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Showing posts with label Antarctica. Show all posts
Showing posts with label Antarctica. Show all posts

Thursday, July 20, 2017

Matthew England wins the 2017 Tinker-Muse Prize. Charles Rotter spruiks mistruths @wattsupwiththat

Sou | 1:00 PM Go to the first of 29 comments. Add a comment
Congratulations to Professor Matthew England of the Climate Change Research Centre (CCRC) at the University of New South Wales. He is this year's winner of the Tinker-Muse Prize for Science and Policy in Antarctica. It's a prestigious award and comes with a prize of $US100,000. The Scientific Committee on Antarctic Research (SCAR) administers the award process independently of the Tinker Foundation.

A pioneer scientist with a rare ability


Professor England does a huge amount of research covering multiple topics. One subject on which he has made an important contribution is increasing our understanding of the Southern Ocean and the Southern Annular Mode (SAM). As stated on his website, "Quantifying the natural variability of Southern Ocean water masses, including their properties and overturning rates, is vital for detecting anthropogenic climate change."

Figure 1 | Schematic depth-latitude diagram showing the major circulation and water masses of the Southern Ocean. The following water masses are highlighted: (1) Antarctic Bottom Water flowing along the abyssal ocean, (2) Circumpolar Deep Water upwelling into the Antarctic Divergence Zone, (3) Antarctic Intermediate Water in the temperature range 4-6°C, and (4) Subantarctic Mode Water in the upper ocean north of the Subantarctic Front (SAF). Source: Matthew England's website

Friday, July 14, 2017

Gigantic ice block, A-68, impressed Anthony Watts so much he came back from his holiday from @wattsupwiththat

Sou | 3:42 PM Go to the first of 21 comments. Add a comment
Photo: John Sonntag, NASA
Most of you will by now have heard that the cracked ice shelf on Larsen C has split the whole way through. This means a gigantic block of ice is now floating free. It's got a name as bland as all the other recorded icebergs: A-68.

The block measures about 5,800 km² in area and weighs more than a trillion tonnes. It is one of the ten biggest icebergs ever recorded.  The weight is equivalent to the weight of 7,142,857,143 fully grown blue whales, the world's largest mammal.  To visualise the area, think of somewhere that's 29 km by 200 km or 18 by 124 miles. The iceberg is around the same size as Australia's largest island after Tasmania, Melville Island north of Darwin, which is 5,786 km² in area.



There's an article at Quartz by ZoĆ« Schlanger, Jennifer Brown and Katherine Ellen Foley, with some other international comparisons, for example, it covers an area twice as big as the Australian Capital Territory and 60 times the area of Paris.

This isn't the largest iceberg ever. The largest recently recorded is B-15, which split off from the Ross Ice Shelf in Antarctica 17 years ago, in March 2000. It was almost twice the size of this one, measuring 295 km (183 miles) by 37 km (23 miles), and having a surface area of 11,000 km² (4,200 sq miles). Wikipedia also lists other recent large icebergs - here and here.

Friday, April 8, 2016

Most of the Arctic sea ice is on land and other WUWT musings

Sou | 3:51 AM Go to the first of 10 comments. Add a comment
Arctic sea ice from 1953
 Willis Eschenbach has been wondering about sea ice trends of the past few decades. He's written a couple of articles but seems to me to be more interested in hiding the trends than exploring them. In today's article (archived here, latest here), he has used HadISST data from the UK Met Office Hadley Centre. I don't know why he chose that over the more often cited Sea Ice Index from the National Snow and Ice Data Center.  I think he's meant his title to this latest article to be sarcastic, in the way that the Dunning-Kruger set use sarcasm: "The Awful Terrible Horrible Global Sea Ice Crisis".

