I always find it interesting as to why some stories get traction in the mainstream media and why some don’t. In online science discussions, the fate of this years summer sea ice has been the focus of a significant betting pool, a test of expert prediction skills, and a week-by-week (almost) running commentary. However, none of these efforts made it on to the Today program. Instead, a rather casual article in the Independent showed the latest thickness data and that quoted Mark Serreze as saying that the area around the North Pole had 50/50 odds of being completely ice free this summer, has taken off across the media.
The headline on the piece “Exclusive: no ice at the North Pole” got the implied tense wrong, and I’m not sure that you can talk about a forecast as evidence (second heading), but still, the basis of the story is sound (Update: the headline was subsequently changed to the more accurate “Scientists warn that there may be no ice at North Pole this summer”). The key issue is that since last year’s dramatic summer ice anomaly, the winter ice that formed in that newly opened water is relatively thin (around 1 meter), compared to multi-year ice (3 meters or so). This new ice formed quite close to the Pole, and with the prevailing winds and currents (which push ice from Siberia towards Greenland) is now over the Pole itself. Given that only 30% of first year ice survives the summer, the chances that there will be significant open water at the pole itself is high.
The actuality will depend on the winds and the vagaries of Arctic weather – but it certainly bears watching. Ironically, you will be able to see what happens only if it doesn’t happen (from these web cams near the North Pole station).
This is very different from the notoriously over-excited story in the New York Times back in August 2000. In that case, the report was of the presence of some open water at the pole – which as the correction stated, is not that uncommon as ice floes and leads interact. What is being discussed here is large expanses of almost completely ice-free water. That would indeed be unprecedented since we’ve been tracking it.
So why do stories about an geographically special, but climatically unimportant, single point traditionally associated with a christianized pagan gift-giving festival garner more attention than long term statistics concerning ill-defined regions of the planet where very few people live?
I don’t really need to answer that, do I?
Aaron, you claim that natural factors can account for the changes we have seen, but you cite not a one. Do you have a candidate or candidates? Keep in mind that your candidates have to do at least as good a job accounting for ALL the evidence.
Re: 489
Notice how the North Pole webcam #3 (Now at 84.3 North) #3, now has a nice tilt, as the melt pool is destablizing the platform.
http://www.arctic.noaa.gov/latest/noaa1.jpg
Obviously its not cold enough at the north pole :)
About ice or not at the North Pole this summer, unless ice flows change drastically I see ice at the Pole all summer. There is something strange by the way Arctic Ocean pack ice is circulating so far, strange is normal for the short term, but not for the long term, old multi-year ice is not heading toward the melting pond North of Alaska same as last year, in fact old ice is heading towards the North Pole, compressing ice towards Russia. A dramatic weather system change is needed to favor a greater North Pole open water scenario.
Joe Hunkins @ 318: It looks as if I’m set to win our bet, yes, although it could still go either way. Of course I hope you win. I’m less likely to win my bet with William Connolley.
Interesting how some of the posters here carelessly throw around insults. How can you expect to have intelligent discourse in such a careless environment?
Hansen and Nazarenko 2004 implied that most of the warming in the Arctic was due to soot. Gavin did not disagree about that conclusion and Chris seems to have completely ignored that discussion which took place over several posts. Likewise, Zender 2007 said the same thing.
[Response: You mischaracterise both H&N and my views. H&N and Zender did single factor experiments which produced more than proportionate warming in the Arctic because of soot. That’s fine. However, saying that ‘most of the observed warming’ is because of soot requires a full study of all the factors and an apportioning of the ‘blame’ (attribution) accordingly. When you do that you find that soot is *not* responsible for most of the warming – in fact, well-mixed greenhouse gases are (figure 9 in Hansen et al, 2007). You can’t just make up conclusions that do not follow from the studies you cite. – gavin]
That is most certainly not the same thing as my saying that all Arctic warming is due to soot. I have no first hand information on the matter, and am simply interpreting other people’s writing.
I’ve been hiking on large glaciers where the air temperature was in excess of 20C. Ice does not restrict the air temperature to close to zero, and if it did the Arctic would never melt. At the north pole, the sun never gets above 24 degrees declination. In order to get any significant melting under that condition temperatures well above freezing are required.
[Response: “Well above freezing” at the North Pole? Care to be more specific? You aren’t going to get above 1 or 2 deg C. Melting occurs when the there is a net energy influx to the ice, which is not purely determined by the sensible heat fluxes. – gavin]
I see a lot of very sloppy discourse going on over here and am disappointed. I expected better from RC.
#486
“So there’s essentially no prospect of a negative forcing that will outweigh CO2 over the next 50 years or more.”
Right, that is what is theorized. So, if global temperatures do not resume significantly upwards in the next 10-20 years (and there is no major volcanic eruption – even though this would only cause a brief 1-3 year drop in temperatures), I would think other major forcings would have to be considered. I certainly think CO2 is a climate forcing, but to me, the definitive proof of its dominance would be to overpower negative forcings from solar/ocean cycles. That would easily be enough to convince me that AGW theory is living up to its billing.
#487
Timothy said: “Why ten years, Aaron?
We have seen the warming of the past century. Those negative feedbacks could have kicked in during any one of those decades.
Why not twenty years from now?
Why not thirty? Forty? Or a hundred years from now?”
Well, Timothy, it actually does appear that negative feedbacks DID kick in during the 50s, 60s and 70s, as those decades did not see a rise in temperatures like the previous and following decades. Those years also coincided with a negative PDO phase and less El Ninos, which would lead one to believe those were major factors.
So, many current predictions have us staying in a period of cooler ocean cycles and perhaps lower solar activity for the next 10-20 years. If that occurs, and if CO2 proves to be a much stronger climate forcing as modeled, then temperatures should at the very least remain steady and most likely rise. Then AGW/GHG theory will be substantiated by direct, empirical evidence that would most certainly silence most of its critics.
BPL (493,4), If you interpret what was actually happening with the scientists and physicists in the 19th century and much of the 20th as a done deal fully growed everybody on board science, then, sorry, you are the one that is blind. And btw I for one would have no difficulty at all “dealing with it” if it was an old fully established science. I don’t understand why its actual youth drives you guys nuts…
#494
“No matter how many times you write that climate science is a young field, you will still be wrong. It isn’t. Deal with it.”
Really? Then explain to me how such an advanced science can have such an incomplete understanding of oceanic/polar relationships? We still don’t know what drives ENSO, the PDO/NPI occilation wasn’t even discovered until the late 1990s and is still just in the beginning stages of being understood, scientists are still trying to figure out why there is such disparity in polar temperatures, etc.
Sure, people have been studying climate for a long time, but compared to many other scientific fields, the knowledge/data stage is still in its infancy. Climate science is largely considered one of the last few true frontiers in science, because there is still so much to be discovered.
Gavin – According to this RSS chart, it would appear that the vast majority of TMT is derived from altitudes less than 10km.
http://www.remss.com/msu/msu_data_description.html#msu_amsu_trend_map_tmt
It is difficult to see how factoring in a cooling stratosphere can account for the large discrepancy with Hansen’s 1980 middle troposphere prediction.
[Response: But indeed it does – the issue is that the stratosphere is cooling much more than the troposphere is warming. You can see the model estimates of TMT in Table 2 in Hansen et al 2007 (you really should read this). RSS has a trend of 0.13 degC/dec, the coupled model has a trend of 0.14+/-0.01, UAH TMT is lower (0.05 degC/dec) indicating the structural uncertainty in the satellites is much wider than the uncertainty in the models. – gavin]
Chris – you chose to ignore the rest of the Hansen 2004 discussion before you started throwing insults and accusations around. How do you expect to have intelligent or sane discourse in such an environment of rancor?
