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kdkd at 00:25 AM on 28 April 2010Tracking the energy from global warming
Ken, From a big picture perspective, the "missing heat" of the last 5 or 6 years is most likely caused by measurement error in a large complex stochastic system. I previously showed you that the OHC/TOA trends were statistically indistinguishable from the Temperature Anomaly / CO2 level trends over similar time scales / number of data points. At the level we're analysing it here, as armchair scientists, this point is extremely important, as it clearly shows the limitations of the conclusions which we can draw from a fairly superficial examination of the data. In turn, this strongly suggests that your argument is based around confusing uncertainty in the measurement systems with flaws in theoretical understanding (thanks Chris!). Unless you can demonstrate some large, statistically robust support for your argument, it's an interesting footnote on how not to draw conclusions from statistical noise. A 30% error term is quite reasonable for systems of this complexity. In the social sciences where I come from, we deal with these kinds of error magnitudes all the time. -
Ken Lambert at 00:15 AM on 28 April 2010Tracking the energy from global warming
Chris #76 We are all waiting for BP to respond to Posts #73 thru #76. Meanwhile your points ignore the 'missing heat' divergence over the last 5-6 years as exampled at the start of this discussion. BP's argument is that the OHC for the top 700m of ocean is a direct measure of the integrated TOA forcing imbalance WRT time because there are no other serious heat storages in the system other than the oceans. So far, only von Schukmann has found 'missing heat' down to 2000m - but we lack a convincing theory of a mechanism to get it there. It should be noted that sea level rise over the last 5-6 years on your above chart has flattened to a slope of 1-2mm/year consistent with flattening temperatures. The 11 year solar cycle varies the solar forcing by at most about 0.25 W/sq.m - when Dr Trenberth postulates a TOA imbalance of 0.9 W/sq.m due to CO2GHG and other heating and cooling effects. If you are claiming that a solar drop of 0.25W/sq.m or less has flattened the temperatures, and if the other heating and cooling effects (aerosols etc) forcings remain the same then the CO2GHG effects must be efectively negated by a 0.25W/sq.m drop in solar, which implies that they are nearer to 0.25W/sq.m than 0.9W/sq.m imbalance (mainly based on a CO2 component of about 1.6W/sq.m) Again the 'missing forcing' would be about 0.65W/sq.m. -
gallopingcamel at 00:09 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
rway024 (#8), "nofreewind" (#3) posed some interesting questions that you failed to address. Instead you attacked his credibility which makes no sense when he was merely asking questions. Why don't you have another go at answering "nofreewind" and this time stick to the point and lay off the "ad hominem" stuff. -
Jim Eager at 23:51 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
Re JRuss@4, those rumors of active sea bed volcanoes adding tremendous heat to the arctic ocean fail to consider the need to warm the entire water column between the sea bed and the surface before there would be any heat gain at the surface to melt any ice. In other words, they are not just rumors, they are complete nonsense. -
Paul D at 22:55 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
Re CBDunkerson and comment no. 22 Some points: 1. Does it matter when the ice sheet has melted? The eventual result is the same. Coastal cities will be flooded and problems for human populations will occur. 2. 3 out of the 4 scenarios you portray are very serious. Lets take the Linear example first. It is generally accepted that the greenland ice sheet will add some 6m or so to sea levels. So in 450 years time a large number of coastal cities will be under water. Ok, 450 years is apparently a long time. But the real problems will still plague coastal cities and communities long before then. Add just 2 or 3 metres in 200 years or so and many coastal city communities will have serious flooding problems. In any case the ultimate fate of many cities will be mass abandonment and migration inland, it doesn't matter when that will happen, the fact that it will happen is the problem. 3. The non-linear scenario doesn't really need explaining once the consequences of the Linear scenario is clarified. Cities would probably start planning for mass evacuation now. 4. If the actual scenario is somewhere between linear and non-linear, then we still have some very serious problems. Evacuation probably needs to be planned for the next century or towards the end of this century. So given that in all probability flooding will occur, risk analysis suggests we should do something about it. -
chris at 22:23 PM on 27 April 2010Tracking the energy from global warming
whoops....I should have said: "Yes the radiative forcing contribution from [CO2] has gone up a tad since 2003" -
chris at 22:04 PM on 27 April 2010Tracking the energy from global warming
