Illustration only: not part of the paper
This paper has been out for a few days, and several people have alerted me to it. This new paper by Compo,G.P., and P.D. Sardeshmukh, 2008: Oceanic influences on recent continental warming. in the journal Climate Dynamics, is now in press. See the PDF here
This paper makes some significant claims regarding what is driving the observed climate changes. The emphasis is on the ocean as the main driving component, and the authors recognize that “a combination of natural and anthropogenic influences” may be at work. While they point to the oceans as a significant driver, they don’t offer much to explain what is driving the oceanic change.
Even so, this is a significant work, and I urge my visitors to read it, because it shows that GHG forcing is not the only occupant of the drivers seat. It also clearly illustrates the need to examine such cyclic ocean influences as the PDO and AMO more closely, and to consider them in projections of temperature.
Abstract:
“Evidence is presented that the recent worldwide land warming has occurred largely in response to a worldwide warming of the oceans rather than as a direct response to increasing greenhouse gases (GHGs) over land. Atmospheric model simulations of the last half-century with prescribed observed ocean temperature changes, but without prescribed GHG changes, account for most of the land warming. The oceanic influence has occurred through hydrodynamic-radiative teleconnections, primarily by moistening and warming the air over land and increasing the downward longwave radiation at the surface. The oceans may themselves have warmed from a combination of natural and anthropogenic influences.”
Conclusion:
“In summary, our results emphasize the significant role of remote oceanic influences, rather than the direct local effect of anthropogenic radiative forcings, in the recent continental warming. They suggest that the recent oceanic warming has caused the continents to warm through a different set of mechanisms than usually identified with the global impacts of SST changes. It has increased the humidity of the atmosphere, altered the atmospheric vertical motion and associated cloud fields, and perturbed the longwave and shortwave radiative fluxes at the continental surface. While continuous global measurements of most of these changes are not available through the 1961-2006 period, some humidity observations are available and do show upward trends over the continents. These include near-surface observations (Dai 2006) as well as satellite radiance measurements sensitive to upper tropospheric moisture (Soden et al. 2005).”
Although not a focus of this study, the degree to which the oceans themselves have recently warmed due to increased GHG, other anthropogenic, natural solar and volcanic forcings, or internal multi-decadal climate variations is a matter of active investigation (Stott et al. 2006; Knutson et al. 2006; Pierce et al. 2006). Reliable assessments of these contributing factors depend critically on reliable estimations of natural climate variability, either from the observational record or from coupled climate model simulations without anthropogenic forcings. Several recent studies suggest that the observed SST variability may be misrepresented in the coupled models used in preparing the IPCC’s Fourth Assessment Report, with substantial errors on interannual and decadal scales (e.g., Shukla et al. 2006, DelSole, 2006; Newman 2007; Newman et al. 2008). There is a hint of an underestimation of simulated decadal SST variability even in the published IPCC Report (Hegerl et al. 2007, FAQ9.2 Figure 1). Given these and other misrepresentations of natural oceanic variability on decadal scales (e.g., Zhang and McPhaden 2006), a role for natural causes of at least some of the recent oceanic warming should not be ruled out.
Regardless of whether or not the rapid recent oceanic warming has occurred largely from anthropogenic or natural influences, our study highlights its importance in accounting for the recent observed continental warming. Perhaps the most important conclusion to be drawn from our analysis is that the recent acceleration of global warming may not be occurring in quite the manner one might have imagined. The indirect and substantial role of the oceans in causing the recent continental warming emphasizes the need to generate reliable projections of ocean temperature changes over the next century, in order to generate more reliable projections of not just the global mean temperature and precipitation changes (Barsugli et al. 2006), but also regional climate changes.”
Roger Pielke writes in his blog:
This is a major scientific conclusion, and the authors should be recognized for this achievement. If these results are robust, it further documents that a regional perspective of climate variabilty and change must be adopted, rather than a focus on a global average surface temperature change, as emphasized in the 2007 IPCC WG1 report. This work also provides support for the perspective on climate sensitivity that Roy Spencer has reported on in his powerpoint presentation last week (see).