Re #497 Steve Goddard
This isn’t really true either:
In fact, the very slow response to greenhouse gas-induced warming of the deep Southern latitudes and especially the Antarctic Circumpolar region (if that’s what you are referring to), was predicted from modelling in the 1980’s, and this can be established simply by looking at the relevant papers from the time. These are reviewed in a recent account:
S. Manabe and R. J. Stouffer (2007) Role of Ocean in Global Warming; J. Meterolog. Soc. Jpn. 85B 385-403.
Here’s a bit of a summary (direct excerpts are in italicised block quotes):
Discussing the early models of Schneider and Thompson (1981) to evaluate the delay in the response of the sea surface temperature to gradual increase in CO2, Manabe and Stouffer say:
In a later model Bryan et al (1988) made the same sort of analysis, investigating the role of the oceans in modulating the response of surface warming to enhanced greenhouse gases.
It’s not just the oceans per se of course. It’s also ocean and air currents, and particularly the mechanisms governing the efficiency of surface heat transfer into the deeper oceans. If this is efficient, the deep oceans will absorb heat and there might be little measured surface warming, at least for a while. So (speaking of Bryan et al (1988)) again:
Later models predict the same hemispherical asymmetry that is seen in the real world.
e.g. discussing the simulations of Manabe et al (1992):
Why is this, one might ask?! Here’s what Manabe and Stouffer say:
and:
(n.b. remember this is a prediction from a model; we’re nowhere near CO2 doubling yet!).
Re # 485 David Cooke: ” the PH of the ocean water has dropped to @ 7.4 …(However, the acid that appears to be contributing to the change in PH has not been documented, to my knowledge. This brings up the question of possible biologic decay and the acidic bacterial wastes generated as the bacteria break down dead phytoplankton in the oceans.)”
David: To repeat what I wrote in another thread (CO2 is Not the Only Greenhouse Gas.. # 38), you really should try reading the literature on the subject of ocean acidification – I provided some references in that post, most of which are free access. If you can find the June 13 issue of Science (available in many public libraries), you should also check out the following article:
Evidence for Upwelling of Corrosive “Acidified” Water onto the Continental Shelf
Richard A. Feely, Christopher L. Sabine, J. Martin Hernandez-Ayon, Debby Ianson, Burke Hales
Science 13 June 2008: Vol. 320. no. 5882, pp. 1490 – 1492 DOI: 10.1126/science.1155676
http://www.sciencemag.org/cgi/content/short/sci;320/5882/1490
That the increasing level of CO2 is causing acidification is very well documented. What acids are you thinking of?
By the way, where did you read that the ocean pH has dropped to 7.4? The Feely et al article I cited above reports some values as low as 7.6, but most studies on ocean acidification report a pH of over 8, which still represents a drop of around 0.1 pH unit; this might seem like a small change, but the pH scale is logarithmic, and it reflects a significant drop in titratable alkalinity, or buffer capacity.
Re #507
Aaron:
In fact the temperature statis during the 1950’s through early 70’s wasn’t due to “feedbacks” but had a major contribution from the atmospheric aerosols that effectively countered the relatively small increases in atmospheric CO2 concentrations during this period (after all atmospheric [CO2] was around 300 ppm at the turn of the 18th/19th century, and had only reached 320 ppm by 1965). So it didn’t take a lot of cooling aerosols from our rather dirty emissions (pre-Clean-Air-Act days!) to counter a rather small forcing from enhanced atmospheric [CO2]
e.g. see Figure 1 of Hansen et al (2005) “Earth’s energy imbalance: Confirmation and implications. Science, 308, 1431-1435
http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_1.pdf
Re #509
Aaron:
This isn’t correct:
The “disparity in polar temperatures” is quite well understood. See my post #511 just above, for an account of what was known about this even in the 1980’s.
And don’t fall for the fallacious argument that since we don’t know everything, that a scientific field is not rather advanced! The science of atmospheres and climate has been pursued since the days of Tyndall in the mid 19th century (it was known then that water vapour and CO2 were the dominant greenhouse gases that gave the Earth an “extra” 30 oC of warmth above its black body temperature…..Arrhenius knew already by the late 19th century that the Earth’s surface temperature rose in a linear fashion in response to logarithmic increases in atmospheric CO2…the study of the glacial – interglacial transitions was advancing in the 19th century and so on).
So climate science certainly isn’t a young field! And the knowledge isn’t “still in its infancy”, and nor is it “one of the last few true frontiers in science” (what about the science of the mind…or the mechanisms and treatment of cancer….or the origin of the universe…or the origin of Life on Earth…and many other examples of scientific frontiers) I would say that climate science is a rather mature science which has taken on a renewed importance and focus in recent decades as a result of a compelling phenomenon – i.e. massive man-made enhancement of the earth’s greenhouse effect and its consequences) .
Anyway, rather than playing semantic games about whether the science is young or old, and highlighting areas of residual uncertainty as if these negated an assessment of “maturity”, it makes more sense to ask a more constructuve question: e.g.:
“is our knowledge and understanding of the climate system and its response to enhanced greenhouse gas forcing sufficient for us to make informed policy decisions with respect to our emissions and their future consequences?”
Aaron, #509
Don’t be a fool.
You’re talking about the NUMERICAL MODELS which is not the science.
And since Newton’s gravitational theory is how many centuries old, why do we still not know WHY we feel gravitational force?
We’ve know inertial mass and gravitational mass are equal.
We still have no idea WHY. Higgs bosons may solve it, but we still aint seen them.
Is gravity still a young science???
Gavin,
I did a Google search for news stories this month reporting that the North Pole might be ice-free this summer for the “first time.” Hundreds of them came up including from most major news outlets. This is particularly interesting since Lewis Pugh swam at the North Pole in open water in July, 2007 in a widely publicized story. How quickly they forget.
http://www.wwf.org.uk/annualreview/0607/high_0000004620.asp
Four days ago the north pole webcam was reporting 4.5C external temperature and there were significant sized pools of meltwater on top of the ice.
http://www.arctic.noaa.gov/npole/2008/images/noaa1-2008-0701-100748.jpg
Today the temperature is 0C and the meltwater is freezing over.
Andy Revkin posted some good pictures showing dirty snow around moulins. From the air, the dirty snow in western Greenland is unmistakable.
http://dotearth.blogs.nytimes.com/2008/07/03/a-tempered-view-of-greenlands-gushing-drainpipes/
[Response: It’s not dirt. That’s mostly how dark old ice is. – gavin]
I will read Hansen’s paper you referred to about stratospheric cooling.
You seem to have implied earlier that the Arctic warm period in the 1940s was primarily due to soot. Is that a correct interpretation of your remark?
[Response: No. I was just curious as to why you didn’t think so since you are so fond of the soot idea. It may have played a role, but without the full attribution studies, I can’t say. – gavin]
I’ve got back from work to find myself superfluous. :)
Steve Goddard,
I note you did not chose to explicitly answer my questions in #471. However in light of what I said in post #334, I am sure you got my point.
Perhaps rather than throw around faux-accusations like “I see a lot of very sloppy discourse going on over here and am disappointed.” You may see the pattern of how much you are getting wrong and upon reflection desist from journalistic forays into a field you are evidently not currently able to comment upon. Some basic thermodynamics would have helped you with the following point:
With regards air temperature being pegged to zero on the Arctic ice: As you don’t seem to be aware of the physics, perhaps some observations may help with this, check out NOAA’s webcam weather data: http://www.arctic.noaa.gov/gallery_np_weatherdata.html You can see how the temperature rises out of the winter, but levels at just below zero.
