Arctic Ice 2009

[Gray-Wolf]

Sooooo, as Iceberg already noted on the old thread, we come into 09' with a pretty low ice extent figure (compared to the last 8 years) and a year on year thinning in average ice thickness (NSIDC/NASA).

Last year ice extents rebounded to within half a million sq km of the 79/2000 average levels before melt began in March (though even with such a 'high start point' by summers end it had reached the second lowest figures recorded.......) , with many of us all calling this (08/09) winter 'cold' I wonder just what the end point of 'ice growth' will be this year?

Last year saw a continuation of the gradual drift of remnant perennial to the north of Svalbard/Greenland (with the majority losses flushed down the East coast of Greenland) on the 'arctic Gyre', as this mass of old perennial reduces will ever more be able to escape the 'log jam' behind Svalbard and end up off East Greenland? As with a 'log jam' if a few of the 'right pieces' move we may well see a swarm of bergs off Greenland this summer as the rest flush out that way.

MetO/Uni East Anglia are calling for a warmer global year than last year. The coming melt season has even less 'old perennial' (+5 years) ice than last year and even less shelf ice .Will this prove significant by summers end?

[paul tall]

No.

[J10]

Arctic_Ice_Autumn_2008.xls

Just to re-iterate my summary at the end of 2008.

Over the past week, the figures on the website have been subject to upward revisions, a couple of days after the initial ice amounts has been posted. So I had been waiting for them, and as a result if further amendments are to be made, I will update the spreadsheets, the last update on the IJIS website, related to ice thicknesses as at the 31st December.

The provisional figure on the 31st December was the lowest in the sequence, about 35,000 lower than the 2004 figures, and on average 140,000 lower than the 2003-2008 figures.

The 2008 minimum ice extent was the lowest with the exception of the 2007 figures.

The 2008 maximum was the 2nd highest, with only 2003 being higher.

The 2008 average ice extent was above 2005,2006 and well above 2007, but below 2003 and 2004.

[Gray-Wolf]

Thanks for the tidy up Jack!

Can we try and keep the thread more 'icy' (and it's processes) and less 'CO2-ey' ta?

The 'mirroring' of the NSIDC plot continues but we are approaching a point were extent dropped away last year......if this years plot heads down the same slope I'll start to think they've messed up this and last years data...LOL

[noggin]

G-W, do you fear arctic ice-melt itself for the effects which it may have, or do you fear it as a sign of something else? If it is the former, what are the effects that you forsee and do you think that there may be unforseen consequences which will render some sort of natural balance?

Genuine questions, BTW. I'm trying to understand where you are coming from. :lol:

[Gray-Wolf]

Hi Noggin!

In answer to your question ,Both!

Climate models have predicted what we are seeing for years (thinning pack leading to catastrophic 'single year' ice reduction events, Arctic amplification, permafrost melt and associated methane releases etc.) but we appear to be ahead of schedule.

The models are as good as there input and it would appear we are ahead of them both in terms of atmospheric CO2 concentration and CO2 production.

We are no closer to altering this trend, no matter how manner delegates fly around the world to argue we find ourselves in the same spot with promises of future action and steady year on year increases in the meantime.

I personally believe that sea ice is beyond 'safe' levels and a single 'natural' event (as we have always suffered) will prove enough to devastate the remaining perennial and so spell doom for the rest of the summer pack.

A warmer arctic means more glacial output from both Alaska and Greenland and ,as recent measures have shown, their meltwaters now overshadow thermal expansion as the main driver of sea level change.

Any further acceleration of meltwater output (apart from threatening so many cities with periodic storm surge inundation) further impacts the shelf systems in Antarctica (which are attached to the glaciers/mainland at a junction at current sea level).For instance, most of Ross ice shelf is grounded on the continental shelf. It's cliffs tower up to 200ft above the Ross Sea.Any 'significant hike' in sea levels would tend to have the front sections try and float (lifting it off the sea bed and allowing 'warm waters underneath) putting great stresses on it's juncture with the glaciers feeding it and leading to the failure of the shelf and it's floating off into the southern ocean.

