Thanks for posting this article, Rasmus. The ORAS4 reanalysis looks very interesting. I have a couple of comments to make though:
The sea level data you’ve used only goes up to 2001 so doesn’t really tell the story of continued increase over the past decade. Church & White 2011 would be better for a longer view (CSIRO site seems to be down at the moment so I can’t find a link), or satellite altimeter data to track the past couple of decades right up to the present, which is the main period of interest after all.
Most assessments of ice sheet contribution to sea level rise indicate an acceleration over the past decade, whereas altimeter-measured SLR has not been faster over the most recent decade (2003-2012) compared to the previous one (1993-2002). This suggests that the relative constancy of SLR is hiding a significant shift in contribution from different sources. In particular, that contribution from land-ice depletion has increased while thermosteric (ocean warming) contribution has decreased in this decade compared to the previous. I doubt this is at odds with the ORAS4 reanalysis, nor with what you’ve written, but thought it worth noting that continued sea level rise does not necessarily mean the sources of that rise are always the same.
I saw The Economist’s piece not as a questioning of sensitivity, but only as a critique of that question. But it did skip lightly over the issue of deep ocean warming, so thanks — many thanks — for picking up where The Economist left off. You’ve added important points about the coupling of atmosphere and ocean.
As more and more people have pointed out the heat accumulation in the deep ocean, a common argument in the denialosphere has been that the measurements are wrong, because how could heat accumulate in the deep ocean without first passing through the top layer and being detected via ARGO floats and the like (apparently they’re also saying this heat was never noticed near the surface).
Could someone please provide me with a response to this claim? Thanks!
Could you say something about how the Levitus and Balmaseda series compare? I have the impression that they are quite similar. Is that correct?
Comment by Bob Shackleton — 26 Apr 2013 @ 10:31 AM
Indeed, increased energy in the deep ocean is ultimately caused by TOA energy imbalance so must have passed through the upper ocean.
The key is that the rate at which heat/energy is “pushed down” into the deep ocean can vary. If you are, for example, looking at the top 300m you’re seeing the result of surface fluxes (energy input/output at the surface) and fluxes between the 300m line and below. Even if you have a constant positive input into the ocean system from surface fluxes, increasing the rate at which energy is “pushed down” to lower levels can quite easily cause measurements in the top 300m to register a flattened trend.
I can offer a simple metaphorical example: Think of a bucket held under a running tap and it has a small hole in the bottom. It’s been setup such that the water level in the bucket (our upper ocean) remains the same because the flow input from the tap is of the same magnitude as the output down the hole into the space below the bucket (our deep ocean). Now let’s say we poke out another hole and simultaneously open our tap further to maintain the same bucket water level. We now have an increased flow into our deep ocean but measurement of our upper ocean would reveal no change. This state of affairs is only possible because of the increased flow input to the top of our ocean – if it hadn’t increased the water level in our bucket upper ocean would have decreased.
LH: ” how could heat accumulate in the deep ocean without first passing through the top layer and being detected via ARGO floats and the like (apparently they’re also saying this heat was never noticed near the surface).”
I can imagine changes in ocean currents that cause deeper, colder water to mix with shallow, warmer water, raising the temp of the deeper water and lowering the temp of the shallow water. The shallow water then more readily absorbs heat from the atmosphere, and all this happens at a rate such that the sampling rate of the ARGO floats misses the fluctuations. So I don’t see why the temp has to rise near the surface before it can rise in the deep ocean.
Years ago, discussing with an skeptic colleage, I told a joke in connection with this, but difficult to put it in English … Seas are most reasonable place for thermal energy to “hide”.
Otherwise, temperatures would further increase and then more energy would go back to space.
Modern technology confirms the “logic” of Nature.
Comment by Rafael Molina Navas, Madrid — 26 Apr 2013 @ 12:07 PM
Anybody cares to explain what are the time boundaries used for the 1.9, 2, 1.6, …°C temperature increases discussed in the Economist or Skeptical Science links?
Is it between 2000 and 2050, between (variable) now and 2100, or any other dates? All these authors seem to assume that all readers know what these dates are and never care to mention them. I am sure this is standard knowledge, but it is not a reason not to mention it. I don’t even know if all the different studies and models are using the same time frame.
I wonder if testing their “little grey cells” would be useful by asking these clever chappies “If average surface temperatures are close to 14ºC and the earth’s core has a temperature in excess of 5,000ºC, how is it that the deep oceans remain so dreadfully cold?” It just might get their thinking unstuck from the “If it’s hotter there, it’s got to have been hotter here!” nonsense. The oceans are thermally a dynamic system with salinity also a major variable. So why should the deep only warm as a result of the shallows becoming excessively warmer first? Do they actually need to warm at all to allow a net downward energy flux?
The problem with focusing on one data set to makes or refute a case like surface temperature is the planet is more complex than that. That the total energy of the system is increasing manifests in various ways including record Arctic ice melt over the last season. So if surface warming seems to have slowed, the extra energy has to have gone somewhere else – otherwise why the record Arctic sea ice low?
Measuring climate sensitivity as a surface temperature delta has to be understood as a long-term equilibrium result not a short-term outcome. Possibly this is a detail we need to communicate more clearly.
As all this is going on the solar cycle is still unusually low, even as it’s supposed to be peaking.
If I remember my ocean circulation correctly, the exchange between the deep ocean and the surface/shallow ocean takes place at only a few regions. What is more, the water there would not be particularly warm, so it is quite possible for it to warm the deep oceans while having little influence on the intermediate regions.
LH @ 6, stay away from those nutblogs! Unless you want to become like them. It’s nutty to look at a large dynamic system and argue that heat moves only by conduction. Convection is what moves heat around on earth and in your body. Except when large masses of air or water on earth are moved to a region with a different temperature, the word advection is used. Think advection. Now think vertical as well as horizontal.
Sometimes descending air over the Arctic causes high pressure there and cold blasts over large parts of the northern hemisphere. Warm air must be moving upward somewhere. One place may be near the equator, where there is an upward current anyway.
Back to the sea. La Niña is a time of strong trade winds, upwelling of cold water along the pacific coast of South America, and good fishing. Blowing across a fetch of thousands of miles, the trade winds actually move water westward. As this surface current crosses the Pacific it warms and produces rain. Much rain may fall back on the same surface current a ways ahead, but some gets away, leaving saltier water behind. At the western side, sea level becomes higher as the blown water builds up. At the same time much rain gets away from this water, making it saltier until it sinks despite being warmer.
Comment by Pete Dunkelberg — 26 Apr 2013 @ 4:36 PM
Ray – for a long time it was thought he thermohaline circulation was the only way the ocean interior was able to be ventilated, but the oceanographic community has realized that wind-driven mixing plays a very large part in this process.
It is notable that the deep ocean warming is occurring in regions where the wind-driven surface ocean currents converge – the edge of ocean gyres. Where these currents collide, the water has no place to go but down – taking heat and air with it. Speed up the winds at certain latitudes and the stronger surface currents and convergence therefore lead to stronger downwelling.
So yes, this deep ocean warming is only confined to specific areas of the ocean so far.
There was a very interesting paper published last year (or early this year) which revealed the formation of powerful eddies (whirlpool-like structures) in the Southern Ocean in areas of strong convergence. See if I can track down the paper.
This is a blow-up of the changes in the heat content of the top 300 meters and then from 300 to 700 meters. The heat contentof the lower, colder body of water is proposed to have been heated by the upper level, even though the heat increase in the lower level is greater than the top.
On the abyssal circulation of the world ocean—IV: Origin and rate of circulation of deep ocean water as determined with the aid of tracers
Henry Stommel∗∗ http://dx.doi.org/10.1016/0146-6313(61)90002-8
Deep Sea Research (1953)
Volume 8, Issue 2, September 1961, Pages 95–110
> Ray – for a long time it was thought he thermohaline circulation was the only way the ocean interior was able to be ventilated, but the oceanographic community has realized that wind-driven mixing plays a very large part in this process.
I heard that but it was long ago. Has it not been understood for quite some time now that tidal energy makes a big contribution to keeping the major “thermohaline” circulation going?
Comment by Pete Dunkelberg — 26 Apr 2013 @ 8:19 PM
Doc Martyn – an argument from incredulity no doubt passes as rational assessment on the contrarian blogs, but this is a blog run by climate scientists. I sense a lot of mole-whacking in your future if that’s the best you can come up with.
Aside from Von Schuckmann & Le Traon (2011), Levitus (2012), Nuccitelli (2012) and Balmaseda (2013), downwards propagation of heat to deeper layers of the ocean have been noted whilst investigating other aspects of climate system. For instance Llovel et al (2012):
“The dependency of global mean thermosteric sea level changes to temperature at different depths down to 700 m is investigated from 1960 to 2010 using two separate gridded temperature datasets, and compared with reconstructed estimates of sea level change. The rates of thermosteric sea level changes are closely correlated with those of reconstructed sea level changes with correlation coefficients larger than 0.8, but the former has smaller amplitudes than the latter, indicating contributions to total sea level change from processes other than upper ocean temperature changes examined here. Most of the net thermosteric sea level rise (~ 92%) can be attributed to temperature changes of the upper ocean (0–300 m), but an intriguing temporal lag is found between thermal anomalies of the upper (0–300 m) and lower (300–700 m) layers in the historical temperature datasets, suggestive of a time-lag associated with heat penetrating from the surface into deeper layers of the ocean“
In areas of strong convergence, and therefore downwelling, it is unlikely that a strengthened circulation will allow heat to disperse horizontally. The most likely destination is further downwards – as the observations attest.
Furthermore, the Earth’s ancient history reveals that the equator-to-pole, and surface-to-deep-ocean, temperatures gradients were greatly reduced when compared to modern-day. This implies that future ocean warming may likewise see greater warming rates (at some point), in the deep ocean and higher latitudes, than the equatorial regions. How this may progress is unknown.
And lastly, you need to appreciate that the oceans are not a passive receptor of global warming. Warming the ocean leads to changes in atmospheric circulation, and the existing heat distributed in the ocean, which changes the wind-driven ocean circulation. The simplified ocean model examined in Xie & Vallis (2011) might provide some enlightenment for you.
crude ocean model:
Consider a shallow tank filled with water. On one end of the tank is a source of cold,
and from there cold water sinks to the bottom, then flows away along the bottom. The water surface away from our simulated pole receives heat from the room by conduction from above. The system has reached equilibrium, the heat conducted down from the warmer surface exactly cancels out the cold advected along the bottom. Now reduce the rate of cooling, and the advection slows. The model is no longer in equilibrium, and is gaining heat, but the surface temperature (away from the cold source) has not changed.
The Red Sox are up four games on the Yankees even though they’ve only played three games together and the Red Sox only won two of those. How can this be? They play in a league and not just a rivalry. If you want full continuity you have to look at the whole situation. Similarly, you are asking a sieve to act as a bucket in your comment. You need to look at energy fluxes out the bottom as well as between the layers and in from the top.
You can rest assured though that the top will usually be warmer than the bottom since colder water is denser. And, no matter how things mix, you won’t get colder reservoirs heating warmer ones. The layers can change energy content at different rates for a while without getting a thermal inversion.
@1 Paul S. Most assessments of ice sheet contribution to sea level rise indicate an acceleration over the past decade, whereas altimeter-measured SLR has not been faster over the most recent decade
There was a paper published within the last couple of years by some of this sites contributors that suggested part of the disparity may be due to an increase in land based water.
Another fact directly related with what discussed here is: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/30yrbaseperiods_Nino34.png
Being the graphic averages of 30 y. periods, they don´t actually show anything related to ENS Osclilations themselves, but the underlying average temperatures. I find ASTONISHING how regularly the curves change …
By the way: I think I correctly guessed the cause of the situation of their April/May maxima, but “miss” other maxima app. in October. Any explaining help?
[Response: Why "astonishing"? Don't those data just show it is warming up, and that the seasonal cycle hasn't changed all that much?--eric]
Comment by Rafael Molina Navas, Madrid — 27 Apr 2013 @ 6:20 AM
Thanks. As I said, my understanding of ocean circulation dates from long ago (mid ’90s), when I edited an article on the subject for Physics Today. It seems to me that it ought to be obvious that little mixing occurs between the mid depths and the deep ocean, since the deep ocean is so much saltier–but then reasoning isn’t a strong point over at WTFUWT.