Glaciers are not the Arctic, you’ve generally got breezes shifting heat off the bare mountains around or from ice-free lower areas. But just try taking the temperature in the relatively static air at foot level. Air is a good insulator and cooler air falls.
#513 – Chris
I am aware of the aerosol theory…however, one thing to consider is that this theory was created before the discovery of the PDO (which happens to coincide just about perfectly with that downturn in temps). Therefore, it is somewhat outdated…though still possible, it makes more sense to me that the negative PDO phase correlates with that period, since aerosols didn’t suddenly start effecting the atmosphere in the late 1940s and then just as suddenly stop in the late 1970s. A pretty sharp start and stop of that cooler period can be seen…
“The “disparity in polar temperatures” is quite well understood. See my post #511 just above, for an account of what was known about this even in the 1980’s.”
I understand there is some rationale behind it, but that doesn’t explain how the South Pole has not followed modeled temperature predictions. Or has it? I have read from several sources about how it was modeled to warm somewhat, but Antarctica as a whole has actually cooled in the past 30 years. There did not seem to be any consensus explanation of this from scientists.
“Anyway, rather than playing semantic games about whether the science is young or old, and highlighting areas of residual uncertainty as if these negated an assessment of “maturity”, it makes more sense to ask a more constructuve question: e.g.:
“is our knowledge and understanding of the climate system and its response to enhanced greenhouse gas forcing sufficient for us to make informed policy decisions with respect to our emissions and their future consequences?”
I absolutely agree that the more important question (rather than how advanced/young climate science is) is what you wrote above? Although, that does get into politics a bit, and I prefer to separate discussion of science/politics as much as possible. Anyway, I personally do not think that our knowledge and understanding of the forces involved in climate change is sufficient for us to take drastic action at this time. But you are certainly entitled to disagree with that.
RE: 512
Hey Chuck,
There were a number of articles that were released between 3 July and 4 July relating to work by Dr. Le Quéré that was linked to my weekly NASA Science News list of articles.
In a offshoot from one of the stories listed there, via a Yahoo link, an article appeared where the author picked up some erroneous data and now I have Parroted it and the article has been corrected. (My memory of the article discussed that the values in the Southern Ocean has been as low as 7.4.)
From my memory, the article references were two fold, there was the discussion by Dr. Feely and his 2007 and 2007 analysis of the Pacific coast in response to highly acidic upwelling waters on the Pacific coast of North America and the discussion of geologic vents generating solutions with up to a ph of 7.4 and it’s influence on sea life. Though the article abstracts in AAAS and the oceanacidification organization that suggests that the average value was more like a drop of 0.1 units from 8.1 or 8.0 to 8.0 or 7.9
The second reference was to Dr. Le Quéré’s work in the Southern Ocean and the Carbon uptake being limited. (Apparently, it was not until she plugged in the variance identified as sourced by anthropogenic CO2 that the data she was researching appeared to make sense.)
In addition, there has been a rash of articles since last Fall regarding oceanic CO2 uptake linked to the projection that between 2100 and 2300 the ocean could return to a ph of 7.4, which it has not been at in over 21My.
As to CO2 being a participating GHG I am quite aware of the other participants as the CDIAC has a great set of references of proposed participants. (The primary participant being water vapor, which of course takes us far off the topic.)
As to my concern of published data in regards to the acidic values there has not been a reference I have viewed that has come out and claimed that the rise in ph was due to Carbonic Acid. I have read that there are areas of surface water where there are deviations in values; however, I have not seen a study that defines the various acids in ocean water solution at depth and the changes there in.
Let me try a different approach Chuck. Do you or anyone else participating here have a reference as to the types of acids collected by oceanic sampling that indicates both the depth and the temperature at the time of the sample? (For clarification, I am looking for acid content in solution not ph.)
Thanx!
Dave Cooke
I’m perplexed. Some here are simply pointing out that there were very few folks working with what we know call climate science until almost mid-20th century. (…matter of fact it was probably the military’s work on radar in WWII that gave its big boost…), or at least through the 19th century. And hardly anyone paid those few folks any heed. It seems neither difficult nor profound nor meaningful to conclude it was then considerably less than an established science. And that, by common logic, would kinda make it “young” today — even if advancing rapidly. Yet the bonkers reaction here is like we’ve thrown a smidgeon of dirt on your dogma and creed, and if it creates even the teeniest of doubt, right or wrong, (which it shouldn’t) it might put the tenet of AGW in jeopardy and must be killed. Boggles the mind.
After Chris falls into the mire within his long post 513, he (surprisingly?) then concludes with the only meaningful and pertinent thought, IMO, in this nonsense.
Re #519 Rod:
Have you got a specific problem with my post #513? After all, one shouldn’t pretend or assume that things that we do know quite well, aren’t known. Or don’t you think so? So if we know pretty well:
(i) why the global temperature was rather “flattish” during 1945ish – to early 1970’s ish….
and:
(ii) why the high Northern latitudes are undergoing considerable more warming under the influence of excess greenhouse forcing than the high Southern latitudes….
it seems pertinent to point these out in the context of Aaron’s posts.
I’m curious to know in what sense you consider that I’ve “fallen into the mire” by addressing those points? After all one can only benefit from clarification of our knowledge and understanding. I thought that was the point of all these threads! I certainly didn’t feel like I’d been “mired” in taking the few moments to clarify those particular issues…
in any case you seem intent in “re-engaging” with the “mire”. I would have thought that the fact that Tyndall et al knew already in the mid-19th century that CO2 and water vapour were the dominant greenhouse gases (they make us 30 oC warmer than the poor Earth “should be”!)…and that Arrhenius worked out already in the late 19th century that the Earths surface temperature responds linearly to logarithmic changes in atmospheric CO2 concentrations…and so on…really does establish atmospheric and climate science as being an endeavour of rather deep historical provenance. Frankly those guys in the 19th century had more or less worked out most of the essentials that inform us now!
Not being funny, but have you never heard of till? What you are mistaking for “dirt” (soot?) does contain an amount of aerosol and windblown dust, however, the bulk of what you’re looking at is rock dust and debris which has been ground from the bed over which the glacier/icesheet is sliding.
This till has been forced up to or deposited on or near the surface by any number of different processes. Including rapid melt induced hydro-fracturing.
Near the snout of a glacier, where ablation is strongest, the till tends to concentrate as the ice melts back. As a result the glacier gets ‘dirtier and dirtier’ until such time as all is left is a pile of till…which is then called moraine!
Rod B (519) — And also physics, cosmology, astronomy, biology, geology, materials science, horticultue, agronomy, genetics, …
Almost all scientists, by count, are currently alive.
This argument about whether climate science is young or old is getting absurd. Let’s try to stay on topic.
[Response: well said – gavin]
Re: #505/510 Steve Goddard:
Where are the “insults” and “rancour” of which you speak? Pointing out the mendacity of misrepresenting scientists by “stitching” together parts of sentences from their papers so as to create a false representation of their work (see my post #499), is not an “insult”. I hope we would agree that one should highlight lies and misrepresentation where we encounter it.
Anyway, the point is to establish what the science “says” on a particular subject, in this case the possible contributions of soot (black carbon) to Arctic warming and sea ice melting.
I’ll itemise (sketchily!) what I consider to be the scientific understanding on “soot” as it stands, and number these for easy reference. You can then easily highlight what you consider to be problematic/erroneous. I’ll use the term “black carbon” (abbrev. BC) in place of your “soot”, but we can assume (unless someone tells us otherwise) that they are equivalent.