We then face many metres of sea level change instead of the 1m currently forecast. So ,we have a changing climate pattern in the northern hemisphere (due to the Arctic amplification) coupled with dramatic sea level changes year on year (due to the floating off of 'grounded' shelf ice and the release of the glaciers behind them).

With the weather in tatters and sea levels forcing millions into refugee camps I foresee a very ragged period for mankind over the next 30yrs, one which may lead to the kind of 'mega death' you hear banded about (1/3 of global population wiped out via various,related means).

[BLAST FROM THE PAST]

http://www.dailytech.com/Article.aspx?newsid=13834

BFTP

[Gray-Wolf]

above is thanks to Cryosphere today (tale of the tapes)

and here are both ends side by side.........

Do you think the papers mistaken???......or shouldn't we be quibbling about over more than 1 million sq km difference at this stage of the game?

EDIT: and though this is the ARCTIC ICE thread here's the global tape from C.T.

Edited January 7, 2009 by Gray-Wolf

[Gray-Wolf]

I can't believe the jury is still out on the ludicrous claims of global sea ice levels.......Ho Hum

For your delight and delectation (above)

How come we lost most of the '2nd year' ice from 07 by the end of 08'? Once again we have a swathe of first year ice but it doesn't seem to fare that well does it? If the splodge of blue from 08' year end fares as well this summer as it's predecessor did then we'll be left with nought more than a thin ribbon of multiyear behind Greenland come Sept 23rd this year!

I only wish to point out the fact to those who trumpeted the success of single year ice retention at the end of last years melt as some kind of 'reprieve' when it is very easy both to discover and see how well 'single year' ice fares by seeing how much transfers into second year ice. Any return to the new 'dipole' synoptic (now the La-Nina influence is fading) will make short work of central arctic ice (as we saw in 07') by warm air/water advection into the arctic ocean via Bering.

[Admiral_Bobski]

I can't believe the jury is still out on the ludicrous claims of global sea ice levels.......Ho Hum

For your delight and delectation (above)

How come we lost most of the '2nd year' ice from 07 by the end of 08'?

Because it's become third year ice by then...? (...and there wasn't much first year ice to become second year ice in 2008...?)

CB

Edited January 9, 2009 by Captain_Bobski

[Gray-Wolf]

Because it's become third year ice by then...? (...and there wasn't much first year ice to become second year ice in 2008...?)

CB

not much of either survived the 08' melt season did it?a quick peep-ette at the image for 08 show the single year surviving in the high latitudes where solar radiation is least (seeing as no multiyear exists over the pole anymore.

Serreze et-al are at lengths to point out the 'compaction event' that occurred at the end of 07' with a stiff northerly 'compacting ice' together in a tight mass. in 08' no such event took place leaving a much less compact pack (by their calculations equal or less than 07').

The other thing of interest is 'drift speed' which ,for reasons yet unknown, has accelerated over the past 7 years. That being so the rapid transport of ice from high to low latitude (as can be seen by the positioning of the remnant multiyear ice) puts any 'thin ice' at risk of melt out by transportation alone (as happened to 07's first/second/third year ice......hence it absence from 08' end of melt plot and the predominance of 'single year.

Did you know that in march 08 we only has 23% of the perennial we had in March 1980! not good, not good at all.

Edited January 9, 2009 by Gray-Wolf

[Admiral_Bobski]

not much of either survived the 08' melt season did it?a quick peep-ette at the image for 08 show the single year surviving in the high latitudes where solar radiation is least (seeing as no multiyear exists over the pole anymore.

Serreze et-al are at lengths to point out the 'compaction event' that occurred at the end of 07' with a stiff northerly 'compacting ice' together in a tight mass. in 08' no such event took place leaving a much less compact pack (by their calculations equal or less than 07').

