The National Snow and Ice Data Centre (NSIDIC) publishes the extent of daily Sea Ice coverage for both the Arctic and Antarctic. These are derived from from meteorological satellite images. Often you see more alarming plots of rapidly disappearing Sea Ice based instead on ‘area’ , for example that produced by Cryosphere Today. The difference is that ‘area’ subtracts all surface pixels which identify from space as being water rather than ice inside a 25 km^2 grid cell. During summer, ‘melt pools’ appear naturally on top of solid ice and as a result the area method treats these as open water, thereby exaggerating apparent ice loss. As NSIDC itself writes:
Scientists at NSIDC report extent because they are cautious about summertime values of ice concentration and area taken from satellite sensors. To the sensor, surface melt appears to be open water rather than water on top of sea ice. So, while reliable for measuring area most of the year, the microwave sensor is prone to underestimating the actual ice concentration and area when the surface is melting. To account for that potential inaccuracy, NSIDC scientists rely primarily on extent when analyzing melt-season conditions and reporting them to the public.
Therefore the temptation of those who want Arctic warming to appear dramatic will tend to use area. This realisation of this tendency only resulted after a twitter exchange with @GreatWhiteCon and his supporters. As a result I will use extent data from NSIDC for the rest of this post. First lets see all the daily values of Ice extent since 1978
Antarctica sea ice almost completely melts every summer, but gains a massive ~ 15 million km^2 each winter. This is twice the seasonal range of the Arctic, where a core amount (5-7 million km^2) survives each summer as perennial ice. This perennial ice has been slowly reducing, but even today remains at about 5 million km^2. If you just look by eye at the trend then it should be another 30 years before the Arctic perhaps becomes Ice free in summer. The following graph now shows how the minimum annual global coverage which occurs around February each year has changed since 1979.
There has been a reduction of about 1.5 Million square kilometers globally. Next we look at the Sea Ice ‘anomalies’, which is the difference between the measured daily values and the average for each day as calculated from 1978 to 2010. The concept is similar to temperature anomalies and is intended to show changes in trends over time.
So the Arctic has lost around 1.6 million km^2 whereas Antarctica has gained about 1 million km^2. While a loss in sea ice is expected in climate models I am not aware of any which can realistically explain the sudden increase in Antarctica. Globally though the net result is a loss of around 0.6 million km^2. This must affect the radiative balance globally slightly on earth since ice has a much larger albedo than water.
The message is that the next time you see some scary graph of vanishing Arctic ice always first check whether it refers to ‘Extent’ or ‘Area’. There is a very large difference between the two!
Here below the Storify recording made by Jim Hunt.
Isn’t there another parameter of ice called thickness, or depth , which may also be significant?
Yes there is but I cannot find any direct measurement of ‘ice volume’ from space (Lidar or something). Do you or anyone else know of such direct measures rather than that deduced from models?
Only if it is a linear trend, and it looks like it is not. Apparently Arctic ice follows a cycle related to AMO.
A signal of persistent Atlantic multidecadal variability in Arctic sea ice
M.W. Miles et al. 2014. Geophys. Res. Lett., 41, 463–469.
“We establish a signal of pervasive and persistent multidecadal (~60–90 year) fluctuations… Covariability between sea ice and Atlantic multidecadal variability as represented by the Atlantic Multidecadal Oscillation (AMO) index is evident during the instrumental record. This observational evidence supports recent modeling studies that have suggested that Arctic sea ice is intrinsically linked to Atlantic multidecadal variability.
Given the demonstrated covariability between sea ice and the AMO, it follows that a change to a negative AMO phase in the coming decade(s) could —to some degree— temporarily ameliorate the strongly negative recent sea-ice trends.”
Check their figure 2. This essentially explains why since 2007 Arctic ice is quite stable and probably is going to be like that for a couple more decades.
Thanks for reproducing my “Storify” here.
However I feel I should point out before anybody gets completely the wrong idea that @GreatWhiteCon is not a “he” but is in actual fact Snow White, the world famous “cowardly cross-dresser”. Here is the whole sordid tale:
As regards thickness & volume, why not start here?
There you will find more flavours than even a drunken sailor could dream of, CryoSat 2 being the nearest thing to that which you seek.
Your argument makes no sense during the winter when there are almost no melt pools. Why cant you admit that Snow White knows much more about the subject and try to learn?
It’s the same argument in winter since mixtures of ‘water’ pixels and ice ‘pixels’ are just as difficult to interpret. Better in my opinion to define within each grid cell a threshold of ice pixels and then sum up each grid cell.
1) What would be your opinion on our planet losing all of its Summer sea ice in the course of one human generation? Would you consider that fast or normal?
2) What would the consequences of this loss be, do you think?
How about Manabe 1992? I repeat, 1992. See here.
You could try data from ICEsat and CryoSat-2 (see for instance ” rel=”nofollow”>this graph).
How can you end your blog post like this when you have shown nothing of the sort? Maybe you could really plot the differences between extent and area, for instance by using these NSIDC monthly averages. Maybe start with September, the month of the minimum sea ice cover.