Willis decided to look at the data from 1974 only because he found that for Antarctica before that time there was not good data. Then he said he removed the seasonal component, which looks like he deducted something from each month. Since Willis used HadISST data, let's look at what the authors of the authoritative text on the subject found in the 2003 paper by Rayner et al:

Friday, November 6, 2015

More snow won't stop the West Antarctic ice sheet from collapsing

Sou | 2:14 AM Go to the first of 6 comments. Add a comment
Anthony Watts reappears in a frenzy of excitement (archived here and cached here). He's discovered a press release about a new paper by scientists from the British Antarctic Survey Expedition, but didn't take the time to read it or the paper. Because of that, he's made a complete ass of himself as he almost always does whenever he writes something on his blog. (Which is probably why he appears so rarely these days. He can't hack the guffaws from onlookers.)

Anthony's headline is wrong. It reads: "Yet another study shows Antarctica gaining ice mass – snowfall accumulation ‘highest we have seen in the last 300 years’". Then, that blogger who rejects out of hand almost every scientific paper he comes across, bemoans the fact that an article at Media Matters tells how a scientist, Jay Zwally, knew that deniers would twist his recent paper.

Monday, November 2, 2015

Antarctic ice - growing or shrinking? NASA vs Princeton and Leeds etc

Sou | 11:26 PM Go to the first of 43 comments. Add a comment
There's a new paper out about Antarctic ice, from H. Jay Zwally and colleagues at NASA. They report that over the period from 2003 to 2008, there was a net increase in ice over all Antarctica of 82±25 Gt/year. This paper looks to be based on a conference paper at a SCAR workshop back in July 2012 (though that doesn't explain why there wasn't data from the past six years in the final published paper).

These findings are different to the results of work reported earlier this year from two scientists at Princeton, Christopher Harig and Frederik J. Simons. The Princeton team found that over the period January 2003 to 2014, there was a loss of ice overall. the overall mass loss from Antarctica since January 2003 at 92 ±10 Gt/yr.

It's also different from the results reported in a paper by Malcolm McMillan and colleagues last year. They estimated the current mass loss over all Antarctica at 159 ± 48 Gt/year. ".

So one group of scientists find that ice has been on balance increasing, while others find that ice has been on balance decreasing.

Sunday, July 12, 2015

Reflections from surface and clouds - is there an albedo expert in the house?

Sou | 4:36 PM Go to the first of 10 comments. Add a comment
Wondering Willis Eschenbach is a mite upset (archived here, latest here) because scientists aren't telling him he's right. In fact, they aren't telling him anything at all. And few of the readers at WUWT are helping him out, though a number are encouraging him with "scientists don't know nuffin'" comments.

Warnings - This article is long and meanders a bit - I have to call a halt at some point. This is just a blog article after all :) If you are looking for definitive answers about albedo, you won't find them. What you will get are some of the interesting bits and pieces I discovered as I went looking. There's no guarantee I've got it all right, either. This is something I've not explored in depth before now. So feel free to quibble in the comments.

Back to Willis Eschenbach. He thinks he's found a problem with a chart in a paper by Graeme Stephens of NASA's Jet Propulsion Laboratory in Pasadena (and elsewhere), and colleagues. The paper is about planetary albedo, which is the the fraction of the incoming solar energy scattered by Earth back to space. It's not a bad introduction to the subject, with some caveats as you'll see. The authors make two main points, as described in the abstract:
  1. the Northern and Southern Hemispheres (NH, SH) reflect the same amount of sunlight within ~ 0.2Wm 2. This symmetry is achieved by increased reflection from SH clouds offsetting precisely the greater reflection from the NH land masses. 
  2. The albedo of Earth appears to be highly buffered on hemispheric and global scales as highlighted by both the hemispheric symmetry and a remarkably small interannual variability of reflected solar flux (~0.2% of the annual mean flux).

Thursday, May 28, 2015

Anthony Watts and his ozone hole deniers are out in force (again)

Sou | 2:29 AM Go to the first of 16 comments. Add a comment
In yet another "claim" headline, Anthony Watts shows yet again how he denies science. Not just climate science but atmospheric chemistry as well. This, mind you, is the same week as he sent his fans to spam Wikipedia denying his denial of science.