The other thing of interest is 'drift speed' which ,for reasons yet unknown, has accelerated over the past 7 years. That being so the rapid transport of ice from high to low latitude (as can be seen by the positioning of the remnant multiyear ice) puts any 'thin ice' at risk of melt out by transportation alone (as happened to 07's first/second/third year ice......hence it absence from 08' end of melt plot and the predominance of 'single year.

Did you know that in march 08 we only has 23% of the perennial we had in March 1980! not good, not good at all.

I'm not sure that we're seeing the same thing in the pictures - I can see a much more compact accumulation of 6+ year ice (covers a smaller area, but has little to no 5-year (or less) ice mixed in with it.

The yellow ice in the first pic (year 4 ice) is now orange in the second pic (year 5 ice), and is far more compact than it was when it was year 4 ice.

Interestingly, the year 3 ice doesn't seem to have survived as well as any other age of ice (the green in picture 1 is yellow in picture 2, and seems to have mostly disappeared).

The big swathe of purple in picture 1 - year 2 ice - is green in picture 2. There has been some loss, as one would expect of younger ice, but not a huge amount.

The straggly blue bits of 1st year ice in pic 1 have become the straggly purple bits in pic 2 - nota great deal of change there.

And then there's the huge new blob of blueness which is the brand new ice from 2008. We'll have to see what happens to that as the year progresses.

CB

[Gray-Wolf]

It is funny that two people looking at the same images can see such different things!

Red (year plus) much reduced in 08 image

orange, strangely absent in 07 in any amounts but there (to the north of Ellesmere Island) in 08 as the yellows of 07 age (not the 'stream' of orange/yellow plotting the outflow between Greenland and Svalbard)

yellow (as above) with the remnant of the 07' 'greens' to the north of the Archipelago (less than 25% of the original mass?)

Green, great losses from 07 to 08

Purple 07 purple appears to have drifted south and by 08 is 3rd year ice on the edge of the outflow between Greenland and Svalbard.

blue. very little in the 07 image. much more present in the 08 image in the higher latitudes.

We both seem to agree that it is the performance of last years (08) single year ice over the coming summer that is of most importance (so far as 'extent/albedo' is concerned) but I have concerns over the last of the old perennial as this is the most resilient ice and yet is now a minority component of the pack (unlike pre 1980 when it was the majority component) as it is now in lower latitudes and is absent from the pole itself. The melting to the North of Greenland/Ellesmere island last summer shows how much climate is now impacting the region and the danger of continued melt of the region.

[MR EXTREMES]

well i think unless the global switch switches then you can kiss the artic goodbye.

its a good thing really because it allows the usa and britain russia canada ect to fight over the resources up there thats if theres any,sorry bit of anger there.

and no offence but its melting it going to dissapear 100% cert so why worry because we cant fix it.

even if we stopped everything that pumps gases into the air it would make no difference lets face it its to late to change our climate.

and its the artic where we are seeing the damage its sad it depressing and id rather not had children because the world they are going to live in is going to be so much different.

[Gray-Wolf]

well i think unless the global switch switches then you can kiss the artic goodbye.

its a good thing really because it allows the usa and britain russia canada ect to fight over the resources up there thats if theres any,sorry bit of anger there.

and no offence but its melting it going to dissapear 100% cert so why worry because we cant fix it.

even if we stopped everything that pumps gases into the air it would make no difference lets face it its to late to change our climate.

and its the artic where we are seeing the damage its sad it depressing and id rather not had children because the world they are going to live in is going to be so much different.

I too believe that there is nothing to be done to save summer sea ice from oblivion.

We went beyond the 'tipping point' (IMHO) before 05' (which was then an accident waiting to happen....with the help of the correct mix of natural augmenters) at the latest and probably as early as 1980 (by virtue of a thinning perennial pack).

