The phrase “considerably larger than expectations” seems to occur with depressing regularity in climate observations.
Image above shows current Arctic sea ice extent compared to the record low 2011/2012 ice season, dotted line, and the average of 1981 – 2010.
Climate models have consistently been unable to capture the speed with which arctic sea ice has declined, especially over the last half decade.
Below, new research on what may be one reason the models have fallen short.
The Arctic isn’t nearly as bright and white as it used to be because of more ice melting in the ocean, and that’s turning out to be a global problem, a new study says.
With more dark, open water in the summer, less of the sun’s heat is reflected back into space. So the entire Earth is absorbing more heat than expected, according to a study published Monday in the Proceedings of the National Academy of Sciences.
That extra absorbed energy is so big that it measures about one-quarter of the entire heat-trapping effect of carbon dioxide, said the study’s lead author, Ian Eisenman, a climate scientist at the Scripps Institution of Oceanography in California.
The Arctic grew 8 percent darker between 1979 and 2011, Eisenman found, measuring how much sunlight is reflected back into space.
“Basically, it means more warming,” Eisenman said in an interview.
Eisenman et al:
The decline of Arctic sea ice has been documented in over 30 y of satellite passive microwave observations. The resulting darkening of the Arctic and its amplification of global warming was hypothesized almost 50 y ago but has yet to be verified with direct observations. This study uses satellite radiation budget measure- ments along with satellite microwave sea ice data to document the Arctic-wide decrease in planetary albedo and its amplifying effect on the warming. The analysis reveals a striking relationship between planetary albedo and sea ice cover, quantities inferred from two independent satellite instruments. We find that the Arctic planetary albedo has decreased from 0.52 to 0.48 between 1979 and 2011, corresponding to an additional 6.4 ± 0.9 W/m2 of solar energy input into the Arctic Ocean region since 1979. Averaged over the globe, this albedo decrease corresponds to a forcing that is 25% as large as that due to the change in CO2 during this period,considerably larger than expectations from models and other less direct recent estimates. Changes in cloudiness appear to play a negligible role in observed Arctic darkening, thus reducing the possibility of Arctic cloud albedo feedbacks mitigating future Arctic warming.
The Study is in PNAS called
Observational determination of albedo decrease caused by vanishing Arctic sea ice
http://www.pnas.org/content/early/2014/02/13/1318201111
This is a tiny dark piece of a much bigger & rosier picture.
More open water causes greater evaporation, which increases snowfall & snowcover in Asia, Northern Europe, Canada & Greenland, contributing to the accumulation of ice mass in glaciers and the Greenland ice sheet. It also increases evaporative and convective cooling of the sea, which is a major negative (stabilizing) climate feedback mechanism, probably not mentioned in the paper (can’t tell for sure, because it’s paywalled), and definitely not mentioned in this article about the paper.
What’s more, unlike the positive-feedback “amplifying” sea ice albedo effect, negative convective & evaporative cooling feedback operate in both daytime and nighttime.
To determine which of the two feedback effects is more important would require comparing temperature profiles for water beneath the ice vs. water w/o ice cover, under otherwise similar conditions.
That would give you a handle on whether sea ice is a net-positive or net-negative feedback mechanism: If the water averages warmer under the ice, then sea ice acts as a negative feedback mechanism, perhaps even in the Arctic summertime.
Unfortunately, I can’t find anyone who knows whether such a study has been done. I’ve asked that question on both skeptical and alarmist climate blogs, and nobody seems to know.
What’s more, it’s important to note that sea ice extent in the Southern hemisphere is above its 1979-2008 average. It is deceptive to discuss only the Arctic, without mentioning the Southern Hemisphere, in an article about “global” effects, particularly in an article about albedo-based climate feedback, since (because of its less extreme latitude) Southern Ocean sea ice is more important that Arctic Ocean sea ice for albedo feedback:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png
The sum of ice extent in both hemispheres, i.e., global sea ice extent, is barely below the 1979-2008 average:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
Note that north of 79.5 N. Latitude is currently experiencing 24 hours/day of nighttime. Lowered albedo does not increase absorption of sunlight when there’s no sunlight to absorb.
What’s more, we know from early satellite data that 1979 represented a peak in Arctic sea ice extent, so comparing recent levels to 1979 exaggerates the downward trend.