This time his headline is about a press release that he copied and pasted, about the ozone layer (archived here). Anthony's denial only comes via his headline: Claim: ‘Severe ozone depletion avoided'. It's not the first time he's denied that ozone-depleting substances such as chlorofluorocarbons (CFCs) react with ozone in the stratosphere, destroying it (see further reading below).

The paper, by Professor Martyn Chipperfield and colleagues, is in Nature Communications. The authors discuss how the ozone hole would have been much worse had the world not agreed (through the Montreal Protocol) to stop releasing ozone-depleting substances. The researchers developed a model to investigate what would have happened if action had not been taken. They describe this as (from the abstract, my dot points and emphasis):
  • A deep Arctic ozone hole, with column values <120 DU, would have occurred given meteorological conditions in 2011.
  • The Antarctic ozone hole would have grown in size by 40% by 2013, with enhanced loss at subpolar latitudes.
  • The decline over northern hemisphere middle latitudes would have continued, more than doubling to ~15% by 2013.

Friday, May 22, 2015

Tasteless and ignorant at WUWT: A repugnant combination in denial of rising sea level

Sou | 11:10 PM Go to the first of 35 comments. Add a comment
Anthony Watts sense of humour would not be shared by most decent people. It might even shock. Today he has copied an ugly cartoon that he said was posted by Rick McKee on Anthony's WUWT Facebook page (archived here). To save you looking, I'll describe it.

The cartoon pictures seven bearded men dressed in gear the colour of the garments worn by Buddhist monks, all wearing a crucifix around their necks. Bearded Christian Buddhists? The men are all kneeling in front of a puddle of water. Behind them is a large figure in black wielding a large knife and wearing a full face mask. That figure is probably meant to signify an ISIS militant. To the right is what I think is meant to be a caricature of President Obama, talking to the kneeling bearded men (I think they are meant to represent journalists brutally beheaded). Underneath is the caption: "I just want you to know I'm throwing the full force of the U.S. military behind stopping the horror of this rising sea level!"

The word "horror" is highlighted in red and underlined.

Anthony thinks this is funny. Seriously. He thinks the brutal murder of journalists in the middle east is cause for mirth and mockery. He put his cartoon under the headline and text:
Friday Funny – the horror of rising sea levels in context
As many know, Mr. Obama made some wild claims about climate at the recent U.S. Coast Guard Academy commencement.
For example:
“The world’s glaciers are melting, pouring new water into the ocean.  Over the past century, the world sea level rose by about eight inches.  That was in the last century; by the end of this century, it’s projected to rise another one to four feet.

Monday, April 20, 2015

Lifting the floor at WUWT, to adapt to sea level rise

Sou | 2:20 PM Go to the first of 15 comments. Add a comment
Over the last couple of days Anthony Watts has handed his WUWT keys over to Eric "eugenics" Worrall. Eric is giving some advice to people living in coastal areas, particularly those areas where rising sea level is going to have a big impact. (Archived here.)

Eric's advice to WUWT-ers who live on the sea shore, is to raise the floor of your house every twenty years. The WUWT article said that Gavin Schmidt's advice was "whacky".  It's Eric's advice that needs to be "whacked".

Eric read an interview with Gavin Schmidt in the Vancouver Sun and picked out one question to write about. Gavin was asked about the future for waterfront cities like Vancouver. He replied that sea levels aren't going to go down. He also pointed out that there is a huge difference between a rise in sea level of one or two feet a century and a rise of one or two metres a century. Gavin wryly commented that the basement won't be the best place for electrical equipment.

Eric did some arithmetic and discovered that two metres in a century worked out at two centimetres a year. (He's not all dumb.) He figured that it would be okay to just lift the house forty centimetres every two decades.

Two little pigs could do it

I don't know what sort of house Eric had in mind. If the house were made of straw, then lifting it wouldn't be too difficult. If it were made of twigs, then it's a bit more of a challenge but do-able. However, if it were built of bricks, then you'd risk the house cracking and collapsing if you tried to lift it by forty centimetres.