Both wind and tides lift the deep water up to the surface. This water must be replaced by dense waters made in the high latitudes. There are two major areas for formation–Greenland-Iceland-Norwegian sea, and around the Antarctic. The current thought as to how the deep ocean is warming is because formation of the coldest bottom water around the Antarctic is slowing down, being replaced by ‘warm’ water from the North Atlantic.
“… The salinity and density of dense shelf water declined abruptly after calving, consistent with a reduction of sea ice formation in the polynya. Breakout and melt of thick multiyear sea ice released by the movement of iceberg B9B and the MGT freshened near-surface waters. The input of meltwater likely enhanced the availability of light and iron, supporting a diatom bloom that doubled carbon uptake relative to precalving conditions. The enhanced biological carbon drawdown increased the carbonate saturation state, outweighing dilution by meltwater input. These observations highlight the sensitivity of dense water formation, biological productivity, and carbon export to changes in the Antarctic icescape.”
The net flow of LW and latent heat is always from ocean to atmosphere and then to space when averaged across the planet, and the oceans receive the vast amount of their energy from SW solar. When we say the oceans are accumulating energy, unless their has been some large increase in SW output from the sun, the only thermodynamically possible way that the oceans can be gaining energy is for the flow from ocean to atmosphere to have slowed. Looking at it from this perspective it would be quite thermodynamically supportable to see how the deeper oceans are storing even more as the entire flow is backing up from shallow to deeper oceans. Accumulating GW gases in the atmosphere alter the thermal gradient between ocean and space, so energy flows less readily from ocean to atmosphere to space, and just like wearing a jacket on a cold day does not force more energy into your body, but rather allows the body to retain more energy. The only difference is that the body gets heat from metabolism and the oceans get warmed mainly from SW solar.
Eric: Many thanks. I agree with you, but the “curves” are all almost exactly equal. As they correspond to periods 5 years delayed from each other, with 25 common y., diferences show unusually regular changes from a 5 year period to another 25-30 y. later … Where are the chaothic properties of of the system that many skeptics argue make impossible any warming (or cooling) “forecasting”?
Even they differences due to the “Niño/Niña” changes themselves are swept by the regular warming trend!
Any comment relative to the yearly maxima app. 40 days after March equinox, but not after September one?
Comment by Rafael Molina Navas, Madrid — 27 Apr 2013 @ 12:58 PM
To Pete Dunkelberg @18
I learnt at school that heat transfers to other bodies by conduction. Convection was the means of moving the body which is holding the heat.
Am I correct or do I need to go talk to my teacher?
Glad to see a bit more focus on heat content as a measure of change to our climate system. I think that pointing to ocean heat content is the best response that can be made to anyone who thinks warming has stalled – surface air temperatures are not the definitive measure of climate change and I’d like to see the habit of treating it like it is replaced by reference to more fundamental measures of change like heat content of oceans (plus land, ice and atmosphere).
What would the “no statistically significant warming for ‘x’ years” test, currently so popular and misleading (popular because it’s misleading) when applied to surface air temperatures, yield for ‘x’ if applied to ocean heat content or combined ocean, land, ice and atmosphere? A statistics ignoramus like myself would guess less than 5.
A bit of digression, but can atmospheric warming have “stalled” because of the enormous emission of reflective aerosols from coal burning in China and India in the last decade or so?p class=”response”>[Response: In principle yes, but the evidence that more heat has gone into the ocean is very strong. As Rasmus wrote, warming has gone unabated; just the balance between ocean and atmosphere has changed --eric]
Tim Jones – since 2006/2007 the level of light-blocking sulfate pollution appears to have decreased. This is attributed to stricter emission standards, and the use of “scrubbing” technology in China that removes more of the sulfate waste from smokestacks. See Figure 1 in Klimont (2013).
Some skeptics argue that for upper layer warming to cause deep layer warming, intermediate layer warming must occur first. (The skeptic may inchoately assume, correctly but irrelevantly, that for the heat flow down some static vertical column to increase, the gradient must increase throughout.) Pete Dunkelberg correctly points out that the skeptics seem to overlook convection (or advection). You point out that heat indeed only is exchanged between bodies through conduction (radiation or latent heat isn’t relevant, here, of course) and that convection merely is a matter of moving heat-containing ‘bodies’ around. This may be true, albeit somewhat pedantic, but it would only help the skeptics if they were arguing that the ‘upper layer body’ can’t warn the ‘deep layer body’ even in the presence of convection because what really happens in that case is that upper and deeper layer ‘bodies’ merely trade place without exchanging heat in between them. But now we seem to have moved from pedantry to sophistry.
The pedant in me strikes again:-
Eric@Response@37 is saying that the continuing rise in Ocean Heat Content infers a continuing global energy imbalance. This is in conflict with the supposition @37 that the recent lack of surface warming is due to increased Chinese emissions reducing that global energy imbalance.
And Rob Painting @39 is linking to a paper that concludes there was a reduction in the sulphate “emissions” both globally and from China since 2006.
In my understanding, the gross level of emissions is not immediately equivalent to the effect the emissions have on climate in that the impact of those sulphate emissions is affected by the latitude of their release. That is Chinese & Indian emissions have greater impact being released at lower latitudes. Klimont et al 2012 Figure One shows the increases in Indian emissions matching the decreases in China’s since 2006, these two being globally the bulk of the low latitude emissions.
I also note in that Figure One – International Shipping (which would have a significant element of low latitude emissions) has doubled over 20 years, a rate of increase about half that of China’s recent decline.
Thanks for all the replies. Got me researching and I came across a diagram that I remember from my school days. It uses images of water to put out fires:
Radiation is likend to a hose pipe directly streaming water on the flames.
Conduction is likened to folks passing a bucket of water hand to hand and then the last person tipping the water on the flames.
Convection is likened to one person running with the bucket fom the source to tipping it onto the flames.
I obviously missinterpretted what was going on here so my teacher was correct after all.
Don’t forget about advection. The advection of warmer air and warmer water plays a big role in Earth’s climate. While it is traditional to lump it with convection, advection gets the notion of horizontal transport much more specifically.
I realize climate skeptics remain, but it’s my impression that they numbered with those who refuse to accept evolution and want to return to the gold standard to fix our economies. If I’m wrong about this will these complex discussions of climate science be convincing? The scientific report is very interesting in itself and I appreciate the more detailed explanations of its content detailed in this blog. As for the reference to the Economist magazine I quit my subscription long ago as their analyses trended to more and more follow the line of thinking that crafted the spectacularly unsuccessful responses to the financial crisis that US FIRE sector instigated.
The problem I have personally with global warming science isn’t a lack of belief that it’s occuring — the evidence is in and it’s hardly a matter of faith — but my lack of understanding what it’s full implications might be. Further, knowing that a catastrophe looms sometime in the future little helps me plan how to respond personnally and even less helps me determine what actions we must take collectively to mitigate the future harms. I apologize if I’m drifting off-topic. My interest in this website and blog series is not just to better understand climate science but to understand its implications for policy. It’s bad enough that the powers controlling our polity seem determined to carry on with their rapine no matter what. I’m left with the knowledge that we’re heading toward disaster, possibly sooner than we want to think, yet I have no good idea what policies to get behind in the unlikely event that some new force wrests power from the vested interests working so hard to promote and exploit the disaster. General suggestions like “Stop burning coal and oil” hardly provide a full answer. I have the impression that a partial import of this suggestion is that we all must stop driving cars; put our air conditioner thermostats at 95F, and heating to 60F; build up limited mass transit and otherwise limit the transport of goods and services between locales … . It will take more than convincing science to achieve these kinds of change and it will take much stronger arguments than the convoluted arguments used to reach the equivocated conclusions climate science promotes. With the ice melting at both ends of our world isn’t it time to throw off some of this reticence to suggest and promote some clear policies and plainly state the consequences of not acting?
#48 Jeremy Grimm–I too follow RC as a non-scientist intensely interested in figuring out likely outcomes and realistic personal and political (policy) responses. I suggest that you will get good science here, but this is not a place for in depth consideration of policy issues. Science is not policy nor vica versa; leave that conflation to the denier crowd.
I suggest a other locations for exploring the conjunction of AGW science and policy–Joe Romm’s blog often has very articulate analyses and informative threads. E.g., thinkprogress.org/climate/2013/04/13/1862211/new-yorker-has-obama-already-given-up-on-climate-change/ I further suggest exploring energy issues (CO2 comes from what? burning fossil fuels for energy): Peak Oil and its cousin EROI (energy return on energy invested–’net energy return’) are two good places to start. Kjell Aleklett and his Uppsala Global Energy Systems Group (UGES) have done an incredible job putting together data and analysis of the global fossil fuel situation and some consequences. His recent book, Peaking at Peak Oil, is a superb summary. EROI is considered in some depth in a number of articles at theoildrum.com, and there’s a recent interview with the originator of the term at http://www.scientificamerican.com/article.cfm?id=eroi-charles-hall-will-fossil-fuels-maintain-economic-growth
Comment by Lawrence McLean — 29 Apr 2013 @ 1:19 AM
@51 Very sorry, but the impression @48 that wannabe skeptics are often “numbered with those who refuse to accept evolution” is well-founded.
Nothing in biology makes sense without evolution. All evolution–as we have known it–is co-evolution. Add to that epigenetics, developmental placticity etc. Probably it’s the words themselves–reductionism/emergentism etc., and the old categories–that are in the way. There is probably less real disagreement than it seems, and more merely semantic exclusivism.
Cladistics, for a salutary/solutinary instance, has been not just a next way of categorizing things, but a next way of understanding them. It’s like a flow chart, a view of process.
Degrees of consciousness come with degrees of complexity. Scopes-trial mind is still with us. No deus-ex-machina is required in order to exit from it. All that is required is a full(er) appreciation of complexity.
It has always seemed to me that the greatness of Darwin had to do with the fact that he was trained in geology. So he was used to imagining things (sic) on the geological timescale. But he made the step of thinking biology on that scale. The key to ‘getting’ the co-evolution not only in the complexity of the eye, but in consciousness itself, may lie with the imagination of time–a sense (of timescale) that is being stretched right now. Ditto, maybe, for ‘getting’ some issues in climate science–as far as the public or cultural consciousness goes.
Somewhere Darwin says: an obstacle to accepting evolution will be the difficulty the mind has to grasp vast stretches of time. (I have lost the exact reference.) One could say the same thing about some issues in climate science.
I really think that the discrepancy is in the measurement noise, 89 vs 100 is a 10% error if the heat is asymptotically equipartioned between the layers. Yet skeptics such as DocMartyn will continue to scream that this noise is the signal.
#50 David Benson–The scenario you link to does not and cannot contain “evidence of the consequences.” There is no such thing as “future evidence”. A major reason it is so difficult to get policy movement is the large amount of uncertainty in the projections of future events based on current trends (“Past Performance is Not Necessarily Indicative of Future Results”). When “warmists” cite such scenarios as if they are “evidence” or “certainties” our credibility is diminished.
I do wish to be clear–I strongly advocate for scientists to speak out about the range of likely consequences flowing from various policy paths. Certainty is not needed to know that some actions, like “business as usual”, are highly likely to have far more unpleasant consequences than other scenarios. I believe scientists have a moral obligation to speak out about those possibilities based on their knowledge and expertise. It takes courage, and I appreciate what I’ve seen from RC authors. We need an order of magnitude more.
Based on updated heat content data from Levitus et al (http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/) the heat accumulated for 0 to 2000 meters from ~1990 to present corresponds to a global average energy imbalance of a bit under 0.45 watt per square meter (assuming I have done my arithmetic correctly). The rate of increase in heat for 0-2000 meters looks to be fairly constant over that period, with only modest variation. Does Balmaseda et al present data which supports a increase in heat uptake over the last decade compared to Levitus et al? (I would look for myself, but the article is pay-walled.)
Comment by Steve Fitzpatrick — 29 Apr 2013 @ 12:37 PM
Hank, this is not the place for an exegesis of Nagel’s views, but in fairness I would point out that in the very brief passage from Nagel’s book quoted at ScienceBlogs by Jason Rosenhouse (who begins by acknowledging that he has not even read Nagel’s book), the phrase “it is prima facie self-evident” does not appear.