My opinion is that it is not going to happen. Already the most pessimistic views based on exponential or sigmoid fits to PIOMAS around 2007-2012 that predicted a nearly-ice free Arctic summer by 2015-2020 made by Maslowski, Wadhams, and Zwally, and popularized by Gore, have failed miserably.
– 2007 Nobel prize laureate Al Gore predicts North Polar ice cap falling off a cliff seven years from now by 2014 based on scientific studies.
Al Gore Nobel lecture.
– 2007 Prof. Wieslaw Maslowski from Dept. Oceanography of the US Navy predicts an ice-free Arctic Ocean in summer by 2013, and says that prediction is conservative.
Arctic summers ice-free ‘by 2013’
– 2007 NASA climate scientist Jay Zwally predicts that the Arctic Ocean could be nearly ice-free at the end of summer by 2012.
Arctic Sea Ice Gone in Summer Within Five Years?
– 2012 Prof. Wieslaw Maslowski from Dept. Oceanography of the US Navy predicts a nearly ice-free Arctic Ocean in summer by 2016 ± 3 years.
US Navy predicts summer ice free Arctic by 2016.
Scientific article: The Future of Arctic Sea Ice
– 2012 Prof. Peter Wadhams, head of the polar ocean physics group at the University of Cambridge, predicts a collapse of the Arctic ice sheet by 2015-2016.
Arctic expert predicts final collapse of sea ice within four years
Now predictions based on worse case CO2 scenarios like those of NSDIC’s Serreze for 2030 are also going to fail.
– 2010 Mark Serreze, director of the NSIDC predicts summer ice free Arctic by 2030.
Arctic ice could be gone by 2030
The question is if more “prudent” scenarios that predict the end of Arctic sea ice for 2040-2080 are likely or not. The evidence of the relationship between Arctic sea ice and AMO suggest that Arctic sea ice will probably not disappear within the 21st century and we will have to see if the warming proceeds over more than a hundred years, as the climate of the Earth is quite cyclical.
Arctic sea ice is linked to AMO, a periodic oscillation:
A signal of persistent Atlantic multidecadal variability in Arctic sea ice. M.W. Miles et al. 2014. Geophysical Research Letters 41, pg. 463-469.
There is no scientific reason to believe that anybody alive is going to see the end of Arctic sea ice. And please let’s not forget that any Arctic or global sea ice minimum within 2015-2016 is the product of El Niño unusual warming, and not part of a long trend, and might be reversed in full by a strong La Niña in the 2017-2018 period.
Q1 – Since Clive hasn’t responded yet, please can you explain how you managed to embed that image in a comment on here?
Q2 – Let’s try a video instead. If this one embeds, what do you make of it?
Very simple. Just paste the link to the figure without tags. WordPress is smart enough to understand that a link that ends in gif, jpeg or png is a figure.
Would it surprise you to learn that I had already experimented along the lines of your suggestion?
Now that my Q1 has been answered, let’s return to my qQ2. What do you make of the video?
Sorry, Snow White. I almost never watch videos. I am a fast reader and videos are a waste of time more often than not. However if you have scientific citations that might be a different thing. I am always interested in what other scientists have to say.
Actually I’m still waiting to see the list of citations that have your name at the top. It must be an extremely long one, or do you type much slower than you read?
First of all, I asked Clive, not you.
Second of all, I definitely didn’t ask for a copypasted Gish Gallop full of strawmen. The community of cryospheric scientists doesn’t consist of just Wadhams (extreme outlier), Maslowski (reports what his model projects, a model that has ocean heat flux as an important factor, unlike other models) and Zwally (he didn’t say anything out of the ordinary with ‘At this rate…could…’). Mainstream opinion is between 2030-2040 for the Arctic to go ice-free for all practical purposes (below 1 million km2).
Third, that paper you cite does not say all of the Arctic sea ice loss is caused by the AMO. It focuses on the Atlantic side of the Arctic where the effect of the AMO is greatest. And here’s the last sentence of the abstract: “This may have implications for understanding the recent negative trend in Arctic winter sea ice extent, although because the losses have been greater in summer, other processes and feedbacks are also important.”
The AMO plays a role, but the writers of this 2012 paper “attribute 0.5–3.1%/decade of the 10.1%/decade decline in September SIE (1979–2010) to AMO driven variability”. Mind you, the paper was published before the 2012 record melting season, which had nothing whatsoever to do with El Niño (just like runner-up 2011). I have looked for a correlation between ENSO and Arctic sea ice extent data, and it simply isn’t there.
If you have real evidence of a 1-on-1 link between AMO and Arctic sea ice loss, I’d be happy to hear all about it.
Even if there is a link between ENSO and Arctic sea ice extent, it would take a while for El Niño induced warming to reach the Arctic. So, no, if there is a new record, it won’t be because of El Niño. If things were that simple…
I can only conclude that for some reason or other you’re afraid the record will be broken again this year. Maybe you realize what the potential consequences of Arctic sea ice loss are. I fully agree.
So what. Participation is free. You don’t like my answer, tough luck.
It is not going to happen. The cooling of the North Atlantic indicates that Arctic sea ice is going to be more resilient that thought.
