Arctic summer ice anomaly shocks scientists

[Tormod]

Satellite images acquired from 23 to 25 August 2006 have shown for the first time dramatic openings - over a geographic extent larger than the size of the British Isles - in the Arctic's perennial sea ice pack north of Svalbard, and extending into the Russian Arctic all the way to the North Pole.

 

lefthttp://hypography.com/gallery/files/5/MERIS29August2006_H_thumb.jpg[/img]Observing data from Envisat's Advanced Synthetic Aperture Radar (ASAR) instrument and the AMSR-E instrument aboard the EOS Aqua satellite, scientists were able to determine that around 5-10 percent of the Arctic's perennial sea ice, which had survived the summer melt season, has been fragmented by late summer storms. The area between Spitzbergen, the North Pole and Severnaya Zemlya is confirmed by AMSR-E to have had much lower ice concentrations than witnessed during earlier years.

 

Mark Drinkwater of ESA's Oceans/Ice Unit said: "This situation is unlike anything observed in previous record low ice seasons. It is highly imaginable that a ship could have passed from Spitzbergen or Northern Siberia through what is normally pack ice to reach the North Pole without difficulty.

 

"If this anomaly trend continues, the North-East Passage or 'Northern Sea Route' between Europe and Asia will be open over longer intervals of time, and it is conceivable we might see attempts at sailing around the world directly across the summer Arctic Ocean within the next 10-20 years."

 

During the last 25 years, satellites have been observing the Arctic and have witnessed reductions in the minimum ice extent - the lowest amount of ice recorded in the area annually – at the end of summer from around 8 million km² in the early 1980s to the historic minimum of less than 5.5 million km² in 2005, changes widely viewed as a consequence of greenhouse warming.

 

righthttp://hypography.com/gallery/files/5/ASAR-AMSR_2005_H_thumb.jpg[/img]Satellite observations in the past couple of years have also shown that the extent of perennial ice is rapidly declining, but this strange condition in late August marks the first time the perennial ice pack appears to exhibit thinner and more mobile conditions in the European sector of the Central Arctic than in earlier years.

 

Both sets of images were taken by two different satellite instruments - ASAR on the left and AMSR-E on the right. In the coloured AMSR-E images, ice cover, or the concentration of ice, is represented by the colour. Pink represents pack ice and the colour blue open water. Intermediate colours orange, yellow, and green indicate lower ice concentrations of 70%, 50% and 30%, respectively. In the ASAR images, ice cover is represented by the uniform grey area which extends radially-outwards from the North Pole, represented by the central black hole.

 

The set of images on the top were both acquired on 24 August 2005, while the bottom left ASAR image was acquired on 23 August 2006 and the AMSR-E on 24 August 2006. In 2005, the uniform grey area in the ASAR image and the pink colour in the AMSR-E image are both consistent all the way around the pole (black hole), indicating pack ice with 100% ice concentration.

 

righthttp://hypography.com/gallery/files/5/ASAR-AMSR_2006_H_thumb.jpg[/img]However in 2006 there is a significant extent of leads - fractures and openings in the sea-ice cover - just below the pole in both the ASAR image, seen as splashes of dark grey and black, and the AMSR-E image (with British Isles shown for scale), seen by the high concentration of yellow, orange and green colours, signifying low ice concentrations.

 

In the last weeks, what was open water has begun to freeze, as the autumn air temperatures over the Arctic begin to fall. Although a considerable fraction of darker leads can still be seen in the area using ASAR, the AMSR-E sensor no longer shows openings.

 

ASAR is an active microwave instrument which sends periodic radar pulses toward the Earth and measures the signals return. AMSR-E is a passive microwave instrument which does not send radar pulses down but receives radiation naturally emitted from the Earth. Passive microwave data contain a certain amount of ambiguity in interpretation of ice types, particularly in mid summer during melting. However, this ambiguity is removed in high resolution active microwave data.

 

Though the reason for the considerable change in the ice pack configuration is still unknown, it is likely due to the stormy weather conditions in August that characterised the month.

 

The effect stormy conditions have on ice is illustrated in this ASAR image, taken on 25 August 2006, as the ice in the red circle is divergent as a consequence of a low pressure system centred on the North Pole.

 

"As autumn freeze-up begins, the current pattern will undoubtedly precondition the ice situation in the Central Arctic for the subsequent ice season," Drinkwater said.

 

Source: European Space Agency

[ronthepon]

I'm not optimistic about this.

[Zythryn]

You know, times like this I really wonder why we aren't doing more.

Even if, as some skeptics state, mankind isn't contributing to GW (which I don't believe for a second) don't the skeptics think we should do something?