Thursday, February 5, 2015

Jim Steele brings the Arctic to Antarctica

Sou | 7:31 PM Go to the first of 16 comments. Add a comment


There's a very odd article at WUWT by Jim Steele about Antarctic sea ice (archived here, latest here). He started off the article saying he'd just read a new paper about Arctic sea ice. The paper, by Neil Swart and colleagues was published in Nature at the end of January.

The introduction to the paper sets the scene:
Internal climate variability can mask or enhance human-induced sea-ice loss on timescales ranging from years to decades. It must be properly accounted for when considering observations, understanding projections and evaluating models.

The scientists were looking at trends in Arctic sea ice in recent years. What they were looking at in particular was the extent to which internal climate variability can affect the trend. That is, how much of the ups and downs in Arctic sea ice could come from internal variability compared to the underlying decline from enhanced greenhouse warming.

The main message from the paper, I think, is that Arctic sea ice decline is not necessarily underestimated by climate models. The recent big dips of 2007 and 2012 could be natural variability. It's difficult to tell.


Thursday, January 15, 2015

Despite the winter ice, Rolf E Westgard's pants catch fire at WUWT

Sou | 1:49 AM Go to the first of 20 comments. Add a comment

Why can't deniers just deny science? Some of them have to go further and make up stuff.

Today there's an article by someone called Rolf E. Westgard who's a petrol head as far as I can tell.  He's been featured here before, waffling on about clouds.

This time he's decided to see how many fibs he can tell in a single "guest essay". As with all good fibs, he skirts around the facts - quite a long way around. He mostly manages to avoid bumping into them.



Wednesday, December 31, 2014

Duet on Ice: More denier silliness at WUWT

Sou | 1:26 AM Go to the first of 21 comments. Add a comment

This will be short-ish - by HotWhopper standards :). It's about a duo of articles at WUWT. About ice at opposite ends of the earth - Greenland and Antarctica.

Jim Steele's Bold Greenland Prediction


Jim Steele wrote an article (without mentioning Camille Parmesan once!) predicting that Greenland will start accumulating ice next year. He pulled something out of thin (Arctic) air and wrote:
And based on historical analyses, Greenland will likely begin gaining mass in the coming years.

Wednesday, December 3, 2014

Shifting into high gear: Amundsen Sea Embayment melt - Antarctica

Sou | 1:47 PM Go to the first of 28 comments. Add a comment

While WUWT has slowed to a crawl the science hasn't. So today I'll just write about a new paper in Geophysical Research Letters (GRL).

A large team led by Tyler C. Sutterley has found that in fast-melting regions of Antarctica, the rate of melt has tripled during the last decade. The team includes scientists from the USA, France, the Netherlands and the UK and includes some whose names you'll probably recognise, such as Eric Rignot and Isabella Velicogna. They did a comprehensive analysis of measurements of glaciers in the Amundsen Sea Embayment over last 21 years, evaluating and reconciling observations from four different measurement techniques. The loss has been accelerating, a lot.

UCI and NASA glaciologists, including Isabella Velicogna and Tyler Sutterley, have discovered that the melt rate of glaciers in West Antarctica has tripled, with the loss of a Mt. Everest's worth of water weight every two years.
Credit: Michael Studinger / NASA  Source: UC Irvine


Tuesday, November 25, 2014

An unsustainable planet - and yellow submarines in Antarctica

Sou | 3:17 PM Go to the first of 3 comments. Add a comment

I was reading WUWT today, there's an interesting article about new research on Antarctic sea ice, which the WUWT-ers are finding difficult to get their head around. Anthony didn't go to any trouble as usual (archived here), he just copied and pasted the press release. If you want to keep up with science news, you'd do better by reading ScienceDaily.com than WUWT. So here's a bit more about it, plus the denialati reaction.