It is natural conflagrations that have brought us the likes of 07's melt season (the perfect storm) but the ice thickness and amounts of perennial has to be hammered before hand providing opportunity for the 'natural driver' to do it's work. There is no going back to the ice pack of the 1940's , apart from with the help of over extended periods of cool summers with light winds 'compacting' the existing floes into a centrally positioned perennial sheet from which further growth may occur, and this appears increasingly unlikely with every 'top 10 temp year' that passes.

As with climate itself I believe that man's impact on the polar regions is small but significant, especially when it augments a 'natural' event. Time on time before we have seen how sensitive climate is to small ,incremental changes (into ice ages ,out of ice ages) and we are hell bent on continuing our 'push' on the climate system even when we see nature responding to those pushes.

Climate shifts tend to be dramatic (beyond certain thresh holds) and it seems (to me at least) a pity that we must witness one of theses climate events, first hand, to rid us of the whining skeptic and provide the impetus for change.

In the 90's I thought the loss of summer ice would be so stunning as to provide this impetus without the need for a 'mega-death' event, I was wrong. The loss of summer ice is being seen as yet another 'business opportunity' by both countries and corporations.....a boon indeed. The art of good business may well be to turn adversity into advantage but this may not best serve the global community.

Edited January 10, 2009 by Gray-Wolf

[jethro]

Here's a new paper about Greenland glaciers, not sure it should be here but thought some may find it interesting.

http://www.nature.com/ngeo/journal/vaop/nc...bs/ngeo394.html

I know some have expressed concerns about ice loss (more particularly Antarctica), once the front tongue is lost, the rest behind, follows swiftly afterwards - seems this is not the case. The concluding sentence of this paper should be noted IMO:

"Our results imply that the recent rates of mass loss in Greenland's outlet glaciers are transient and should not be extrapolated into the future".

[Gray-Wolf]

Below is a link to another article on the paper

http://www.terradaily.com/reports/Massive_...ntists_999.html

The excerpt is also worth noting

Vieli cautioned that his findings, published in Nature Geoscience, are narrowly focused on one glacier, and that sea levels could still rise higher than the IPCC's original projections.

Other Greenland glaciers behave differently, and the dynamics of the Antarctic ice sheet are still poorly understood, he noted.

Nor should the new study "be taken out of context to suggest that climate change is not a serious threat -- it is," he added.

The ice sitting atop Greenland could lift oceans by seven metres, though even the gloomiest of climate change projections do not include such a scenario.

--------------------------------------------------------------------------------------------

So ,we are looking at the behaviour of the terminus of 1 glacier here.

Edited January 14, 2009 by Gray-Wolf

[jethro]

I know it's only the one glacier, as that's the only one they were studying but I think it's fair to say the assumptions made about the ice cap so far, are premature. If these actions are replicated across Greenland and there's no reason to assume they won't be, if it's normal glacial behaviour; then perhaps glacial retreat won't be the assumed done deal.

He also says " Vieli also noted that the data alarming the scientific community only covers a span of a few years. It may be ill-advised, he suggested, to project a trend on the basis of what may turn out to be a short-term phenomenon."

Seems like sensible advice to me.

[Iceberg]

I am trying to find a link to the full paper rather than just the extract if anybody has one that would be appreciated. (and no I don't want to pay).

It would be unfair for me to prejudge this without reading the entire paper.

I also think it's fair to say that a number of other investigations to other glaciers have taken place and basal slippage is a very important factor in these, what this seems to tell us is that this might not be an important factor in All Glaciers.

[Admiral_Bobski]

Here's a thought:

When glaciers "die" they retreat - the exposed fringes melt first and work their way back to the source.

Glacial growth occurs from the source of the glacier. The glacial fringes don't advance so much as they are pushed from behind.

If Greenland's glaciers start extending out into the ocean and calving into the water then there must be extra input at the source of the glacier.

Where does that extra input come from? At the end of the day it comes from the oceans, so the extending glaciers are only replacing the water that has fed their growth in the first place.

If Greenland's glaciers are melting then they should retreat from the ocean rather than pour into it.