Nimbus-5, Nimbus-6, and Seasat-1 all made sea ice measurements via passive microwave radiometry prior to 1979. We still have good quality Nimbus-5 ESMR (passive microwave) measurement data of sea ice from December 11, 1972 through May 16, 1977, but NASA discarded or lost the Nimbus-6 and Seasat-1 measurements of sea ice extent. (Nimbus 6 was active from June 1975 until March, 1983; Seasat-1 was active from June 1978 until October 1978.)
Nimbus-5’s ESMR instrument continued to operate in a degraded mode through March 1983, but the 1977-1983 data doesn’t seem to be available on-line; perhaps it has been discarded or lost, too.
The inconvenient truth is that those early satellite measurements showed that sea ice extent was increasing, and peaked in the late 1970s, a fact which was reported in the first two IPCC Climate Assessment Reports, but has been “scrubbed” from the last three:
http://citebite.com/e1u8r0l1m6tnb
http://tinyurl.com/SAR-seaice-79peak
I hope it is just coincidence that NASA is less careful to preserve data which contradicts the CAGW narrative than data which supports it.
“It is deceptive to discuss only the Arctic, without mentioning the Southern Hemisphere”
I don’t much care to be called deceptive by one such as yourself. Seriously suggest you rephrase that, and get back to me.
But thanks for the teachable moments.
http://www.youtube.com/watch?v=MPnj9eR7t0g
http://climatecrocks.com/2013/01/03/next-time-someone-tells-you-antarctic-ice-is-growing-show-them-these/
http://climatecrocks.com/2013/07/14/guest-post-its-ice-melt-season-deniers-let-the-conspiracy-theories-flow/
http://nsidc.org/cryosphere/sotc/sea_ice.html
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
http://climatecrocks.com/2013/12/02/reposting-eric-rignot-at-agu/
http://climatecrocks.com/2013/04/11/pesky-reality-intrudes-in-denierville-again-danish-ice-maps-from-the-30s/
Trolls say things on the internet that they would never say to a guy on the next barstool, let alone a blackbelt in uniform. Go figure. There oughtta be a law.
I hope some day to find myself on a bar stool next to Dave Burton, with all that implies. Does that make me a bad person? Or a hero?
Or a drinking buddy? 🙂 He didn’t call you a liar did he? Maybe I should make my icon a picture of me in my black belt uniform. I don’t go in bars with it. It requires respect. With all his talk about sailors, you would think the probability of meeting him in a waterfront saloon would be high.
Is there an echo-echo-echo in the room? Dave is back with the same old crap he has posted on a number of threads over the past few months. He has been embarrassed there by a multitude of others who have exposed his faulty logic, cherry picked data, and general inability to see any truth but his own self-delusional variety (all archived on his website, of course).
He is back on his sea ice EXTENT kick again, and has the temerity to say “It is deceptive to discuss only the Arctic, without mentioning the Southern Hemisphere”. Yeah, Dave, let’s talk (briefly) about the southern hemisphere, which has a small percentage of the world’s land mass and population and is of little concern to the majority. Wildfires and record heat waves in Australia, record heat in Argentina, and things happening to the antarctic ice that are worrisome. ALL of it due to AGW.
Dave would like to distract us from looking at the northern hemisphere, where global warming is occurring most rapidly, and weather extremes due to global warming are occurring with greater frequency. Look around where you live, Dave—-it’s SHTF time!
(and I’m sure he hasn’t even looked at the graph or read the article).
I will say it for you, WHAT? Yes, I do see a repeat there. Dave thinks increased evaporation due to increased heating may cause cooling. No shit, I kid you not. He is really puzzled by it and would like to destroy everyones remaining active brain cells teasing coherence out of this insanity. Me, I will just laugh.
Yes, the “fractured physics” of Dave’s heating-evaporation-cooling insanity makes me literally dizzy every time I read it. I am glad I am sitting in a chair at the computer and that it has arms to keep me from hitting the floor when I semi-swoon—-if Dave is allowed to keep this up, I may need to install a seat belt. (And then we can perhaps alternate FYSB for “fasten your…” with WHAT?)
Its really sad when denier logic makes you go back to your college physics textbook just to see if you are crazy or not. I comfort myself with the knowledge that there is more than one physics teacher on this blog that would most likely rapidly correct any undue ideas I might err with. Skeptical Science is a great place to hang out for learning and to find out how much one does not know. A quick trip there usually grounds me dealing with a decidedly less intellectually gifted class of denier here. It makes me quite certain that a lot of denier rubbish here comes in the category of sheer ignorance, and sometimes a little bit of knowledge is a dangerous thing.