First the research itself. There's a press release at ScienceDaily.com about how scientists have produced detailed, high-resolution 3-D maps of Antarctic sea ice. That means ice thickness as well as showing how ice behaves in winter (there's not much sea ice in summer around Antarctica). Here's a map highlighting the areas that the scientists wrote up about in the paper in Nature Geoscience. As always, click to enlarge.




Wednesday, October 22, 2014

On Antarctic ice: The ongoing ignorance of deniers at WUWT

Sou | 4:55 PM Go to the first of 36 comments. Add a comment

Some people will put down the disinformation spread by Anthony Watts to him being plain dumb and ignorant. Others will say that he's not really as dumb as he looks and sounds, he's just deceitful and has made a business out of conning the ignorant.

I don't know where on the idiot-liar scale Anthony Watts lies.



These past couple of days Anthony Watts has:

Now he's claiming (archived here) that John Cook at SkepticalScience.com said that Antarctic sea ice is the result of the Southern Ocean getting warmer. He even linked to the web page where John Cook gave the following reasons for the increase in Antarctic sea ice:
  1. the drop in ozone levels over Antarctica, resulting in stronger winds, which creates polynas, which freeze up and add to sea ice.
  2. a change in ocean circulation with top layer of the ocean being colder and fresher, which freezes more easily than more saline water at the same temperature. It's colder at the top because of more snow and rain as a result of warmer air temperatures.

Saturday, October 11, 2014

Australia's Environment Minister, Greg "I am the egg man" Hunt - how embarrassing

Sou | 2:04 AM Go to the first of 7 comments. Add a comment

In Australia, about the closest we have to a Science Minister these days is Greg Hunt, the Minister for Envirnoment.


Talking about a 20-year Antarctic Strategic Plan, released today, Australia's Environment Minister , Greg Hunt said:

"Whether it's in relation to the walrus population, whether it's in relation to penguins, you can have iconic species which can attract community interest,"

The ABC website commented dryly:
Although no walruses live in Antarctica, the Minister's commitment to preserve Antarctic biodiversity was welcomed by Antarctic researchers.





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Thursday, October 2, 2014

Not so fast, WUWT! Antarctica could melt quite quickly.

Sou | 9:54 PM Go to the first of 7 comments. Add a comment

In another "it won't happen to me" article at WUWT, Anthony Watts decides that all the science is wrong again. Not that he'd be able to tell, even if he had a year to try to figure it out according to his close friend and ally, Willis Eschenbach.

There is a new paper out in Nature Communications about meltwater pulses and accelerated ice loss from Antarctica. It describes model simulations of Antarctic ice sheet evolution over the last 25,000 years. What was found was "several episodes of accelerated ice-sheet recession, the largest being coincident with meltwater pulse 1A." The abstract continues: "This resulted from reduced Southern Ocean overturning following Heinrich Event 1, when warmer subsurface water thermally eroded grounded marine-based ice and instigated a positive feedback that further accelerated ice-sheet retreat."

Below is a clever animation from the Nature Communications article, demonstrating how the warmer sub-surface of the ocean can melt Antarctica.

Tuesday, September 16, 2014

Tectonic Anthony Watts moves continents using waste heat from little pockets of humanity!

Sou | 5:43 AM Go to the first of 20 comments. Add a comment

If you want to visit Antarctica, don't go to Anthony Watts for directions. This is where he says it is:

Warming doesn’t seem to be a problem when you look at the satellite data for the Antarctic continent, in fact, there is a slight cooling:

Anthony Watts has the power to move a continent


This is his "proof" of the slight cooling of the continent of Antarctica:

Source: WUWT with annotation by HotWhopper

This is how far he's managed to move the continent:

Adapted from Google Earth

(If you're on the home page, click read more to find out why Anthony took it on himself to move an entire continent. Plus there's lots, lots more...)

Saturday, August 16, 2014

Antarctica and rising seas, plus querying Holocene temperature trends

Sou | 2:44 PM Go to the first of 6 comments. Add a comment


Worrall's up with that?


