Antarctic’s PIG Threatening Sea Levels

It was recently suggested that the amount of Antarctic ice has been growing in volume. Now comes news of glacial shrinkage that has the British Antarctic Survey worried: they say it could lead to a significant rise in global sea levels.

Pine Island Glacier (PIG), West Antarctica, in 1985 - from Scott Polar Research InstituteIt was only a few days ago that I posted Being Economical With The Truth, in which I discussed how Christopher Booker, writing in Telegraph Online, pooh-poohed the recent findings about 2007′s Arctic sea ice summer shrinkage because, in the ensuing winter months, it’s expanded again to previous winter coverage. What I didn’t include in my post was his further assertion that, according to a graph recently published by the US National Oceanic and Atmospheric Administration (NOAA) titled “Southern Hemisphere Ice”, Antarctic ice has expanded in recent years, well above its 30-year mean — further proof, he thinks, that all the guff about global warming is nonsense.

However, research conducted in part by the University of Bristol and recently published in Nature Geoscience (to which I referred in my January 14th post Antarctic Ice Loss Confirmed) refuted this — it said increasing amounts of ice mass have been lost from West Antarctica and the Antarctic peninsula over the past ten years. I guess that leaves Mr. Booker out in the cold, so to speak.

And now further research from another authoritative source shows that a number of huge Antarctic glaciers are giving cause for concern because of the speed with which they’re rushing headlong into the ocean.

Map of West Antarctica - from BBC NewsThe British Antarctic Survey has recently had a group of scientists camped out on a collection of West Antarctica glaciers — what BAS scientist David Vaughan described as the weak underbelly of the West Antarctic ice sheet — in a remote part of the continent. The glaciers cover an area the size of Texas, and their findings show that they’re slipping more swiftly towards the ocean than ever previously recorded.

According to satellite measurements, three of the huge glaciers in this area have been speeding up for more than a decade. The biggest of them, the Pine Island Glacier, or the PIG, is causing the most concern. Julian Scott, who’s just returned from the region, told the BBC: “This is a very important glacier; it’s putting more ice into the sea than any other glacier in Antarctica. It’s a couple of kilometres (1.2 miles) thick, it’s 30km (18.6 miles) wide and it’s moving at 3.5km (2.2 miles) per year, so it’s putting a lot of ice into the ocean.”

BAS Skidoos In West Antarctica - from BBC NewsThe team drove skidoos over the ice for thousands of kilometres taking measurements as they went, using radar and boreholes. The last time this area was visited by scientists was in 1961. More recently, satellites have been used to track changes. According to those measurements, the glacier was accelerating by around 1% a year throughout the 1990s. Julian Scott’s sensational finding this season is that “The measurements from last season seem to show an incredible acceleration, a rate of up to 7%. That is far greater than the accelerations they were getting excited about in the 1990s.”

The reason for this sudden acceleration does not seem to be warming in the surrounding air. It could be something to do with a deep ocean current that’s channelled onto the continental shelf, close by the glacier’s mouth. As there’s not much sea ice to protect it from the warm water, it could be undercutting the ice and lubricating its flow. But there’s also evidence of a 2,000-year-old volcano that erupted through the ice. It’s possible that the whole region could be volcanically active, releasing geothermal heat which is melting the base of the ice and helping its slide towards the sea. David Vaughan believes the risk of a major collapse of this section of the West Antarctic ice sheet should be taken seriously.

Julian Scott In West Antarctica - from BBC NewsJulian Scott hopes to figure out whether what’s been recorded is an exceptional surge or whether it heralds a major collapse of the ice, and he’s left some GPS measuring instruments behind on the glacier. The BAS researchers say that if the glacier continues to race along, discharging most of its ice into the sea, the PIG alone could raise global sea levels by 25cm (9.8 inches). That might take quite a while — perhaps decades, or even a century, they suggest — but neighbouring glaciers are accelerating too. If the entire region lost its ice, global sea levels would rise by 1.5 metres (59 inches).

This is definitely one PIG that needs to be kept under close surveillance.

Read my Climate Change posts in chronological order by using the Climate Change Log.