How Climate Model Complexity Influences Sea Ice Stability. Wagner & Eisenman 2015. Journal of Climate 28, 10, 3998-4014.
“the stability of the ice cover vastly increases with the inclusion of spatial communication via meridional heat transport or a seasonal cycle in solar forcing, being most stable when both are included. If the associated parameters are set to values that correspond to the current climate, the ice retreat is reversible and there is no instability when the climate is warmed”
Exactly, and it is not properly quantified, nor properly included in models. Hence the melting is probably going to be less than expected.
During past interglacial, not only all Arctic sea ice melted, but also almost all of Greenland ice sheet. That’s the reason Greenland ice cores end in the Eemian. We are not going to get that warm in this interglacial. We will run out of fossil fuels within this century.
This one looks like it is going to be a complete failure. Decades from now people will wonder why cryospheric scientists looked so sure and yet got it so wrong. The answer is because they think in linear terms instead in cycles, and were too lazy to read about the previous phase of Arctic melting that was well reported by scientists during the 1930’s and 40’s, and mostly reverted in the 60’s.
Have you actually read Wagner & Eisenman 2015? Have you read Eisenman’s earlier work? Have you read this comment of mine posted shortly after the 2015 paper was published?
Note that Wagner & Eisenman are not attempting to model the “real world”!
Of course they aren’t. They set to find out why some simplified and regional models predict non-linear instability of sea ice, when most GCM do not. For that they needed a model with the least complexities to demonstrate where the instability was coming from. I guess the referees understood why they needed such a model.
So what’s any of that got to do with the topic of the original post? Extent versus area, and by implication global versus regional?
If a simplified model agrees with GCM’s that there is no hysteresis in sea ice cover should global temperatures decline it doesn’t prove diddly squat (to use the scientific terminology) about what happens to sea ice when global temperatures are increasing.
I too am still eagerly awaiting your list of published papers.
I agree that there could be some surprises with natural variability in Arctic Sea Ice. It must depend also on the AMOC and if this follows a natural cycle then we would expect variatiuons in ice cover. The accurate satellite data is still to short in time to observe any 60 year period.
I am certainly not happy about the loss of sea ice from the Arctic. I am not happy about most of the impacts on the natural world from 7 billion popoulation and rising. I just don’t know what to do about it, and nor do I suspect does anyone else. It is glib nonsense to pretend that all we need to do is to curb carbon emissions and somehow everything will be OK – It won’t. Human nature being what it is someone will burn most of the easily extracted fossil fuels. Individuals are driven by greed and the desire to improve their lot. Just look at the annual burning of the rain forests in Borneo and Sumatra mainly to plant Palm Oil and Bio-Diesel. You cannot police the developing world.
If the arctic sea ice disappears completely during September it would be a shame – but not a disaster. Only if the Greenland Ice sheet melts would there be serious consequences and large sea levels rise. During the last interglacial125,000 years ago (Eemian) it is likely that the Arctic was ice free, temperatures 3C warmer than today and sea levels about 3m higher. If you look at the coastline of Devon and Cornwall you can see the old water levels across Sand Dunes like the Braunton Burrows. Yes the climate would change but there would not be a climate ‘disaster’.
Thanks a lot for the reply, Clive.
I agree. I just hope that when enough individuals realize that the consequences of Arctic sea ice loss could have negative impacts on them, and that Arctic sea ice loss itself is a harbinger of more to come, the culture changes and the really nasty risks are reduced. I’m rather pessimistic that this will come about, but you know, think like a pessimist, act like an optimist.
Well, it depends on how you define disaster. And the current rate of change is rather uncommon, so analogies with previous interglacials are dodgy. Furthermore, it’s good to realize that the consequences of Arctic sea ice loss don’t start when September sees its first day of ice-free conditions, and neither do they stop developing then.
You seem to be good with statistics, and so, again, I would like to urge you to quantify the difference between extent and area (that you say is very large), and explain why one consistently produced metric is better than the other. There’s more to Arctic sea ice than a cursory looks tells you.
You can find links to various data sets at the top of the Arctic Sea Ice Graphs website.
Some more shock news for those that worry about Greenland:
“Jakobshavn is continuing massive calvings”
Clive – Are you by any chance local to Braunton Burrows?
I’m sorry, I screwed up the link to the ICEsat/CryoSat-2 graph.
)Clive: You didn’t – I added a plugin so all you need to do now is to add an image is put the URL on a line all by itself)
Thanks for your kind words Lawrence.
Since Clive his so keen on extent as an indicator of the health of global sea ice perhaps he could share his thoughts on this graph of Arctic sea ice extent, hot off the virtual presses this very morning?
A techie question for you Clive.
How might one go about embedding a graph in a comment here? It seems Neven and I have both tried, but failed miserably!
All you have to do now is to put the URL to the image all on a line by itself.
Did you actually read those papers? Neither appear to reach the conclusions you attribute to them.
Is it possible that you were deceived by a cheery picker at a climate change contrarian site and innocently posted them here?