Berényi Péter at 13:01 PM on 24 April, 2010 lots of problems with your argument Peter. 1. "We have a negative energy balance for the last six years. The climate system is not gaining energy, but losing it." That's almost certainly incorrect. Since sea levels are continuing to rise (see below), it's almost certain that the climate system continues to gain energy. You're making the logical error of equating uncertainty in measurement systems as an indication of a flaw in theoretical understanding. As always, we need to resolve the uncertainties in measurements before making interpretations about phenomena and our understanding of these. 2. "But wait, CO2 has increased from 375 ppmv to 389 ppmv between 2003 & 2010. The change in radiative forcing during this period is about 5% of a CO2 doubling." Yes the change in radiative forcing has gone up a tad since 2003. And global temperatures have risen through at least 2005 (e.g. here or here). Since around 2002 the solar output has descended through the decreasing part of the solar cycle to an abnormally extended minimum. Under normal circumstances we expect the downward part of the solar cycle to give around 0.1 oC cooling contribution to surface temperature (lagged by a few months). In other words it should temporally counter all the surface warming from CO2-induced greenhouse forcing during this period. We might expect a slightly larger effect of the proesent extended solar minimum. So there's nothing surprising about the fact that surface temperatures haven't risen very much since 2002/3.
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CBDunkerson at 22:01 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
The Greenland ice sheet covers about 2.85 million cubic kilometers and one cubic kilometer of ice weighs about 0.9 gigatonnes... so we are looking at a total of around 2.57 million gigatonnes. Prior to about 1999 Greenland's ice sheet was pretty much in mass balance. It had dipped slightly and then rebounded in the 70s, but otherwise nothing but minor fluctuations for decades. Since 1999 it has dropped at a precipitous and accelerating rate. If we assume that this acceleration stops and Greenland will continue losing ice at 286 gigatonnes per year then it would take about 9,000 years for the entire ice sheet to melt (which matches Berenyi's 15 g out of 150 kg = 10,000 years pretty well). If we instead assume that ice loss will continue to increase at a LINEAR rate equal to what it has been recently (a little under 25 gigatonnes per year) then it would take about 450 years. Finally, if we assume that the rate continues to double every six years then it would take about 60 years. We probably need AT LEAST a decade more data to get any kind of handle on what sort of long term trend we are likely to see, but if ice loss is being driven by CO2 caused warming then the answer will likely be somewhere between the last two figures... though since we are looking at such a small time frame, slightly increased CO2 levels over that period would have a negligible impact, and we are really talking about the melt rate at the CURRENT CO2 level. If CO2 continues to increase the melt time would decrease. -
kdkd at 21:51 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
The butterfly effect is a casual expression referring to to something called "sensitivity to initial conditions". The outcome of the energy calculations will still require that the energy is spent somewhere, be it on change in ice conditions, temperature changes or whatever. In fact, that the (old) models predict precocious arctic warming, and relatively little tropical warming is an example of this sensitivity dependent on initial conditions that you refer to. However it's not a "get out of jail free card" for not needing to understand how energy calcualtions and statistical probabilities work, it's rather more subtle than that. -
Riccardo at 21:32 PM on 27 April 2010CO2 effect is saturated
qball17, Miskolczi's "paper" is well known and badly flawed. As Eli at Rabett Run ironically puts it, his theory could be summarized in just two sentences: "The greenhouse gas theory that has been used for the last century is TOTALLY WRONG! The proof is left as an exercise for the reader.". -
Arkadiusz Semczyszak at 21:31 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
"I's very unlikely" - This is very vague in the context of chaos theory, "butterfly wings" ... 9% or 80-90% - "the same end result" ? It,s only "weather" ? -
kdkd at 21:19 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
Arkadiusz #18 I'm not sure of the purpose of repeating what I said back. My point was that the weather that causes the melt is at least somewhat independent of the climate (e.g. manifested by temperature anomaly. Modeling the temperature and the climate are essintially independent tasks. I's very unlikely that a model of the weather will be able to falsify a model of the climate. -
Arkadiusz Semczyszak at 21:11 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
"... but you'd have to develop an understanding of what the RELEVANT parameters were." - exactly yes ... -
CBDunkerson at 20:59 PM on 27 April 2010Has Arctic sea ice returned to normal?