I was beginning to think that Anthony Watts had sold off his blog to Eric Worrall, who is a nobody, just another also-ran denier who comments a lot on various blogs. He is big on opinions and very short on knowledge. (Most of his articles are shallow and silly. I've written about them on occasion, like here and here and here.) I was starting to think that because of a rash of nothing articles by him filling up the daily WUWT quota. Turns out it's just that Anthony has been travelling or working or something or the other, and his normal workforce wasn't coming up with anything he could blog. Except for Tim Ball. But he's a complete write-off and I've already spent way too much time on his conspiracy theories.

Given that WUWT has been so boring the past couple of days, I'll write about two new science papers instead.


Antarctic melt will raise sea level by 1 to 37 cm this century


First there's a new paper from scientists at the Potsdam Institute for Climate Impact Research (PIK), which estimates sea level rise this century from the melting of Antarctica. If you were hoping for an estimate to the nearest centimetre, be prepared to be disappointed. The research team came up with a range from one centimetre to 37 centimetres this century. That seems not terribly helpful until you learn that the upper limit is quite a bit higher than what was projected in the latest IPCC report. From ScienceDaily.com:
For the first time, an international team of scientists provide a comprehensive estimate on the full range of Antarctica's potential contribution to global sea level rise based on physical computer simulations. Led by the Potsdam Institute for Climate Impact Research, the study combines a whole set of state-of-the-art climate models and observational data with various ice models. The results reproduce Antarctica's recent contribution to sea level rise as observed by satellites in the last two decades and show that the ice continent could become the largest contributor to sea level rise much sooner than previously thought.
"If greenhouse gases continue to rise as before, ice discharge from Antarctica could raise the global ocean by an additional 1 to 37 centimeters in this century already," says lead author Anders Levermann. "Now this is a big range -- which is exactly why we call it a risk: Science needs to be clear about the uncertainty, so that decision makers at the coast and in coastal megacities like Shanghai or New York can consider the potential implications in their planning processes," says Levermann.
The scientists analyzed how rising global mean temperatures resulted in a warming of the ocean around Antarctica, thus influencing the melting of the Antarctic ice shelves. While Antarctica currently contributes less than 10 percent to global sea level rise and is a minor contributor compared to the thermal expansion of the warming oceans and melting mountain glaciers, it is Greenland and especially the Antarctic ice sheets with their huge volume of ice that are expected to be the major contributors to future long-term sea level rise. The marine ice sheets in West Antarctica alone have the potential to elevate sea level by several meters -- over several centuries.
According to the study, the computed projections for this century's sea level contribution are significantly higher than the latest IPCC projections on the upper end. Even in a scenario of strict climate policies limiting global warming in line with the 2°C target, the contribution of Antarctica to global sea level rise covers a range of 0 to 23 centimeters.

Right now the contribution of Antarctica to sea level rise is minimal. This paper shows that could change in the near term. Going by other studies that's pretty likely. I've written before about a raft of studies that came out a few weeks ago, particularly looking at West Antarctica - here and here and here.


Was the surface temperature rising or falling in the Holocene?