CB

Edited January 14, 2009 by Captain_Bobski

[Gray-Wolf]

I think you'll find them in full retreat (think of the Petermann Glacier in N. Greenland) and that which is flowing into the sea are large chunks of collapsed Glacier (along with record amounts of meltwater). Just before 'petermanns crack' caught the public eye ,this past year, it shed a chunk half the size of Manhattan island into the sea to the north of Greenland (bit crowded up there with all the fragments of the ice shelves shed from Ellesmere island bobbing about too!). I think NASA (MODIS and AQUA) have some fine images of a few of the larger glaciers as they retreat up their valleys.

Edited January 14, 2009 by Gray-Wolf

[Admiral_Bobski]

I think you'll find them in full retreat (think of the Petermann Glacier in N. Greenland) and that which is flowing into the sea are large chunks of collapsed Glacier (along with record amounts of meltwater). Just before 'petermanns crack' caught the public eye ,this past year, it shed a chunk half the size of Manhattan island into the sea to the north of Greenland (bit crowded up there with all the fragments of the ice shelves shed from Ellesmere island bobbing about too!). I think NASA (MODIS and AQUA) have some fine images of a few of the larger glaciers as they retreat up their valleys.

Yes, but he point is that the full mass of glacial ice on Greenland won't just slide into the seas. After the initial loss of ice at the coasts, the retreating glacier will melt, leaving behind meltwater pools that will either evaporate, remain as lakes or run off into the oceans at a sedate rate. The point I am making is that the return of glacial waters will take place over a long period of time and not in discrete catastrophic events (always assuming, of course, that glaciers on Greenland continue to retreat and don't stall or even start to grow again).

Basically, I think the case for catastrophic sea rise is being severly overstated.

CB

[Tn9]

The top climate story of 2008, as it was in 2007, was the extraordinary summertime sea ice retreat in the Arctic. For the second consecutive year, we experienced the opening of the fabled Northwest Passage through the Canadian Arctic waters. Explorers have been attempting to sail the Northwest Passage since 1497, and 2007 and 2008 are the only known years the passage has been ice-free. In addition, 2008 saw the simultaneous opening of the Northeast Passage along the coast of Russia. This meant that for the first time in recorded history, the Arctic ice cap was an island--one could completely circumnavigate the Arctic Ocean in ice-free waters. Although the summer ice extent in 2008 finished 9% higher than 2007's record minimum, it was still an extraordinary 34% below average, according to the National Snow and Ice Data Center. Furthermore, the ice was thinner at the September 2008 minimum compared to 2007, so the total ice volume (thickness times area) was probably at its lowest point in recorded history in 2008.

Figure 1. Daily arctic sea ice extent for September 12, 2008. The date of the 2008 minimum (white) is overlaid on September 16, 2007--last year's minimum extent (dark gray). Light gray shading indicates the region where ice occurred in both 2007 and 008. Image credit: National Snow and Ice Data Center.

The Arctic "perfect storm" of summer weather in 2007 did not repeat in 2008

The summer of 2007 saw a "perfect storm" of weather conditions favorable for ice loss. Unusually strong high pressure over the Arctic led to clear skies and plenty of sunshine. Arctic winds, which usually blow in a circular fashion around the Pole, instead blew from the south, injecting large amounts of warm air into the Arctic. How unusual were these conditions? Well, at last month's meeting of the American Geophysical Union, the world's largest scientific conference on climate change, J.E. Kay of the National Center for Atmospheric Research showed that Arctic surface pressure in the summer of 2007 was the fourth highest since 1948. Cloud cover at Barrow, Alaska was the sixth lowest. This suggests that once every 10-20 years a "perfect storm" of weather conditions highly favorable for ice loss invades the Arctic. The last two times such conditions existed was 1977 and 1987.