What Nagel actually wrote was “prima facie highly implausible“. And of course, modern science tells us a great many things that seem “highly implausible” even to people who know them to be true.
Nagel also describes the view he is discussing as “the untutored reaction of incredulity” and a “naive response” — which sounds to me much like the language used by yourself and others to criticize climate change deniers who reject science that they find “implausible” thanks to their “untutored incredulity”.
GISS forcing data shows the net climate forcing levelling off since about 2000, yet some argue (based on ocean heat content data) that global warming has actually accelerated in this period. It seems to me that there is a contradiction here (I know about warming ‘in the pipeline’ but that can’t really explain acceleration). What is the most likely explanation for the apparent contradiction?
[Response: Recent trends in forcing are quite uncertain since we don't have good aerosol data (either emissions or concentrations) so I am doubtful that there can be a strong contradiction here (since that would require more accurate forcings). - gavin]
If winds are important to earth’s sources and sinks of energy, wouldn’t it be bad then to slow them down with Windmills?
I’m also concerned about Solar power, especially the potential for very efficient panels. All those panels will convert heat into electricity, thereby cooling the locations at which they are installed, and then send it around to locations, where the electricity will be turned back into heat. Especially if this is used for heating, it could take high heat areas and cool them down, but heat up potentially cooler places. This would increase the mean temperature of the earth, a very bad thing.
Convection, conduction, advection got me thinking about sitting in a bathtub of slightly warm water and a warm bathroom. Let the water stabilize (no moving around) and then slowly turn on the hot water (or the cold) and let your feet and your seat tell you what’s going on. If you have a heat lamp in the room then radiation comes into play.
Ed, you need to think this through a little more. Without any numbers, consider that a forest interferes with the wind. Is this a problem?
Photovoltaic solar panels remove something less than 20% of the energy of visible light as electricity, but they have a fairly low albedo so that the overall effect is some local warming. Consider that trees also have a low albedo, so should we not be trying to regenerate the large areas of forest that have been decimated?
This apparent contradiction also bothered me for a while. Let me add something to what Gavin already said. Informal talk about “global warming” is liable to confuse two distinct phenomena. “Global warming” most commonly refers to a positive rate of change in global average surface temperatures. Lets label this ‘SGW’. But “global warming” also can refer to the positive rate of energy gain by the whole troposphere/oceans system that results from a radiative imbalance at the top of the atmosphere. Lets label this different phenomenon ‘RGW’ (‘R’ for radiative).
Now, it is important to note that radiative imbalance is a function of both radiative forcing and surface temperature. When there occurs a positive step change in forcing, surface temperatures eventually increase until enough heat escape from the surface and into space through the 8-14 µm ‘atmospheric window’ and the radiative balance is thereby restored. This means that changes in surface temperatures and changes in forcing both can cause variations in the rate of RGW. If internal variability, such as the surface cooling associated with La Nina episodes, causes an increase in RGW, this means that a temporary reduction in SGW can cause an increase in RGW, or, paradoxically, ‘global cooling’ can cause ‘global warming’. But the paradox merely stems from a failure to distinguish ‘surface global warming’ from ‘radiative global warming’. Such considerations, together with the uncertainty about total forcing mentioned by Gavin, pretty much take care of the paradox.
Comment by Pierre-Normand — 29 Apr 2013 @ 11:23 PM
DocMartyn’s comment appears to be simply factually inaccurate. The blue line in his image represents 0-700m, not 300-700m as he suggests.
He shows the intervals graphically but his math shown on the side of the figure does take into account the differential and not cumulative.
I don’t think it matters because it is likely systemic noise. The ratio of 7.5 heat units over 700 meters versus 3 heat units over 300 meters is 7.5/3*300/700=1.07, which is only 7% higher than top-down diffusional flow would predict.
I responded right away to DocMartyn, because I had recently modeled the OHC profiles and found that my model fits were also not as “perfect” as I would like to see.
The 300-700m interval is receiving slightly more heat than the 0-300m interval assuming top-down diffusion and proportional volumes.
If it is not measurement noise or errors then perhaps it is a bottom-up flow that pushes slightly more heat in the lower interval first than the upper. This possibility has been mentioned elsewhere by commenters in this thread.
Generally speaking, the march of entropy demands that heat is dispersed over available states in the system, and any transient solution to the heat equation should approximate this proportional partitioning.
My issue again is that DocMartyn is nit-picking the details without seeing the general agreement. We will likely see this error diminish with time.
I wonder if testing their “little grey cells” would be useful by asking these clever chappies “If average surface temperatures are close to 14ºC and the earth’s core has a temperature in excess of 5,000ºC, how is it that the deep oceans remain so dreadfully cold?
Thanks. It looks to me like the Levitus et al data shows a continuous increast from 1990, while Balmaseda et al show a substantial drop post post 1990 (Pinatubo?) and later rapid recovery. Why do you think the two are consistent with each other?
Comment by Steve Fitzpatrick — 30 Apr 2013 @ 9:57 AM
In regards to Pierre-Normand’s distinguishing between the SGW and RGW signals, I would think that the GW signal can be split according to a Ocean above surface measure and a Land-only measure (LGW). Then the average can be pro-rated according to the 70/30 split between ocean and land. If half of the excess heat is being absorbed by the ocean according to the OHC signal, then the actual GW would be as follows
GW = 0.7 * (1/2*LGW) + 0.3*LGW = 0.65*LGW
And this is pretty much what we see. The GISS measure of global temperature anomaly is about 2/3 of the BEST land-only temperature anomaly. GISS shows about a 0.8C anomaly, while BEST is about 1.2C over the last 100 years. This seems like a very intuitive take on what is happening with regard to the role of OHC.
This is in regard to Pierre-Normand’s distinguishing between the SGW and RGW signals. I would suggest that the GW signal be split according to a Ocean above surface measure and a Land-only measure (LGW). Then we can weight the measure according to the 70/30 split between ocean and land. So if half of the excess heat is being absorbed by the ocean according to the OHC signal, then the actual GW would be as follows
GW = 0.7 * (1/2*LGW) + 0.3*LGW = 0.65*LGW
And this approximately reflects what we see. The GISS or HADCRUT measure of global temperature anomaly is about 2/3 of the BEST land-only temperature anomaly. The GISS shows about a 0.8C anomaly, while BEST is about 1.2C over the last 100 years. This seems like a very intuitive take on what is happening with regard to the role of OHC.
I am probably missing something fundamental here, so bear with me!
What is the relationship between the temperature of the ocean surface and the temperature of the air above it?
The huge total thermal capacity of the oceans, which is about a million times greater than the total thermal capacity of the atmosphere, means they can absorb a lot of extra energy with only a very slight rise in temperature. If the temperature of the oceans only rises very slightly in response to TOA forcing surely this limits how much the atmosphere can rise in temperature in response to the same TOA imbalance? Is it possible for the oceans to be perpetually cooler than the air above them? Is there not a continual trend towards equilibrium with excess atmospheric heat that might otherwise cause a rise in the difference in temperatures between air and ocean finding its way into the oceans?
In other words surely it is not possible, in the long term, for the atmosphere to rise in temperature any faster than the ocean?
I am not saying that anybody is suggesting that, but if the IPCC is projecting a +3c rise in atmospheric temperatures then they must be projecting a +3c rise in ocean temperatures too. Is there enough of a TOA energy imbalance to provide that kind of heat input into the oceans?
The peak and dip around 1990 from pinatubo is present as a smaller feature in Levitus than in Balmaseda. The latter shows a drop od 4e22J (0-2000m) while Levitus is perhaps half that. But given that the error bars on Levitus are about 2e22 J and say 1e22 J in Balmaseda. I think the two are not so far apart.
Firstly my apology for earlier taking this thread off topic with evolution. It was only meant as a direct observation to post #48 who meantioned it. Nagel’s book needs to be read before any reviews are considered. A must read for anybody with interest in linking biology and consciousness.
Oblak @70. My little ‘laymen brain’ cells tell me that it’s a small amount of heat that comes from the core as geothermal energy. Most energy is converted to mechanical movements in plate tectonics and the like. Interested to know if this is still considered by the mainstream.
Ed Barbar, in addition to Steve’s point, conservation of energy applies. Moving energy from one part of the earth’s surface to another cannot increase mean surface temperature.
[Response: not quite. Transfers of heat for instance from tropics to poles will affect local processes differently and change factors (like ice cover, clouds or water vapor amounts) that impact the global energy balance in ways that don’t necessarily cancel in the global mean. As far we can tell though, these are small net effects. – gavin
Firstly my apology for earlier taking this thread off topic with evolution. It was only meant as a direct observation to post #48 who mentioned it. Nagel’s book needs to be read before any reviews are considered. A must read for anybody with interest in linking biology and consciousness.
Oblak @70. My little ‘laymen brain’ cells tell me that it’s a small amount of heat that comes from the core as geothermal energy. Most energy is converted to mechanical movements in plate tectonics and the like. Interested to know if this is still considered by the mainstream.
[Response: The amount of heat that gets to the surface of the earth from below is of order 50 milliwatts/m^2 In contast, the mean heating of the surface from above (from the sun) is 340 watts/m^2. Geothermal heat is totally neglible compared with solar heat (except during a volcanic event, and then only when you are on top of the volcano!). --eric]
The question asking why oceans are so cold was from my comment @12. I assume @70 was asking for an answer but the point of the question was to present an undeniable truth to denialists that would gets them thinking how ridiculous their understanding of ocean heating actually is.
If it is 5,000ºC below the oceans and on average 14ºC above, the cold oceans must be continually warming. The Earth’s crust insulates below reducing the warming from that source to a trickle (although still significant over geological time). And the oceans insulate themselves from the full heat of atmosphere & solar radiation because cold water sinks down away from the warmth at the surface. That cold water comes from the poles and that is why the oceans are so cold.
With the poles warming, that cold polar water is in shorter supply. With global warming, the warming of that cold polar water, a process that hasn’t just started because of AGW, a process that prevents the oceans from freezing over during ice ages – that warming of that cold water from the poles will increase. But the bottom of the ocean will remain nigh on freezing until sea ice disappears year-round at both poles.
The huge total thermal capacity of the oceans, which is about a million times greater than the total thermal capacity of the atmosphere, …
Eh, no. More like hundreds of times greater. Consider that the atmosphere is roughly equivalent to 10 m of water, while the oceans are on average 2000 m deep. That’s 200x (bear with me, order-of-magnitude wise).
Consider also that the ocean is not a single big bucket of water. It has structure. Most exchange of heat between atmosphere and ocean on the relevant time scale concerns the surface layer, some 200 m or so. Getting heat from the atmosphere to the deep ocean takes on the order of a thousand years, the time scale of ocean overturning. See this.
Martin Vermeer# 81,
The heat capacity of the atmosphere is closer to 3.5 meters of ocean , though the exact value depends on how much latent heat is considered. The average depth of the ocean is close to 4 Km not 2 Km. So total ocean heat capacity is on the order of 1,200 times the atmosphere above it. Taking the heat capacity of the atmosphere above land into consideration, the ocean’s heat capacity falls to about 800 times larger than the total atmosphere.
Comment by Steve Fitzpatrick — 1 May 2013 @ 8:22 AM
Martin @ 81, “Getting heat from the atmosphere to the deep ocean takes on the order of….”
Let’s try minutes, and work back from there a little if you wish.
Fully equilibrating the deep ocean takes a long time. But the vertical currents that are part of the THC evidently go as fast as the horizontal currents, else how would it all work?
Phil Scadden #78 – Further to Gavin’s points you could also increase global average temperature by shifting energy to areas with more surrounding land, such as NH mid-to-high latitudes. Land areas warm faster than ocean areas, which means you get a warming uptick in the land-dominated region, without a similar-size cooling in the ocean-dominated region energy has transferred from, so the overall average shows a warming.
You can see this demonstrated in the shape of the annual cycle for global average temperature, which peaks in Northern Hemisphere summer despite the Earth receiving considerably more energy from the Sun during the Southern Hemisphere summer. The cycle is dominated by fast warming and cooling of NH land in response to seasonal insolation.
