Atmospheric Solar Heat Amplifier Discovered

For decades, the supporters of CO2 driven global warming have discounted changes in solar irradiance as far too small to cause significant climate change. Though the Sun's output varies by less than a tenth of a percent in magnitude during its 11-year sunspot cycle, that small variation produces changes in sea surface temperatures two or three times as large as it should. A new study in Science demonstrates how two previously known mechanisms acting together amplify the Sun's impact in an unsuspected way. Not surprisingly, the new discovery is getting a cool reception from the CO2 climate change clique.

Scientists have long suspected that changes in solar output may have triggered the Little Ice Age that gripped Europe several centuries ago, as well as droughts that brought down Chinese dynasties. Now, in a report in the August 28 issue of the journal Science entitled “Amplifying the Pacific Climate System Response to a Small 11-Year Solar Cycle Forcing,” Gerald A. Meehl et al. have demonstrated a possible mechanism that could explain how seemingly small changes in solar output can have a big impact on Earth's climate. The researchers claim that two different parts of the atmosphere act in concert to amplify the effects of even minuscule solar fluctuations.


Solar irradiance variation during 11-year cycles.

Global sea surface temperature (SST) has been observed to vary by about 0.1°C over the course of the 11-year solar cycle. This should require a change in solar irradiance by more than 0.5 W m–2, but the globally averaged amplitude change from solar maximum to solar minimum is only about 0.2 W m–2. There has long been a question regarding how this small solar signal could be amplified to produce a measurable response. In fact, the lack of a plausible mechanism has been used to discount the Sun's effect on climate by those who support carbon dioxide as the primary driver of global warming. That line of argument may no longer be persuasive. As the report's authors state in the paper's abstract:

Two mechanisms, the top-down stratospheric response of ozone to fluctuations of shortwave solar forcing and the bottom-up coupled ocean-atmosphere surface response, are included in versions of three global climate models, with either mechanism acting alone or both acting together. We show that the two mechanisms act together to enhance the climatological off-equatorial tropical precipitation maxima in the Pacific, lower the eastern equatorial Pacific sea surface temperatures during peaks in the 11-year solar cycle, and reduce low-latitude clouds to amplify the solar forcing at the surface.

The two mechanisms mentioned have been modeled individually in the past, and neither alone proved sufficient. Prior to this new report both mechanisms had not been included in the same model. Some models operate from the top down, beginning with the small changes in the sun's ultraviolet radiation that occur during the solar cycle. The enhanced UV radiation, which promotes stratospheric ozone production and UV absorption, warm that layer of the atmosphere differently at different latitudes. The temperature gradients this creates provide a positive feedback amplifying the original solar forcing while affecting the climate in the lower atmosphere.

Other models work from the bottom up, using a mechanism that centers around the equatorial Pacific Ocean. Solar energy added during the peak of a solar cycle causes more water to evaporate from the ocean's surface. Through a long chain of changes in atmospheric and oceanic circulation, this results in fewer clouds forming in the subtropics. Fewer clouds mean more solar energy reaches the ocean, resulting in a positive feedback loop that amplifies the Sun's climate impact.

The problem to date has been that neither mechanism had a large enough impact to account for observed temperature changes. Suspecting that the two might reinforce each other if modeled together, Meehl et al. decided to modify some existing climate models: “Here we use several related climate model versions wherein we can include both mechanisms separately (an atmospheric model with no stratospheric dynamics or chemistry coupled to ocean, land, and sea ice; an atmospheric model with stratospheric dynamics and ozone chemistry driven by specified SSTs and sea ice) and then combine them (the atmospheric model with stratospheric dynamics and ozone chemistry coupled to the ocean, land, and sea ice) to test if they can, indeed, amplify the climate system response to solar forcing to produce responses of the magnitude seen in the observations.”

Two existing models were chosen, one each for the two distinct mechanisms identified above. These were a global coupled climate model,the Community Climate System Model version 3 (CCSM3), and a version of the Whole Atmosphere Community Climate Model (WACCM). The first model, CCSM3, has coupled components of atmosphere, ocean, land, and sea ice. It does not have a resolved stratosphere and no interactive ozone chemistry, so the CCSM3 includes only the bottom-up coupled air-sea mechanism. The second model, WACCM, is a global atmospheric model run with climatological SSTs and changes in solar variability with other external forcings are held constant. It has no dynamically coupled air-sea interaction, but does include a resolved stratosphere and fully interactive ozone chemistry that can respond to the UV part of the solar forcing. Given this configuration it should include the top-down UV stratospheric ozone mechanism.


Composite averages for December-January-February (DJF) of peak solar years: Observed SSTs for 11 peak solar years in the left column; Precipitation for three available peak solar years in right column. Credit: G. Meehl, Science.

After confirming that neither model on its own faithfully reproduced the observed changes in temperature over a solar cycle—both predicted changes about a third the size of those observed—a new model was constructed using the atmospheric component from WACCM coupled to the dynamical ocean, land, and sea ice modules in CCSM3. This hybrid model produced negative SST anomalies in the equatorial eastern Pacific of greater than –0.6°C, much closer to the observed values of –0.8°C. In the researchers' words: “Thus, these models indicate that each mechanism acting alone can produce a weak signature of the observed enhancement of the tropical precipitation maxima, but when both act in concert, the two mechanisms work together to produce climate anomalies much closer to the observed values, thus amplifying the relatively small solar forcing to produce significant SST and precipitation anomalies in the tropical Indo-Pacific region.” Results for both SST and precipitation can be seen in the figure above, taken from the report.

