supply of known oil reserves. Now it's up to 45 years, and pre-tax gasoline prices adjusted to the CPI are the lowest ever.

Why? Because technology has made it easier to find new oil fields at lower costs, to extract more from those fields, and even to pump oil from fields once thought dry.

Ehrlich tells Atlantic readers, "Since natural resources are finite, increased consumption must inevitably lead to depletion and scarcity."

Wrong. Look at copper. As it became scarcer, industry used new technology to switch to equal or even superior materials. Copper phone wiring went the way of the dodo, replaced by glass fiber optics that are dirt-cheap and made out of a raw material even Ehrlich doesn't fear for - sand. They are also vastly superior in the number and quality of transmissions they can carry.

But on and on Ehrlich goes. "Human-induced land degradation," he says, "affects about 40% of the planet's vegetated land surface," and is "accelerating nearly everywhere, reducing crop yields."

Reducing? Our silos runneth over, as yields continue to increase all over the world. For example, corn is now the world's most important crop. Here and worldwide, we now harvest about 50% more corn per acre than 30 years ago. And, says Hudson Institute analyst Dennis Avery, crop yields can be raised from the current world average of around 1.2 tons per acre to six to nine tons. And advances in genetics promise to dwarf even these increases.

Again, technology has thwarted Ehrlich's predictions, and you needn't be Nostradamus to know it always will. Ehrlich will still garner those accolades because, while in reality he's always wrong, politically he's always correct.

[blam]

"I'm at about 520 feet now, so I'm probably safe."

LOL. I'm a 25 feet, I'll be able to fish out my back door at high tide.

[RightWhale]

Do you have any idea how much water you would have to add

Isostatic rebound would subtract some of the volume since the interior of Greenland is below sea level, but the calculation is roughly correct.

[djf]

Soon, you might be able to snorkle in your living room!

You could build a nice little reef thingy.
Kool!

[blam]

"...had to turn almost exclusively to fish as the climate no longer supported growing enough forage. Turned out they weren't very good at fishing and didn't have enough food."

I saw that program too and made a note of the descrepancy about the fish...Diamond says there are no remains of fish bones in any of the middens and he said they would have survived to be found today. So...

The Seal and fish eating Inuit remain there to this day.

[ApplegateRanch]

I'm at about 520 feet now, so I'm probably safe.

I'm at 4,200; BUT, judging from all the 100s of feet of limestone under me, I won't bet either way.

[eddie2]

A few years ago I saw a TV show about a wealthy dude who dug up a World War fighter that was one of several that had to crash land in Greenland. Since WWII it had become buried with about one hundred feet of snow. I don't understand how this jives with global warming. Can anyone explain this.
Dittoes the stone age man found frozen in northern Europe.

[Hayzo]

I'm at 16 feet, you might hit me in the head with your lure! :>)

[ken in texas]

The whole article dances around the ACTUAL OBSERVED FACT that ocean levels aren't rising at all currently, in spite of the "ravages" of "global warming".

That's because now that we have global warming, the air can absorb more evaporation from the water. So, even though we have gazillions of gallons of new water flowing into the oceans, most of it is evaporating into the atmosphere. We now have an ocean over us... we're doomed!!! :-)