[Tormod]

Global warming is a fact, and humans are most likely contributing to it. What's not established is whether the observed changes in climate has anything to do with human activities.

[Turtle]

Global warming is a fact, and humans are most likely contributing to it. What's not established is whether the observed changes in climate has anything to do with human activities.

 

A new study (from Norway no less) appears to indict we humans:

http://www.cnn.com/2006/TECH/science/09/15/global.warming.sun.reut/index.html

[Jay-qu]

I am inclined to think that we do have something to do with it, but isnt it also a natural process? after it warms we cycle back to an ice age.. the planet has been around for billions of years, and will be around for billions more, are we too modest to think we dont have such an impact on this planet?

[Tormod]

Well, I didn't imply that humans have not contributed. I simply pointed out that AFAIK there are no direct evidence that humans have caused the trend in global warming.

 

I don't doubt for a second that a couple of hundred years of pumping exhaust into the atmosphere and toxins into rivers have made lasting damage on our environment. We do have direct evidence that CFC gases break down ozone in the higher layers of the atmosphere, but it does not follow that this means that CFC contributes to global warming.

 

Global warming as a phenomenon has happened before and will happen again.

[Boerseun]

We inhabit such a thin slice of the planet, from sea level to only a few thousand feet up (and a handful a couple of hundred miles up, but that's artificial an' don't count!). But the planet is wholly indifferent to our antics on the surface, we might kill off a couple o' species and then exit stage left ourselves.

 

My fear is that seeing that most of human concentrations are in coastal cities, can civilization survive tens to hundreds of New Orleans/Katrina events annually?

 

The info on the ice as mentioned in this article is quite scary - but you can only ask yourself; so where did the ice go?

 

1) Evaporated, which means that there's more water vapour in the atmosphere, water vapour being a greenhouse gas as well. This will heat up the planet further, and melt more ice, which will inject more water vapour, etc. This water vapour will eventually rain out, raising sea levels.

 

2) Melted, simply raising sea levels.

 

In both cases, sea levels will rise, raising the probability of Katrina-like flooding all over the planet.

 

And if it is indeed a natural phenomena, so be it. But we shouldn't be shortsighted and accelerate it. That's just plain stupid on a global scale.

[Turtle]

1) Evaporated, which means that there's more water vapour in the atmosphere, water vapour being a greenhouse gas as well. This will heat up the planet further, and melt more ice, which will inject more water vapour, etc. This water vapour will eventually rain out, raising sea levels.

 

2) Melted, simply raising sea levels.

 

In both cases, sea levels will rise, raising the probability of Katrina-like flooding all over the planet.

 

And if it is indeed a natural phenomena, so be it. But we shouldn't be shortsighted and accelerate it. That's just plain stupid on a global scale.

 

Melting ocean ice in the Arctic will not raise sea levels because the weight of the ice displaces the same weight of water. Like melting ice cubes in a glass of water don't raise the level.

If the extra moisture in the atmosphere precipitates as snow, it may simply grow glaciers and not raise the sea level either.

Well, I didn't imply that humans have not contributed. I simply pointed out that AFAIK there are no direct evidence that humans have caused the trend in global warming....

Global warming as a phenomenon has happened before and will happen again.

Agreed. Moreover, ice ages separate these global warming events/periods. As we have seen here at Hypog over the last many months, every new scientific study adds data that compounds the complexity of this very sticky wicket.

[Boerseun]

Melting ocean ice in the Arctic will not raise sea levels because the weight of the ice displaces the same weight of water. Like melting ice cubes in a glass don't raise the level.

True. Didn't think about that. But if that is happening at the North Pole where the ice sheet is floating (which won't raise sea levels as per your ice-cube analogy), the same can be inferred to be happening with the Greenland ice-sheet, which isn't floating. That'll be a doozy. And with that being said, the Antarctic ice cap have also been shrinking. And that sucker ain't floating either (well, the biggest part of it ain't floating).

If the extra moisture in the atmosphere precipitates as snow, it may simply grow glaciers and not raise the sea level either.

Granted, it may. But it seems as if that's not the case, either. Glaciers all over the world have been shrinking now for quite a while.

 

My point is simply that whether Global Warming is a natural cyclical phenomenon or not, we shouldn't accellerate it. And injecting greenhouse gases into the atmosphere en masse is achieving simply that.

 

If the Antarctic and Greenland ice sheets were to melt and raise sea levels by a few feet, it will be disastrous for sea-level cities, where most of the world's populations live, incidentally.

[Turtle]

Granted, it may. But it seems as if that's not the case, either. Glaciers all over the world have been shrinking now for quite a while.