1. Hansen and Nazarenko [Proc. Natl. Acad. Sci. (2004)] identified BC as a potentially major contributor to reduced albedo of ice and snow in both polar and mountain glacial locales.
2. These authors later reassessed the impact of BC albedo effects. They consider that the total contribution of BC albedo effects on ice/snow to be equivalent to a contribution of 0.065 oC to total global warming since 1880 [Hansen et al. (2007)]. This doesn’t preclude significant local effects on especially spring snowmelt.
3. A detailed analysis of BC in Greenland ice cores [McConnell et al (2007)] defines the deposition of BC from industrial emissions since the start of the “industrial age” (1850ish). These authors show that (at least in the Greenland ice cores sampled) the greatest effects of black carbon on Artic ice occurred in the period rising from around 1900 to 1930, and then dropping back down to low levels by 1950, with occasional pulses (due to forest fires) from then.
So the dominant effects of black carbon on Arctic ice albedo seem to have been in the early to mid 20th century, and perhaps that was a significant contribution to the Arctic warmth in the early part of the 20th century. The median estimated surface forcing (during early summer) was around 0.42 W/m2 before 1850, and was around 1.13 W/m2 in the period 1850-1951, with values as high as 3.2 Wm2 in the early 20th century. It’s been around 0.59 W/m2 since 1951 to present.
Like Gavin, I’m surprised (see your post #497 and his responses) that you didn’t consider the possible role for BC in early-mid 20th century warming, considering that BC deposition in the Arctic regions seems to have been extremely strong in these periods!
4. Note that Dr. Charles Zender (who you speak of) is a coauthor on McConnell et al (2007) cited in point #3 just above.
5. Zender (2007) of which you refer (your post #505) doesn’t seem to exist. It’s possible that you are referring to Flanner et al (2007) on which Dr. Zender is also a coauthor. These authors modelled the effect of BC on global land and sea ice snow pack in 1998 (a strong boreal fire year) and 2001 (a weak boreal fire year) and determined that BC makes a strong contribution to albedo reduction coincident with snowmelt onset especially in years (like 1998) with lots of BC from boreal fires. The forcing during spring over the Tibetan plateau is especially marked….
6. While BC makes a contribution to warming and snow/ice melt due to surface deposition and reduction of albedo, the overall contribution of atmospheric aerosols (of which BC is a presently a non-seperable part) to the global thermal balance seems to be rather strongly cooling. This is apparent from the balance of forcings [e.g. see Hansen et al (2005) and Hansen et al (2007) again].
7. This point is explicitly discussed in a very recent review on BC and atmospheric brown clouds (ABC’s) by Ramanathan and Carmichael (2008). As indicated by the estimated forcings (tabulated at the bottom of my post #499 above) the overall aerosol forcing is globally a strong cooling one. Thus while BC may well be contributing to Arctic warming and sea ice melt (more likely it’s main contribution was during the earlier parts of the 20th century – see point #3 above), overall the manmade aerosol effect on Arctic warming/sea ice melting is not clear. It may be a net cooling one, it may be a net warming one, it may be about neutral…
8. and so on…..
J. Hansen and L. Nazarenko (2004) “Soot climate forcing via snow and ice albedos” Proc. Natl. Acad. Sci. USA 101, 423-428
http://pubs.giss.nasa.gov/docs/2004/2004_Hansen_Nazarenko.pdf
Hansen, J. et al. (2005) Efficacy of climate forcings; J. Geophys. Res., 110, D18104
http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_2.pdf
Hansen, J et al. (2007) Climate simulations for 1880-2003 with GISS modelE. Clim. Dynam., 29, 661-696
http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_3_small.pdf
M. G. Flanner et al (2007) Present-day climate forcing and response from black carbon in snow J.Geophy. Res. 112, D11202
http://www.agu.org/pubs/crossref/2007/2006JD008003.shtml
J. R. McConnell et al (2007) 20th-century industrial black carbon emissions altered arctic climate forcing; Science 317, 1381-1384.
http://www.sciencemag.org/cgi/content/abstract/317/5843/1381
V. Ramanathan & G. Carmichael (2008) Global and regional climate changes due to black carbon; Nature Geoscience 1, 221-227.
http://www.nature.com/ngeo/journal/v1/n4/abs/ngeo156.html
#500 Ray Ladbury:
“…when someone shows me that I am wrong, I usually thank them for their efforts. This is one reason why I am still happily married.”
Now there’s some useful advice we can all take home with us, regardless of what we believe we know!
#502 LG Norton:
I’m not believing anything until I see a fleet of submarines emerge in front the camera.
#505 Steven Goddard:
Steven, I don’t think anybody else here has come close to being as nasty to you as I’ve been, and you shouldn’t even consider me as “here” because I’m an arriviste at RC. (In any case I’m reforming my RC character, taking a cue from Gavin.) I do hope you’ll sincerely reassess your published remarks about Dr. Hansen in light of your own feelings about how you’re treated here, and even more I hope you’ll bring whatever you’re considering including in future articles here for “peer review” via fact checking and critique of your accuracy. It may not always prove pleasant, but your work will be the better for it.
Gavin,
A good flight to see Greenland is London to San Francisco in late summer or early autumn. The flights generally go near Nuuk and you can plainly see the very dirty snow along the western margins of ice sheet. Miles and miles of dark grey to nearly black snow. There is a reason why Zender and Hansen have recognized that dirty snow is a major contributor to melting.
[Response: That’s not because of soot. – gavin]
So my curiosity is peaking about 1940 Greenland. It was warmer in 1940 than now, yet CO2 levels were lower. We can’t quantify the soot factor or the “natural variability” factor. So how can anyone say with any degree of confidence what has caused the warming over the last 25 years?
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=431042500000&data_set=1&num_neighbors=1
[Response: Because it is coherent with warming all over the world. – gavin]
And what is causing the exceptionally cold summer they are having this year?
http://www.summitcamp.org/transport/weatherstation/mainpage.py?view=Month
http://wxmaps.org/pix/temp2.html
Will there be any Earth Observatory papers published about the low number of melt days on Greenland this summer, and will they make headlines at the BBC?
[Response: ‘Exceptional cold’? Perhaps you’d care to point out some basis for that? – but even if correct, it’s just the weather. The climate changes are about the trends. – gavin]
David Cooke writes several places above that he is unaware of any reason that increasing atmospheric carbon dioxide will increase ocean pH or that the observed increase in ocean pH is due to carbon dioxide, as opposed to something else.
Possibly excess citric acid from a surfeit of orange peels?
C’mon. Don’t pretend ignorance, it’s unglorious.
Look it up. Good grief. You know how to find these:
Anthropogenic carbon and ocean pH
K Caldeira, ME Wickett – Nature, 2003 – antalya.uab.es
… methane hydrate degassing. When carbon dioxide dissolves in the ocean it lowers the pH, making the ocean more acidic. Owing to a …
Cited by 161
Reduced calcification of marine plankton in response to increased atmospheric CO2.
