David, I actually read that article...very well done, and certainly you make accurate enough points about the oceans to be on target with the larger truth. This last line from your post: "Meanwhile... we wait." Is true, for a bit longer, though I think, with the looming ice-free summer Arctic coming in the next few years, the days of waiting will be shorter. I know of many "lukewarmers" who have actuall fallen into the trap of listening to those calling for a recovery of the Arctic sea-ice, not fully understanding the true death-spiral the Arctic sea ice is in. The inertia toward that is just too strong now. Once we have our first ice-free summer Arctic, certainly well before 2030, and I think before 2020, many "lukewamers" will move strongly to the warmist side of things and realize that it is later, and worse than they thought. Again, nice job on getting that message out in your article.

Shared, "Indefinitely" is a long time! The oceans can buffer a lot of energy and a lot of CO2, but there simply is no free lunch when you put as much GH gases in the atmosphere as humans have over such a short time frame. Somewhere the piper will be paid. The cryosphere is paying the price right now, as the earliest canary in the coal mine to fade away, but eventually the ocean warmth and acidity will alter the ability of the oceans to support life. The PETM extinction event is a good guide here. We have simply got to turn off the human carbon volcano as quickly as possible if we want to slow down the current species extinction rate and the eventual rather grim prospect a warm an largely lifeless ocean.

David, You make some excellent points, and just to amplify a bit: This undo focus on the troposphere which can be seen even in the definition of climate sensitivity is indeed myopic, and short-sighted as well. The ocean heat content increase has been at least as damaging and most likely more so to the Arctic sea ice extent and global cryosphere than the tropospheric warming. The warmer ocean water has been advected to the Arctic and has been both "eating away" at the ice from the bottom as well as being released into the Arctic troposphere, adding to top melt. The absolute failure of the climate models to accurately model this advective process and the resultant very rapidly declining Arctic sea ice shows how myopoic the undue focus on the troposphere has been. The oceans will be calling the shots for the climate--and always have-- period, and it's being seen first and foremost in the Arctic and of course the global cryosphere. The oceans are the "dog" and atmosphere just rides along as a noisy tail (which can wag a lot even when the dog is steady). My whole point in writing this post was to shift the focus and conversation from the tail back to the big ocean dog that contains the vast majority of the energy of the system and will dictate where the troposphere will head.

NeilT, I think the point in focusing on charts from the 1980-2012 timeframe is that for that data period we have charts that have reliable data that show a constant warming with no let up, i.e., there had been no pause in the accumulation of energy in the Earth system, and those who focus on the fickle and relatively low thermal inertia and storage of the troposphere either do so out of ignorance or some other less noble intent.

Steve Bloom said: "The Arctic sea ice will go fast, the Arctic Ocean and surrounding continental margins will warm quickly, various feedbacks will kick in (more), and our descendants if any will probably be wishing the process had stopped at a Pliocene-like state." ____ This kind of talk does not make you very fun at parties I take it? Seriously though, how can this view and the view as held by the denialists still coexist? How long until one of them melts away like the Arctic sea ice?

A-Team, As usual, you are a fountain of highly educational stuff. Question: What about the speed at which CO2 (and methane and N2O) have been accumulating? Does the speed of change as one approaches potential tipping points matter? It just seems to me that even comparing the current period as we are around 400 ppm CO2 with other periods such as the Pliocene might need to take into account the overwhelming of natural feedback processes. Given that anthropogenic GH gas emissions are akin to a carbon volcano going off, and as such, volcanoes rapidly overwhelm all feedback systems such that the local ecosystem collapses rapidly. Now, granted in the case of a volcano we've come to learn that the ecosystem can repair itself rather rapidly, but this only happens AFTER the volcano stops erupting. I suspect (and this is just my gut hunch) that the speed at which we are approaching an ice free summer Arctic (and then an ice free winter Arctic) is very rare event in the history of the planet, and this speed of change would figure greatly into whatever kind of "stability" would or would not exist on the other side of an ice-free Arctic. As long as the human carbon volcano keeps erupting, no stability will be found.