This is a short term effect of course. In order to keep this type of warming going you would have to perpetually shift more and more energy into the land-dominated region, which is impractical in the long-run.
Thanks for the clarification on ocean heat capacity. I would be interested if anybody has a view about whether a +3c rise in atmospheric temperatures in response to a doubling of CO2 also means a rise of +3c in ocean temperatures?
Or does it mean a rise of +3c only in atmospheric temperatures? In which case how can that happen? Surely if the oceans are increasingly “cooler” relative to the atmosphere then heat will find its way from warmer to colder somehow?
Perhaps someone can provide a more technical answer but comparing atmospheric and ocean temperature as like-for-like information is not a simple matter due to differences in pressure and density of the different materials. I guess the basic answer would be that ocean temperatures will tend towards values in balance with atmospheric temperatures, but that doesn’t necessarily mean a measured 3ºC change in both.
I’ve always figured that sea level rise is the simplest diagnostic of global warming overall, because most added energy will soon show up in the oceans, and the same is true of net melting of land ice. (With some allowance for short-term exchanges with other reservoirs in both cases.)
But the reversal of sign of thermal expansion of water at ~4 deg C is a complicating factor. Is this negligible in the big story, given the amount of added heat going into water already warm enough to actually expand?
#85 Matthew L,
Those are complicated questions. The temperature at great depth has a lower limit which is set by the temperature at which ocean water freezes (it can never be colder than that). Cold water is more dense than warm water (although salt concentration also has an influence), so very cold water at high latitudes tends to sink, especially in winter, and flows across the ocean bottom worldwide; the ocean at great depth is therefore everywhere cold and fairly uniform in temperature. Cold, deep water is (on average) continuously upwelling at lower latitudes, though the rate of upwelling does vary with region. Warming from the surface takes place mainly due to ‘eddy driven down-mixing’ where turbulence generated by the shear imposed by horizontal currents, both surface flows and at different depths) leads to mixing of shallower, warmer surface water with deeper cold water. In the absence of shear, the very little heat would make its way downward, because lower density warm surface water floats on colder (denser) deep water. The combination of cold upwelling deep water and eddy driven down-mixing of surface heat leads to a fairly rapid drop in water temperature with depth, along a profile which is called the ‘thermocline’. Net warming at the ocean surface in the thin (20 to 200 meters) well mixed layer, which is where the ‘ocean surface temperature’ is measured, must of course lead to a change in the shape of the thermocline over time, with the greatest warming in the well mixed layer and less warming at increasing depth. How total total heat accumulation evolves over time, and how much warming will take place at different depths over time is not completely understood. In any case, very significant warming at great depth (eg. >1C warming at 1-2 Km or greater) in response to a 3C warmer surface would likely take place only on very long time scales (hundreds of years or more). The sinking of cold water at high latitudes and upwelling at lower latitudes is called the ‘thermohaline circulation’.
There are lots of good sources of information on physical oceanography on the web if you look.
Comment by Steve Fitzpatrick — 1 May 2013 @ 12:30 PM
And further still to #84 and #78, the energy radiated from a spherical blackbody isn’t proportional to the average surface temperature to begin with. You’d need to raise temperatures to the fourth power before averaging.
The smaller the temperature gradients, the less energy is radiated from the surface (assuming a constant average surface temperature).
Because the gradients on Earth aren’t that large to begin, this is a relatively small effect but when you’re concerned with mere fractions of a degree, it’s something else to take into account.
Comment by Anonymous Coward — 1 May 2013 @ 1:17 PM
Re:reversal of sign of thermal expansion of water at ~4 deg C
I think this applies to fresh water, not saline water in the ocean.
“I would be interested if anybody has a view about whether a +3c rise in atmospheric temperatures in response to a doubling of CO2 also means a rise of +3c in ocean temperatures?”
No. You did not understand the heat capacity comment that you made earlier. The same amount of energy going into the ocean will result in a smaller change in temperature than would be the case if that energy was going into the atmosphere. This is because of the ocean’s larger heat capacity – the greater mass means there are more molecules to divvy the heat up into. That’s why the absolute changes in ocean temperature are smaller than surface temperatures.
An analogy: Two villages, but one village’s population is a thousand times larger than the other. Supplying the same amount of food to the larger village, that the small village typically consumes, will result in starvation. Supplying the same amount of food to the small village, that the larger village typically consumes, will result in oversupply and waste.
Titus, you might be interested to know that possible heating of our environment from deep within the earth was one of the first things to be investigated when the question of how the earth gets its temperature was first scientifically studied.
Reviews aside, there is much more to read and think about in areas that Nagel touches on. I’m thinking of studies of consciousness and biology and especially evolution. As Nagel admits, his science comes from reading popular works. It is a strong inference that he is influenced by creationism, especially the ID version. In fact he very favorably reviewed a book by a leading IDist named Meyer. The book has “signature” in the title. This puts Nagel in “Dunning-Kruger” territory regarding evoloution and related matters. If you are interested in evolution, study it! Learn the real thing before accepting criticisms from someone who doesn’t get it himself.
For a couple helpful books on biology and consciousness:
_Braintrust_ by Patricia Churchland
well followed by … umm I forget the title but EO Wilson’s latest book – it’s on aspects of group selection but that’s not in the title as I recall. You will see though that group selection has much relevance to evolution of morality, a big topic of Nagel’s.
I hope Nagel will just be the start of your explorations. As in in other aspects of life, your first love may not be your last but it is good to have one all the same.
Pete Dunkelberg wrote: “About T. Nagel and the matter of biology, consciousness and everything …”
What I find interesting about such discussions is that in most cases, the word “consciousness” is never really defined.
And oddly enough, the philosopher types seem to be more concerned with defining exactly what they mean by “consciousness” than do the scientist types.
I’ve seen biologists go on and on making pronouncements about “consciousness” but when pressed to define that term, they can offer (at best) only vague and nebulous notions that they would never, EVER accept as the basis for serious discussion of questions in biology.
The same applies to such terms as “mind” and “intelligence” which people often bandy about as though they knew exactly what they meant by them, which they don’t.
I mean really, there are still scientists who question whether “consciousness”, “mind” and/or “intelligence” even exist in other primate species, let alone other vertebrate species, let alone other species further removed from us paradigmatically “conscious” human beings. (Is an ant colony “conscious”? After all, the individual ants communicate and coordinate their activities with complex chemical signals, not unlike the neurons in our brains, so why should that communication not give rise to “consciousness”?)
Others question (more reasonably in my opinion) whether and how we might even be capable of recognizing these capacities in other species. Nagel’s famous 1974 essay, “What Is It Like To Be A Bat?” touched on this question, and Carl Sagan wrote an essay on what it might be like to be a tick.
How can we possibly answer such questions? If we cannot answer them, then where do we get off making general statements about “consciousness”? And until we can at least approach those questions, we are a long, LONG way away from answering much more challenging questions about the nature, arising and role of “mind” or “consciousness” or “awareness” or “intelligence” in Nature.
Comment by Steve Fitzpatrick — 1 May 2013 @ 5:39 PM
Matthew L (April 30, 12:21) “What is the relationship between the temperature of the ocean surface and the temperature of the air above it? “
Not sure that anyone has answered this to you satisfaction yet. There isn’t a simple answer in the sense of a single equation, but I can describe some of the principles,
To begin, there are really three temperatures we need to think about – not two. Those three are air temperature, ocean temperature, and surface temperature. The distinction arises because the surface isn’t actually air or ocean – it is the boundary between the two. Also, neither air nor ocean temperature are uniform as you move away from the surface – each will have a gradient in temperature, dependent on the various fluxes of energy.
Nonetheless, when we talk air temperature (the full term you will sometimes encounter is “surface air temperature) we are talking about a short distance above the surface (usually about 1.5m over land) – to distinguish it from air temperature at higher altitudes – and for ocean temperature (again, “ocean surface temperature” is the term), we are talking about the ocean close to the surface.
At the surface, the ocean temperature and air temperature will match, and we have “surface temperature”. How this links to the temperatues above and below the surface is where life gets more complicated. One approach is called the “surface energy balance” approach, which is based on the idea that the surface has no thickness, so it has no mass, so it can’t store energy. Since it can’t store energy, the sum of all energy fluxes must cancel (conservation of energy). The major energy fluxes are:
- input of solar radiation (down from the atmosphere)
- input of IR radiation (down from the atmosphere)
- reflection of solar radiation (up towards the atmosphere)
- emission of IR radiation (up towards the atmosphere)
(These four make up the net radiation input)
- loss of thermal energy to the atmosphere
- loss of water vapour to the atmosphere (the energy lost is the energy required to evaporate the water)
(These two are convective/turbulent energy transfers related to atmospheric motion)
- loss of thermal energy down into the ocean (also convective/turbulent mixing)
I have ignored conduction (very small compared to turbulent mixing. Would be an issue on land where conduction into soil replaces convection), and the fact that solar radiation can penetrate some distance into water (not so much an issue on land). We also won’t worry about photosynthesis or other chemical reactions involving energy for now.
So, to get back to your question, rephrased as “what is the relationship between ocean and air temperatures?”, the answer is “it depends”, and it depends on the current balance of the various energy terms. In particular, it can vary depending on the relative size of the terms that carry energy away from the surface to the atmosphere, versus the term that carries energy into the ocean. Solar radiation is always a net input, IR radiation is usually a net loss to the atmosphere, thermal and evaporative fluxes are usually a net loss to the atmosphere when net radiation is high, and thermal energy into the ocean is also usually a net input to the ocean when net radiation is high. At night, when solar input is zero, net IR is a loss, and both air and ocean will be moving energy towards the surface to make up for the IR loss.
All this can be expressed mathematically, and the relationships quantified. To know longer-term averages, you really need to (in the absence of sufficiently-detailed direct measurements) run climate models. As a broad sweeping generalization, the atmosphere gets its heat primarily from the surface, where most of the solar energy is absorbed, and atmospheric temperature decreases with height. (There can easily be several degrees of difference between air temperature at 2cm, and 2m. Think hot sidewalk on a summer day. Then think cool grass, which has the same air temperature above it at 1.5m, but a very different surface temperature where your feet make contact.) Ocean temperatures, where sunlight penetrates to some depth and water is mixed thoroughly, will tend to be a bit more uniform to moderate depths (metres to tends of metres).
Does this help? Does it lead to follow-up questions?
#92–Thanks for linking my Fourier piece, Pete. I was going to mention Fourier in response to Titus, but you beat me to it.
Essentially, Fourier laid out the broad outlines of a terrestrial heat budget, back in the 1820s. There were some things, like the ‘temperature of space’ about which he was pretty incorrect–quantitatively if not qualitatively. But his paper is definitely seminal, usually being credited as the first link in the chain of scholarship that led to the modern theory of climate and the greenhouse effect. As far as I know, that is definitely the case as far as theoretical groundwork goes.
But my personal nominee for first “greenhouse” paper goes to William Charles Wells’ “On Dew,” which (in addition to achieving a very good analysis of its subject) provides a remarkable series of observations of what we now call “downwelling long wave radiation.” See:
SecularAnimist, be a bit cautious about demanding precise definitions or insisting that such are a necessary condition for much of anything. Do you think Newton, when developing calculus, had good definitions of “continuous function” or “real number?” Fourier, when developing advance mathematical techniques to analyze heat transfer much later, still got by without these. Indeed, can you define these terms off the top of your head? No? But you can do math anyway. And as the ultimate coup, recall that mathematicians finally decided to base it all on undefined terms!
It is true that the use of the same term for different things without explanation may lead to confusion. See for instance What is the thermohaline circulation? (and somewhere I think there is an article on five definitions of heat found in scientific usage.)
Often is is good to allow a concept, and so also a definition, to develop gradually over a long period of usage. Continuous function and real number are cases in point. Perhaps the THC is too. What about “number?” If you know the sort of constructs that the reals “are”, it is not unreasonable to ask if they are really numbers or something else. If you say yes they are numbers, then what about imaginary numbers? If you say yes again, then what of surreal numbers? It seems that the number concept is still not finished.
What then of consciousness? You may think it is a state, but persons closer to brain studies are inclined to say it is a process. Some say that it develops through interactions, especially with other persons within a culture, and that an isolated human would lack it.
