Greenland melting fast

"18,000 years ago when hundreds of thousands of cubic miles of ice were stacked up on the continents as glaciers, sea level was 120 m (390 ft) lower, locations that today support coral reefs were left high and dry, and [ame="http://en.wikipedia.org/wiki/Coast"]coastlines[/ame] were miles farther basinward from the present-day coastline. It was during this time of very low sea level that there was a dry land connection between Asia and Alaska over which humans are believed to have migrated to North America (see [ame="http://en.wikipedia.org/wiki/Bering_Land_Bridge"]Bering Land Bridge[/ame]). However, for the past 6,000 years (many centuries before the first [ame="http://en.wikipedia.org/wiki/History_of_writing"]known written records[/ame]), the world's sea level has been gradually approaching the level we see today. During the previous interglacial about 120,000 years ago, sea level was for a short time about 6 m higher than today, as evidenced by wave-cut notches along cliffs in the [ame="http://en.wikipedia.org/wiki/Bahamas"]Bahamas[/ame]."

 

AFAIK this is the first time that radar (surface level measuring) and gravity satellites' data have been compared. This is stuff that could not be done a few years ago, and it indicates cross-platform agreement and that melt now is greater than previously thought. It does not tell us whether future melt wll be more, less, or the same, but I don't see it as good news.

Kinda takes us back to the IPCC melt predictions which have lately been assailed as being too conservative. If that 'fear-mongering' source was too conservative, then we may be looking at a bit more excitment in the future. No surprise for our readers who have been 'keeping current'.

Mojo, you might have sent us to this wiki page instead:

Fileost-Glacial Sea Level.png - Wikipedia, the free encyclopedia

because it uses multiple sites to avoid errors associated with isostatic rebound, sediment dating, and other local issues. I did look at the Bahamas wiki page though (curious) and I did not find your bold sentence beginning with "During" in it. Can you help?

Or if not, can you see that a +6 meter sea level then would be incomptible with a Bering land bridge? I mean, come on, you are talking to your adult friends here.


But let's go back further in time...

Sea level was about 220 meters higher during the PETM (55 million years ago), no big ice on earth, about 6 oC of (apparent proxy) warming, and at least 1500 gigatons C added to the atmosphere as evidenced by the stable isotope ratios. (Don't miss the PETM wiki page either)

Now, as there are only about 4000 gigatons C total stored in fossil fuels, and because nobody in their right mind would contemplate putting a large fraction of that back in the atmosphere, we have nothing to worry about.

Um, right?

 

Oh, I sorry, you say 120,000 years ago for Bahamas +6 meters, that is certainly not out of line with other estimates for that interglacial. Entirely my fault.

You were only saying that sea level has varied substantially over geological time, and with that I wholeheartedly agree.

Not looking forward to the next +6 M though. I'm thinkin' Banglasplash.

 

Yes, mojo, it's happened before without human help. This time it's our fault: the Earth is warming rapidly during an era in which it would be starting to cool into another glacial period if only natural forces alone were at work. Don't buy any south Florida real estate.

 

I still find that argument absolutely worthless since all of those major fluctuations were prehistoric.

It is similar to people saying that climate change is no big deal because major shifts have happened before in Earth's history. Then the always try to link to a Wiki page that describes a certain period of time in which the global mean temperature was much higher, usually the Mesozoic, as if climate scientists were not aware of such periods. lol

 

Prehistoric?
Sea levels have been rising for the past 18,000 years continuously, up to and including the present.

 

Really, even through the ice age the water rose continuously? Where did the ice come from?

 

Sometimes its good to look at the facts.

The X axis on the graph below is in thousands of years before present. The graph is estimated sea level. The flat area labeled "B" on the graph pretty much spans western civilization.



You can see the discussion around that here:
6.4.3.2 What Was the Magnitude of Glacial-Interglacial Sea Level Change? - AR4 WGI Chapter 6: Palaeoclimate

So, yep, sea level changes. Nope, no so much since, say, Jesus walked the earth.

If you really have to have it spelled out: Question: Is the current sea level rise just a continuation of historical trend? Answer: No.

6.4.3.4 What Is the Long-Term Contribution of Polar Ice-sheet Derived Melt Water to the Observed... - AR4 WGI Chapter 6: Palaeoclimate

"Models of postglacial RSL history together with Holocene observations can be employed to assess whether or not a significant fraction of the observed globally averaged rate of sea level rise of about 2 mm yr–1 during the 20th century can be explained as a long term continuing influence of the most recent partial deglaciation of the polar ice sheets. Based upon post-TAR estimates derived from geological observations of Holocene sea level from 16 equatorial Pacific islands (Peltier, 2002; Peltier et al., 2002), it appears likely that the average rate of sea level rise due to this hypothetical source over the last 2 kyr was zero and at most in the range 0 to 0.2 mm yr–1 (Lambeck, 2002).:"

This is another of those topics where all you have to do is look at what the people with skin in the game are doing, and you can directly separate the bullsh@@ers from the rest. My brother lives in Portsmouth (VA), in a house that is 6' above sea level. He is uber-conservative, does not admit to the need to do anything about global warming. Except on this topic, where, oddly enough, he seems to have a keen interest.