The 2008 melting season began in March with slightly greater ice extent than had been measured in previous years, thanks to a relatively cold winter during 2007-2008. However, since so much ice had melted during the summer of 2007, most of the March 2008 ice was thin first-year ice, which extended all the way to the North Pole. The total ice volume in the Arctic in March 2008 was lower than what the record-breaking year of 2007 had seen. This led to speculation that a new record minimum would be set in 2008, and Santa's Workshop would plunge into the ocean as ice melted at the North Pole. However, the "perfect storm" of summertime weather conditions did not materialize in 2008. From May through July, cooler temperatures and winds less favorable to ice loss occurred. When very warm temperatures moved into the Arctic in August, the ice loss rate accelerated to levels higher than in 2007. However, with sunlight waning, ice loss was not able to reach the levels seen in 2007. Arctic temperatures in the summer of 2008 were up to 4°C cooler along the Siberian coast than in 2007 (Figure 2).

Figure 2. Difference in surface temperature (°C) between the summer of 2008 and the summer of 2007. Blues and purples indicate areas where is was cooler in 2008. The biggest change was over the Bering Sea between Alaska and Russia, where exceptionally sunny weather with southerly winds in 2007 caused record-breaking warmth. Image credit: NOAA/ESRL.

The future of arctic sea ice

Climate models have done a poor job predicting the recent record loss of arctic sea ice (Figure 3). None of the models used to formulate the official word on climate, the 2007 United Nations IPCC report, foresaw the shocking drop of 2007-2008. At the December 2008 AGU meeting, Wieslaw Maslowski of the Navy Postgraduate School hypothesized that the reason for this was the models' improper handling of ocean currents and how they transport heat. He blamed 60% of the melting during the past decade on heat brought in by ocean currents, and projected that summertime arctic sea ice would completely disappear by 2016. Dr. Jim Overland of NOAA's Pacific Marine Environmental Laboratory was more conservative, projecting a 2030 demise of arctic sea ice. He thought we would be "hanging around where we are for a while", and thought it would take two more unusual summers like the "perfect storm" of 2007 to push the system to an ice-free state. He further noted that while summertime air temperatures have been near record levels the past few years in the Arctic, there has been one period of comparable warmth, in the 1930s and 1940s. The year 1941 still ranks as the warmest year in the Arctic, though 2007 was virtually tied with it. However, the warmth of the 1930s and 1940s was different than the current warming, and was caused by the Siberian High moving unusually far east over Europe, driving warm, southerly winds over Greenland. The warmth in the past decade, in contrast, is associated with a warming of the entire planet, and is not due to an unusual pressure pattern driving warm air into the region. This means that the current warming is accompanied by much warmer ocean waters, which have helped caused much of the arctic sea ice loss the past two years by melting the ice from beneath.

Figure 3. Arctic sea ice extent from observations (thick orange line) and 13 model forecasts used to formulate the 2007 IPCC report (light lines). The thick black line is the multi-model ensemble mean, with the standard deviation plotted as a dashed black line. Image has been updated to include the observed 2007 and 2008 measurements. Image credit: Arctic sea ice decline: Faster than forecast by Stroeve et al., 2007.

The impact on the jet stream

The unprecedented melting of arctic sea ice the past two summers has undoubtedly had a significant impact on the early winter weather over the Northern Hemisphere. Several modeling studies presented at the December AGU meeting showed that sea ice melt on this scale is capable of injecting enough heat into the atmosphere to result in a major shift in the jet stream. Dr. Overland remarked that the early cold winter over North America this winter, and the exceptionally cold and snowy early winter in China last winter, were likely related to arctic sea ice loss. The sea ice loss induced a strong poleward flow of warm air over eastern Siberia, and a return flow of cold air from the Pole developed to compensate. Thus regions on either side of eastern Siberia--China and North America--have gotten unusually cold and snowy winters as a result.

The impact on sea level rise

The loss of arctic sea ice will have little impact on sea level rise over the next few decades. Since the ice is already floating in the ocean, melting it does not change sea level much--just like when ice melting in a glass of water will not change the level of liquid in the glass. In the case of sea ice, there is a slight sea level rise, since the fresh melt water is less dense than the salty ocean water it displaces. If all the world's sea ice melted, it would raise global sea level by only 4 mm. This is a tiny figure compared to the 20 feet of sea level rise that would occur from complete melting of the Greenland ice sheet--which is on land.