What is a definition anyway? (By analogy with your comment SA, I shouldn’t talk about definitions without defining them ;) AFAIK the definition concept began to develop in the 6 to 5 hundreds BC. Somehow, people communicated long before. Regardless, a definition of a noun is in general a hybrid of two descriptions. First, it is a description of word usage. “When term T is used, it means this, or sometimes that, or ….” Second it is a description of a thing. “Granite is” – followed by describing certain minerals or even better pointing to same. Asking for an exact description of the second kind as a precondition for progress toward gaining that knowledge is not likely to help.
Comment by Pete Dunkelberg — 1 May 2013 @ 11:58 PM
Pete Dunkelberg and SecularAnimist.
Again my apology for taking this off topic. I appreciate your thoughtful comments. My interest is more basic than defining consciousness. Since my school days I have always had a niggling doubt about how a chemical reaction created a cell that could immediately self sustain and reproduce itself. Let alone evolve RNA for DNA and all that follows. Nagel’s book offers some thoughts on openings of thought processes. Only if you are brave and prepared to open yourself up.
Back on topic: Thanks Eric for the confirmation of the low geothermal numbers. Interested if there is any development of thinking around the earth core energy taken up by driving the mechanical movements of the surface.
“I wish it weren’t true but it looks like the world is going to blow through the 400ppm level without losing a beat. At this pace we’ll hit 450ppm within a few decades,” said Ralph Keeling, a geologist with the Scripps Institution of Oceanography which operates the Hawaiian observatory.
The last time CO2 levels were so high was probably in the Pliocene epoch, between 3.2m and 5m years ago, when Earth’s climate was much warmer than today.
A suggestion–doubt based on ignorance of biology is not a valid basis for judging a scientific theory of life, just as ignorance of how the greenhouse effect works is not a basis for judging climate science.
Evolution is a fact. This has nothing to do with the origin of life. However, the research there also suggests that abiogenesis is the likely origin of life.
Nagel’s latest book was reviewed last winter by H. Allen Orr in New York Review of Books, February 7 issue. Well worth a read (the review). At risk of going beyond the theme of this thread, I offer up excerpts from it because I think Orr’s review speaks indirectly to the larger issue of how we as humans and as a global society are reacting to the findings of the earth sciences regarding anthropogenic global warming, climate disruption, and their ensuing ecological and socio-economic consequences:
With regard to whether the idea of mind “poses some insurmountable barrier to materialism,” Orr makes two points:
“Science has, since the seventeenth century, proved remarkably adept at incorporating initially alien ideas (like electromagnetic fields) into its thinking. Yet most people, apparently including Nagel, find the resulting science sufficiently materialist.”
“. . . [T]here might be perfectly good reasons why you can’t imagine a solution to the problem of consciousness. As the philosopher Colin McGinn has emphasized, your very inability to imagine a solution might reflect your cognitive limitations as an evolved creature. The point is that we have no reason to believe that we, as organisms whose brains are evolved and finite, can fathom the answer to every question that we can ask. All other species have cognitive limitations, why not us? So even if matter does give rise to mind, we might not be able to understand how.”
The conclusion of Orr’s review:
“The question, then, is not whether teleology is formally compatible with the practice of science. The question is whether the practice of science leads to taking teleology seriously. Nagel may find this question unfair. He is, he says, engaging in a “philosophical task,” not the “internal pursuit of science.” But it seems clear that he is doing more than this. He’s emphasizing purported “empirical reasons” for finding neo-Darwinism “almost certainly false” and he’s suggesting the existence of new scientific laws. These represent moves, however halting, into science proper. But science, finally, isn’t about defining the space of all formally possible explanations of nature. It’s about inference to the most likely hypothesis. And on these grounds there’s simply no comparison between neo-Darwinism (for which there is overwhelming evidence) and natural teleology (for which there is none). While one might complain that it’s unfair to stack up the empirical successes of neo-Darwinism with those of a new theory, this, again, gets the history wrong. Teleology is the traditional view; neo-Darwinism is the new kid on the block.
“None of this is to suggest that evolutionary biology will not, someday, change radically. Of course it might; any science might. Nor is it to suggest that materialism represents some final unassailable view and that teleology or, for that matter, theism will inevitably be spoken of in the past tense by many scientists. It is to say that the way to any such alternative view will have to acknowledge the full powers of present science. I cannot conclude that [Nagel’s book] does this.”
Finally, regarding neuropsychology’s 100+ year exploration of consciousness and mind: see S. Pinker’s wonderful book, How the Mind Works.
Thanks for answers: Now that I know the right question to ask, yes, fresh water is densest at ~4 deg C (why calm lakes freeze suddenly, etc), but sea water basically always has a positive coefficient of thermal expansion. Bottom line for scientific amateurs: heat energy added to the oceans will give you expansion and higher sea levels, without worrying about various ocean temperatures. (There are details about temperature, salinity, and so forth.) This very fact explains why I hadn’t seen references to the 4-degree threshold in general discussions of global warming and sea level.
Turning ice into water sucks up a lot of energy. Therefore, water and ice at near the same temperature have very different energy content. So wouldn’t you expect ice melt to result in lower temperatures? Isn’t that what happens in a glass of scotch?
Calls for science to incorporate teleology or other non-material causes are up against a core principal of science, namely intersubjective verifiability. Unless an observation can be reliably and accurately reproduced by other disciplined observers, it can’t be distinguished from an illusion, a hallucination, or a misguided interpretation of an ambiguous signal; it has no claim to consideration as a fact.
Assuming a verifiable set of facts, competing hypotheses that attempt to explain them are up against peer review. Nagel may claim that “empirical evidence” shows neo-Darwinism to be “almost certainly false”, but unless he can convince a majority of evolutionary biologists of that, he’s just another guy making unsupported claims. As a non-scientist, I’m not going to waste my time on him. I’ll stick with the expert consensus.
Mal Adapted wrote: “Unless an observation can be reliably and accurately reproduced by other disciplined observers, it can’t be distinguished from an illusion, a hallucination, or a misguided interpretation of an ambiguous signal; it has no claim to consideration as a fact.”
Of course, that is the basis upon which hard-core behaviorists deny the existence of subjective experience.
I think Sloop’s excerpts & summary of Orr’s review of Nagel’s book exemplifies why such discussions are usually so unfruitful — participants bring to them a jumble of ill-defined notions, sloppily conflated ideas, and dogmatic views.
So often I see these kind of discussions bring out the worst in both “sides” (and people almost always wind up “taking sides”).
Based on the “arguments” typically presented, one would think that on the “science side” science has not progressed beyond naive 19th century mechanistic materialism, and on the “philosophy side” that the be-all and end-all of thinking about the nature, arising and role of mind in the universe is 1st century Middle Eastern monotheism.
The “debate” over whether the world is a dead machine set in motion by random accidents or a dead machine remote-controlled by the God of Abraham is about as barren as it gets.
#101 Ray Ladbury “Evolution is a fact. This has nothing to do with the origin of life. However, the research there also suggests that abiogenesis is the likely origin of life.”
Ray, the emergence of life appears to be less than widespread in the knowable universe (at least as it has so far been observed). So “Abiogenesis is the likely origin of life” is an unwarranted presumption.
Religions have sought an explanation for the emergence of life and they have failed ludicrously and abysmally. Most thinking people now realise that science is probably the only discipline which could possibly enable us to understand how to explain such a deep and so-far unknowable truth.
So is it not high time for science to start thinking outside the box of its much lauded and justly revered enlightenment?
Read all of Orr’s essay. It is far from uniformly condemning Nagel’s latest treatise. And Nagel is certainly not “just another guy making unsupported claims.”
I suggest that you too quickly dismiss the work underway along this fascinating scientific frontier. Progress has definitely been made via numerous hypotheses and much intriguing evidence. The search is far from over, but I’ll grant that you appreciate how that is not itself evidence for the existence of a cosmic diety.
simon abingdon wrote: “Ray, the emergence of life appears to be less than widespread in the knowable universe (at least as it has so far been observed).”
Really? When did we develop the ability to detect the presence or absence of bacteria on extra-solar planets? I must have missed that.
simon abingdon wrote: “Religions have sought an explanation for the emergence of life and they have failed ludicrously and abysmally.”
It’s interesting to note that when the Buddha was asked about the origin of life, his response was that the world of living beings had “no discernable beginning”. Which was an accurate characterization of the available empirical evidence 2500 years ago.
“Ray, the emergence of life appears to be less than widespread in the knowable universe (at least as it has so far been observed). So “Abiogenesis is the likely origin of life” is an unwarranted presumption.”
For all practical purposes, none of the universe has been observed with instruments that can detect the presence or absence of life. In fact, from this point of view, not even our own solar system has been thorougly observed.
You’re arguing, essentially, from personal incredulity.
With all due respect, your aphorism strikes me as facile and a bit muddled.
To compensate partially for my participation in the hijacking of this thread, I point to how Rhode Island’s coastal zone management (CZM) agency, the RI Coastal Resources Management Council (CRMC) is addressing current and future sea-level rise (SLR). It is about to incorporate an expanded SLR policy into its federally-approved CZM Plan and has begun a special area management planning process (SAMP) that will entail in-depth research on shoreline erosion rates, coastal sediment flows and regimes, modeled shoreline inundations, and then engagement with towns and Rhode Islanders to help them digest (knowledge is definitely essential to understanding) the consequences of those findings for coastal development, erosion management, and natural hazard response and recovery.
CRMC’s SLR Policy projects 3-5′ of SLR along the RI coast by 2100. It is thoroughly justified by and built from references and analysis of recent climatological and oceanographic findings, including the weakening of the Atlantic MOC apparently noted in the Balmaseda et al paper discussed in this post. It mandates that all future CZM decisions in RI account for this level of overall inundation. Furthermore, the CRMC possesses nationally unique authorities to regulate development along RI’s shoreline and within the state’s marine waters.
The CRMC Shoreline Erosion SAMP was launched this spring and will continue for three years. It is a compelling, still unfolding model and case study for study by students of US CZM.
The work of this agency (and state) is a welcome, alternative model to policies recently legislated by North Carolina regarding the relevance and applicability of scientifically based SLR projections to coastal development planning and management. Rhode Island is not an island (as many Americans assume); but it is a city state wrapped around an estuary. Its entire geography is a coastal watershed. Hence, it takes the promise, abundance, and risks posed by the ocean very seriously.
Aphorism and Petard aye? Well, this is a blog after all and I’m conscious of taking it off topic. I never intend this.
Sloop: I counld’t agree more with the work that you are engaged in. I followed the building of the Thames Barrier in London which was an incredible feat of engineering based on the then latest knowledge and understanding. IMO this needs to be done all the way down the US East Coast, the Outer Banks NC especially look at great risk. Not to mention consequences of NY.
Hank: As with my reply to Sloop I’m all for scientific knowledge having input into political decisions.
And thanks for getting us back on topic!!! I’ve actual learnt a lot. Including my new word ‘advection’
They find many of the building blocks of life even in cosmic dust. Laboratory experiments have produced more complex building blocks under conditions thought to persist on early Earth. Each new experiment continues to add to understanding.
So to you and Simon, I would ask, why “think outside the box” when the scientific method is producing steady progress, as it should?
Well there’s been talk of evolution and origin of life (OOL). Life clearly did and does evolve. It also started early in earth’s history, although the details still elude us. Conveniently, the current issue of Nature Chemistry is on it. How long does it take? We know it didn’t take too long, and no one in science supposes it happens immediately. For all we know though, when a young planet freshly coated with cometary organics reaches the right temperature it may take just a thousand years. So why hasn’t it all been worked out? Because no university allows you that long to finish your dissertation.
sidd, back on topic for you. You have heard that once heat is dissipated into deep water, it can’t come back to bite us. But it may still change the surface environment as follows: Large currents depart the poles. The global current maps make it look as though the same water keeps circulating. But of course the currents lose water to general mixing along the way. That’s what keeps the deep oxygenated. So new water must enter the currents, primarily at the polar descent points. So the Southern Ocean around Antarctica advects in Pacific water to replace what goes out the bottom. And this water is hotter than it used to be, and melts ice, pushing the Pine Island glacier back thirty kilometers IIRC.
I opine that abiogenesis is not entirely off-topic for Real CLimate. After all the paleoclimatology of pre-biotic Terra was probably rather different and, at least, the time of abiogenesis is of importance to paleoclimatology.