The Virginia Tidewater region has both land subsidence and sea level rise to deal with. So it's, in effect, ahead of the curve in terms of impact. City planners are waking up to the fact that if they are putting in 50 to 100 year infrastructure, they have to figure on some number of feet of sea level rise. What that number is can be questioned, but that it's positive and growing is not. Retrofitting existing neighborhoods, with present technology, turns out to be ludicrously expensive. At this point, its starting to look like the city is going to have to pull back from the water, around the edges, over the next century. Not a pleasant prospect if you own a waterside home. But it's either that or live directly adjacent to a sea wall.

 

Yes, prehistoric includes just about everything prior to approx. 3100 BC and can include anything prior to the last millennium depending on the region and culture in question since it's all based on accurate written history. Here's a great book on the subject. http://www.world-archaeology.com/books/prehistory-the-making-of-the-human-mind/

I also used the word major to describe fluctuations. That clearly makes a difference. I hate to single you out but your post smacks of typical misuse of science to try and prove a point of which makes no sense.

 

"So, yep, sea level changes. Nope, no so much since, say, Jesus walked the earth. If you really have to have it spelled out: Question: Is the current sea level rise just a continuation of historical trend? Answer: No"

I gather because the rate of rise is less today than it was 18,000 years ago you fail to understand any continuation.
The high rate of rise 18,000 years ago is simply due to the vast amount of ice covering the planet made for a huge rate sea levelrise.
Once most of the ice melted,the rate tapers down.BECAUSE NOW THERE'S LESS ICE TO MELT.
Doesn't mean that todays melting isn't connected to the past.That's just your narrow bias.

 

I'm talking about a span of time 18,000 years ago until. and including TODAY.Today is not prehistoric.

 

Mojo, why don't you just go over to Greenland and tell those crybabies climate change is a myth. I'm sure they'll be relieved to learn all that melting ice is just their imagination.

 

That's not how it works. As ice melts and land is exposed albedo is reduced and melting rates increase. This is basic physical geography. At no point during the last 47,000 years has the planet run out of ice to melt so you point doesn't make sense.

Care to point out at what period in historic time we have experienced major sea level change?

 

I should know better, but:

You seem to be arguing that if there's less total ice, then there must be less total ice melting ... or something.

Seemingly plausible. In fact, not bad in concept.

Now look at the OP. The point, ... per the OP ... is that the melt is increasing, right now, conditional on the amount of ice there is, right now.

Clear enough? Less total ice, yet more total melt. Compared to the recent past.

 

In many ways it seems that the following need not be said. So what's wrong with me? do not know.

For several thousands of years sea level has been calm. I offered the data and so did Chogan2. Now, with new studies causing this thread, it very well may not continue in a complacent way.

Melt-rate increase now acts contrary to less ice available, and cannot easily be associated with decadal cycles like AMO and PDO. Rapid future sea level rises of large-fractions-of-meter-to-meter-to-few-meters could cause striking harm to the human enterprise. Columbia U's CIESIN is on it, and Colorado's Pielkes could be.

Only an epically rare fool could say "let's not try to understand that because it could cost $millions to do so".

I call upon the Koch brothers, here and now, to invest a small fraction of their assets to fund the science. Might have to crimp a bit on grants to SPPI, FEI, OSMI, etc. or megayachts, but get a grip. The point here is to prevent the people you aspire to sell things to from dying. Dead customers = no good.

Prob. have to send direct emails to Koch, oil companies, coal companies to get their ears. Maybe cc to some media. But the new theme is thus: You want living customers to buy your goodies, best for you fund to earth-system science research to find ways to keep your customers from dying.

Would it no be better for governments to fund such research? Well heck yeah. But most of them are tight on funds now and looking for ways to economize. Costs associated with procuring fossil C, and allowing fossil-C externalities to remain 'off the books' appear to be causing a circling of the wagons.

So, where to go to fund science of the earth system? Say 'fool' if you will, but the world's most renumerative industry (fossil C) kinda sticks out for me.

Would those guys do it wrong? Maybe, to some degree. Yet my faith in science is so strong that if studies get funded, the ones that tell us things we need to know will pass journal review.

Koch funding Earth-observing satellites? Why not? Rich comes from selling somebody something. If your clients cannot buy your stuff, rich doesn't happen.

Wacky eh? maybe so. Let's see how it plays out. From where we are now, it could just be that no other industry than fossil C could fund (= lead) us towards a more comfortable future.

As always, I hope that my PC pals can provide suggestions and reining in. But make no mistake; I aim for a paradigm shift with fossil-C industries paying to maintain their client base.

 

Hey D, are you starting to suspect that this very rare calm interglacial period we've enjoyed for so long may be coming to an end?

 

Funny, in'nt: on the one hand the Kochs and their ilk seem to want to buy the future, and on the other hand they don't seem to care what it will look like.

 

as long as iceland doesn't melt.