Climate uncertainties (such as clouds in modelling/so called pause in surface temperature rises) have been amplified by denialists/sceptics/contrarians as an excuse against action. Any overestimate by the IPCC or any other official organ has been pounced on, publicized and scorned. Any ambigious email has been picked up and hearings held and yet more precious time wasted.
As a counter argument to using uncertainties as an excuse to do little or nothing, scientific uncertainties should be used to urge more action. The recent climatic/weather anomalies involving flooding in the U.K and drought in California is an example of a possible threshold of a serious permanent shift of the Arctic jet stream current, which if the pattern persists would be a dangerous tipping point. It is uncertain, only time will confirm or deny the theory.
Other uncertainties or “climate surprises” include a large release of methane, from the huge Arctic reservoirs of methane hydrates, sudden sea level rise caused by West Antarctic ice sheet melt, ocean circulation pattern changes, any of which could cause abrupt and catastrophic changes. Uncertainties should not be used as an excuse to ignore the problem because there are too many certainties that point to an escalating worsening of climatic conditions on our planet. Humans and many of our co-inhabitant species may not be able to adapt.
Is our generation really worth a lot more than future generations ?
Are our countries worth more than mid latitude countries ?
Why are we holding back ?
Is our generation really worth a lot more than future generations ?
Are our countries worth more than mid latitude countries ?
Why are we holding back ?
Dave Burton would answer the first two questions with a question in return.
“What have future generations and mid-latitude countries ever done for us?”
And his answer to the third would be “Because the greedy rich haven’t quite finished raping the planet and accumulating even more useless wealth”.
My parents often recanted the amazing spirit generated during World War Two that brought everyone together to fight the tyranny of Nazism. It would be great if we could show some of that spirit now against a possible even greater evil.
recounted or recalled not recanted
I’m old enough to have personally experienced some of that “amazing spirit”. I was just a kid, but it was apparent everywhere you went. This is no longer the country it was during the 40’s, 50’s, and 60’s unfortunately, and we have the rise of the “selfish ones” to thank for that—-I speak of those who put profits and personal gain ahead of country and the greater good. They don’t give a rodent’s rear end for anything beyond that.
“That extra absorbed energy is so big that it measures about one-quarter of the entire heat-trapping effect of carbon dioxide.”
Could someone please tell me whether I’m reading that right?
I believe that is correct. The feedback is large. experts weigh in.
I don’t quite follow the argument that this is an explanation for the models failure to keep up with the speed of ice loss. Those models definitely include albedo effects, and hence they include ice albedo feedback. So unless the models are missing something else (darker ice & snow?) it doesn’t really explain the problem.
The IPCC was conservative. Anything it did not know for sure, it omitted, mostly positive feedbacks, related to ice melt and so on. Thats what happens when you don’t know all the inputs, and you are conservative. As the reference points out, sometimes uncertainty works against you.
http://climatecrocks.com/2014/02/19/arctic-albedo-feedback-measured-larger-than-expected/comment-page-1/#comment-50326
BTW, computer models is kind of a colloquialism. The models are equations and data. The computer is just used to do complex calculations quicker. There certainly are papers describing the mathematics and data. Try Trenberth.
At the angles of incidence in the arctic water has an albedo similar to that of ice in that it varies between .2 and 1. Whereas ice is about .4
Loss of sea ice in the arctic does not reduce albedo, it has not effect.
nasa video here
you’ll excuse me if I believe NASA scientists and not anonymous internet posters.
call it my bias.
If by “anonymous internet posters”, you mean Matt, he can be found making comments on a number of sites. Several folks on SkS have wasted a lot of time trying to get him off his denialist “kick” and listen to reason (with little success).
I found this quote on another site that may reveal some things about Matt, including that he cares little for proofreading his crap (and that is also shown in his post here).
Says Matt, “Personally I thing (sic) AGW science is simplisitic (sic), incomplete, and emotionalied (sic), and thus does fall into the category of a religion”.
Do we have an O-Log clone among us?
Take a physics class
By the way a new word for you with albedo it’s called absorption.
http://nsidc.org/cryosphere/seaice/processes/albedo.html