Berenyi, as noted previously in comment #50... the ICESat satellite provided Arctic ice volume measurements which closely matched the PIOMAS model. ICESat is no longer functioning, but the Cryosat II satellite launched several weeks ago will be able to provide the same sort of data in a few months. Thus, this September we will be able to compare PIOMAS not just to the measured sea ice extent, but also the actual measured volume. If it continues to match up to then it would seem to be a fairly solid model. In any case, the fact is that we DO have direct ice volume measurements and they will tell us whether it is 'recovering' or not. robhon, in addition to albedo not being much of an issue during the arctic Winter it needs to be understood that sea ice extent is not DIRECTLY determinative of albedo. Sea ice area, the total surface area of ice floating in the ocean, determines albedo. This differs from extent in that extent is not the area of the ice itself, but rather the area of the ocean which is at least 15% covered with ice. So the extent can be as much as 1 / 0.15 = 667% as great as the ice area. This means that minor fluctuations in extent may or may not tell us anything about albedo... the extent could have changed because the area of the ice did OR because the ice was more or less spread out. This is one of the reasons why extent is really only useful for determining long term trends and making statements about 'recovery' based on minor variations in a couple of years are not just 'disingenuous' but clearly unfounded. -
kdkd at 20:47 PM on 27 April 2010CO2 effect is saturated
qball17 #13 That's not a proper scientific paper, it's a paper from the partisan Science and Public Policy Institute (home of among others the rather badly discredited "Lord" Christopher Monkton, and the australian geologist Bob Carter). If there was any merit in the presentation/summary that you printed, then it would be easy for him to publish in a reputable scientific journal. So you have to ask the question why hasn't he? The papers cited at the top of this page are a much better source for you to form your opinions from. -
kdkd at 20:34 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
Arkadiusz #16 There's an old saying in the field of computational neuroscience: "The implementation is independent of the architecture". That is, there are many different paths to the same end result. As far as Arctic ice loss goes, predictions from fairly old models (I have a text book about 20 years old that presents a model predicting ice loss specifically from AGW) state that ice loss is hypothesised to occur due to warming caused by CO2. The model has nothing to say about the mechanism by which this occurs - it could be by the ice being pushed around differently by changes in weather/win patterns, or it could be by it sitting there melting. The models don't care, they just predict the outcome, not the mechanism. So the changes in wind patterns are not any sort of evidence for or against the anthropogenic cause of Arctic ice loss. You could of course try to develop a model looking at what different mechanisms of arctic ice loss may occur under different global warming scenarios, but you'd have to develop an understanding of what the relevant parameters were. -
qball17 at 20:17 PM on 27 April 2010CO2 effect is saturated
hey guys, i think you should all look at Dr. Ferenc Miskolczi's theory on the saturated effect of greenhouse gases. you can download his paper for free on scribd. http://www.scribd.com/doc/25071132/The-Saturated-Greenhouse-Effect-Theory-of-Ferenc-Miskolczi . i would love it if you guys have a look at it and get back to me.. because it looks very very convincing.. so if someone can have a look at the math involved and see if its all legit that would be excellent.. here is the link to the summary report of his findings aswell; http://www.scribd.com/doc/25071473/Saturated-Greenhouse-Effect-Theory He says that the climate models used by the ipcc are based on old math from the 1920's which make an assumption that the atmosphere is infinitly large.. he redoes the math with proper boundary conditions and comes up with very interesting results.. i'll leave it up to you guys to look further into it email me on coatesy91@hotmail.com if you'd like to send me your thoughts if youd prefer that than this comment cheers -
Arkadiusz Semczyszak at 20:02 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