Comment by David B. Benson — 2 May 2013 @ 10:01 PM
Simon wrote: “Ray, the emergence of life appears to be less than widespread in the knowable universe (at least as it has so far been observed). So “Abiogenesis is the likely origin of life” is an unwarranted presumption.”
If there is any logical connection between the two sentences quoted above, it escapes me. The statistical frequency of life in the universe says nothing about abiogenesis versus divine creation or any other alternative ‘myth’ you may construct–at least until the actual pathway[s] by which abiogenesis takes place can be traced in sufficient detail to calculate probabilities.
People have taken some generalized stabs at this, I know, but I doubt that anyone can claim anything like rigor in such calculations.
Thank you Mr. Roberts for the reference to Gouretski(2013), I always look forward to deep ocean measurements. I am intrigued by their finding that since the 1920s the deep Atlantic below 2000m exhibited slight cooling and freshening. I have a suspicion that the trend has changed to warming lately (Purkey,Kouketsu,Johnson…) although the freshening (a la von Shuckman) might yet persist.
i wonder what the thermodynamic properties of large amounts of suspended solids would be on vertical circulation and heat retention . it would seem reasonablre that there should be a discernable effect.
T. Kukulka, G. Proskurowski, S. Morét-Ferguson, D. W. Meyer, K. L. Law. The effect of wind mixing on the vertical distribution of buoyant plastic debris. Geophysical Research Letters, 2012; 39 (7) DOI: 10.1029/2012GL051116
The logical connection between the paucity of the data and “abiogenesis is the likely origin of life” being an “unwarranted presumption” is manifest. Note (for example) #125 David B. Benson “Dr. Koonin estimates the probability of abiogenesis. In his estimation it is indeed a tiny number”. To prevent such escapes in future do not relax your grasp.
Abiogenesis is usually put in opposition to exogenesis, a less grand panspermia-type theory. The advantage of panspermia (which a pared down version largely loses) is that it vastly opens up the time and volume over which abiogenesis can occur. It is a sort of infinite monkeie with infinite time and infinite typewriters approach to writing the works of Shakespeare-type solution to the problem of getting life to come into existence as quickly as it did on Earth. Both theories exclude divine intervention. http://en.wikipedia.org/wiki/Abiogenesis#.22Primitive.22_extraterrestrial_life
I think your assertion that there is a paucity of life in the Universe is unfounded. I’m curious what evidence you are relying on for that conclusion. Or put another way, what evidence would you expect to see if the Universe were teeming with life?
Interstellar distances are sufficiently large to explain the lack of “visitors”. And if aliens were trying to contact other life forms (which they might not be, given the possibility that there might be predatory aliens out there), they would probably not be broadcasting broadband, but rather directionally due to the huge power demands of interstellar transmission. And why would they send signals toward us out in the exurbs of the galaxy rather than toward the galactic center?
What is more, our own experience indicates that any civilization capable of sufficiently advanced technology to make its presence known would capable if not likely to destroy itself. The Fermi Paradox is a paradox only if you don’t believe in relativity or if you ignore human experience.
Start with a thimble full of air. The exact arrangement of molecules in that thimble is wildly improbable. But generically, the thimble being full of air is extremely probable. That’s hint 1: to get beyond “Everything’s improbable, in the usual way” you need to look at general types of outcomes.
Next, the air in the room. Will it all move to one corner? No, even though that is a general type of event, not a specific molecular arrangement in the corner. Will just all the oxygen go to one corner? No. How about just all the water vapor? No again. But go outside and look up. OMG clouds! that’s almost impossible! How could it happen? Well, there is a cloud-forming process in nature. No multiverse needed. When you learn the cloud forming process, you can make a reasonable estimate of their probability, even though the exact details of any particular cloud will still seem extremely unlikely. Just about everything in nature is the result of some process, and to estimate the probability you need to look a both a type of outcome and the process.
Back to Koonin. I don’t have that book but I think he sees this problem: To get a basic life form working (including natural selection) you need very good (but not perfect) replication. But, he says, you needed replication and selection to arrive at that point in the first place. He does not see a process that solves this “chicken and egg” problem. And without the process, surprise! he gets that tiny number. A number arrived at by this method is the probability that you used the right process.
Koonin has certainly done a lot of good research in moloecual biology. It would not be unique though if that turns out not to guarantee “big idea” argumentative papers. Note that researches have not decided to quit, and steady step by step progress continues. Note that in addition to various pre-RNA World possibilities, there are also non-RNA possibilities (Wachterhauser, Kaufman (those two should get together)).
Without the process, the best estimate of the probability is to note that it didn’t take too long on earth.
Comment by Pete Dunkelberg — 3 May 2013 @ 11:52 AM
#132 Ray Ladbury “what evidence would you expect to see if the Universe were teeming with life?”
Ray, depending on how you define “life” I’m pretty sure that the solar system is pretty well devoid of life apart from here.
I dismiss the possibility of intelligent life elsewhere in the universe on the simple grounds of improbability. There are just not enough stars to combat the formidable odds against.
I believe 1000^8 is a generous estimate for the number of stars in the visible universe, so if we find that we can identify more than 8 independent 1/1000 conditions needed for the evolution of intelligent (technical) life then it looks like we’ll have run out of candidate stars other than the sun and may count ourselves very fortunate to have beaten the staggering odds against being here at all.
For starters here’s an outline menu for a candidate planet: (1) Orbit nearly circular and stable for billions of years, (2) Surface mainly water with corresponding temperatures, (3) A large moon keeping our tilted axis stable, (4) A large defensive outer planet such as Jupiter.
And as far as intelligent life (as we know it) is concerned: (5) A timely extinction paving the way for mammalian life forms, (6) Eventual evolution of bipedalism and the opposable thumb, (7) Discovery of fossil fuels and the control of fire, (8) Development of agriculture and civilisation, (9) An industrial revolution leading to the mastery of technology.
One could easily refine these lists and think of dozens of other unlikely fortuities.
If we give each of the nine occurrences above a less than 1 in 1000 chance of happening for a given planetary system, it looks like we just ran out of stars.
And the answer to Fermi’s “where are they?” turns out to be “they just ain’t anywhere”.
“Dr. Koonin estimates the probability of abiogenesis. In his estimation it is indeed a tiny number”
The probability of the single planet Earth, among the unimaginable number of bodies in the universe, evolving to what it currently is . . . is at most an even tinier number. The probability that a single [conscious? intelligent? aware?] species on the planet Earth will be the cause of it’s demise is a very much larger number. We should be attending to that. ;)
simon abingdon wrote: “I dismiss the possibility of intelligent life elsewhere in the universe on the simple grounds of improbability. There are just not enough stars to combat the formidable odds against … if we find that we can identify more than 8 independent 1/1000 conditions needed for the evolution of intelligent (technical) life …”
In short, you are dismissing the possibility of intelligent life elsewhere in the universe on the grounds of “formidable odds” that you just made up.
You claim that “Discovery of fossil fuels” (#7 in your list) is a requisite for the evolution of intelligent life? Are you kidding?
What you’ve got here is more like a list of requirements for the existence of a Duplicate Earth out of a Star Trek episode where the extraterrestrials making First Contact with humans all speak perfect English, rather than requirements for the evolution of intelligent life.
Frankly, I’m not sure we humans would even recognize extraterrestrial intelligence if we encountered it, given that we seem to have difficulty even acknowledging (let alone understanding) the intelligence of the other species with whom we share this planet.
Simon, in their famously pessimistic book Rare Earth: Why Complex Life Is Uncommon in the Universe Ward and Brownlee give their meaning of “uncommon” away in two places. Right at the beginning they say that the book will disappoint anyone who believes in a Star Trek universe with alien space ships everywhere you roam. Then at page 250 or so, when explaining why they think SETI won’t succeed, they say that there are probably several civilizations with radio telescopes in our galaxy, but the galaxy is so big that we are quite unlikely to ever detect them, or they us.
Wikipedia mentions 170 billion galaxies in the observable galaxies in the observable universe. For every planet with advance life, there must be many with some sort of microbial life. You had better check the Jovian moons again.
Simon, the criteria you apply are not essential. Kepler has identified thousands of planets with stable orbits, and some within the range to support liquid water. It is not clear that a moon is essential, and while it is not clear that a giant guardian planet is essential (it may even be harmful to chances since it led to bombardment by comets and asteroids early in Earth’s history), large planets do not seem to be rare.
As to the rest of your criteria, they are nothing more than anthropocentrism–there is absolutely no reason why other planets should have a history of life similar to that of Earth.
As to your formulation of the problem, it is fallacious. I can prove by a similar argument that I don’t exist or that you don’t exist or that pretty much whatever proposition you choose to falsify is impossible. One problem is that you are assuming the probabilities are independent–many of them are correlated. Another is that your estimates of the probabilities are all rectally extracted–and they are about what you’d expect given that origin.
You might reflect that Mr. Benson’s comment was as yet unmoderated as I wrote…
But I still disagree with you, however disagreeable a tone you may choose to take: the ‘odds’ of abiogenesis really can’t be estimated reliably, the odds of potential alternate theories still less. Therefore, conclusions one may choose to draw really aren’t meaningful.
And worse, we’re a priori–a much *too* informative prior, perhaps one could say. That we are here can’t prove that we aren’t highly improbable.
Ray, you say “As to your formulation of the problem, it is fallacious… your estimates of the probabilities are all rectally extracted”. Maybe so, but you yourself can’t even produce the merest scintilla of real evidence that the universe actually is “teeming with life” let alone harbouring intelligent extraterrestrials.
You and your fellow-travellers seem to think that despite their overweening hubris SETI and the astrobiologists (don’t make me laugh) are going to come up trumps any day now.
[Response: Even a discussion about life in the universe has to be politicised? 'Fellow-travellers'? Really? This is both stupid and off-topic even in an open thread. Enough thanks. - gavin]
#144 [Response gavin] You’re too touchy. It should have been obvious that I was referring to contributors who shared Ray’s view of the likelihood of extraterrestrial life. I have no interest in Ray’s political views nor could they possibly be any of my business.
“… Arctic Ocean sea-level rise is an important indicator of the rapid environmental and ecological changes in the Arctic region, but it is not well observed ….” (six slides with some info and sources, from an “Ocean Surface Topography Science Team Meeting” September 2012 )
Obviously climate models have been way too conservative and are far off the actual warming trend. Conclusively they are wrong as they are enable to foresee the collapse of summer arctic ice. This will have probably significant consequences as positive feedback or may be climate switch in the coming years.
Are there any serious modeling of the effect of arctic ice loss on thermohaline temperature, methane degasing and run away effect on temperature ?
Thanks for answering.
“If more of the heat from global warming is going into the ocean, does that reduce the amount of surface warming (both transiently and long-term) that we should expect from doubling CO2?”
I interpret the land temperatures to provide an earlier foreshadowing of the eventual long-term surface warming, while the sea-surface temperatures to be a transitional temperature. This means that the global temperature has proportions of the SST and land temperature in its computation. Moreover, from the ratio of SST and land, we can estimate roughly how much heat is being sunk by the ocean depths.
I think it is interesting how well the numbers compose for the Hadley/CRU data sets. This essentially agrees with the current interpretation that approximately 1/2 of the excess heat is being absorbed by the ocean depths.
How does weakening of the Atlantic meridional overturning circulation contributes to the increase in the rate of deep ocean warming? If one conceives of the AMOC as a king of large scale current that works *against* convection, then it may look like weakening it would indeed have an effect similar to that of increasing convection. Is that how one can think of it? But if the AMOC itself is driven by the sinking of cold water in high latitudes, then it seems to be a form of convection. So, I have a hard time to picture how it may work towards increasing the rate of deep ocean warming. The case of PDO/ENSO is much more intuitive.
Pierre-Normand – you’re assuming that the AMOC will weaken. That’s pretty “old school” thinking, and contradicted by a lot of paleoclimate data.
Invigoration of the Antarctic Circumpolar Current by intensified westerlies, and a southward shift of the strongest westerlies so that they align with the ACC should lead to increased ventilation of the ocean interior.