Being Economical With The Truth

Is there no such thing as human-induced climate change? Is it all just a natural blip? The Telegraph‘s Christopher Booker seems to think so. Meanwhile, the Unknown Country web site has put solar radiation back in the frame as a candidate for climate disruption — but have they each arrived at these differing positions by cherry-picking the available information to suit their own agendas?

Al GoreIf Al Gore and the Intergovernmental Panel on Climate Change (IPCC) are to be believed, the debate about whether or not global warming is caused by human activity (what’s now called Anthropogenic Global Warming, or AGW) is all-but solved. We are the culprits — at least to a 90% certainty, given the current evidence. Our continuing output of the greenhouse gas carbon dioxide (CO2) into the atmosphere is dangerously upsetting the delicate balance of the planet’s climate and is leading to global warming. The most obvious physical evidence for this is the rate at which Arctic sea ice appears to have been melting during the past few years.

Northern Hemisphere Sea Ice AreaHowever, Christopher Booker, writing in the Telegraph on 4th February 2008 (an article since moved to Booker’s online Notebook and re-dated 18 April 2008), questions this evidence. He points out that while news outlets such as the BBC were keen to report the December 2007 findings on Arctic sea ice loss (which I also quoted in my post The Maya And The Arctic Meltdown), which showed that the summer of 2007 heralded the biggest loss of Arctic sea ice since 1980 (down to 4.2 million sq. km), they’ve been less keen to report that by February 2008, the winter sea ice had recovered to an area of almost 13 million sq. km again — as shown by figures and graphs released by the US National Oceanic and Atmospheric Administration (NOAA). Mr. Booker feels that these findings have been conveniently ignored by the “warmists” who would rather suppress such information because, he implies, it harms their cause.

Minimum Arctic Sea Ice Extent 2005 and 2007, With 30-Year AverageMy reading of the situation is that the scientists quoted in the article to which I referred fully expect the sea ice to return each winter. They also said that what will help determine the extent of the summer melt in 2008 and in future years will be, amongst other things, the thickness (or perhaps I should say thinness) of that returning winter sea ice and how it’s affected by the warm water advected from the Pacific and Atlantic oceans into the Arctic region. Personally, I will not be surprised to hear, later this year, that the Arctic sea ice has once again retreated to minimal levels — perhaps even more so than in 2007. Mr. Booker, meanwhile, seems happy to use this return of the winter sea ice to dismiss the notion of any form of climate change. I infer from the tone of his article that he’s of the opinion that whatever’s going on, it’s much more likely to be part of a natural cycle. It seems to me he’s the one who’s filtered the available information to suit his own purposes.

Stormy WeatherBut then, I would feel like that. I’m not a “warmist”, but I have no doubt something very bad is going on with the climate, so I’m dismayed when I read articles that seek to undermine that position. My main concern is not about whether it’s anthropogenically induced or a natural phenomenon. Whatever’s causing it, I think we should be preparing for a sudden, nasty shock when we reach a “tipping point” and things change very quickly indeed.

I try to avoid using the term “global warming” too much when writing about this subject (unless I’m quoting someone else who said it), because I think it’s a misnomer. Climate change, or climate disruption, are more accurate terms in my view. The planet may be growing continually warmer (and there is, as you might expect, considerable dispute even about this — see David Whitehouse‘s article, Has Global Warming Stopped?, published online on 19th December 2007 by New Statesman as an example), but that doesn’t necessarily mean our future climate here in the northern hemisphere will simply continue to feel warmer than it has in the past, or warmer than it already is now.

I worry that it may suddenly become very much cooler. (That makes me a coolist, I suppose.) This is based on articles and research I’ve read online and in books and other publications — and on a gut feeling. Hardly scientific, I know, but that’s why I’m trying to better understand the incredibly complex processes underlying climatic balance.

Our sun has a major influence on global climate — and there appears to be a major and unexpected change taking place on the sun, according to Whitley Strieber’s Unknown Country web site. In my post Climate Change: Sunspots? Or Us? I wrote about some research, reported by BBC News Online, that appeared to break the theoretical link between solar activity and global warming. Recently, Unknown Country published information on its Superstorm QuickWatch page that put solar activity back on my radar — not as a cause of global warming, but global cooling.