The impact on melting of the Greenland Ice Sheet

The big concern with arctic sea ice melt is the warmer temperatures it will bring to the Arctic, which will bring about an accelerated melting of the Greenland Ice Sheet. As the sea ice melts, the resulting warmer average temperatures will increase the amount of dark, sunlight-absorbing water at the pole, leading to further increases in temperature and more melting of sea ice, in a positive feedback loop. As temperatures warm, partial melting of the Greenland Ice Sheet will raise global sea levels. While no one is expecting 20 feet of sea level rise from the total melting of the Greenland Ice Sheet for many centuries, even one meter (3.3 feet) of sea level rise due to the partial melting of the Greenland Ice Sheet can cause a lot of trouble. The official word on climate, the 2007 IPCC report, predicted only a 0.6-1.9 foot sea level rise by 2100, due to melting of the Greenland ice sheet and other factors. These estimates did not include detailed models of ice flow dynamics of glaciers, on the grounds that understanding of the relevant processes was too limited for reliable model estimates. The IPCC estimates were also made before the shocking and unexpected loss of arctic sea ice of the past two summers. In light of these factors, a large number of climate scientists now believe the IPCC estimates of sea level rise this century are much too low. The most recent major paper on sea level rise, published this month by Grinsted et al., concluded that there was a "low probability" that sea level rise would be in the range forecast by the IPCC, and predicted a 0.9 - 1.3 meter (3 - 4.3 feet) rise by 2100. Pfeffer et al. last month concluded that a "most likely" range of sea level rise by 2100 is 2.6 - 6.6 feet (0.8 - 2.0 meters). Their estimates came from a detailed analysis of the processes the IPCC said were understood too poorly to model--the ice flow dynamics of glaciers in Greenland and Antarctica. The authors caution that "substantial uncertainties" exist in their estimates, and that the cost of building higher levees to protect against sea level rise is not trivial. Other recent estimates of sea level rise include 1.6 - 4.6 feet (0.5 - 1.4 meters) by Rahhmstorf (2007).

What would 3 feet of sea level rise mean?

Rising sea levels will lead to permanent and intermittent flooding in low-lying coastal areas across the world. A global sea level rise of .9 meters (3 feet) would affect 100 million people worldwide, mostly in Asia. The impact of hurricane storm surges will significantly increase as a result of sea level rise. Given a 3 foot rise in sea level, Hurricane Ike's storm surge would have overwhelmed the levees in Port Arthur, Texas, flooding the city and its important oil refineries. Galveston's sea wall would have been overtopped and possibly destroyed, allowing destruction of large portions of Galveston. Levees in New Orleans would have been overtopped, resulting in widespread flooding there, as well. I'll have a full analysis of who's at risk, and what the risks are, in a series of forthcoming blog posts this year.

What can we do?

One reasonable suggestion, presented by Trish Quinn of NOAA at the December 2008 AGU meeting, would be to limit the amount of crop residue burning that goes on in Eastern Europe and Asia each year. These fires generate large amounts of black soot that blows into the Arctic. These black particles on the white ice leads to a significant amount of warming during the summer months, when the black particles absorb sunlight.

For more information

The wunderground sea level rise page has detailed background info on sea level rise.

The wunderground Northwest Passage page is also a good reference.

realclimate.org has a nice post summarizing the recent sea level research.

I'll have a new blog post Wednesday or Thursday.

Jeff Masters

[BARRY]

Funny isn't it when Arctic ice shows a big increase this thread go's all quite

[pottyprof]

Funny isn't it when Arctic ice shows a big increase this thread go's all quite

Shhhhhhhh.. You'll wake everyone up..

Intersting tho isn't it?

The Ice I mean not the fact that its quiet.. But then again thats interesting too..