In the last 30 or so years, the oceans have been warming down to deep seas, parallel to the warming of the atmosphere. The extra energy stored in the oceans is roughly a factor of 10 more than the extra energy stored in the atmosphere. Thus, iti is not a big surprise to me that the authors conclude the oceans drive the climate changes.
Assume for the moment, the anthropogenic greenhouse gases are causing the extra ocean warming, by blocking the infrared radiation of the surface. Penetration depth of infrared radiation in water is of order 1 Millimeter. How can you warm the oceans down to 1000s of meters with such a coupling? It is much simpler to warm the oceans with sunlight (penetration depth of order 100 Meter). Basically, these are Stevensons arguments against Levittus.
The Compo et al paper is another mosaic stone for the validity of a solar activity model of climate change.
We shouldn’t ignore global dimming or albedo changes. The following workshop is of great interest in this regard:
http://www.astro.lu.se/~torben/earthshine/index.html
This paper is also extremely informative
Enric Pallé & Pilar Montañes-Rodriguez: Modern Observations of the Earth’s albedo
The first slide in Mike Lockwood’s presentation is also interesting
Mike Lockwood & Jaemin Lee: Proposed Space-Based Earthshine Observations
Anthony
Bruce Leybourne and Chris Smoot have been publishing on this for a while:
http://www.geostreamconsulting.com/papers/Leybourne_Oceans_Fin.pdf
Leybourne has proposed a plausible energy source of the observations discussed in the paper you base this post on.
Leybourne and Smoot also in the New Concepts in GlobalTectonics Newsgroup http://www.ncgt.org
Keep up th good work too 🙂
jeez
And CO2 is what percentage of the atmosphere?
Hmmmm….
We have to do this calculation because we want to know the comparative sizes of the masses of possible greenhouse gases.
All the water in the ocean is a possible greenhouse gas, right?
And all the CO2 dissolved in the ocean is a possible greenhouse gas.
Basically, what is the ratio between the CO2 in all the liquids of earth, both atmospheric and oceanic?
According to this article http://earthtrends.wri.org/updates/node/245 to ocean contains 50 times as much CO2 as the atmosphere. After saying that, the authors claim the atmospheric increase in CO2 has changed the surface alkalinity by 30%.
My basic chemistry is telling me that can’t be true. Total alkalinity would be dictated by molar concentration of CO2 in solution, which in turn, is a function of the entire mass of the oceanic solution.
In any event, the recent satellite surveys of total life activity indicates living creatures and plants are responding well to recent trends by increasing the total mass of living matter by 6% over the last five years.
So, increased CO2, which we know is a fertilizer for land plants is perhaps also a fertilizer for plant life in the seas?
If true, don’t we all have the duty to increase CO2 in both the oceans and atmosphere to encourage life?
Also, I seem to recall from my elementary school years that the Gulf stream is responsible for keeping Europe warm? I also recall a paper demonstrating the jet streams passing overhead here in North America contribute to the warmth of Europe by picking up heat from a warmer North Atlantic during the cold winter months, and carrying it into the landmass of Europe.
This paper then, should come as no surprise to anyone familiar with elementary school science teachings, at least those made available to me in Denver during the late 50s and early 60s.
Ben Franklin made his mark as a scientist with his studies of the Gulf Stream. English navigators refused to credit his work as he was a mere colonist. American navigators accepted his conclusions. The result? British ships took more time to cross the Atlantic on average than American ships. They refused to move a little to the south and fought a current all the way across.
Perhaps there will be a similar resistance to this paper by many? Perhaps political activists will push on with their plans to tax carbon, even though it has nothing to do with global warming? Are we doomed to see a parallel between British navigators and modern day activists, with the attendant economic consequences?
One more question: what causes the oceans to warm and cool in these huge multi-year cycles? We might say the sun, but it is also following its own cycles. At best mankind has been watching temperatures, salinity, velocities and so forth for only a couple of centuries.
Wouldn’t modesty be an appropriate mood at this time for mankind?