Rob Painting, I’m not assuming this. I’m reacting to the comment in the original post regarding Balmaseda et al. (2013) “A weakening of the Atlantic meridional overturning circulation (MOC) may have played a role in the deep ocean warming.”
That’s what I was trying to understand. It’s a question about the recent past. I’m just trying to figure out how the weakening of the AMOC could have contributed to an increase in deep ocean heat content, as they suggest it might have. I can’t picture it so I’m seeking enlightenment.
Hank – the idea that the AMOC may undergo long-term slowdown is old school. The AMOC appears to have slowed, and may do so further in the near-future – as the polar oceans warm and land-based ice ends up in the ocean, thereby raising the buoyancy of surface waters. But the invigoration of the thermohaline circulation via the Southern Ocean, and the build up of heat at lower latitudes, may get it moving again. That would be more in line with physical considerations, and paleoclimate data from past warm periods.
One ocean heat source I haven’t noticed much, is the amount of heat contributed by undersea sources such as volcanoes, and other assorted heat pipes.
[Response: You haven't noticed it much because it actually doesn't matter much. I've said it before but I'll say it again: averaged over the earth's surface (or ocean bottom, geothermal heat is milliwatts; heat from the sun is hundreds of watts. Unless you are sitting right on top of the volcanoe, it does not matter. --eric]
Robin #163 there’s a link in that picture. Scroll to the bottom. ‘Sveta’ is Svetlana Jevrejeva who compiled the numbers.
[Yep, for those of you old enough, that's close to where John, Paul, George and Ringo started off...]
Comment by Martin Vermeer — 10 May 2013 @ 12:02 PM
As a lay reader I hesitate to comment, but Paul S in comment number 1 refers to a a SLR puzzle that I too have been wondering about. The recent estimates for increased glacier melt do not seem to fit with the near constant SLR (satellite data) trend unless the thermosteric contribution to expansion has reduced. As I understand it this would fit with more of the heat passing down into colder waters where the expansion for a given quantity of heat would be less. The 2010/2011 6mm fall in SLR was predicted by Nasa science to be the result of strong La Nina excessive rains captured on land by the Queensland floods and NE South America. This seems to have been confirmed by the subsequent end 2011/2012 return of sea level to the trend line. But interestingly SLR continued rising during 2012 and now into 2013 as shown by http://climate.nasa.gov/key_indicators/. Assuming there is no problem with the satellite measurement, could this be an indication that the combined steric and glacial melt contributions are now responding more strongly to the heat that is already in the Earth system ? If so this might also suggest that climate sensitivity is not less than previous concensus estimates. My apologies if I am misunderstanding something fundamental. It will be interesting to sea what SLR does next.
I take the point that with the satellite data record limited to the last twenty years, an exponential rise could be hidden behind the apparent linear trend.
I floated the idea that the current uptick in the rate of sea level rise during 2012/2013 (ENSO neutral conditions) might indicate that a stronger sea level response to global warming may now be taking place. Accepting that it might turn out to be just normal variation and data error combining to give a temporarily misleading record,I was wondering what other explanations readers might suggest.
I forgot to thank you for responding to my amateur post. I deeply admire the time and effort that busy scientists put into realclimate.org. It is a truly excellent web resource for giving to a global public audience, the evidence based resources for understanding climate science, accessing data, and honest discussion of conflicting ideas.
Cowards! You can’t even answer a few simple questions to unearth the truth! You refused to publish my post. You can’t handle even the simplest opposing view. Shows what your “science” is worth. Enjoy your crumbling religion ;)
“In addition, they found that the deep ocean has warmed over the recent years, while the upper 300m of the oceans have ‘stabilised’.”
That’s just silly. ARGO can’t find it. You seem to suggest that hot water doesn’t rise. There’s even a comment here from someone stating “heat is not temperature”. WHAT?!
Notably your “chart” above doesn’t show any acceleration whatsoever and, there’s no Y-scale. Are you measuring this in phlogistons?
Sea levels have been rising for tens of thousands of years, since the last deep ice age ended. There’s no acceleration evident today. Have you taken land subsidence into account? Have you even noticed charts of where it’s slowed?
How did the Australian Aborigine cross the oceans to get here? Maybe you should see this:
You seem utterly convinced that man-made CO2 (still a tiny trace gas in our atmosphere at 0.0397%) is going to burn the planet to hell tomorrow. Of course, when it comes to doomsayers, it’s always tomorrow, next week or in the future. That just continues until the next fearmongering “fad” comes along to be likewise always “predicted” in the future. Some questions for you:
Every exhalation is around 4% CO2 (40,000ppm – atmospere now 397ppm). How is it you don’t burn your tongue in the sun when you exhale that ENORMOUS 4% of CO2?
How is it that delicate aragonite corals evolved when CO2 was some 20x higher than today?
With CO2 so much higher in the past and you expecting a LINEAR scale to CO2 heat trapping effect, why was there never a runaway greenhouse, ever?
How is it that CO2 was many times higher than today even during deep ice ages?
You understand that CO2 is necessary for photosynthesis and farmers actually pump CO2 into their greenhouses to increase yields, right?
Do you know that Viking graves in Greenland now are in permafrost – something you can’t dig without hydraulics? Vikings colonised and farmed Greenland 1000 years ago, why did they leave 300 years later?
The Little Ice Age is documented in paintings from the 1600’s where the Thames and Hudson rivers froze 10ft thick and the locals held fairs on them. Are you aware of this at all? Are you aware this was caused by the “Maunder Minimum”, a time when very few Sunspots and Solar activity occurred?
Do you remember when an imminent “ice age” was predicted in the 70’s?
Are you aware that Global temps rose sharply between 1910 and 1940, then fell sharply between the 40’s to the 70’s? Did Man have something to do with it or is my next question the answer?
Do you understand the cycles of the oceans (PDO, AMO, ENSO) and their impact from warm to cool and back again over regular decadal scales?
Why is it that in a desert, you can fry during the day and freeze at night, but not in the tropics? What magical atmospheric component is missing in a desert to cause this and therefore, is CO2 actually trapping any catastrophic heat at all? A clue – notice how the night is usually warmer when it’s overcast?
Have you noticed that CO2 continues to climb but Global temps have flatlined for the last 17 YEARS? Why the disconnect?
Are you aware that according to well understood physical parameters, the effectiveness of CO2 as a greenhouse gas diminishes logarithmically with increasing concentration and from the current level of ~397 ppm, accordingly only ~5% of the effectiveness of CO2 as a greenhouse gas remains beyond the current level?
Do you understand that warm water outgasses CO2 – try opening a warm and a cold bottle of soda water. Do you now understand that the oceans could never become “acidic”, considering their pH ranges from 7.9 to 8.3, depending on where you measure it and, that the pH scale is also logarithmic?
How do you explain the findings of ancient tools and tree stumps under retreating glaciers?
Have you seen the geologic records that show CO2 rising AFTER temp rises by some hundreds of years?
Have you discovered Milankovitch Cycles – how the Earth has cyclical wobbles in its orbit being tugged on by other planets causing major changes in our distance from the Sun?
Have you discovered that on very regular cycles, the Earth suffers a major ice age about every 100,000 years lasting many times longer than our current interglacial? Do you think that’s connected to my previous question?
Why is it that some 90%+ of species live around the Equator?
Figures are readily available to show winters kill more people than summers – have you looked into them and why do you think retirees look forward to living in warmer climates?
Are you aware that the Arctic ice extent is now the same as the 1979 annual mean? Do you really think it’s going to be “ice free” at all this NH summer?
Are you also aware that cat 3+ cyclones making landfall in the US and tornadoes are at record lows? The NOAA has figures on that if you dare look.
Does it make sense that “climate scientists”, being largely (if not totally) government funded, need to continue blaming Man for CO2 ills since governments want to tax us on it and, if they say it’s not, they’ll lose their job?
Frankly, all of the tip-toeing, cherry-picking and completely unscientific (if not impossible) explanations I see on this site in support of AGW are truly far-fetched wonders of the age. You seem to suggest that surface winds are somehow stopping hot water from rising? Nonsense. All that rubbish and referencing to desperately try and explain-away the now 17 year warming pause.
If you get all the charts and scale them by whole degrees (something we might physically feel – maybe) then they’d be a straight line not even resembling static.
People, have a good look around and you’ll find there are more questions that require answering before spouting for certain that Man is to blame for climate change. It’s been doing it for billions of years and will continue to do so. There’s NO peer-reviewed study out there that can scientifically and unequivocally state that they can filter out Man’s warming signal from the natural noise.
If you keep believing point-blank the government and the lamestream media, you’ll look like a fool (you’re rapidly getting there) and have a lighter wallet to boot. Don’t be a puppet or a parrot to them. Remember this:
“When a well-packaged web of lies has been sold gradually to the masses over generations, the truth will seem utterly preposterous and its speaker a raving lunatic”.
If you refuse to publish this post or delete it, the volumes about your “science” will have been spoken.
[normally this would go to the borehole. We're going to allow this one through for amusement however. -moderator]
Re- Comment by Olaf Koenders — 14 May 2013 @ 8:58 AM
The reason that your previous post is published in the Bore Hole is that every statement you make is either outright wrong or irrelevant while accurate information is readily available. Try the Start Here section on this site or the even more digestible form at SkepticalScience- http://www.skepticalscience.com/
Olaf, you are being laughed at which is rather sad because you obviously believe everything that you wrote. However, it shows that you have let yourself be misled by misinformation. On the other hand, suggesting to practicing scientists that they have missed something obvious because you have misunderstood the facts is frankly an act of appalling arrogance. If you prefer misinformation, then noone can help you. If you care about truth, pick the “fact” that you think is most telling and compare it to what the science really says (not what some unqualified blogger tells you it says). Then move to next “fact”. Do it one at a time. SkepticalScience.com is a good place to start with references to the science. READ the science. Some misinformation sites also reference papers but tell you it says the opposite to what it actually says, safe in the knowledge that deniers wont bother to check. This will tell you which sources to trust.
Mr. Koenders: How did you find out ? You are too clever for us. We always thought the Industrial Revolution was a bad idea, and for centuries we have been faking data, muzzling deniers, conspiring with green ecofascists to return human society to hunter gatherer lifestyles governed by our secret cabal of purple shamanistic druids. Even bicycles, wheelbarrows and arithmetic were to be outlawed in our sustainable, glorious vegan communes. But, alas, we are undone! Run to the hills! Flee to the valleys! Mr. Koenders has found us out. Our fiendish plans will come to naught! Woe is us !
Well Olaf, that’s quite an amped up little Gish gallop you’ve got there. I Googled around for a little background on your take on things and didn’t much care for the crusty hole I seemed to be headed down, so I backed out.
Apropos of nothing in particular, and after some random musing, this thought occurred to me–just putting it out there as a sort of general PSA: Guns and amphetamines don’t mix.
Just a comment on sensitivity (since it’s in the news these days – NYT anyway – and it’s relevant to this post):
Usually this is described as the sensitivity (variously defined in terms of time scales of course) due to doubling of CO2. However, nobody ever seems to mention: doubling from *what*? Offhand, I would not expect doubling from 400ppm to give the same delta T as doubling from, say, 250ppm.
Best answer I can find (wikipedia article on climate sensitivity, referring to IPCC 4th report) is that doubling corresponds to 540ppm, which would mean the baseline standard is 270ppm CO2.
Is that a universally agreed-upon standard for these kinds of studies? That is, does “doubling” universally mean going from 270ppm -> 540ppm?
Obviously we want apples-to-apples comparisons here, so it seems important to me that somebody make this clear. Apologies if this was in the original post. Regardless, whenever I see news articles on doubling (including posts here, if I am not mistaken), this information is often lacking.
Thanks so much,
Comment by Peter Todd Williams — 15 May 2013 @ 10:32 AM
I see the software ate the link;
‘oogle: “olaf koenders” climate
That’s persistent repetition.
As the dependence is logarithmic in CO2 concentration, it doesn’t matter what your baseline is–double the concentration and you’ll get roughly an additional 2.8 degrees of warming. Normally, they are talking warming over pre-industrial levels, so roughly 270-280 ppmv.
Peter Todd Williams (181) on sensitivity — “doubling from what”
This is a good question, and there’s two parts involved in answering it. The first question is what the radiative forcing is for successive CO2 doublings (essentially how effectively does each doubling of CO2 reduce the rate of radiation loss to space)? The the second question is how differently feedbacks may behave as a function of the initial climate state?