@Javier certainly doesn’t seem to be scientifically literate enough to appreciate the difference between a “prediction” and a “projection”. By way of explanation of the difference see:
If Javier hails from the once Great Britain, perhaps he is an avid Mail reader?
Hehehe, couldn’t be more wrong on that. I’m a scientist and I’ve been reading papers for decades. I don’t know if you are capable of distinguishing between the different sections on a paper: Abstract, Introduction, Materials and Methods, Results and Discussion/Conclusion. The meat is in the results. What goes in discussion/conclusion is the scientists opinion. The data is usually correct, the interpretation of the data might be incorrect, as different scientists reach different interpretations from the same evidence.
The evidence shows very conclusively that Arctic ice is linked to AMO cycles. This explains why in September 2015 we had more sea ice than in September 2007, which means no significant melting for 8 years. 2015 was the warmest year on record yet no minimum was broken in September. We will see in seven more months if we break the record of 2012 or not. In any case 2017-18 should sea some Arctic ice recovery and it is possible that by then we have over 10 years without Arctic melting. Not good for Serreze’s projections and predictions.
Ho, ho, ho. Javier!
I even had the odd paper published in a reputable academic journal many moons ago. Plus a few more that were “Top Secret”. Where might I find an example of one that you’ve written in the public domain?
Given your analysis I can predict with high confidence that it won’t in the field of sea ice.
Now let me see if I can get Clive’s fancy new plugin to work. First let’s try the global sea ice area one that’s under discussion…..
Excellent! Thanks Clive.
Can we finally all agree that the global sea ice minimum area for calendar year 2016 is lower than all other years in the Cryosphere Today record going back to 1979?
Yes – I agree that 2016 minimum is the lowest ‘area’ for global sea ice cover as derived by Cryostat Today. However for global sea ice ‘extent’ 2007 and 2011 were lower than 2016.
Hmmm… On my screen the interesting bit at the far right is cropped off. You can always open it in a new tab I suppose, but is there anything the webmaster can do to resize things to fit the site’s width?
Hmm – Perhaps I need to find a WordPress plugin which autoscales images !
This one works for me:
I assume it handles images in comments as well, but I’ve never previosuly been forced to think about the issue!
I always resize my graphs to 740 px wide so they fit in any screen.
The problem is always the same. All those trends are meaningless because they only go from 1979, so they only catch a phase of the cycle. If one wants to make a fool of oneself, a sure way is to extract a linear trend from a cyclical phenomenon. We probably need 80 years of data to know where the Arctic ice is going. Alarmism at this point is unjustified.
The difference between a prediction and a projection is that the first is made by ‘hard’ science, whereas the second is the result of ‘fuzzy’ science.
For example the prediction of Gravity Waves was made by Einstein in 1916 and finally observed this week. His prediction was correct even if proved 100 years later
Examples of ‘fuzzy’ science projections are things like:
– eating butter causes heart disease
Again, you link to a scientific paper that doesn’t say what you think it says. Do you do this on purpose? I hope you’re aware of the possibility of misleading readers.
Not for one second does this paper say that “cooling of the North Atlantic indicates that Arctic sea ice is going to be more resilient that thought”. It’s about whether there is a tipping point in Arctic sea ice loss due to the albedo-ice feedback, causing an irreversible crash to ice-free conditions, as simpler models suggest, or whether loss up until ice-free conditions progresses linearly, as more complex GCMs suggest. Quote from the conclusion: “The present model simulates sea ice loss that is not only reversible but also has a strikingly linear relationship with the climate forcing as well as with the global-mean temperature.”
Arctic sea ice loss may very well be reversible, and let’s hope it is, but for that the forcing of greenhouse gases needs to be reduced first.
Given the fact that you repeatedly misquote scientific papers, I’m going to guess that you don’t have a clue as to what goes into models that simulate Arctic sea ice loss.
The only person so far who seems 100% sure about anything, is you. To think and then actually say that there is zero anthropogenic influence on Arctic sea ice loss and that ice-free conditions are impossible, given what has happened so far, is a sign of dogmatic thinking and zero skepticism. My experience is to not waste time on discussions with people who have that attitude. Good luck with your certitudes.
Not true, NevenA. Arctic sea ice seems to have expanded during the 60’s and 70’s while greenhouse gases were increasing. Regarding global mean temperatures we have several examples of them going in the opposite direction to GHGs. In fact that appears to have been the norm during the past 6000 years when temperatures were going down and GHGs were going up.
I haven’t misquoted anything. You are now making things up. Straw man arguments and false accusations indicate poor debating skills and/or poor arguments.
Again false accusations and straw man arguments. I never said there is zero anthropogenic influence on Arctic sea ice loss and that ice-free conditions are impossible.
Nobody knows how much anthropogenic influence there is on Arctic sea ice loss, not you, not me. Ice-free conditions are not impossible, just very unlikely within 21st century. Most cryospheric scientists have not understood the nature of the problem they are studying. It happens all the time in science and appears to be even more common in climatology.
Now lets combine those two graphs that you post over and over:
Oops! It looks like AMO and Arctic sea ice might be more related than previously acknowledged.