"The decline in the Arctic sea ice from 2005 to 2007 was caused by winds, according to a NASA study . Atmospheric pressure conditions set up wind patterns that compressed the old thick sea ice, loaded it into the Transpolar Drift Stream and then increased its flow rate out of the Arctic along East Greenland. By this the perennial thick sea ice in March 2007 essentially was confined by winds to the Arctic Ocean north of Canada. Consequently, most of the Arctic Ocean was dominated by thinner seasonal ice than usual, melting faster. In addition, this thin ice is more easily compressed and responds more quickly to being pushed out of the Arctic by winds. This thinner seasonal ice conditions facilitated ice loss, leading to the 2007 record low amount of total Arctic sea ice." "Oceanic control of the warming processes in the Arctic - a different point of view for the reasons of changes in the Arctic climate" - professor A. Marsz, 2009. Summary "The paper describes the strong correlation between the sea surface temperature (SST) in the region of the Gulf Stream delta and anomalies in surface air temperature (SAT) in the Arctic over the period 1880-2007. This correlation results from the transfer of a variable amount of heat from the Atlantic tropics into the Arctic through oceanic circulation (AMO - Atlantic Multidecadal Oscillation). Reaction of sea ice is the main mechanism controlling the heat content in water carried to the Arctic and influencing the SAT. Sea ice may either increase or limit the heat flow from the ocean to the atmosphere. The genesis of the 'Great warming of the Arctic' in the 1930s and '40s is the same as that of the present day. Both may be considered to be attributable to natural processes and are not demonstrably associated in any way with a supposed 'Global greenhouse effect'. CHANGES IN THE CONCENTRATION OF CO2 IN THE ATMOSPHERE COULD ONLY EXPLAIN 9% [!] OF VARIATIONS IN THE SAT IN THE ARCTIC." "Greenland Ice Sheet Surface Air Temperature Variability: 1840–2007*" Box et. al. 2009, AMS - "The annual whole ice sheet 1919–32 warming trend is 33% greater in magnitude than the 1994–2007 warming." (http://www.worldclimatereport.com/wp-images/greenland_xmas_fig1.JPG). By this work in the years circa 193X-5X in Greenland was warmer than today ... -
Berényi Péter at 19:49 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
Speaking of visual depictions...
Imagine a fat man, weight 150 kg (330 lbs) losing 15 g (half an ounce) a year. This is the type of slimming cure Greenland is going through recently.
Response: LOL, can I ask what value you used for the total ice mass of the Greenland ice sheet and your source?
Of course, when I look at that picture, it reminds me of the numerous papers that have looked at the last interglacial when temperatures were 1 to 2 degrees warmer than now (eg - the warming expected from some of the more optimistic emission scenarios). They found that sea levels were at least 6 metres higher than current levels. Looking at all the ice still stored in Greenland, it's not hard to see why. Going on past history, Greenland (and Antarctica) are very sensitive to sustained warmer temperatures. -
sailrick at 18:38 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
It seems to me that talk about whether the MWP was as warm as tody, has little relevance to today's situation, which is one in which it is the future that is of concern, with possible runaway global warming, caused by man releasing into the atmosphere, within a few hundred years, the carbon that nature has been sequestering in the form of coal for 65 million years. That has never happened before. We know CO2 is a greenhouse gas and how much we are emitting. The greenhouse effect has been known for over 150 years. We know that on our current path, CO2 concentrations could triple from pre industrial levels in this century. If you knew nothing else about climate change or maybe had never heard of it, or the politics of it, and you learned the above, what would your initial reaction be? I would think common sense would give you concern. So why are so many intent on denying it? -
barry1487 at 17:57 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
'Human industry' did not double? There's no reason why regional ice loss rate should match the vector on global CO2 emissions. The dynamics in play are completely different. What they have in common is increased warming. I would caveat the top post by mentioning that 7 years of data is a little short to make confident analyses of trends. -
RSVP at 16:55 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