Here again, though, perhaps all is not quite as it seems.

Jan 4th 2008 Sunspot - from Spaceweather.com (click for larger image)I give a lot of credence to the information this web site provides, so I was disappointed to find an inaccuracy in its reporting on this subject. Inferring that the sun is possibly about to enter an unusually quiet phase, the site said that despite the appearance of a high-latitude reverse polarity sunspot on December 14, 2007, the sun, as of February [2008], remained devoid of the sunspots that would signal the beginning of the next solar maximum. However, according to information archived at SpaceWeather.com, this statement is not true — its archives show that while the December activity caused a good deal of excitement amongst the solar physics community who’ve been looking out for the first “official” sunspot to mark the beginning of Solar Cycle 24, the December activity turned out not to be the hoped-for sign — because it never developed into a sunspot. However, there was a further outbreak, sighted on 4th January 2008, which did become a sunspot and in doing so it did officially kick off Solar Cycle 24 (pictured — click for larger image). I hope this minor inaccuracy was merely an oversight by the Unknown Country team that will soon be corrected. They’re right, however, in saying that things have been quiet since Solar Cycle 24 began — the SpaceWeather.com site’s archives show that no other high-latitude, reverse polarity sunspots have developed since that first one in January. This possibly ominous sign gives the Unknown Country team the collywobbles — and, in turn, me too — though SpaceWeather.com doesn’t think it’s unusual.

The Sun, 19th February 2008 - from Spaceweather.comNotwithstanding their date error, the general thrust of the Unknown Country piece elaborates on solar activity’s effect on our climate, and it makes sobering reading. Normally, it says, the appearance of such a sunspot signals the beginning of a period of higher solar activity, and NASA scientists had predicted in 2005 that the 2008-2011 solar max would be one of the most intense on record. The lack of activity since December (or, more accurately, January) has the Unknown Country team worried that the sun may really be entering a quieter, longer-term cycle. (Image shows the sun on 19th February 2008 — devoid of any sunspots.)

 A Painting By Hendrick Avercamp Depicting Life During The Little Ice AgeThe last time the sun went into “hibernation” began in approximately 1250, and lasted, with cyclic changes, into the mid 18th century — a period we now call “The Little Ice Age”.

At present, it continues, the gas profile of the atmosphere is similar to that which appears at the end of interglacials, and it is possible that, if another period of reduced solar output is in the offing, a new ice age could begin, following a pattern similar to that predicted in the book [The Coming Global] Superstorm. In the past, increased solar output has led to the retreat of glaciers, exposing millions of square miles of previously frozen soils to thawing, with the result that massive quantities of methane have entered the atmosphere, resulting in even higher temperatures and, in the end, the appearance of another interglacial period of relatively warm weather. During this period, greenhouse gasses have at first declined, then risen again as continued increases in solar output have resulted in high arctic heating.

Then, when solar output suddenly drops again, a period of extremely violent weather has followed, culminating in a winter of very extensive snowfall over the northern hemisphere, followed by a summer where the combination of the increased reflectivity of the snowpack and reduced solar output causes the snow to fail to melt, with the result that the next winter brings more snow, and another ice age commences.

There’s my worry in a nutshell — in just a single year, the earth could be set on a path leading to an extended period of freezing temperatures lasting centuries.

Whether or not climate change is human-induced, or human-assisted, may, in the end, turn out to be a moot point. There are bigger influences playing their part — and you can’t get much bigger than the sun. There’s a lot more research being conducted into what’s happening to our solar life-giver, and I’ll be keeping an eye out for it.

I agree with the Unknown Country team when they write that at present, the question of what the sun will do over the next few years is of overwhelming importance in understanding how humanity might most usefully minimize the effects of what appears to be a period of sudden climate change that is rapidly gaining momentum.