For the first part, there’s not much uncertainty; it doesn’t matter too much where you start from, at least over reasonable range of CO2 concentrations that is relevant for Earth. That’s because CO2 reduces the rate of radiation loss to space in roughly equal increments for successive CO2 doublings. That is, if the mean outgoing longwave radiation is OLR(0) then the OLR after each CO2 doubling can be roughly fit by the function OLR=OLR(0)-a*log(2). The coefficient “a” is approximately 4 W/m2, so the forcing on earth’s energy budget is approximately linear in log(CO2). I’m using log base 2 in this context. So everything else being equal, going from 250 to 500 ppm is the same as going from 500 to 1000 ppm.
The second part that translates radiative forcing into temperature change involves the possible non-linearity of climate feedbacks. This would be especially prevalent if there was a huge “tipping point” in feedback strength. A classic example would be the transition into Snowball Earth. Assume, for example, a complete ice-covered Earth transition occurred as you approach modern day CO2 concentrations divided by 16 (roughly 20-25 ppm). The temperature change is dT. Then dT(CO2/2) ≈ dT(CO2/4) ≈ dT(CO2/8) but there would be a much larger reduction in temperature as you go to CO2/16, since the ice-albedo feedback becomes very large.
For “relatively small changes” around the modern day climate, it probably doesn’t matter too much. That is, dT(CO2 x 2) ≈ dT(CO2 x 4)/2. This isn’t self-evident, but for that linearity to break down, you’d need to find a feedback that had a big impact on the planet’s energy balance and had a bifurcation point centered right near Earth’s modern climate.
I suggest that mechanism (left open in the paper) might be examined pretty thoroughly using a combination of Argo float current data and Windsat wind speed and direction data. http://www.nrl.navy.mil/WindSat/ Windsat data is measuring the effect of wind on the ocean surface, with the wind speed inferred from that. So, it is actually the perfect instrument to gauge momentum transfer to the ocean from the wind in a spatially and temporally resolve manner.
Agreeing with Ray and Chris, if you start at 300 ppm and got to 600 ppm, the change in temperature will be the same as when you start at 500 ppm and get to 1000 ppm. It is the multiplication rather than the starting point that is important.
Chris’ description is also correct but you do need to know something particular about how climate sensitivity is defined. The doubling is instantaneous. The radiation loss is immediately cut by about 4 W/m^2, but this situation cannot continue. The system warms until the top of the atmosphere can radiate at its former rate. Thus, climate sensitivity is defined as a transition from one radiative equilibrium state to another. So, you need to pay attention to your baseline temperature. Taking today’s temperature as the baseline for a doubling to 800 ppm from today’s concentration will not work because the system would not be starting from radiative equilibrium.
I realize I’ve oversimplified. Instantaneously doubling carbon dioxide does not immediately cut outgoing emissions by 4 W/m^2 because water vapor is a fairly large part of that number. Now water vapor is very responsive and is considered a fast feedback but is is tied to temperature which has a delayed response owing mainly to the heat capacity of the oceans, so the water vapor feedback is not at full strength until warming is complete. So, there is really no time when the radiation to space is reduced by 4 W/m^2 even with an instantaneous doubling used in the climate sensitivity formalism.
[Response: Not really. If you could actually double CO2 instantly holding everything else constant, you would have an instant change in OLR of ~4 W/m2. If everything else is allowed to adjust the imbalance comes down quite quickly, but the first year average imbalance would still be around 3 W/m2. - gavin]
In 21 DocMartyn jabbered: “Thermodynamically incontinent.”
Let me read to you from a recently purchased book, “Bioluminsecence” (revised edition, 2012) by O.Shimomura. Page 380 where he discusses Knowledge and it’s application towards understanding a new Bioluminescent mechanism: “Accurate and undistorted knowledge is more important. It will be disastrous if one’s mind is preoccupied with incorrect or distorted preconceptions. The fundamental laws of science and chemistry are absolute and fully trustable. However, various theories, rules and hypotheses made on experiential bases are not laws; these should be trusted only with reservations, especially when studying an unusual phenomena like … ”
Now imagine I have a big red hot brick in my 3rd floor living room. I carry the brick out onto my 3rd floor deck and drop it into my backyard and then run down and carry the brick into the basement. The basement starts warming. The intervening space does not. Thermodynamic incontinence? I can see how your confusion arises. I too detect incontinence but I’m afraid it’s origins are not thermodynamic.
Comment by John E. Pearson — 17 May 2013 @ 9:05 AM
“At the 2 × CO2 equilibrium, the global mean increase
in G, the total greenhouse effect, is around 20 W/m2, sig-
nificantly larger than the 4 W/m2initial forcing and dem-
onstrating the overall affect of the LW feedbacks is positive
(in this model). That is, the extra net absorption by CO2
has been amplified by the response of water vapor and
clouds to the initial forcing. The 20 W/m2
greenhouse effect enhancement is associated with a 15 W/m2 extra emission
from the surface (since the planet has warmed by 2.7°C) and
a 5 W/m2 reduction in outgoing LW that balances a 1.5%
increase in planetary albedo (due to increased cloud cover, a
negative (SW) feedback).” http://pubs.giss.nasa.gov/abs/sc05400j.html
I’m interested in the delayed 15 W/m^2 but got mixed up.
One paper not mentioned by Balmaseda et al. that discusses a mechanism of enhanced interaction between deep water and wind as a result of global warming is Bakun (1990) Science 274 198. In this mechanism, stronger alongshore winds, caused by a higher contrast in pressure between land an ocean owing to early warming of the land, drive surface waters offshore and allow cold deep water to climb the continental shelf and produce stronger upwelling of cold water. http://swfsc.noaa.gov/publications/cr/1990/9003.pdf
Because these upwelling systems are important for ocean ecology, they have been studied in the ecological literature and trends in stronger upwelling have tended to be confirmed there.
It is possible that greater removal of deeper water by the upwellings can help to explain the increased heating of deeper water elsewhere by building a circulation pattern. If so, then some, at least of the wind interaction proposed by Balmaseda et al. (they propose trade wind interactions) could be owing to the effects of warming rather than just independent decadal scale variability in wind behavior. Trade winds have a longer swath over which to work, but alongshore winds have both a warming enhanced heat engine and an underwater slope to help them. And, as Bakun noted, a potential positive feedback in that cold upwellings enhance the pressure contrast already enhanced by warming of the land.
“What is the IR content of solar irradiance in w/m2 ?”
Not sure that’s usefully answerable as asked. Total IR has been given (though not in m/m2, obviously) as a tad over 50% (which surprised me.) However, it’s ‘near infrared’, which means it’s not the same bands Earth radiates. (As you can see in the graph linked below, the sun emits little radiation indeed at wavelengths longer than 4 micrometers, whereas Earth’s radiation is centered at roughly 12 micrometers.)
So, the question is, why do you ask? Knowing that could help make answers relevant.
I wonder, though, do you hold the misconception that only IR warms the surface? All wavelengths absorbed will warm, not just IR. If the total absorbed solar energy value is really what you want, then the EOS site (above) give the June global mean as 187 w/m2. See figure 6.
So as I understand they argue that on shorter time the heat going in to the ocean will not come back? And that the preciding 40 years or so is enough time to get the climate sensitivity for about 50-100 years in to the future… reasonable?
can not say I know how the oceans will react… seams uncertain at least. And a short time frame might be better then a paleo nr for the next 50 years. But how much of ice and say forest changes will it capture? (and how much will addition from tundra etc. contribute to future levels of CO2?)
“The most likely value of equilibrium climate sensitivity based on the energy budget of the most recent decade is 2.0 °C, with a 5–95% confidence interval of 1.2–3.9 °C (dark red, Fig. 1a), compared with the 1970–2009 estimate of 1.9 °C (0.9–5.0 °C; grey, Fig. 1a) …”
“The best estimate of TCR based on observations of the most recent decade is 1.3 °C (0.9–2.0 °C; dark red, Fig. 1b). This is lower than estimates derived from data
of the 1990s (1.6 °C (0.9–3.1 °C); yellow, Fig. 1b) or for the 1970–2009 period as a whole (1.4 °C (0.7–2.5 °C); …”
TCR is the transient climate response.
From the figure, the new estimates are not so far away from the old. But I suspect that using only and estimate based on a single decade might be … hasty …
Both the Earth and the Sun emit pretty much as black bodies. For black bodies of the same size, the hotter one emits more at all wavelengths than the cooler one. For black bodies of the same temperature but different sizes, the larger one (more surface area) emits more radiation at all wavelengths. The Sun is both larger and hotter than the Earth so for both reasons it emits more IR radiation than the Earth.
The Transient Contrarian Response, as expected, is high when there is any mention of climate sensitivity being not as high as it might be. (I think it has some sort of inverse-square relationship.)
One of the takes on planet Wattsupia for instance, is titled New paper shows transient climate response less than 2°C. Given IPCC AR5 use a central TCR figure of 1.9°C, this title hardily heralds stunning revelations, or indeed justification for the conclusion reached. “The take-home message from this study … is that the … IPCC AR5 … ECS and … TCR … are out of line with instrumental-period observational evidence.
Of course, we cannot expect those on Wattsupia to be bothered by such misrepresentation of a single scientific paper when they delight in mashing the totality of science.
The paper’s lead author describes his findings thus – “Recent observations suggest the expected rate of warming in response to rising greenhouse gas levels, or ‘Transient Climate Response,’ is likely to lie within the range of current climate models, but not at the high end of this range. However, with current emissions trends, this would lead to very high temperatures to the end of the 21st century.
“The eventual long-term warming after stabilization remains rather uncertain, but for most policy decisions, the transient response over the next 50-100 years is what matters.”
Three further authors from the paper also give their comment here, ‘here’ being somewhere that is mindful of presenting a reliable and honest account of the paper, unlike on Wattsupia and those other the planets in the deniosphere.
Balmaseda et al’s proposal that trade wind intensification may help to explain the distribution of ocean heat content trends with depth may not fully apply to the strongest feature in their map (fig. S06) of heat content trends below 700 m during the years 2000 to 2009. That feature, in the East of the Atlantic has the morphology of a plume at about 40 deg North latitude. In the Atlantic, trade winds have weakened recently. http://www.sciencedaily.com/releases/2011/02/110206132902.htm
There are also a number of structures near Antarctica in fig. S06 that could be associated with wind or with other sources of vertical flows. Still, in keeping with the folk song theme of this post I’d say “Down in the basin, the basin so low, turn those layers over and hear the wind blow.”
In the current situation, where the north is heating and the south is not, if the sea level rises that means the global ice quantity is INCREASING. Why ?
Most of the north pole ice is made of pack ice which is floating – exactly like an ice cube – on the ocean : the only way to get it make the ocean rise is to put more ice on it (when it melts, nothing happens to the sea level)
On the South pole, it is the opposite, most of the ice is on the earth, and we know it is globaly not melting yet.
The only other alternative would be because thermal dilatation of the waters but certainly not because of ice melting.
I’m wondering if Balmaseda et.al. 2013 Distinctive climate signals in reanalysis of global ocean heat content takes data from below 2000m into account. The paper repeatedly refers to heat storage “below 700m” as a class of data but puts no lower depth limit on it.
Balmaseda et.al. cite Levitus et.al. 2012 World ocean heat content and thermosteric sea level change, and Kouketsu et.al. 2011 Deep ocean heat content changes estimated from observation and reanalysis product and their influence on sea level change.
Levitus rejects concluding something about what’s happening below 2000m saying “we simply do not have enough… data from depths exceeding 2000m available to ascertain if there is a contribution from this layer”.
Levitus et.al. acknowledges the Kouketsu et.al. attempt: “If the results of Kouketsu et.al. are correct, this would mean a contribution of 1.6×10 to the 22nd power J from the ocean region in the 3000m – bottom layer”. Balmaseda et.al. total ocean heat content to 2009 appears to be about 20×10 to the 22nd power J. which I take it means Levitus et.al could be ignoring 8% or so of the heat accumulating in the ocean.
Levitus et.al. are careful to describe what they are talking about as the ocean in the 0 – 2000m layer.