There is a clear doubling rate associated with the two blocks for 2002 and 2009, yet human industry did not double during that same time frame. This could lead one to conclude that the melting does not correlate with human activity, and furthermore, even if it did, changing human behaviors will not stop it. It would be interesting to see a similar ice cube representation for a much earlier year, and as HumanityRules commented, how this matches up with the entire Greenland icesheet. -
Geo77 at 16:51 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
John- If I were in the audience my first question would be how long would it take to lose half of the Greenland ice sheet to melting at a rate of appx. 300 gigatonnes per year? Also, Humanity Rules comment should give you forewarning to be prepared for questions about the MWP and early Norse settlements. If there is more or almost equal ice volume in that area of Greenland today when compared to the Norse settlement period you're going to lose some of your audience regardless of the science. -
HumanityRules at 16:32 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
The Climatic Research Unit made a merged SW Greenland temperature record which showed the 1940's were as warm as the present period. (It's contained in the PDF linked at the top of their page) Many of the same group have recently produced a paleoclimate reconstruction of Greenland temperature going back 1400 years showing a MWP as warm as present day. Greenlands temperature has shown a fair amount of natural variation no doubt allowing periods of retreat and advance over the past 1400 years. The real skill is putting the changes of the past decade into a context that fully aknowledges this natural variation. Terms such as "steadily accelerating ice loss" are meaningless without putting a timeframe on them. -
Philippe Chantreau at 16:26 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
About sea ice area, The graphs of sea ice area anomaly at Cryosphere Today do not support the assertion that Arctic Sea ice has increased. The Tale of the Tape shows that it has not experienced a meaningful positive anomaly since 2003, even with the new baseline including all years until 2008. The global sea ice shows negative anomaly at or greater than 2 million sq.km for the past 4 years. The last positive anomaly of similar magnitude was in 1988 -
robert way at 14:28 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
nofreewind, First of all, its a glaciologist not a "glacierologist" as an individual who studies "glacierology" (as you would put it instead of Glaciology) I can assure you that your credibility was lost with that one sentence. Secondly, Greenland has not been melting for 150 years. See Wake et al. 2009 for confirmation of this. There have been many periods of growth over the last 150 years. Thirdly, Glaciers still retreat with increased precipitation because they are dependent mostly upon Summer Air Temperature even more than Winter Precipitation. Ablation occurs faster than accumulation. Fourthly, The rate of sea level rise is currently at 3.4 mm per year (Cazenave et al. 2008) whereas the TAR (IPCC Third Assessment Report) predicted rates of 1.9 mm per year. That's an 80% acceleration over the expected results... So I don't see how you indicate that the rate of sea level rise is not accelerating? -
James Frank at 14:25 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
The visual is interesting. In terms of illustrating the size, you lose something by stacking the cubes into a larger cube. There is far more volume there than one sees at first glance. Something like a bar graph (2 dimensional instead of 3, even though we're measuring volume) would help avoid that. Or, as someone already pointed out, a comparison image of the ice in the sheet. If that was too large to work, perhaps the ice added in the same years? -
scaddenp at 14:19 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
JRuss - Antartica needs more precipitation on the cap than it loses in calving. Check the papers on ice loss. antarctica gaining ice Arctic sea ice grew from 2004 to 2009? Would take some special cherry-picking to support that, like the cherry-picked range for temperature. Try the long term data - eg Graphs in Has-Arctic-sea-ice-returned-to-normal And the old "volcanoes under the ice" trick. This is disinformation. Dont fall for it. Some discussion at dotearth -
robert way at 14:15 PM on 27 April 2010Has Arctic sea ice returned to normal?