Let’s see,
McKitrick’s paper finds that up to 50% of the warming is due to UHI.
This paper finds that up to 70% of the warming is due to PDO.
Even Leif admits that up to 30% of the warming is due to TSI increases (without going into whether cosmic ray affects are real).
So up to 150% of the recent warming has been accounted for by factors other than CO2.
The graph of Alaska temperatures (post 1976 PDO shift) shows no trend.
http://climate.gi.alaska.edu/ClimTrends/Change/7707Change.html
Anchorage is having one of it’s coldest summers on record.
http://www.adn.com/anchorage/story/473786.html
Right now the so-called summer of ’08 is on pace to produce the fewest days ever recorded in which the temperature in Anchorage managed to reach 65 degrees.
If you look at ocean temperature and the heat content, isn’t this what ARGO system robots are supposed to measure — Temperature at depth? Didn’t some of the first conclusion show that the oceans contain about 80-90% of the Earth’s heat?
If people think the atmosphere is heating the planet, they should try boiling water with a hair dryer.
What we know, you could write a book. What we don’t know, would fill a library.
Mark,
“Ok, stupid question here. How can I tell if this paper has been peer reviewed and approved?”
Approved? Papers need to be approved now? I certainly hope not.
Let me see if I have this right:
– The sun was running at a grand maximum from the 1950’s until the mid- to late-1980’s. The oceans warmed in that period and with them, air temperatures. Most of the projected “dangerous” global warming would be in the seas, 80% – 90% worth.
– The 1998 el Nino disgorged huge amounts of accumulated heat. Since then the oceans cooled slightly and air temperatures plateaued.
– Now we’re seeing a marked cooling. Keenlyside (don’t get complacent), Trenberth (missing OHC), et. al. are going back to the AGW drawing board.
– We’re possibly in the onset of a broad period of a 30-year negative PDO and perhaps AMO, NAO, etc., might *ABSORB* extra heat from the air, but with the dimming sun, less so.
– Ice-free Arctic waters would (IIRC) release more heat from emissivity than they would absorb from solar radiation.
So doesn’t this point to the seas as large, dynamic heat-exchange systems that are dominant in climate dynamics?
– The sun’s functionally dimming enough for at least another -0.2 to offset, and with cosmic rays effects, possibly up to a total of -0.8 degrC offset.
Wouldn’t that mean the sun & the seas are dominant in climate dynamics?
– The air has dried in the middle & upper troposphere, not the lower as predicted by the GW models. Antarctica is drier than had been predicted, so is far less prone to warming than thought.
So that leaves us with two problems:
– Greenland’s rate of melt. If CO2 isn’t doing it and won’t make it much worse in the future, then the obvious first order remediation then is to scrub soot & ozone from human emissions which combined in the springtime Arctic cause the largest warming anomalies in the ice & in the air.
– Aerosol dimming (a low level of scientific understanding).
Is it possible that the sun influences ocean temperature?
The Sun’s Great Conveyor Belt has slowed to a record-low crawl, according to research by NASA solar physicist David Hathaway. “It’s off the bottom of the charts,” he says. “This has important repercussions for future solar activity.”
“Normally, the conveyor belt moves about 1 meter per second—walking pace,” says Hathaway. “That’s how it has been since the late 19th century.” In recent years, however, the belt has decelerated to 0.75 m/s in the north and 0.35 m/s in the south. “We’ve never seen speeds so low.”
http://science.nasa.gov/headlines/y2006/10may_longrange.htm
Tarpon’s comment takes the prize today – I love it!
“If people think the atmosphere is heating the planet, they should try boiling water with a hair dryer.”
Kinda does put things in perspective, now, doesn’t it?
It’s worth noting that oscillators respond to fixed forcings differently than periodic forcings. The responses for periodic forcings can be much, much larger than for fixed.
At first glance, PDO and ENSO could show a response to rising levels of CO2, but no response at all to a fixed elevated level. They can, however, resonate to the beat of solar variation.