Well done, you used the AMO graph that isn’t detrended. You know, the one that contains the signal of global warming? As Wikipedia has it: “The AMO signal is usually defined from the patterns of SST variability in the North Atlantic once any linear trend has been removed. This detrending is intended to remove the influence of greenhouse gas-induced global warming from the analysis.”
Thanks for showing that the AMO can’t explain all Arctic sea ice loss (just 5-31% according to Day et al. 2012 that you obviously still haven’t read), and that there’s more to it than cycles. The AMO may go negative and this might cause Arctic sea ice loss to plateau or slightly reverse (perhaps in combination with negative feedbacks), or it might not, but then, when the AMO goes positive again…
A lot of people make this mistake wrt the AMO. The only question is: Will you persist in making this mistake and cause others to make it as well? The fact that we don’t understand everything, is an argument for being careful about how we proceed as a society, not against it. Especially if you look at what has happened so far.
Over and out.
Incorrect again. The detrending removes any warming influence whatever its cause. It cannot remove “greenhouse gas-induced global warming” since nobody knows how much is that. It makes no sense to remove the warming from the AMO while leaving it in the Arctic ice signal. After all the warming is increasing the AMO as much as it is increasing Arctic melting.
Again straw man argument, your specialty. I never said that AMO explains all Arctic sea ice loss. You should learn from me to quote with exact words in order to answer that, and not invent opponents arguments that are easy to knock off.
Day et al. 2012 base their analysis on models that are more likely to be incorrect than correct. Their estimate could easily be off by a factor of two or more. Only time and more evidence can tell the contribution of AMO to Arctic ice melting, but it looks that it could be very substantial and that immediately implies that all predictions of Arctic sea ice melting are too alarmist and incorrect.
We will have a better understanding of Arctic sea ice dynamics then. And global warming is unlikely to continue forever. Sooner or latter it will start reversing and we will become worried with the cooling instead of the warming.
Which has nothing to do with the discussion. Arctic sea ice alarmism like that of Maslowski, Wadhams, and Serreze serves no purpose except discredit climatologists when prediction after prediction comes and fails. The fact that we don’t understand everything, is an argument for scientists being careful about what the evidence really supports and what it doesn’t.
Javier – I see that you’ve driven by again without answering a number of questions, so I’ll try and make it easier for you by itemising them:
1) Where can I find a list of papers in reputable scientific journals that you have (co)authored?
2) What’s Wagner & Eisenman 2015 got to do with the topic of the original post?
3) Do you “agree that the global sea ice minimum area for calendar year 2016 is lower than all other years in the Cryosphere Today record going back to 1979?”
4) Since you don’t care for videos, what do you make of this graph?
5) Why do you suppose that “those who want to gloss over Arctic warming [like] to use global sea ice area”?
Thanks in anticipation.
Wagner & Eisenman 2015 show that the inclusion of seasonal and latitudinal variations in a model increases the stability of the sea ice cover and show that two types of models that showed tipping points and bistability are incorrect. in other words, improving the models shows that sea ice cover is more stable, not less, and that the response to the forcing is linear and therefore tipping points like Serreze’s death spiral are not supported.
As we learn more about sea ice we see that it is more stable, not less. The errors are to the side of alarmism.
I never have problems with the data. The data is what it is. If we are at a minimum in global sea ice I have no problem with it. To me what is surprising is not a minimum in sea ice since we are at the warmest point in centuries, but that for the last 45 years, with so much warming, global sea ice shows almost no trend at all. Very surprising. Not much change in albedo from that. That is a positive feedback that is not working as expected.
Piomas Arctic volume chart shows changes in Arctis sea ice volume since 1979. It says nothing about what is going to happen next. As 2014 showed more ice than 2007 a change of trend is possible. We do know that AMO has just changed and we do know that Arctic sea ice is related to AMO, so it is not that you should get all your information only from that graph. By tracing a straight line on a phenomenon that has a cyclical component you set yourself for failure. That trend will be broken.
That’s all I have to say at this point. I do not accept any request for personal information over the internet. Clive has my email and my complete name, and he is welcomed to check my publication record if he wishes to do so.
So to summarise:
1) No answer
2) Irrelevant answer. The OP is about area versus extent.
3) No answer
4 a) I don’t “get all my information only from that graph”. See e.g.
4 b) Where do you get all your information?
4 c) You mention albedo, which is an important topic. Area versus extent? Summer versus winter? North versus south versus global?
5) No answer
Please can you try and do better the next time you drive by?
I did gave you an answer to #1 in the last paragraph, just not the answer you wanted.
#2 is irrelevant only to you. I was answering to NevenA comment here:
and we were discussing Arctic sea ice loss. My citation was relevant to that discussion.
#3 has been answered. I said I accept the data that shows a minimum in global sea ice.
Re. #4b, I get my information from scientific publications and scientific organizations.
Re. #4c, Albedo: global albedo.
“Taken across the planet, no significant global trend appears. As noted in the anomaly plot below, global albedo rose and fell in different years, but did not necessarily head in either direction for long.”
As I said. No significant trend in global sea ice and no significant trend in global albedo. Very curious for a planet warming so fast. And obviously a minus in the predicted positive albedo feedback and consequent climate sensitivity.