DumbSci, You make a good point, but of course sea ice volume and extent are such very different metrics as all the denizens here of course know. As for those who want to argue points about Antarctic sea ice, I would welcome such discussion in as much as it would at least get the discussion off the incessant prattling on about the troposphere-- it's energy content is puny compared to the oceans.

Anthony, I agree on the steps, and you can see those on many different time frames, even in the charts above. That being said, by these broadest measures, the trends are clearly upward for energy accumulation in the Earth system, or downward in the case of sea ice. Also, It will very interesting to see if an ice free winter Arctic does develop by 2040. The models are not showing it for many centuries, but the models have been so wrong about so much related to sea ice and the Arctic. If it happens that soon, an entirely new Pliocene-like era will indeed come about very rapidly.

John, I expect the 80N DMI to turn around pretty quickly to higher temps in the next few days. The higher pressure anomaly is sill working its way down from the stratosphere and I think may have some effect in the next 10 to 20 days on surface pressure. You can see that here, where it's been descending a few km a day: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_AMJ_NH_2013.gif ECMWF shows the first wave of high pressure and higher temps could be setting up over the Beaufort beginning around May 28th. That area could intensify and expand if the current stratospheric anomaly descends with larger force and persistence.

Wow, 500! Thanks for the great efforts Neven... In regard to the Lake E data, I've been a big fan of looking at Paleoclimate data for the most accurate assessment of what the "sum of all feedbacks" will be for the Earth system level of sensitivity to a doubling of CO2. I think Hansen is exactly on target here in suggesting that the feedbacks (both negative and positive) are just too darn complicated for the models to really give us the most accurate idea of what will happen at 560 ppm. We just don't have the math and dynamics right to model things right. The complete and utter failure of the models to predict the rapid Arctic sea ice decline is the prime example of this. The Lake E sediment data is one of the cleanest looks back into the Plicene we'll ever get. Because it represents the "sum of all feedbacks" at the time for 400 ppm CO2, we know it can be trusted as giving the full story. Now granted, other variables may have been different back then such as ocean currents, etc., but overall, the Lake E data tell us pretty convincingly that when you hit around 400 ppm, you're going to get a much warmer Arctic. The real problem is, it probably took centuries back then for the CO2 to settle on 400 ppm, but we've blasted up there so fast, that we're likely to even get more bizarre climate reactions, not to mention the fact that 400 ppm is just a stopping point as the Human Carbon volcano continues to erupt with much vigor...

Here's something very much worth watching. There's a large and intense high pressure area in the Arctic stratosphere that has been migrating down toward the troposphere over the past few weeks: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_AMJ_NH_2013.gif It remains to be seen if it will reach into the lower troposphere, but IF it should, it would hit about the time that the June melt and maximum solar insolation hits. Would make for a very intense period of melt across a broad area of the Arctic.

Fufuf...said: "What is the dark side's plan for post icial arctic?" ____ This is an interesting question, and surely it will depend on the "so what" factors involved in an ice-free summer Arctic. If wacky extreme weather is conclusively found to be the result (i.e. more blocking events, more Hurricane Sandy's, etc.) then the "so what" answer will be a strong one. If we simply get more revenue from the Arctic (oil, shipping, tourism) that is ice-free, then the "so what" might actually be much different. A worse-case scenario is of course that the "so what" to an ice-free Arctic is that we get some huge burps of methane and other releases of carbon from melting permafrost and we see GH concentrations sky-rocket, then we could see some of the scenarios develop that the so-called "alarmists" have been warning about for some time. In which case there would be some big push for geoengineering efforts, but at that point, it might be just a tad too late...

Veli Kallio, Your post was quite interesting. I'd like to hear more about this "Last Dryas" event specifically. Obviously a northern Atlantic choked with sea ice would do interesting things to the AMOC. Do you really see this happening? And if so, how intense, how long, and over what regions do you see a Dryas like cooling lasting?

Veli Kallio, Your post was quite interesting. I'd like to hear more about this "Last Dryas" event specifically. Obviously a northern Atlantic choked with sea ice would do interesting things to the AMOC. Do you really see this happening? And if so, how intense, how long, and over what regions do you see a Dryas like cooling lasting?