U Riebesell, I Zondervan, B Rost, PD Tortell, RE … – Nature, 2000 – ncbi.nlm.nih.gov
… exchange. The present rise in atmospheric CO2 levels causes significant changes in surface ocean pH and carbonate chemistry. Such …
Cited by 195
Middle Eocene Seawater pH and Atmospheric Carbon Dioxide Concentrations
PN Pearson, MR Palmer – Science, 1999 – sciencemag.org
… The carbon dioxide content of the atmosphere [measured as the partial … pCO 2 )] affects the content of the surface ocean, which in turn affects seawater pH. …
Cited by 71
[PDF] Accelerating carbonate dissolution to sequester carbon dioxide in the ocean: Geochemical
K Caldeira, GH Rau – Geophysical Research Letters, 2000 – geol.ucsb.edu
… Cretaceous mass extinction — possible biogeochemical stabilization of the carbon cycle and … and HJ Herzog, Near field impacts of reduced pH from ocean CO …
Cited by 44
Carbon dioxide on the early earth
JCG Walker – Origins of Life and Evolution of Biospheres, 1985 – Springer
… on the pH of the ocean. Equilibria in the carbonate system are illustrated in Figure 2 as functions of P, the partial pressure of carbon dioxide in bars, and …
Cited by 80 …
RE: #518
“What kind of acids” isn’t going to help. Strong acids completely (or nearly so) dissociate when in solution – in other words the acid part (H+) and the anion part (various) separate. Weak acids will stay, in part, as a molecule – and carbonic acid is weak – but these amounts depend on the equilibrium concentration of the ions NOT where they came from originally. For example, I could make a solution from sodium chloride and dissolved carbon dioxide, and also make the exact same solution from sodium carbonate and hydrochloric acid. First year chemistry.
If the pH shift isn’t caused by dissolved Carbon dioxide, then what do you propose is causing it?
Steven Goddard @ 515:
Lewis Pugh swam in a lead. There have been leads of various sizes at or near the pole in late summer, many times, over the decades. Everyone who knows anything about the pole knows this. There are many, many photos of submarines and/or ice-breaking vessels at the pole, some in leads. There was a story in 2000, discussed at enormous and tedious length earlier in this very comment thread, concerning a lead of a few kilometres at the pole.
The story this year, as anyone with basic reading ability should be aware, is that arctic sea ice experts (such as Serreze at the NSIDC) believe there might be open ocean at the pole this year. Not leads. Open ocean. As in, navigable, not by ice breakers but by regular surface vessels, all the way from a coast (possibly Alaskan), to the pole.
Not leads. Open ocean.
Do you understand the difference between a lead and open ocean?
No experts are saying that this will happen this year. That depends on the weather. But it might happen. We have ten weeks of melt season left, and all the ice north of the Beaufort Sea is looking decidedly iffy.
Firstly, please bear in mind that the north pole webcam is not at the north pole. It’s at 84.8 degrees north. It’s about as far from the pole as London is from Aberdeen or Lyon. So citing it to discuss conditions at the pole itself is just plain daft. Here’s the map showing this year’s station drift:
http://www.arctic.noaa.gov/gallery_np_weatherdata.html
Secondly, that same webpage has a graph of the temperature so far this year, from the weather station. You’ll see that the temperature rises in the spring, and then plateaus at zero. That’s the latent heat of the ice, keeping it there. The effect is even more visible in the actual weather data:
http://www.arctic.noaa.gov/weather_data/2008/07100_hdr.wx
The temperature reported is very stable, between about -3 and +1, 24/7, for many weeks.
However, the webcam images themselves show temperature, as recorded by a sensor on the webcam itself. This is not official weather station air temperature; it’s the temperature of a sensor on the camera. The webcam information page says: “The temperature shown on the image is the temperature of the camera, and may be warmer than the surrounding air temperature (think about how your car heats up on a sunny day)”. 4.5 degrees might indicate exposure to sunlight; as you can see in the pictures until 7th July the webcam was exposed to sunlight. However, you’ll notice that the webcam was moved between 7th and 9th of July, from one side of a white structure to another. Out of the sun, possibly? And if you look at the most recent picture from webcam 1, you will see a meltpond – the same meltpond as in all the pictures taken by that camera this July:
http://www.arctic.noaa.gov/npole/2008/images/noaa1-2008-0710-171602.jpg
Lastly, the picture you refer is not from “Four days ago”. It’s from 1st July, nine days ago (day 183).
Gavin,
The NCEP maps have been showing southern Greenland 2-10 degrees below normal all summer. More recently, the cold has moved north as well.
http://wxmaps.org/pix/temp2.html
[Response: I saw that, but NCEP is neither climatology nor real data and may have significant biases over significant topography and far from input data. But it isn’t really important. – gavin]
I assert that until an adequate explanation is given for 1940 Greenland warming, any theories about current warming are not on solid footing. CO2 was considerably lower in 1940, yet temperatures were higher.
[Response: This is nonsense. Greenland is not the world – and fixating on remote places with poor data quality is simply cherry picking. Maybe I could explain everything that had ever happened in Greenland, would the next comment be how without an adequate explanation of changes in Ulan Bator, or Diego Garcia no theories can be on solid footing? Please, be serious.]
A very interesting study would be to correlate the NASA Greenland melt maps with snow albedo. My guess is that they would line up quite closely.
[Response: Of course: wet snow is darker than fresh snow and ice is darker than snow and water is darker than ice – this has been known for decades, if not centuries. It’s just another one of those darn positive feedbacks…. -gavin]
Hoy! Someone never seen blowing dust, dirt, even blowing little rocks in the Arctic. Quite common in the spring, summer or fall, dirtying glaciers , big ones and small ones alike, a clue on the big ones, there is more dirt on the edges, many lands have no soil in the Arctic. Also temperature variances at the North Pole, I can tell stories, when its very warm there when it shouldn’t be and very cold when it shouldn’t be. Weather is weather, not always directly proportional to sun disk elevation (declination??…. at the equator perhaps) , always a matter of so many other factors. Like the Polar Ice Cap, which seems to be vanishing more from the Pacific side of the Pole. Having lots of ice at the Pole now is not because it is colder there, the chap who swam last year at this time could have done the same thing in March when it was -35 C, this happens on occasions, there is extra flowing ice towards the Pole now a days (compression for the ice connaisseur). The summer melt is not over, and it usually happens near the continents. To have a solid idea of what is happening would be to have. as someone wrote, an ice volume check, or an ice thickness map, just to have a better idea of the melting, extent is a matter of momentum and winds on most occasions. NOAA sat pics makes it hard to tell whether there is still a significant surviving ice thickness for the first year type. Hold on to your guns quick draw McGraws! But show me an ice thickness link, and lets see….
Re #528
to add a quantitative perspective to your post….
Yes carbonic acid is not a strong acid. However it is pretty much fully dissociated (to bicarbonate and H+) in sea water, since the pKa defining the equilibrium dissociation is very much below the pH of sea water:
so for:
H2CO3 (carbonic acid) = = = = = HCO3- (bicarbonate) + H+
the pKa is around 6.4
the pH of sea water is around 7.8-8.0ish. We can calculate the degree of dissociation of carbonic acid to bicarbonate using the Henderson-Hasselbalch equation! Thus:
pH = pKa + log ([base]/[acid]) (with bicarbonate and carbonic acid being the “base” and “acid” in this instance)
so in sea water at pH 7.8 [bicarbonate]/[carbonic acid] = 10^(7.8-6.4) = 15.8
and at pH 8.0 = 39.8
in other words, although carbonic acid is not a particularly strong acid, 94% or more of the molecules of CO2 that partition from the atmosphere into the ocean surface waters and become hydrated to carbonic acid, dissociate to bicarbonate and release a proton into the surrounds…..
Meanwhile, in the middle of the winter near the other pole:
http://www.livescience.com/environment/080710-ice-shelf.html
Steven Goddard, Just a suggestion. Maybe, just maybe you might have been better received here had you not accused the entire scientific community of fraud. Real scientists take accusations like that pretty seriously and do not throw it around lightly. Now you show up here [edit] -and it appears your knowledge of climate is quite confused. Moreover, even though you are at one of the premier resources for learning about climate, you are more interested in pontificating and telling us how disappointed you are that you’ve been ill received by some. I have to say, sir, that you did not disappoint me. You were about what I expected.