…and then, there’s this article in The Australian…
“No smoking hot spot” by Dr David Evans (consultant to the Australian Greenhouse Office from 1999 to 2005) http://www.theaustralian.news.com.au/story/0,25197,24036736-7583,00.html
His first of four points appears to dovetail with today’s post:
“1. The greenhouse signature is missing. We have been looking and measuring for years, and cannot find it.
Each possible cause of global warming has a different pattern of where in the planet the warming occurs first and the most. The signature of an increased greenhouse effect is a hot spot about 10km up in the atmosphere over the tropics. We have been measuring the atmosphere for decades using radiosondes: weather balloons with thermometers that radio back the temperature as the balloon ascends through the atmosphere. They show no hot spot. Whatsoever.
I believe many posters here thus far are taking this study out of context.
This research is a very good example of how good science is performed. Please note that there is a very specific assumption which forms the basis of this analysis: the oceans have warmed. Go a step further, and notice that, at a more fundamental level, the cause of the warming of the oceans is not part of the analysis. It’s taken to be true, as it forms a necessary requirement for their hydrodynamic-radiative teleconnections (read: feedbacks).
Essentially, what the researchers are saying here is that when the oceans warm, the air becomes more humid. Naturally occurring circulations in the atmosphere then distribute this moister air in such a way that some regions receive it, some don’t. The shift for some areas to see more humid air more often results in a warming in those areas, due to the greenhouse effect (with water vapor as the primary GHG).
Notice that this is, more or less, an identical mechanism as proposed in a CO2 driven global warming theory. The difference here is the mechanism by which the air becomes more humid – although that difference isn’t really significant, and more importantly, it’s not mutually exclusive. This is what happens when good science is done – alternative theories which are robust enough to describe identical phenomena compete until one of them is proven to be insufficient, or both of them are merged together to create a unified theory.
The last paragraph of the author’s conclusion (not Pielke’s commentary) says it all: Regardless of whether or not the rapid recent oceanic warming has occurred largely from anthropogenic or natural influences… A poster or two here has suggested that the oceans haven’t been warming; if this is your position, then it is logically inconsistent to claim that this paper is the death knell to AGW, because by your own assumptions the premises on which this paper is based is fundamentally flawed and the result must be rejected.
Furthermore, the authors definitively state that global warming is occurring: the recent acceleration of global warming may not be occurring in quite the manner one might have imagined. The authors are not rejecting AGW but offering another mechanism by which it acts on the global climate (specifically, through regional perturbation). The middle paragraph of their conclusion is not a rebuttal on inaccurate temperature records, but rather an announcement of uncertainty – they cite recent research into oceanic temperature patterns as continuing field of research. Note that their conclusion based on this continuing research is not to throw everything related to AGW out the window, but rather to emphasize that natural variability in ocean temperature should not be discarded – they make no quantification of the magnitude of its influence.
A final point, all good conclusions cite future areas of research. This paper cites a specific one: more work must be done into ocean heat mechanisms. Why? So that they can generate better models. I’m sorry, but the irony kills me; to make a hasty generalization, I’ve notice that many posters here distrust models, yet this paper is really nothing more than a clarification of another field of model research which is just beginning! As a matter of fact, the abstract alludes to the fact that models were used as the primary line of evidence in this research: Atmospheric model simulations of the last half-century with prescribed observed ocean temperature changes, but without prescribed GHG changes, account for most of the land warming. It is logically inconsistent to claim that the models are intrinsically flawed and claim that this research supports that conclusion, because this research is based on those same models.
In summary, I look very forward to sitting down with this paper tonight; it sounds like a great read! However, we mustn’t jump to conclusions; in no way does this paper refute AGW. It is merely a proposal of an alternative mechanism through which the climate can warm, and specifically includes AGW as the root cause of that mechanism.
From my reading of it, the key claim is this:
“Overall, the results suggest that the dominant mechanism for the land warming in these simulations is enhanced downwelling longwave radiation. This enhancement is associated with increases of both upper tropospheric humidity and temperature over land, which themselves can occur in these simulations only through oceanic forcing, by experimental design.”