I actually commented over at Watts Blog about how it was disingenuous for him to insinuate that volume was increasing at the end of his blog post and I got a couple snippy comments back but no refutation. -
brjohn9 at 14:08 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
JRuss, it's misleading to talk about a "decline in Global temperature from 2004 to 2009," not least because NASA puts 2005 as the warmest year on record. It puts 2009 as tied for second warmest. The real point is that fractions of a degree off the all-time record do not constitute a meaningful "decline" in temperatures. Even if that statement was true, Arctic sea ice has increased marginally in surface area since its all-time low in 2007, but it remains far belows its average extent in decades previous. Moreover, while the surface area has recovered somewhat, there is strong evidence that much of the new ice is so-called rotten ice that will melt again easily, rather than the multi-year ice that is resistant to melting. Also, the Arctic sea ice minimum is driven by factors much more complex than the global average temperature. Finally, why are you repeating crazy "rumors" you "heard" about active volcanoes melting Arctic sea ice? Let's stick to actual science, shall we? -
JRuss at 13:34 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
My handbook of Chemistry & Physics [1962]says the density of ice is 0.917. Taken to the minus one-third power, that would be 1.0293 km on a side for Gt cube. [Yes, that assumes the ice is pure H2O and is without voids.] I heard the other night that Antarctica ended its 2010 'Summer' at minus 100 degrees Fahrenheit. So perhaps the Antarctic can now gain back some ice. Because of the decline in Global Temperature from 2004 to 2009, the arctic ice has grown in area. The rumors I have heard is that there are three active volcanoes in the arctic ocean that are adding tremendous heat to the arctic ocean and that prevents a gain in the thickness of the thin ice covering the arctic ocean. -
nofreewind at 12:41 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
Ok, Greenland has been warming and loosing ice for well over 150 years and surely that guy above has some pretty cool photography. I was able to catch his show on cable and the pictures were beautiful on my TV. Call me a skeptic, but I don't completely "trust" that this ice loss necessarily correlates with the big TV that I watched the James Balog show on. We know man has pumped tons of CO2 into the atmosphere and the amount has risen exponentially since the mid 1850's. But why were many of the worlds glaciers retreating at a good pace in 1900 when we emitted only 1/8th of the CO2 that we are now? Why were the glaciers in Greenland retreating throughout much of this century when the Greenland temperatures were stable? The same thing was evidenced by the paper written by the glacierologist from India. If man has been only responsible for temperature rise from 1975 onward, why were glaciers melting since 1850? Why are glaciers retreating if the world precipitation is supposed to be increasing because of the super computer climate models, just like the heavy snowfall this winter in the NH was all expected and "modeled" apparently, (but i'm not so sure about that, because there were many IPCC references of less snowfall, but I guess the theories seemed to just change this year in light of the new data. I did the same things as this did here in Montana at Glacier NP and came up with the same results using the raw data from NOAA. Temperatures didn't seem to rise but glaciers did melt. Call me a skeptic, but I am not so sure we have anything to worry about. Surely world sea levels are rising, but isn't this about the same rate as it was when man was just getting started to discover the wonders and wealth of burning fossil fuels over 150 years ago? Last point(sorry for being bandwith hog on this post), but this is my favorite glacier picture, scroll to page 3. Is all of the above "unprecedented" just like the CO3 above 300 and just like the dramatic rise in temperatures pointed out this century? On page 3 the guy is standing on tree stumps created from a glacier that formed 3,000 yrs ago, this may seem like a long time, but is just a blink of the eye in geologic time. -
HumanityRules at 12:22 PM on 27 April 2010A visual depiction of how much ice Greenland is losing
I don't suppose you could add a depiction of the full size of the Greenland icesheet as well to put this in perpective? -
kdkd at 11:32 AM on 27 April 2010Skeptical Science Housekeeping: flags, printable versions, icons and links... lots of links
It might be an idea to put the source code for SS up in a version control repository somewhere. That way you can get your code autited, and members of the community might want to add features. Good work on the site by the way.Response: Being a novice at the whole open source community, my initial question to this is wouldn't it also be an opportunity for hackers to peruse the code looking for vulnerabilities? -
ubrew12 at 11:15 AM on 27 April 2010A visual depiction of how much ice Greenland is losing
Apologies if I got this link from this website (I forget sometimes), but this James Balog talk about time-lapse video of melting glaciers is quite stunning. The visual pyrotechnices start at minute 9. At around minute 14:30, he starts showing video from Greenland, and its truly amazing.Response: Thanks for the link. Here's the video embedded: -
Berényi Péter at 09:07 AM on 27 April 2010Has Arctic sea ice returned to normal?
There is a sharp conceptual difference between things measured vs. assumed based on a computational model like PIOMAS (Pan-Arctic Ice-Ocean Modeling and Assimilation System). In this sense sea ice extent is measured, volume is not measured, not even calculated. These values are based on a computational model, heavily interlinked with other models. It is extremely difficult to verify such a thing. However, they have a Seasonal Ensemble Forecasts of Arctic Sea Ice from April 2 to September 26, 2010 in three days steps made at the end of March (for scientific research and education only). I have made a backup, just in case. In five months we can check if sea ice extent prediction is correct or not.
That is, the model is falsifiable. We can put more faith into ice volume reconstructions provided the ice extent prediction in fact will not be falsified. The September 2010 arctic sea ice extent is predicted to be 5.3 million square kilometers. We'll see.