Does anyone else have the feeling this thread and another recent thread have been hijacked by several libertarians home on summer break. They are not the people for whom RC has an obligation to win over. Their questions, retorts, topic choices are worthy of debate topics in a contrarian society monthly meeting.
It is not irresponsible to ignore trolls and mischief makers. They have motives different from commenters seeking answers to questions they cannot, or have failed to, find answers on their own. Help the latter and ignore the former. That is my advice. Likely we would walk away from the former if we confronted them at a party or social gathering having given them the opportunity to show their real intent.
They will not leave but you patient, knowing and generous souls do not have to encourage them either.
John McCormick
Aaron, Actually, I think your examples of PDO and ENSO are pretty good examples of why climate science is mature. After all, they are not climatic themselves, but rather part of the noise that obscures climatic trends on short timescales. When a field is sufficiently advanced that it has the luxury of characterizing the noise on its subject matter as well as its subject matter, that is pretty mature (think electronics).
And still you have not given us a single candidate for an alternative driver that can explain the trends we are seeing. Do you have one or do you just not want to admit there is no other viable answer except anthropogenic causation.
Chris (520), actually I was referring to only part of your post 513, the part dealing with young and old, not the science substance. It’s the young-old debate that I think is inane and was pleased when you extricated yourself from it with your closing words of wisdom, which I heartily endorse. Then, unable to pass up a road mine when you see one, I guess, you jumped right back into the fray in #520.
I said, “…very few folks working [in] … climate science …. at least through the 19th century. … hardly anyone paid those few folks any heed. … [so couldn’t be] an established science.” You now say (paraphrasing), ‘but Hey! Two lonely guys [I’ll grant, maybe a couple more] did some stuff back then [that everybody else gave short shrift to], but turned out [a number of decades or so ago] to be pretty good.’
Even though you’re saying, in essence, the same as I, you somehow claim this validates it as a long-established science. I think this is an amazing logical conclusion… though it might be good for the dogma protection.
But, whatever…
Ray (500), mostly I was just pulling your chain (hint: a winking smiley face). I just thought the juxtaposition of Twain’s words about the worst stuff is “what we know for sure that just ain’t so” with your words of the unassailable unchallengeable climate science that you know for sure was a tad ironic.
RE: 532, 528, 527
Hey Chris,
If I understand you correctly, are you suggesting that the dissolved Carbonic Acid disassociates and forms bicarbonate and hydrogen? Is this to be taken as a suggestion for the observed reduction in oceanic Carbonic Acid? Certainly the observed AGW CO2 participation dissolved in the ocean should have a clear isotope marker, which should also be visible in the calcium carbonate formation.
Hey Paul,
Contrary to to the feedback I am seeing, I am not suggesting that CO2 is not driving ocean acidity. I am simply curious if the observed ocean ph change could be related to other biologic processes. Especially in the recent light of the expansion of “Dead Zones”, oceanic turn over, and discoveries a few years back suggesting the gases released by decaying phytoplankton could have been participating in the formation of clouds.
Hey Hank,
It is clear that scientists with greater education then I have established an AGW GHG/Oceanic Acidity association. It is clear that for the significant data vacuum, as observed by Dr. Le Quéré, the AGW GHG participation seems to resolve the issues regarding observations of ocean CO2 uptake.
There is data by NOAA, the SeaWiffs satellite package and the Woods Hole Institute that demonstrates phytoplankton blooms in regions of high nutrient run off. There are also recent studies that support the observation of high amounts of dimethyl sulfides in regions containing decaying phytoplankton found on the west coast of North America, the South Pacific, the North Sea and the Southern Ocean.
( http://earthobservatory.nasa.gov/Newsroom/MediaAlerts/2006/2006110623606.html ) For me this leads me to the question of, whether or not biologic processes could explain limited oceanic CO2 uptake?
My main interest in the content of participants in the column remains. Especially in light of what I sense is a limiting mixing factor caused by a reduction in Wind/Wave interaction in the Temperate Zones ( http://www.gfdl.noaa.gov/~gav/REPRINTS/VS_07_GWnCIRC.final.pdf ) and a warming of the Sea Surface Temperatures. Restated, my main interest is identifying the ocean column acid content at this time. However, if as Paul suggests, acids disassociate in solution/brine, that this may not be possible.
At risk of being redundant, I am curious whether or not you may have a reference that addresses the question I posed to Chuck? Not that the conclusions in the studies are incorrect, only that I am curious as to the balance of participants in the ocean column. If you have supplied it, I must have missed it in the plethora of studies you have provided. (Oh BTW, have you seen the latest they are actually deploying buoys starting this past week that measure PH.)
Cheers!
Dave Cooke
Chris (532), I might have missed it, but I have a basic question. Does the extensive dissociation of carbonic acid in seawater mean that there is very little if any CO2 dissolved as molecular CO2? I think you said maybe 6% of all absorbed CO2. Does this apply to fresh water (ballpark)? Is it just the 6% “pure” CO2 solute that is the parameter in Henry’s law, or is the CO2 dissociated into carbonic acid considered as part of the solute for Henry’s law?
Thanks for any help.
Steven Goddard, you’re getting ridiculous, and I’m surprised gavin has chose to continue responding
before the satellite era, all you have to represent that thousand-plus-mile-long ice sheet and surrounding land is a handful of mostly-southern, all-coastal stations (so anyone who actually says that they know what Greenland was doing should be viewed with doubts). Most people have Greenland a bit warmer now, but with lots of uncertanties.
Global warming so far is nearly 1 degree. That is large compared to decadal-average global-average variability, so we can see the warming signal clearly. But, it is not large compared to variability over shorter times and smaller areas, so it is virtually guaranteed that there are still places that are not (yet) anomalously warm, or record warm, or what have you. The smaller the area and shorter the interval, the larger the variability. Greenland is large, but much smaller than the globe. The earlier warming seems to have had a bit of solar, a bit of lack-of-volcanic, maybe a bit of ocean (Atlantic Meridional Oscillation), and possibly some black carbon (see the piece by McConnell et al. 2007 in Science).
Re # 518 David Cooke:
No surprise there, since the addition of carbonic acid lowers the pH of an aqueous solution. As for ocean acidity, as I noted earlier, ocean acidification has been documented by the drop in pH, but also the decrease in titratable alkalinity (TA; sometimes referred to as acid neutralizing capacity, ANC) – that decrease in TA is essentially a measure of acidity. Ocean chemistry has been studied pretty intensively for the past 100 years, or so; any good university library will have chemical oceanography textbooks that summarize what is known.
What acids do you think would be produced by bacteria? And why do you think these acids would be sufficient in sufficient quantity to lower the pH of the world’s oceans?
And why do you think the measured increase in CO2 partial pressure in the ocean is insufficient to explain the observed declines in pH and TA? This is pretty fundamental aquatic chemistry (it applies to your blood plasma equally well).
In response to Aaron
I had said in 487:
Aaron responds in 507:
The northern hemisphere actually saw cooling for through much of the mid-forties to early seventies. In contrast, the southern hemisphere saw statistically significant cooling for only one year — and globally we experienced statistically significant cooling for only six years.
Please see:
Hemispheres
August 17, 2007
http://tamino.wordpress.com/2007/08/17/hemispheres/
Mainstream science attributes the cooling to the effects of anthropogenic reflective aerosols. Such tropospheric aerosols have a half-life of approximately seven days — which explains why their effects were predominantly in the industrialized Northern Hemisphere, not the Southern.
*
The IPCC considers the role of aerosols uncontroversial enough that they state it matter-of-factly in a Faq:
Likewise we know that as the result of environmental laws were put in place in the major industrialized nations (e.g., the United States and countries in Western Europe) which reduced such pollution in the early seventies — and with the reduction in aerosols we saw the beginning of the modern era of global warming ~1975.