These are modeling results. How well do they measure up to observations? I can attest, from my own number crunching, that most warming is occurring in the NH over land. So this could be a plausible explanation.
But I’m curious about the modeled increase in upper tropospheric humidity. Isn’t that contradicted by observations?
I.e.,
http://www.cdc.noaa.gov/cgi-bin/Timeseries/timeseries.pl?ntype=1&var=Specific+Humidity+%28up+to+300mb+only%29&level=300&lat1=30&lat2=60&lon1=180&lon2=-180&iseas=1&mon1=0&mon2=11&iarea=0&typeout=2&Submit=Create+Timeseries
previously discussed on WUWT here:
http://wattsupwiththat.wordpress.com/2008/06/18/a-window-on-water-vapor-and-planetary-temperature/
Note: I ran my plot limited to 30N-60N since this would be where most of the land warming is taking place. Anthony’s plot was global.
Before Anthony called attention to this, I was using the NOAA site to track precipital water vapor in the tropics, since this should be steadily rising under my understanding of the AGW hypothesis. And it isn’t:
http://www.cdc.noaa.gov/cgi-bin/Timeseries/timeseries.pl?ntype=1&var=Precipitable+Water&level=2000&lat1=30&lat2=-30&lon1=180&lon2=-180&iseas=1&mon1=0&mon2=11&iarea=0&typeout=2&Submit=Create+Timeseries
So I’m wondering if we don’t have yet another model run which isn’t doing a very good job of replicating actual climate observations. Or am I missing something (always possible!)?
It looks to me like wordpress chopped off my links.
Here is a tinyurl to the first amputated link:
http://tinyurl.com/5h3fr7
And the second one:
http://tinyurl.com/5764h3
And for a more accurate experiment, try using that hairdryer on an olympic-sized swimming pool…
AGW hysteria finally gotten into your head?…..or both?
Too much Ultima VII.
Arrrrr.
Someone finally noticed the 800 lb gorilla in the room.
Thar she blows!
And CO2 is what percentage of the atmosphere?
Proportion: 385 ppmv. Amount: 760 BMTC.
Arrrr.
To realize that the oceans play a role in the earth’s climate is rudimentary.
Isn’t it?
Arrr . . .
PArtick Henry,
“The Sun’s Great Conveyor Belt has slowed to a record-low crawl, according to research by NASA solar physicist David Hathaway. “It’s off the bottom of the charts,” he says. “This has important repercussions for future solar activity.””
I’m sure we’ll see a headline soon, to wit, “Sun’s Conveyor Belt slows to unprecedented levels, increasing CO2 levels on earth blamed, poor and minorities to be most affected.”
counters,
“the recent acceleration of global warming may not be occurring in quite the manner one might have imagined. ”
Are you not assuming that when the researchers refer to ‘global warming’ they mean AGW? I don’t agree with this assessment as they appear to be meticulous in differentiating between statements of general ‘global warming’ and AGW by placing the qualifier ‘anthropogenic’ when referencing human caused warming. They did not do so here so I would assume they intended this as a reference to warming without ascribing causation.
counters:
//However, we mustn’t jump to conclusions; in no way does this paper refute AGW. It is merely a proposal of an alternative mechanism through which the climate can warm, and specifically includes AGW as the root cause of that mechanism.//
Agreed, but it would seem to at least add another bit of evidence to refute that “the science is settled.”
Counters,
You make some very cogent arguments and unlike many of the comments here, you do not make inferences beyond the scope of the paper.
To me it looks like the gist of this paper is that:
Oceans are warming (by both GHG’s and natural variability) >> warming increases water vapor over oceans >> water vapor gets transported over land >> water vapor acts as a GHG and warms land surface.
Isn’t this just a complementary process model for what we already know? This does not preclude processes that involve terrestrial warming via GHG’s and terrestrially originated water vapor. And in no way is a refutation of the current models or basic conclusions of AGW theory.
This looks like a paper that will help us refine our understanding of the climate system, but it will not overturn the current paradigm.