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nofreewind at 08:59 AM on 27 April 2010Has Arctic sea ice returned to normal?
>are the folks at WUWT being disingenuous to make any claims about sea ice extent in March when winter sea ice extent is going to have very little negative feedback GOSH NO!!! Because This NASA page from October of 2007, after the record summer low, explains how the lower "perennial" ice during the previous two winters combined with unusual wind patterns is what led to the record low. Also, NASS specifically states in their article that the March 2007 ice was the lowest ever for that month, so, in turn, NASA knows that the March Ice extent, which leads to perennial ice, is very important. What is going on is that many, including NASA - see YouTube, made predictions that the Arctic Ice was on a one way downhill slide because of feedbacks caused by open water, but just like the stock market and other things in nature (think Hurricanes after Katrina) nature has a way of fooling us all. We ALL just have to wait and see what happens. Things have a habit of reversing themselves and it is VERY IMPORTANT that artctic ice recovered in 2008 from the 2007 low and even recovered more in 2009 and is showing signs of continuing that recovery, it is what it is. -
Flowers blooming earlier now than any time in last 250 years
In my previous comment, it should state that "the hours of daylight for particular days of the year are NOT changing". -
Flowers blooming earlier now than any time in last 250 years
johnd, you state that warmth is primarily driven by lengthening hours of daylight. I hate to state what seems like a tautology to me, but isn't warmth also driven by, well, temperature? If the temperature for a particular day of the year is increasing due to AGW, that will change the date of blooming. Yes, length of day is a factor, yes, soil water content is a factor; but so indeed is temperature. In my area (Pennsylvania, Wash. DC) we have hardiness zone creep; the DC Cherry Blossom festival is occurring earlier and earlier over the years, and the mix of fastest growing/best adapted plants is shifting to warmer varieties. Note that the hours of daylight are NOT changing. -
Rob Honeycutt at 07:28 AM on 27 April 2010Has Arctic sea ice returned to normal?
The discussions here are always very high quality and often well beyond my own level of knowledge on climate change (I come here mostly to learn), but I have a question for everyone. Please pardon me if this is obvious. If I understand this right the issue with sea ice extent is in regards the lower albedo of open sea during the summer months, right? Winter sea ice extent has little effect on albedo because the arctic is mostly in darkness. My question is, are the folks at WUWT being disingenuous to make any claims about sea ice extent in March when winter sea ice extent is going to have very little negative feedback? -
Ed Davies at 05:19 AM on 27 April 2010Skeptical Science Housekeeping: flags, printable versions, icons and links... lots of links
Ah, right, err, sorry. Maybe that should have been "any professional programmer who writes a feed generator like that needs a bloody good talking to". Still, generation of markup, whether it be HTML or XML, needs a bit of care with this sort of thing - there wouldn't be so many cross-site scripting loopholes if everybody got it right. -
hu? at 02:50 AM on 27 April 2010Trenberth can't account for the lack of warming
"There is a TOA imbalance of 6.4 W m−2 from CERES data " I'm not sure what this means...but it does not say CERES data indicates an imbalance at all. Where is this 6.4 W m-2 figure coming from? -
sleepership at 22:21 PM on 26 April 2010Flowers blooming earlier now than any time in last 250 years
Here in southern New England we have had the earliest spring bloom in my lifetime (56 years)- We had the warmest March in record- 16 degrees above normal- and thus far April will be at least 10 degrees or more above normal- with the earliest 90 degree weather (April 7th) setting another record. The Hardwoods- Mapple & Oak see a leaf progression today-April 26th- about 10-12 days too early. My garden already has summer perennials robust. I have a windmill palm- trachycarpus fortunei- that suffered little cold damage with minimal winter protection growing well- the palm has been in the ground here- for several years- we are now a zone 6-7- with 'zone creep' the zone 7 line creeping north from the Connecticut coast- should see us become a zone 7 in 10-15 years. With the Co2 level PPM now at 391- it seems the climate models prediction of a rapid rise in temperature at 400 ppm most likely being accurate. Also models have predicted that after 2010- the rise in temperatures would accelerate- are now entering the zone of severe weather/climate change? -
HumanityRules at 21:50 PM on 26 April 2010Has Arctic sea ice returned to normal?