Here's a more contextual image of the current high pressure anomaly in the stratosphere over the pole; http://tinypic.com/r/2zf23id/5 Will it work its way down to the surface? If so, when, and with what force and how long will it linger? The timing during peak insolation over the Arctic could have a major influence on early summer melt.

Put me down for 2.95 million sq. km. for the Sept. mean extent. I do have to say that the nature, timing, and speed of the descent of the current high pressure anomaly in the Stratosphere to the troposphere could have an impact on the melt at a key point in the summer melt season. This high pressure anomaly can be seen here: http://tinypic.com/r/ayv7fr/5 This high pressure could remain in the stratosphere, though it has indications it will not and is descending. Should it hit the lower troposphere with strength over the Arctic at about the same time as peak insolation, we'll get vigorous melt and lots of ponding.

Respectfully, I sincerely believe Chief Hydrologist's guess as to sea ice extent needs to thrown out if the mix. Not only is it absurdly high with a flimsy basis, I happen to think he has intentionally posted this high estimate in an attempt to raise the overall average. I've followed his posts for many years and quite frankly-- I think he just enjoys being a fly in the ointment-- especially with those who happen to think humans are altering Earth's climate in significant ways.

Hans said: "If the seas were 30 feet higher when CO2 levels were previously this high, means the heat hasn’t had sufficient time in the atmosphere to penetrate the oceans." ------ Hans, I am not picking on you, but there are a few misperceptions here in your comment that should be cleared up. First, the direction of energy flow on a net basis across the planet is always from ocean to atmosphere. Literally the oceans keep the atmosphere warmer than it would be without the oceans. The vast majority of the energy in the oceans comes directly from SW solar penetrating down into the ocean. Second, the majority of the extra energy retained by the Earth system due to the rapidly increasing GH gas concentrations has already "gone into the oceans". I put this in quotes because it is the common way even scientists speak about the energy imbalance caused by adding GH gases, but it is thermodynamically inaccurate. GH gases in the atmosphere are not adding heat to the oceans, but rather they ultimately slow the rate of exchange of energy from ocean to atmosphere. This is no different than you putting a jacket on to keep warm in the winter. The jacket (i.e. greenhouse gases) does not add energy to your body, but slows the rate of flow from your body to the cold air outside the jacket (i.e. outer space). Thus, adding GH gases to the atmosphere slow the rate of energy flow from ocean to atmosphere to space. This is the exact reason that ocean heat content has been rising so dramatically over the past 40+ years. Finally, and most importantly, the energy that the ocean is retaining is creating huge effects on the Earth system already, and will continue to do so now for centuries (and with increasing GH gas concentrations, the effects will even get more severe). Melting sea ice is just one of the effects. And in the coming decades, once we are well passed the first ice-free summer Arctic milestone, and well on our way to a Pliocene-like climate, the oceans will be many meters higher than they are today, but not because the atmosphere is heating the oceans, but because the warmer atmosphere and warmer oceans combined will be reducing the amount of ice in Greenland and Antarctica so dramatically.

Sorry, here's the current pressure anomaly: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_2013.gif

I commented about this a few days ago, but I wanted to bring to everyone's attention some unusual mid and high stratospheric warmth over the Arctic that has been developing for the past few weeks and is certainly outside what is normal for early May. First, have a look that the typical patterns for stratospheric warmth (after January SSW events), by looking at 2006 and 2009 Look closely at these charts for what the stratospheric temperature profile looks like from about 30 hPa all the way up around May 1st: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_2006.gif http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_2009.gif Now look at this years: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_2013.gif Also, look at the pressure anomaly: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_2013.gif You can see quite clearly that we had a late season "soft" SSW, and this has created this anomalous warmth in the mid and upper stratosphere. We see this also in the AO index, that went negative when this "soft" end-of-season SSW hit: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index.html How this plays out and works down into the troposphere as the real melt season begins will be interesting to watch, but given that I previously said that 2013 was most similar to 2006, I now would say that 2013 has diverged greatly from 2006 and stands out on its own as a very unique situation in the polar stratosphere.