#5 has no relevant answer. Supposing about other people’s motives, thoughts or intentions is an exercise in speculation and futility.
Perhaps you should work on your reading comprehension. It seems you did not read correctly my answers. I hope that by numbering my answers this time you don’t get lost again.
2) You still haven’t answered the area/extent question. Please do so.
3) See 2
4 c i) See 2.
4 c ii) You still haven’t answered the summer versus winter question. Please do so.
4 c iii) You still haven’t addressed the north versus south question. Please do so. This may help:
The comment above was my reply to Javier’s comment here.
And one last remark:
It’s funny that you say that because I just read a comment from a certain Javier on this recently published 1935-2015 reconstruction of Arctic sea ice. That’s the 80 years of data you need to know where the Arctic sea ice is going, right?
If that is you, Javier (and I think it’s you because you use the data in that graph you posted earlier), then you are well aware that there is no cycle to be seen in the September data:
And for comparison, here’s the AMO graph:
Let’s try again.
Last time (sorry, Clive):
I fixed the image width problem so now it should rescale all images to fit within the comment space.
Let’s see if we can get back to the point (from my perspective at least) of the original discussion on Twitter? Clive says:
Therefore the temptation of those who want Arctic warming to appear dramatic will tend to use area
In actual fact the irresistible temptation of those who want to gloss over Arctic warming is to use global sea ice area. For a topical example of this behaviour see:
Actually the problem is built in bias on both sides. Instead of rationally assessing the problem, and what if anything we can do about it, we just get fed propaganda. This is true both from some skeptics and some main stream climate scientists. I am pretty sure the answer lies pretty much in the middle. We have a problem. It isn’t as bad as made out. We have to get off fossil fuels anyway in the next 50 years, but a rush to build solar and wind farms now is pure lunacy as they can’t deliver. Better invest in new nuclear and efficient solar.
The fact that governments around the world indulge in irrational energy policies doesn’t alleviate the “CAGW” problem. In fact it exacerbates it.
Whilst I agree with you about the right sort of “new nuclear” I also have a soft spot for wind turbines, as my professional alter ego recently took great pleasure in pointing out to UKIP’s illustrious energy spokesman!
How many years do you suppose it will be before any sort of “new nuclear” is up and running in the once Great Britain?
Why the difference between the Arctic and Antarctic? Here is a possibiliity.
My recent paper (in peer review at present) said climate modulation was entirely due to ice albedo, and the reduction of albedo by dust. So it is entirely possible that the world is naturally cooling (an extension of Holocene cooling, as has been noted). However, because of NH industrialisation in India and China, who don’t give a flying-figg about pollution and emissions, the Arctic ice is getting covered with particulates. And soot particulates are 50 times as powerful at changing albedo than dust.
This soot will make the winter snows melt more quickly, exposing the land and reducing albedo much quicker in the year, increasing NH warming. This would explain the snow extent graphs, where winter snow is increasing, but spring snow is decreasing. The result of all this is that Antarctica is naturally cooling and growing ice, while the Arctic should also be cooling, but is actually warming because of a China-induced reduction in albedo.
However, if this is true, then the reason for recent Arctic ice melt is Greenpeace. It was Greenpeace who demanded renewable energy, and made Western industry uncompetative. And so industry relocated to China, where pollution is not an issue. So NH pollution increased, and the Arctic ice albedo reduced and melted. So the destruction of Arctic ice and poly bears (nort that poly bears are endangered) is all due to Greenpeace.
This is my ice age modulation paper (with a summary image kindly donated by Clive Best).
Modulation of Ice Ages via Precession and Dust-Albedo Feedbacks
I remember that Gavin Schmidt a year or so ago was proposing that soot emissions from China could be the primary cause of the hiatus in global warming.
Well what goes up must come down!
Here is a similar paper that says glacial melt in the Alps was due to industrial soot.
End of the Little Ice Age in the Alps forced by industrial black carbon
And here are NH snow extent graphs for winter and spring. What would cause greater winter extent, but lower spring extent? Answer – industrial soot from India and China. So the spring melt is assisted by a lower albedo, the land is exposed earlier in the season, and the northern hemisphere warms as a result.
Ralph, you surely don’t imply that industrial soot is the only possible answer.
How about this one?
A warmer planet means a higher humidity and higher precipitation planet on average and therefore more snow precipitation in winter. A planet with more CO2 means a planet with higher minimum winter and night temperatures and therefore a planet where snow melts earlier in spring.
Soot is not at all required to explain changes in snow patterns.
A few of problems with that. Firstly, the prediction from Dr David Viner of the CRU was for less NH winter snow, not more. Secondly, there has been no total warming for the last 18 years, which rather nullifies warming as a reason for the recent Arctic spring snow regression. Up to ’98 perhaps, but not the last 15 years. Thirdly, a CO2 explanation should apply to Antarctica in the same fashion, which is not happening. This is a regional effect, not a global effect – Antarctic ice is growing.
1) See my image above?
No total warming? Gotta reference?