Polar Ice Center have alot of supporting data for thier ice volume model here http://psc.apl.washington.edu/zhang/IDAO/index.html It includes forecasts for the Bering Sea and the whole Arctic. It looks like the model is at least underestimating the ice extent as of today. It'll be interesting to see how this works out. -
CBDunkerson at 21:20 PM on 26 April 2010Has Arctic sea ice returned to normal?
HumanityRules is correct that the 'Polar Ice Center' graph in the article shows modeled results... we don't have sufficient data to accurately calculate Arctic ice volume for the entire timeframe. Thus, what they have done is taken measurements in an attempt to determine a general relationship between ice extent, concentration and volume... which they then project with the model based on observed extent and concentration data. However, from 2003-2007 ICESat gathered data on Arctic sea ice which provided sufficient detail to compute volume... and those results match the model quite well;
There are certainly uncertainties around the model values. Ice extent has been the de facto standard for decades simply because it was the only data available. For ice volume we've only got five years of reliable data (and even that has some uncertainties) which cuts off since ICESat broke down. The recently launched CryoSat II and forthcoming ICESat II should give us much more precise data for a longer period going forward.
All that said, the claim that Arctic sea ice is recovering or has recovered based on just two years of extent data is plainly absurd. Both because it ignores basic statistics and because extent is only one of three variables needed to compute volume (the others being concentration and thickness)... which makes it a poor proxy for determining total ice amount.
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Riccardo at 21:20 PM on 26 April 2010Has Arctic sea ice returned to normal?
Any single short term (i.e. weather) event is, by itself, not that significant. It is significant only when summed up to a previous trend. For Arctic sea ice it's definitely downward and one or two years of presumed "recovery" are not going to change this. Personally, I'm not interested in any climate "icon" if considered outside the global changes, we always need to put things in the proper context. So I'm happy to leave these icons to the media. But I have to admit that climate changes are more evident in some variable or process than in others; the Arctic sea ice shrinking is one of these. -
uh1h at 17:41 PM on 26 April 2010Hockey stick is broken
when 18,000 year old glaciers like the Chacaltaya melt away entirely after haveing obviously survived the MWP its a no brainer that it is warmer now at least in Bolivia. -
embb at 16:28 PM on 26 April 2010Are we too stupid?
Jacob:I claimed a tax and trade restrictions is not like a trade war. And major euoropean econimists claim it is, they actually warned France against it. I go with their opinion. Jacob:States, individuals - no matter. Tit-for-tat beats all-defection. No organization. No judge. No God. Just maths. This is completely false. Once again: for individuals there is a higher authority, namely the state, that can punish defection and reward cooperstion, ON THE SHORT TERM. Taxes would not work if tghe state collected taxes only to avoid an uncertain catastrophe in 100 years, this is even in YOUR article, for heavens sake. So, what is the punishment and what is the reward in the case of the carbon taxes? Surely not the good feeling that the state avoided the global warming??? And what is the higher authority in your view? Can you give a clear answer to that? If not, your statement that it does not matter whether we talk about states or individuals is clearly untenable. Jacob:I have never postulated that. It is the point of the post to analyse how to avoid defection. You must have missed that. You are right, I missed that. So, how can defection be avoided? Can you give a concrete answer? I mean if you just name reciprocity, I would be interested to know how reciprocity would work in the case of carbon taxes and how would the punishment of defection look like? Jacob:What are your solutions to mitigate climate change? You must have something considering your clear stance. What I have are doubts. I am in this discussion to clear them, as yet not with much success :) -
johnd at 16:17 PM on 26 April 2010Has Arctic sea ice returned to normal?
chriscanaris at 13:52 PM, your last two paragraphs make valid points. Both ice caps make it difficult to determine when things are in balance simply because of basic logistics. Energy takes the long road in and the short road out. Anything that forces a change on one side of the ledger may not be balanced by an equal and opposite force on the other side, at least within the region. It may well not tell us much about the global climate because the balance desired is to be found elsewhere in a different form. -
4 billion at 15:17 PM on 26 April 2010Has Arctic sea ice returned to normal?
Incredible that volume is the same now as during the 2007 summer.
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