Here' s an older NASA Story that is related to SSW events, but from a diifferent angle: http://science.nasa.gov/science-news/science-at-nasa/2001/ast11oct_1/

Shared, I guess I take a longer-term view of any potential equilibrium point, and am convinced by the momentum already displayed in the disturbance of the cryosphere that even if we could somehow keep CO2 at current levels it would be many decades to centuries before the full Earth system would reach any equilibrium...i.e. Greenland and Antarctica will continue to respond to 400 ppm for several centuries and we can't reach full equilibrium as long as they continue to change. Considering the fact that we can pretty much bake into the cake at least 450, 500, or even 600 ppm of CO2 (and we haven't even talked much about methane and N2O) before humans get their act together and really take charge of this Anthropocene, we can guess that we'd better prepare for many decades of very chaotic weather, and thus, many centuries before any equilibrium will be reached. I think the most important issue-- one broached by the AMEG braintrust-- will humans be able to feed 7+ billion of us with such chaotic weather? On a rather negative (but objective) point of view of course, is that nature could find a way to get this big carbon volcano (anthropogenic greenhouse emissions) under control on her own terms, as in disrupting human society so much that human greenhouse gas emissions are brought under control through that disruption, thus, solving the problem whether we like it or not. I find it more than curious for example, that in all the crazy weather events that I see happening all over the world, that I often see automobiles overturned, on top of each other, or otherwise non-operable. This certainly reduces human carbon footprints rather immediately. I AM NOT suggesting in any way an intentonal "Gaia's Revenge" in this at all, but rather, that once weather becomes that disruptive, the human carbon footprint is decreased automatically, without our intention or compliance. Again though, the main concern should be along the lines of AMEG's concern-- global food supply disruption and the chaos and suffering that can result from that.

Regarding the early melt season, I noticed right now we have a very unusual end-of-season "soft" SSW going on, which can be seen in both stratospheric temperatures and pressures. The AO index reached a peak high and then started dropping as this late "soft" SSW has proceeded. This high pressure will likely warm Arctic temps up at lower tropospheric levels in the next few weeks, pushing any residual cold air left over from winter out. I've not ever seen a stratospheric warming pattern like this at this at this point in the season. Quite odd...

Shared Humanity, As long as GH gas concentrations continue to rise, the anthropogenic carbon volcano continues to erupt and any chance of equilibrium is impossible. Certainly an ice-free summer Arctic may be a quasi-equilibrium point, but from there, who knows. We probably need to follow Hansen's lead and start looking to the Pliocene for some potential equilibrium points. The question arises: (and certainly AMEG has covered this well) Given that a Pliocene-like climate may be in our future, or something even warmer, will will still be able to feed 7+ billion humans?

Excellent start of the season perspective Neven. Two areas that are worth watching early are the declines (or lack thereof) in both the Barents and the Kara, as any real "recovery" would come from these areas. Over the past few days the Barents has shown how rather weak its ice has been, with a dramatic drop: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.6.html Often the Kara will lag the Barantz by a few weeks in terms of trend, so it will be worth watching it. So far it is a bit healthier than last year: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.7.html The amount of open water earlier in the season for both the Barents and Kara can be good indicators of how the melt season will progress. Last year both started out below average (especially the Barents) and we of course had a record low year. If the Barents continues declining rapidly and the Kara begins to join in then 2013 could give 2012 a real run. Of course anything is possible in the Arctic, but I am not "feeling" a virtually ice-free condition this year, but something more akin to last year or even slightly higher. Of course another Great Arctic Cyclone or two would change the prediction! Overall, I want to watch the Kara for a few more weeks to see if that build-up you mentioned is something that will hold, or decline rapidly once the real melt season begins. On the Pacific side I look for this area to be the real leader in terms of early season melt-out. The Bering is only slightly lower than last year at this time, but the ice is overall not in as good of shape. I think it will be ice-free earlier this year, which will lead to the Beaufort opening up earlier (along with the lower amount of MYI).