2) Antarctic ice is growing? Do you mean sea ice? Gotta reference? Watched my “storify”?
>>No total warming? Gotta reference?
Wood For trees. The RSS and UAH satellite records show Global Warming.
>>Antarctic sea ice is growing? Gotta reference? Watched my “storify”?
That Storify is unwatchable. Too strobascopic. But the article on this page says that Antarctic sea ice has grown by a million sq km. I think all the evidence confirms this.
There is clearly a disconnect between the Arctic and Antarctic climate response, with some warming and sea ice reductions in the north, and no warming and increasing sea ice in the south. But the Warmists are desperate to cover this up by only mentioning the Antarctic peninsular. (BBC scare stories of 7ºc temperature rise in 50 years.) But the truth is that Antarctic temperatures have been steady for decades.
Why the difference between north and south? A global gas explanation like CO2 or H2O cannot explain this, but soot from India and China can. The real reduction in Arctic ice began in 2000, just as China started industrialising and covering its cities in smog, as we have all seen. And that smog has to settle somewhere, as Clive says in his post above. And the paper on Alpine glaciers I linked above, shows that sooty ice sheets melt very quickly and may be responsible for all European glacial retreats (rather than warming). And images of Antarctic ice do show them covered in dirt and soot (below).
It is only a theory, but one that is worth pursuing further because it explains many of the seemingly contradictory observations. But nobody will investigate, because there are no grants to study albedo warming rather than CO2 warming.
You do realise that sea ice floats on the surface, not in the troposphere?
Here’s the latest high resolution sea ice data from Antarctica:
Does it look like it’s currently increasing to you?
What is interesting is that the seasonal change in sea ice extent over Antarctica is more than twice as large as that over the Arctic. Southern summers receive 15% more solar radiation than northern summers exceeding any anthropogenic CO2 forcing. Perhaps Arctic sea ice response will just become more like the Antarctic in the future.
Haven’t you got an extraneous ant in there Clive? Assuming so, then personally I wouldn’t bet on it.
Water (largely) surrounded by land versus land surrounded by water?
Firstly, Viner’s failed predictions have nothing to do with the argument. More precipitation means more snow. You do know about ice core deposition rates and its relationship with temperatures and precipitations.
Secondly, there are many types of warming and global average is probably the least informative. You have to look at minimum temperatures for March, April, May, and June in the Northern hemisphere. Those are the months that show a greater reduction in snow.
Thirdly, Antarctica is out of the question for your NH data based argument, but it is an interesting issue. Most of Antarctica is too cold to melt, and according to Zwally is gaining ice,
But West Antarctica is also increasing its snow accumulation at the highest rate in 300 years:
and also due to being 3 km high and extremely cold, colder than the troposphere, it has been proposed that the Greenhouse effect works in reverse there, and the more CO2 the colder it gets.
How increasing CO2 leads to an increased negative greenhouse effect in Antarctica
I don’t say I am buying that explanation, but I can’t say is not true either.
>>Firstly, Viner’s failed predictions have nothing to do
>>with the argument. More precipitation means more snow.
On the contrary, they cannot get away with ‘heads we win, tails you lose’. They made a prediction, and it failed miserably.
And their prediction is pertinent. The idea was that the NH snow-line would move further north as the world warmed, so the level of precipitation would be irrelevant in formerly snowy regions, which would now experience rain. But it did not, the snow-line moved further south, which demonstrates a lack of understanding of the dynamics of a (possibly) warming world.
>>Antarctica is out of the question for your NH data based argument.
Not at all. The Arctic shows some warming, while Antarctica does not. The global CO2 based theory cannot readily explain that, but albedo changes in the NH can.
>>The correlation between spring temperature and
>>Snow Cover Extent (Figure 4.20) demonstrates
>>that trends in spring Snow Cover Extent are linked
>>to rising temperature.
Whoah there. Do you not see chickens and eggs here?
What causes the warming? The IPCC are so wedded to CO2 they will not even dare look outside their little Warmista box. But what if the warming is actually caused by dust-soot albedo, rather than temperature. It is the sooty ice that causes the melting, and exposes the land to reduce the albedo even further, and this extra insolation absorption then causes the warming. See this paper by Painter et al:
Radiative forcing by increasing deposition of industrial
black carbon to snow may represent the driver of the abrupt
glacier retreats in the Alps that began in the mid-19th century. Ice
cores indicate that black carbon concentrations increased abruptly
in the mid-19th century and largely continued to increase into the
20th century, consistent with known increases in black carbon
emissions from the industrialization of Western Europe. Inferred
annual surface radiative forcings increased stepwise to 13 – 17 Wm2
between 1850 and 1880, and to 9 – 22 Wm2 in the early
1900s, with snowmelt season (April/May/June) forcings reaching
greater than 35 Wm2 by the early 1900s. These snowmelt season
radiative forcings would have resulted in additional annual snow
melting of as much as 0.9 m water equivalent across the melt
So Alpine glaciers were retreating BEFORE there was any modern warming. Why? Because the melt was due to reducing albedo, not global warming. And the same is most probably true in the modern era. So the IPCC is probably wrong – the most likely cause of the earlier spring melt is industrial soot from China.