Active Sun, 12 September 2005Contrasting Unknown Country’s concerns about a quiet Solar Cycle, SpaceWeather.com comments that many forecasters believe Solar Cycle 24 will be big and intense. Peaking in 2011 or 2012, (coinciding, perhaps with the end of the Mayan calendar?) the cycle to come could have significant impacts on telecommunications, air traffic, power grids and GPS systems. In this age of satellites and cell phones, the next solar cycle could make itself felt as never before. The furious storms won’t start right away, however. Solar cycles usually take a few years to build to a frenzy and Cycle 24 will be no exception.

“We still have some quiet times ahead,” says David Hathaway of the Marshall Space Flight Center, reassuringly.

Phew. That’s good news, at least. If it can be believed.

 

Read my Climate Change posts in chronological order by using the Climate Change Log.

Polar Meltdowns: More Evidence Emerges

When the Antarctic’s Larsen B ice shelf broke apart in 2002, human-induced climate change was blamed. Now two scientists claim there was rather more to it. Meanwhile, up north, a huge fracture in the Beaufort Sea ice pack has researchers worried about its implications for the future.

Iceberg debris after collapse of Larsen B - image from the BBCIt was 656 feet (200 metres) thick, had an area of 1,255 square miles (3,250 sq. km) and weighed around 500 billion tonnes. In March 2002, the Larsen B ice shelf broke apart. This was not an entirely unexpected event — in 1998, researchers from the British Antarctic Survey had predicted that several ice shelves around the western peninsula were doomed because of rising temperatures in the region, but they were shocked at the speed with which Larsen B collapsed. At the time the reason seemed to be Antarctic summer heatwaves linked to global warming, pure and simple. But now Neil Glasser of Aberystwyth University in Wales and Ted Scambos of the USA’s Colorado University have claimed, in a new study, that it had been teetering on the brink of collapse for decades, and that glaciological and atmospheric factors were also invoved.

Speaking to the BBC, Professor Glasser acknowledged that while global warming had a major part to play, he emphasised that it was only one of a number of factors that contributed to the collapse. Because meltwater in large amounts appeared on the ice shelf just before it broke up, it was assumed that air temperature increases were responsible. But their new study explains that ice-shelf break up is more complex and not simply controlled by climate. “A number of other atmospheric, oceanic and glaciological factors are involved,” he said. “For example, the location and spacing of fractures on the ice shelf such as crevasses and rifts are very important too because they determine how strong or weak the ice shelf is.”

Dr Scambos, of the University of Colorado’s national snow and ice data centre, added that Larsen B had probably been in distress for decades before its ultimate collapse. “It’s likely that melting from higher ocean temperatures, or even a gradual decline in the ice mass of the peninsula over the centuries, was pushing Larsen to the brink.”

Beaufort Sea Ice Pack Fracture - image from Environment Canada/NOAAMeanwhile, at the other end of the world, a huge fracture in the Beaufort sea ice pack is causing concern amongst scientists. Discovered this winter, the fracture could be a sign of things to come as climate change continues to warm the Arctic, says David Barber, a climate scientist with the University of Manitoba. First discovered in December, the fracture occurred in the Beaufort ice pack off the west coast of Banks Island in Canada’s Northwest Territories.

Normally, the central ice pack is pushed away from the coast during the winter as coastal ice expands and forces it into the sea. Usually when this occurs, there’s enough old ice in the central ice pack to resist the coastal ice, but that’s not the case this year, said Barber. Coastal ice, pushed by high pressure systems, has sent the central ice pack deep into the Beaufort Sea and towards Siberia, creating the vast fissure.

Banks Island location - image from Wikipedia“It’s the first time we’ve seen it happening so dramatically like this because we lost so much ice last summer,” Barber told CBC News. “We’re starting to think this is what the future’s going to look like.” Barber’s been leading a team of researchers who’ve been aboard the ice-breaker Amundsen, currently over-wintering in the ice of the Beaufort Sea so they can study the changes close-up. The expedition, said Barber, has proved invaluable, if not particularly encouraging. “It’s been an extremely interesting year but kind of depressing,” he said. “It’s interesting in a bad way.”

The polar regions are a concern to climate specialists studying global warming because those regions are expected to feel the impact of climate change sooner and to a greater extent than other areas.

Read my Climate Change posts in chronological order by using the Climate Change Log.