Another interesting paper was challenging the prevailing view that global surface temperatures were falling during much of the Holocene. The question is referred to as the Holocene conundrum, which I've never heard of before. Maybe you have. The paper was by an international team of researchers, with the lead author being Zhengyu Liu from the Nelson Center for Climatic Research and Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison.  Some excerpts from ScienceDaily.com:
Writing in the journal Proceedings of the National Academy of Sciences today, Liu and colleagues from Rutgers University, the National Center for Atmospheric Research, the Alfred Wegener Institute for Polar and Marine Research, the University of Hawaii, the University of Reading, the Chinese Academy of Sciences, and the University of Albany describe a consistent global warming trend over the course of the Holocene, our current geological epoch, counter to a study published last year that described a period of global cooling before human influence.
The scientists call this problem the Holocene temperature conundrum. It has important implications for understanding climate change and evaluating climate models, as well as for the benchmarks used to create climate models for the future. It does not, the authors emphasize, change the evidence of human impact on global climate beginning in the 20th century.
"The question is, 'Who is right?'" says Liu. "Or, maybe none of us is completely right. It could be partly a data problem, since some of the data in last year's study contradicts itself. It could partly be a model problem because of some missing physical mechanisms."
Over the last 10,000 years, Liu says, we know atmospheric carbon dioxide rose by 20 parts per million before the 20th century, and the massive ice sheet of the Last Glacial Maximum has been retreating. These physical changes suggest that, globally, the annual mean global temperature should have continued to warm, even as regions of the world experienced cooling, such as during the Little Ice Age in Europe between the 16th and 19th centuries.
The three models Liu and colleagues generated took two years to complete. They ran simulations of climate influences that spanned from the intensity of sunlight on Earth to global greenhouse gases, ice sheet cover and meltwater changes. Each shows global warming over the last 10,000 years.
Yet, the bio- and geo-thermometers used last year in a study in the journal Science suggest a period of global cooling beginning about 7,000 years ago and continuing until humans began to leave a mark, the so-called "hockey stick" on the current climate model graph, which reflects a profound global warming trend.
In that study, the authors looked at data collected by other scientists from ice core samples, phytoplankton sediments and more at 73 sites around the world. The data they gathered sometimes conflicted, particularly in the Northern Hemisphere.
Because interpretation of these proxies is complicated, Liu and colleagues believe they may not adequately address the bigger picture. For instance, biological samples taken from a core deposited in the summer may be different from samples at the exact same site had they been taken from a winter sediment. It's a limitation the authors of last year's study recognize.
"In the Northern Atlantic, there is cooling and warming data the (climate change) community hasn't been able to figure out," says Liu.
With their current knowledge, Liu and colleagues don't believe any physical forces over the last 10,000 years could have been strong enough to overwhelm the warming indicated by the increase in global greenhouse gases and the melting ice sheet, nor do the physical models in the study show that it's possible.
"The fundamental laws of physics say that as the temperature goes up, it has to get warmer," Liu says. 

I wonder who wrote that last sentence? Press releases often put words into people's mouths without their knowledge.

I expect the other paper they are referring to is the Marcott study, which was a detailed estimate of global surface temperature trends for the entire Holocene. I don't know what the reaction is from the rest of the paleo community. If you come across comments on the paper, or (informed) blog articles about it, I'd be interested to see them.

Update

Richard Telford has a blog article about the Zhengyu Liu paper, at his blog Musings on Quantitative Palaeoecology. (H/t Steve Bloom).
[Sou  - later in the day on 16 August 2014]


A. Levermann, R. Winkelmann, S. Nowicki, J. L. Fastook, K. Frieler, R. Greve, H. H. Hellmer, M. A. Martin, M. Meinshausen, M. Mengel, A. J. Payne, D. Pollard, T. Sato, R. Timmermann, W. L. Wang, R. A. Bindschadler. "Projecting Antarctic ice discharge using response functions from SeaRISE ice-sheet models." Earth System Dynamics, 2014; 5 (2): 271 DOI: 10.5194/esd-5-271-2014

Zhengyu Liu, Jiang Zhu, Yair Rosenthal, Xu Zhang, Bette L. Otto-Bliesner, Axel Timmermann, Robin S. Smith, Gerrit Lohmann, Weipeng Zheng, and Oliver Elison Timm. "The Holocene temperature conundrum. PNAS", August 11, 2014 DOI: 10.1073/pnas.1407229111

Thursday, July 3, 2014

About increasing winter Antarctic sea ice and decreasing summer Arctic sea ice

Sou | 5:35 AM Go to the first of 8 comments. Add a comment

Science deniers are making a lot out of the growth in Antarctic sea ice, mostly over winter.  Strangely enough they aren't accusing scientists of fabricating the data, for a change.

Here's a chart from The Cryosphere Today (not, as Anthony's ill-informed "guest" referred to it, Today Cryosphere or maybe just Cryosphere). It's hit a record high for this time of year - ie since 1979.