Last time I checked, anthropogenic reflective aerosols were not a feedback to carbon dioxide.
*
Aaron continues:
Ah — climate modes… At least one for every ocean basin. The Pacific Ocean has ENSO, PDO, the mock-El Nino by Japan, and then of course there is the Indian Diapole — although I am not sure that the last of these would count as a climate mode of the Pacific Ocean.
I believe you are right: there is a causal relationship between climate modes and global warming. However, there is reason to think that the causation flows in the opposite direction. This view has been a part of the literature for some time.
Please see for example:
During periods of global warming, ENSO tends to be in a positive phase (more El Ninos which are stronger and last longer) and the North Atlantic Oscillation and tends to be in a positive phase. The reason being? The system is chaotic and sensitive to its environment, particularly the forcing, whether it is solar in origin or due to greenhouse gases. In the troposphere at least there is very little difference between the two and how they affect the climate system. However, with warming due to solar forcing, one expects both the troposphere and the stratosphere to warm (with the ultraviolet of increased sunlight being absorbed in the stratosphere by ozone), whereas with greenhouse gases one expects the stratosphere to cool while the troposphere warms — as the increased opacity of the atmosphere below the tropopause to infrared radiation reduces the thermal radiation reaching the stratosphere. I will give you the answer in a little bit, but you might try guessing which way the trend in mid-stratospheric temperatures has been — while the tropospheric temperatures have been rising.
*
Do you understand what a climate mode does? Let’s consider the example of El Nino.
Here is a fairly basic explanation:
Climate oscillations aren’t magic. They don’t cause energy to disappear or reappear. What they do is move this heat content around. Warm salty water sinks, cool fresh water rises — and perhaps it will have something to do with the trade winds. But the heat is still there. And until the surface temperature rises to a sufficient degree for the thermal radiation it emits to compensate for the increased opacity of the atmosphere, there will be an imbalance between the rate at which energy enters the climate system and the rate at which energy leaves the climate system. And the heat content will go up.
They are called “climate oscillations” for a reason: they cause the climate to “oscillate.” They always give back what they take from the climate system — only later. They don’t cause trends and they can’t explain why the planet has warmed since the beginning of the twentieth century any more than a magician can pull a quarter out of your ear.
*
Aaron continues:
Who predicts this and on the basis of what?
I know that the Hadley Centre predicted a couple more years or so “no-trend” earlier this year, but this was by taking into account ocean circulation and the distribution of heat content in the ocean. Particularly El Nino. And afterwards? The temperatures continue their long trajectory upward.
*
Regarding solar activity — if this were the dominant cause of global warming, one would expect the stratosphere to warm while the troposphere warms. But what we have seen is the opposite. If the sun were responsible for twentieth century global warming, one would expect solar irradiance to have increased along with global warming. However, but for the normal cyclical behavior, the sun has been more or less flat since 1951 — and in fact it trended somewhat down during the latter part of the twentieth century.
The reason why we conclude that carbon dioxide is the primary forcing in the recent rise in temperature isn’t simply one of correlation. We know from spectral analysis that it absorbs and emits thermal radiation. We know its distribution in the atmosopheric column.
We can measure it’s emissions at different altitudes. We can image those emissions from satellites at a variety of altitudes, measure it from planes, balloons and the surface. We have spectral measurements of atmospheric constituents at over a million different wavelengths. As such, the forcing due to carbon dioxide is well-known. We can do the same with solar variability, and while the exact effects of aerosols are more uncertain given their diversity and distribution, no such difficulties exist in the case of solar variability or carbon dioxide.
In fact, this is what pictures such as the following rely upon for measuring concentrations of greenhouse gases at various altitudes:
NASA AIRS Mid-Tropospheric (8km) Carbon Dioxide
http://www-airs.jpl.nasa.gov/Products/CarbonDioxide/
The image is carbon dioxide at 8 km. You will notice the plumes rising off the heavily populated east and west coast of the United States. What is being measured is the infrared radiation being absorbed and then reemitted by carbon dioxide. The thicker the carbon dioxide, the more opaque the atmosphere becomes to the infrared radiation in that channel. So in essence, you are seeing the enhanced greenhouse effect in action when you look at that photo.
The forcings due to solar variability and carbon dioxide are given with a fair degree of accuracy by the following GISS data:
http://data.giss.nasa.gov/modelforce/RadF.txt
In watts per square meter, forcing due to well-mixed greenhouse gasses relative to 1880 was 1.6053 in 1978 and was 2.7487 in 2003. Given the leveling off of methane, the good majority of the difference between the two years is carbon dioxide. Forcing due to solar variability relative to 1880 was 0.2232 in 1978 and was 0.2233 in 2003. Not much of a difference between the two years, is there? Clearly, relative to 1880, the increase in forcing due to well-mixed greenhouse gasses (principally carbon dioxide and methane) has exceeded that of solar variability.
Increased solar irradiance cannot explain the cooling of the stratosphere. It can’t explain why nights have warmed more quickly than days. It can’t explain why winters have warmed more rapidly than summers. The increased insulation of carbon dioxide can — as it slows the rate at which thermal radiation is able to make it to the stratosphere and as it insulates the nights and winters against the loss of heat. Increased solar irradiance would have the opposite effect.
*
For more ways in which we have our fingerprints all over global warming, please see:
Global Warming 101
Human Fingerprints
http://www.ucsusa.org/global_warming/science/Fingerprints.html
*
Aaron continues:
Aaron, the scientific case for our understanding of anthropogenic global warming is quite strong — and it has been for some time. If you haven’t the time to learn about all of the science yourself, you may want to examine the statements by scientific bodies in this matter.
Please see:
The American Denial of Global Warming
http://www.youtube.com/watch?v=2T4UF_Rmlio
Every major scientific organization which has issued a statement in this matter has come down on the side of climatology. In large part it really is just a matter of physics — despite the complexity of the climate system.
Please see:
The Consensus on Global Warming:
From Science to Industry & Religion
http://www.logicalscience.com/consensus/consensusD1.htm
It includes links to those statements.
Where then is the opposition to doing something about climate change coming from?
I will give you a hint.
As I pointed out (but you simply ignored), we can’t wait for the world to become dependent upon alternative fossil fuels. Not with twice the emissions per unit of energy for synthetic oil produced from coal. Not with three times the emission per unit of energy for oil produced from tar sands. Not with the investment and commitment in infrastructure that this would entail.
Not with what we have learned of past periods of global warming — or of the potential for strong positive feedback from the carbon cycle. Not with the warming which is already in the pipeline and the additional warming that this would entail. Not with the droughts that this would entail or the loss of coastal cities due to rising oceans. Not with the lives that will hang in the balance.
Gavin,
Most long term GISS records north of 60 latitude show a similar pattern to Greenland – i.e. as warm or warmer in the 1940s than now.
Mayen, Angmagssalik, Akureyri, Godthab Nuuk, Nar’Jan-Mar, Kanin Nos, Arhangel’Sk, Tromo/Skatto, Sodankyla, Haparanda, Bodo Vi, Vardo, Murmansk, Salehard, Nar’Jan-Mar, Kanin Nos, Turuhansk and Hanty-Mansijs. What I am describing is hardly isolated to Greenland.
A good image showing dirty snow in Greenland is in Hansen’s Illinois Wesleyan presentation – the slide titled “Surface Melt on Greenland”
http://www.columbia.edu/~jeh1/2008/illwesleyan_20080219.pdf
This picture was taken up a little higher on the ice sheet, and as you can see there is quite a bit of dark matter in the upper layers of the ice, despite the absence of any exposed rock. Closer to the coast, the ice gets very filthy.