That Viner failed his prediction does not mean that you argument that snow/ice melting (and global warming) is driven by dust/soot is correct. Let’s not get sidetracked here.
It does not violate any physic law that I know that it happens as you say, but I think it is very unlikely. Here are some arguments:
– LIA was a period of lower solar radiation and higher vulcanism which affected the entire planet. The end of LIA does not appear to require an industrial revolution that took place only in Western Europe and Eastern US. Similar cold periods during the Holocene ended naturally. The warming from the depths of LIA up to 1950’s appears to be essentially a natural phenomenon.
– You would have to demonstrate that the strength of the purported cause matches the intensity of the effect. About 75-80% of the albedo is due to the atmosphere, and most of what’s left comes from the poles. There’s very little albedo coming from extra-polar ice and snow. The changes in albedo from whatever ice did melt could be too small to cause significant changes in temperature.
– And you would have to demonstrate that those changes in albedo have taken place. As far as I know, Albedo hasn’t changed since 2000 despite significant Arctic melting between 2000 and 2012, and changes in global sea ice. My impression is that albedo is mainly an atmospheric thing, and thus cannot be responsible for global warming.
I have looked into Painter et al. 2013. I don’t see it particularly convincing either. I don’t see why the warming out of LIA and the industrial revolution could not be simple coincidence.
Ralph, more on your second reason to reject a relationship between global warming and spring snow melting. IPCC has this to say:
“The correlation between spring temperature and Snow Cover Extent (Figure 4.20) demonstrates that trends in spring Snow Cover Extent are linked to rising temperature, and for a well-understood reason: The spring snow cover-albedo feedback. This feedback contributes substantially to the hemispheric response to rising greenhouse gases and provides a useful test of global climate models (Fernandes et al., 2009) (see also Chapter 9).”
Figure 4.20 | Relationship between NH April SCE and corresponding land air temperature anomalies over 40°N to 60°N from the CRUtem4 data set (Jones et al. 2012). Red circles indicate the years 200-2012. The correlation is 0.76. Updated from Brown and Robinson (2011).
Occam razor says the warming does the melting [of NH snow in Spring].
My impression is that albedo is mainly an atmospheric thing, and thus cannot be responsible for global warming.
Read the paper I linked, the albedo warming in the Alps was caused by ice-albedo, not atmospheric albedo (which would have the opposite effect). But as far as I know nobody is monitoring the contamination of Arctic ice by Chinese emissions, and therefore the albedo reductions that result. Personally, I think that would be more useful than monitoring Co2 emissions.
Are you familiar with the “Dark Snow” project?
No, not seen this before. Interesting. I said that D-O events may be linked to wildfires, and Cox is saying much the same thing here. I shall write to him. Thanks for that.
My pleasure Ralph,
But aren’t you referring to Jason BOX?
Getting back to the OP, CT global sea ice area has just posted another lowest *ever value:
14.324 million square kilometers.
But DMI have discontinued their 30% ice chart, because it was showing far too much ice.
DMI deprecated and stopped supporting their 30% threshold extent metric many moons ago. As you can tell from a mere glance at that graph!
Look again. The discontinuation is in Jan 2016.
Not a lot people know that Paul Homewood evidently isn’t the only one suffering from a bad case of snow blindness. Why don’t you look again Ralph?
Latest sea ice plot from DMI shows lowest ever Arctic sea ice extent for time of year
Getting back to the OP yet again, yesterday NSIDC global sea ice extent posted its own “lowest *ever” value. A mere 16.707 million square kilometers:
Have you ever done anything to offend Anthony Watts Clive? When I posted a link to your blog at WUWT the comment mysteriously vanished without trace!
I am puzzled by the use of “lowest ever” with an asterisk by the “ever”. The asterisk sometimes seems to get lost. What does it mean ? Maybe it means “Lowest recorded” ? If so why not just say “lowest recorded”?
Bob – If you were to click the link you would discover at the bottom the page the helpful hint:
* Since satellite records began
I’m afraid I resort to cut n paste to speed things up on frantic week(end)s like this one
Has anyone calculated the difference in Arctic sea ice trends if you remove the Sea of Okhotsk from the mix?
And I’m also curious whether any of the commenting experts know if Okhotsk was always included as part of the Arctic ice measurements or only during the post-1979 satellite era?
Few people have PhD’s in climatology, so when Dr Hans Jelbring (one who has) strongly supports what I have said I would suggest you ought to heed this new 21st century breakthrough in our understanding of planetary temperatures and heat transfer mechanisms.
So please note this strong support from Dr Hans Jelbring (PhD climatology) in an email I have just received reading …
“Dear all, Including politicians, laymen and scientists.
I am strongly supporting what Doug is writing below based on the fact being one of few scientists who actually have a doctorate in climatology. All of you who believe in authority should believe what Doug is saying below which is according to my own research and what some qualified scientists have told since many years. ….
I would also like to give credit to Doug Cotton who never seems to give up in his fight against ignorance among both politicians and scientists.”
(There’s more detail at http://climate-change-theory.com )
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