Source: The Cryosphere Today

The main reasons for the increase in sea ice are described very nicely in this thread on the Arctic Sea Ice Forum (h/t Neven). As AbruptSLR points out:
...on average the Antarctic Sea Ice Area is going up by 0.2% per year, and the average thickness is going up 0.2% per year, resulting in an average sea ice volume increase of 0.4% per year.  However, these numbers are orders of magnitude lower than the corresponding changes taking place to the Arctic Sea Ice.

I did this chart last year (you can read my previous article on the subject here, with some reading material about models not projecting the observed increase in Antarctic sea ice). I combined the Arctic and Antarctic at their respective minima to illustrate the point. That means I've put the September values in the Arctic with the February values for Antarctica. It's missing the latest years. I'll update it after September if I remember to do so. Click to see it larger, as always.

Data source: NSIDC

The big impact on climate is in the summer. It's summer ice cover that affects albedo, not mid-winter ice, when the poles are in darkness. (Not that there's any sea ice at the South Pole.)

As for why the sea ice in the southern oceans is increasing, AbruptSLR has this to say (and a lot more besides):
Denialist should be aware that not only is the average water temperature in the Southern Ocean increasing with time, but also the air temperature above the Southern Ocean is increasing with time, and the following linked research makes it clear that the most significant reason why the Antarctic Sea Ice is increasing is due to the formation of the seasonal Antarctic ozone hole after the mid-1980's created by anthropologically induced chlorides in the upper atmosphere over Antarctica; which in turn caused the circumpolar Antarctic westerly wind velocity to increase (see the following abstract for the influence of this increased wind velocity on the Antarctic Sea Ice); and the linked reference indicates that the intensifying regional winds in Antarctic is one of the most significant factors accounting for the increasing maximum extent of Antarctic sea ice. 

There is a lot of useful information and references to scientific papers in that thread. I don't have time to research and write about this right now. And I doubt I could do it any better than AbruptSLR in any case, and probably a lot worse.

Again, here is a link to the discussion. It's well worth a read, especially for anyone who wants to rebut denialist nonsense on the subject.

As for what's happening in the Arctic, well somewhat surprisingly, the ice extent is dropping quite a bit. It doesn't look as if it will break the 2012 record low though. Neven's blog is the place to go to keep up with what's happening there.

Source: Arctic Sea Ice Monitor

From the WUWT comments


Anthony Watts prefers to focus his readers attention on Antarctica, rather than the Arctic and to spread his usual disinformation about. Here are some of the mindless comments he hoped for and got:

Lucius von Steinkaninchen says:
July 2, 2014 at 11:24 am
* * * It’s getting colder around Antarctica and so the ice is growing * * *
In a world of some fields of Science degenerated enough to forget Occam’s Razor, it is so refreshing to see a simple model tying up cause and effect…

Bob Diaz says:
July 2, 2014 at 11:25 am
It appears that reality does not agree with the computer models.
How could reality be so wrong??? ;-))

Ben Howison says:
July 2, 2014 at 11:27 am
Looks kinda like a hockey stick, doesn’t it? 

Shawn from High River is about the only person who says something sensible, but I doubt he realises it. He says:
July 2, 2014 at 11:29 am
When these pesky facts get in the way of the prevailing theory,they just modify the theory to suit the facts

JimS says:
July 2, 2014 at 11:41 am
It is all so logical, it is astounding that no one can catch onto a very simple principle.
At the north pole, when sea ice trends to diminish, that means it is a sign of global warming.
However, at the south pole, on the opposite side of the earth, sea ice is increasing. But since this is on the opposite end of the earth, increasing sea ice means that is a sign of global warming.
These are opposite poles you see, so the exact opposite trend means the same thing. It is all global warming! 
Sheesh! (/sarc) 

John Schwartz says:
July 2, 2014 at 11:51 am
Just doesn’t fit the narrative, does it…