Being a Nordic ski racer, I am quite tuned into the differences in appearance and quality of wet snow and dirty snow. I suggest you take a flyover over Greenland later in the summer and see for yourself. It is an amazing sight – two miles of ice.
BTW – I don’t think it is constructive to use words like “nonsense” in conversation. Assuming that the person you are talking to is of lower intellectual stature is generally in error.
Rod, if you’re going to continue to flog the “young science” horse despite its having been declared dead by our host, please explain why physics is not a “young, immature science”. Because, after all, at the time of Einstein there were only a couple hundred people in the entire world who called themselves “physicists”, and of those, only a handful were involved in the ground breaking revolution that swept the field a century ago.
The fact that there’s a couple orders of magnitudes (at least) more people doing physics today in no way undermines the work done a century ago. The numbers of people involved aren’t what matters, it’s the results they get that count.
And your attempt at paraphrasing is something I just don’t get:
They had grasped the essence of CO2s role in our climate, but of course they had no way to predict that we’d burn so much fossilized carbon that, a century and a half later, the amount of CO2 would be doubled. They were working in an interesting corner of science that at the time didn’t seem closely coupled to the fate of future generations of humanity. So what? Doesn’t impact the quality of the work at all, nor its correctness, nor ITS AGE.
Re: Greenland and North Pole temperatures:
Here are the 2m temperatures of Greenland (averaged over the whole area) 1979-2008, using Reanalysis 2 data. Individual years are gray with darker colors indicating more recent years, 2008 is black and 2007 red; blue is the 1979-2007 mean, green the 2003-2007 mean.
Not exactly a cold summer so far. Of course there may come colder weeks (and years). That’s weather.
I already posted plots for the North Pole temperature above, but here are updated plots: North Pole; zonal means (Arctic Ocean) at 85° N, 81° N, 75° N; whole Arctic (north of the Arctic Circle), Arctic without land. And, to compare, global temperature using Reanalysis 2 data.
Also see the anomaly maps at CDC. You can also plot zonal anomalies there.
BTW, there might be a big polynia developing near the pole at ~ 86° N / 150° E. It’s been an area of low and declining ice concentracion since 2 weeks, and it’s not just melt ponds as you can see on the MODIS pictures.
And, if anybody is interested in, I’ve made an animation (6 MB) of the last 6 weeks sea ice with buoy positions (daily data from here, but doesn’t seem too reliable).
Rod B posts:
And if you don’t post a straw man caricature of what I said and then add in a personal insult, people will take you more seriously.
Aaron writes:
I don’t know — maybe the same way astronomy could be an advanced science long before there was a consensus about the existence of dark matter? Or the same way nuclear physics could be an advanced science even though we still don’t know how to build a fusion reactor? Or the same way physiology could be an advanced science even though we didn’t know about the existence of one of the muscles in the face until c. 2000? What makes you think an “advanced” science is one that knows everything there is to know about a field? That won’t describe any real science, ever.
RE: 528
Paul said, “For example, I could make a solution from sodium chloride and dissolved carbon dioxide, and also make the exact same solution from sodium carbonate and hydrochloric acid.”
Hey Paul,
(Warning: This is posting starts off OT and appears to only demonstrate a bit more of my ignorance, I appreciate the tolerance shown to date.)
Given the choice of placing my hand, in a 4.4 liter container of water containing 1.5kg of magnesium sulfate and a liter of 70% hydrochloric acid versus 4.4 liter container of water containing 1.5 kg of magnesium chloride and 70% sulfuric acid, I would choose the former rather then the latter. Sorry, I am no chemist and I am out of my element there.
I am worried that my main point appears to have been lost. I am concerned with identifying the various acidification process contributions in the oceans. As with the atmosphere and GW, there appear to be many contributors (forcings) in the reduction of ph in the oceans.
The recent work defining the processes that explain the changes in the oceans ph and CO2 uptake appears to mimic the original work I saw in the 80’s and 90’s, regarding AGW. Based on what we know currently, it is clear that the AGW CO2 is the primary driver of the oceans ph change. Whether that changes over time or not depends of further research and I am hoping there will be more work forthcoming in the near future.
To get back to the subject; however, I am curious. Has anyone noticed that the conversation regarding Arctic Ice reduction has gotten a bit side tracked? I was hoping we could return to the original discussion. I am interested if anyone has noted that the problem in the Arctic may not be that the days with temperatures higher then freezing (of fresh water). While at the same time, the days where the temperatures are higher then the freezing point of brine have increased.
Based on the earlier conversations with Pat Neuman it is curious that the average days below 273K seems to not have increased more then 2% (If my rough analysis is correct.) while at the same time the average days above 255 K seems to have increased about 15%. This would appear to be in alignment the AGW theory… I am curious if there could be an alternative reason for the Arctic Ice Melt other then the reduction in the low deviation in atmospheric temperature…
Thanx,
Dave Cooke
Summing up my argument –
Paraphrased, Dr. Hansen implied that we have “reached a tipping point” caused by CO2, as proven by the “Arctic,” which has behaved “exactly” as predicted in the 1980s.
Pointing out the logical fallacies in that argument.
1. There is little or no empirical evidence that the Arctic is behaving any differently than during the last warm period in the 1940s. Temperatures are no higher across most of the Arctic than they were 70 years ago.
2. Other factors besides CO2 – such as ozone, soot and natural variability are large and not well understood theoretically or empirically. Thus it is not yet possible to establish how much of the warming in the Arctic is due to CO2 relative to other factors.
3. The polar predictions from the 1980s (which are the basis of the argument) have had to be adjusted significantly. The Antarctic has cooled or not warmed significantly. The claim that events have proceeded “exactly” as predicted is not accurate.
Given all of the above, and the fact that the Arctic is no warmer than 60 years ago – the claim of a “tipping point” in the Arctic appears to not be on solid ground.
[Response: Ah. The joy of erecting and demolishing strawmen…. 1) is false, 2) is partially true, 3) is misleading. I love the way you take a single line in an newspaper interview and elevate it to a theory with the exactitude of Newton’s laws. Predictions in the 1980s were that the Arctic would warm faster than the rest of the world and it has. That was all that was said. If you want a serious examination of how 1980s projections panned out – caveats and all – then see Hansen et al, 2006. If you prefer to focus on over-extrapolating one-line comments to journalists, carry on! – gavin]
Re : Clarence
Thanks for the Greenland temperature analysis.
I commented above that, until recently, the anomalous cold has been isolated to southern Greenland. Northern Greenland has been above normal. Given that the vast majority of melt takes place in the south, it would make sense to weight it more heavily in this discussion.
RE: 542
Hey Chuck,
First, as to the balance of constituents in sea water I am more curious in the observations of the more recent sampling programs.
You asked, “And why do you think the measured increase in CO2 partial pressure in the ocean is insufficient to explain the observed declines in pH and TA?”
I think mainly because I am ignorant that there has been an measured increase in CO2 partial pressures fully mixed in the ocean column.
Where you asked, “What acids do you think would be produced by bacteria?”
I have not begun to research the participants to any degree, yet. Logically, I suspect there likely would be amino acids released by dead phytoplankton, as well as acidic sulfuric compounds from anaerobic bacterium. I ran across one study indicating an increase in silicate based acids; however, I have not gone any further then this at this time.
The data that Chris shared earlier suggests that the acids disassociate and form other compounds hence they are likely unmeasurable directly. Hence, my request for further information is invalid and I withdraw the request until have done some more homework.
Cheers!
Dave Cooke