 

My point is simply that whether Global Warming is a natural cyclical phenomenon or not, we shouldn't accellerate it. And injecting greenhouse gases into the atmosphere en masse is achieving simply that.

 

If the Antarctic and Greenland ice sheets were to melt and raise sea levels by a few feet, it will be disastrous for sea-level cities, where most of the world's populations live, incidentally.

 

First point: Glaciers have been shrinking all over the world, but not all of them. The glacier in the Mt. St. Helens volcano in my back yard is actually growing inspite of the ongoing eruption. Others are growing as well, like this one in Alaska:

http://pubs.usgs.gov/fs/fs-001-03/

Second point: Agreed

Third point: The melting Greenland ice also threatens to shut down the thermohaline circulation which then has the potential to freeze out the British Isles and their environs as well as affect global climate.

[Tormod]

Also, in the Antarctic, ice levels are declining in some spots but actually increasing in others - there is no trend showing *less* ice in Antarctica, as there is in the Arctic.

 

More clouds does not necessarily mean warmer climate. We'd need quite thick cloud layer for that (like on Venus, where the clouds are so think that the atmosphere gets insanely warm and the pressure extremely high). Clouds also shut out the heat from the sun so it can work both ways - ie, clouds can have a cooling effect.

[Zythryn]

Well, I didn't imply that humans have not contributed. I simply pointed out that AFAIK there are no direct evidence that humans have caused the trend in global warming.

 

Unfortunately the climate system is incredibly complicated. However, we do have a lot of evidence indicating that there is a link. Human activities may not be the ONLY contributing factor, but it does seem that it is a factor.

 

One of the suspicious correlations is the CO2 levels that have been measured each year since the 1950s and the amount of CO2 we have been pumping into the air.

 

While this could all be a coincidence, as we learn more and more it seems to hold up.

 

Earth does undergo natural cycles of warming and cooling. I won't say it is impossible that we are undergoing a normal climate swing. However, the more we study and learn the less likely that appears. More likely we are accelerating the process. If this is the case, or even if there is a small chance this is true, it would be in our best interests to try to stop accelerating the process.

 

I am glad studies are being done to research other possibilities (thanks for the link Tormod). The more we can rule out as contributing factors the sooner we can come to a consensus about what needs to be done.

[Tormod]

The more we can rule out as contributing factors the sooner we can come to a consensus about what needs to be done.

 

Good point.

 

One thing people tend to forget when they read about the global warming trends is that in many places there has been a *cooling* over the past 100 years. The climate, as you point out, is chaotic, and as such it can be different from city to city, and from district to district.

 

It's imperative that we don't blindly accept that global warming is happening *because* of human factors. We need to isolate *which* part of the global warming is contributed by us.

 

It would be equally disastrous for the climate if we came up with a brilliant idea to reverse the warming and start a cooling trend... :)

[Zythryn]

It would be equally disastrous for the climate if we came up with a brilliant idea to reverse the warming and start a cooling trend... B)

 

I agree, which is why it is even more critical to slow down the damage we are doing BEFORE we get to a point where we are forced to try to reverse the trends.

 

I don't trust our ability to reverse the trends without making the issue worse.

 

Slowing down the damage, on the other hand, is easy and safe (by easy I mean we understand how to slow it down and the action on our part will have no detrimental affect in and of itself).

[Tormod]

Slowing down the damage, on the other hand, is easy and safe (by easy I mean we understand how to slow it down and the action on our part will have no detrimental affect in and of itself).

 

It does show a huge fallacy, though: since we have no idea what it is we are doing that is adding to the global warming effect, nor how much it is contributing, we could be spending more energy shooting pigeons with cannons when the resources could be spent more wisely elsewhere.

 

For example, when estimates show that (say) 60,000 people in a given area will be displaced due to increased sea level, how do we battle that?

 

Or, on the other hand, might it be better to spend that energy finding a cure for a disease which kills millions of people every year?

 

I think global warming needs to be put in a more enlightening perspective than the "it's going down the drain too fast" which the media tends to use.

[Boerseun]

It does show a huge fallacy, though: since we have no idea what it is we are doing that is adding to the global warming effect, nor how much it is contributing, we could be spending more energy shooting pigeons with cannons when the resources could be spent more wisely elsewhere.

Well, whether we can quantify it to the nearest digit or not is immaterial. Fact remains, pumping millions of tons of carbon that was isolated from the rest of the system for millions of years into the atmosphere each year, simply cannot be a good thing.

 

It's no use we ignore the obvious.

 

Sure, we don't know exactly how much damage is being done, but damage is being done nonetheless, and it surely is something we can do something about.