Instead of being off by a factor of three as the conventional models were, their new model was within 25% of the actual observed SST variation, a huge improvement indicating that the combination of mechanisms is much more than the sum of their individual effects (see the plot below). This combination of effects enhances precipitation maxima, reduces low-latitude cloud cover, and lowers the temperature of surface waters in the tropical Pacific Ocean, resulting in the larger warm-to-cold variation. “This highlights the importance of stratospheric processes working in conjunction with coupled processes at the surface,” they concluded.


DJF precipitation as observed and from the models. Credit: G. Meehl, Science.

While this result is from modeling, not empirical evidence, it is an important one. As I have often said on this blog, modeling is what you do when your intuition fails you and you need new insights. This combination of mechanisms, building a new hybrid model that simulates conditions not captured by previous models, is a great example of how models should be used. Note that this new model still did not reproduce the observed data, but it did get much closer to reality—an indication that the coupled atmospheric mechanism approach could be on the right track. “The atmosphere and oceans are a big coupled system,” says Joanna Haigh of Imperial College London, who developed the top-down mechanism, “but it's incredibly complicated.” Of course more physical observations will be necessary to lend credence to this hypothesis, but finding evidence is much easier once the cause is know (or at least suspected).

Why then, should this report be getting the cold shoulder from the climate change community? Writing in the same issue of Science, Richard A. Kerr reported, “like much work in the long-controversial field of sun-climate relations, the new modeling is getting a cool reception.” This is because of what the existence of a coupled atmospheric solar amplifier could mean to climate change theory overall. Though Meehl et al. include the obligatory “this response also cannot be used to explain recent global warming” statement at the end of their report, what remains unsaid is that if this effect is present for decadal solar variations it would also be present for longer term changes in the Sun's output.


Historical solar irradiance variation.

As I have previously reported, scientific evidence from NASA points to changes in the type of solar radiation arriving at the top of Earth's atmosphere as a possible trigger for other powerful climate regulating mechanisms. Scientists have discovered, that while total solar irradiance changes by only 0.1 percent, the change in the intensity of ultraviolet light varies by much larger amounts. According to Judith Lean, a solar physicist at the U.S. Naval Research Laboratory in Washington, D.C., its possible that long-term patterns—operating over hundreds or thousands of years—could cause even more pronounced swings in solar irradiance (see “Scientists Discover The Sun Does Affect Earth's Climate”). The discovery of the solar heat amplifying effect provides the causal link between historical changes in solar activity and climate change.

Previously, the direct impact of increased irradiance on global avarage temperature has been estimated at around 0.25°C last century—a three fold amplifying effect would raise that to 0.75°C. This leaves practically no warming effect for CO2 to account for and renders the whole anthropogenic global warming argument moot. In other words, if the atmospheric solar amplifier theory is correct anthropogenic global warming is wrong, a useless theory describing a nonexistent phenomenon. It seems like poetic justice that a modeling experiment may point the way to discrediting global warming once and for all.

Be safe, enjoy the interglacial and stay skeptical.

Ozone Fluctuations and the Thermosphere

I am very curious: Several years ago, the Thermosphere collapsed. It was 'an order of magnitude' larger than anything ever seen before.

I have to wonder if that collapse also plays a role, since the sun went quiet? Especially since the world appears to be(?) heading into a cooling cycle.

Are you sure this model is accurate?

Are you positive that those 2 models are not adding up info instead of just interact with each other? That would be another explanation for this results.

salvia

Correctness, not accuacy is the question

As the paper reported, adding things up does not give the level of warming predicted by the model, so that is not another explanation. And it is not a matter of accuracy, complex models are not very good at giving accurate predictions of natural phenomena. Rather, it is the indication that the amplifier exists at all that is the important result—insight not numbers.

Amplification

This is not directly related but is an example of amplification I have not seen commented on elsewhere.

It is widely accepted that the cycle of ice ages is driven by the Milankovitch cycles. The change in solar radiation at 65N in July is taken as an indicator and this varies by 24%. However the change in whole-earth-whole-year radiation is much smaller: 0.7% maximum over the several cycles. What is interesting is that the change in whole-earth-whole year radiation which took us out of the previous ice age was very much smaller only 0.07%. This is an example of how very small changes can be amplified to produce major effscts. See:
http://www.climatedata.info/Forcing/Forcing/milankovitchcycles.html

From this article: The

From this article:

The enhanced UV radiation, which promotes stratospheric ozone production and UV absorption, warm that layer of the atmosphere differently at different latitudes. The temperature gradients this creates provide a positive feedback amplifying the original solar forcing while affecting the climate in the lower atmosphere.

Could that possibly mean that the "ozone hole" is part and parcel of this temperature gradient effect? Would that lend weight to the idea that the ozone hole phenomenon has been going on long before man noticed it?

O3

There again it could be down to the ozone response...
The Sun shines, ozone absorbs a lot of the UV, let's the rest of the sunlight through.
The Sun shines stronger, more sunlight causes ozone depletion by increasing depleting molecules' formation, more UV gets through and warms the ocean surface (UV doesn't get very far in sea water, up to a metre ~). More water vapour is produced by the oceans, the atmosphere warms a little due to the "GHG" effect. More CO2 is released by the warmed ocean surface layer, less absorbed. Biomass responds to increased fertilisation by CO2, increased water availability and increased sunlight and produces more water vapour.

Sunlight decreases, less reactions among ozone depleting molecules occur, ozone recovers, less UV reaches the oceans, water vapour and CO2 levels fall, the atmosphere cools, clouds form more readily and further reduce sunlight penetration. Oceans cool, oscillations reverse and sea ice increases, amplifying the reduction in sunlight penetrating the water.

There are many aggravating and mitigating factors, big ones are volcanic cooling influence on stratosphere temperature and H2O levels that deplete ozone and offset stratosphere cooling.

UV penetration governed by TSI influence on ozone levels seems to govern the tropospheric temperature. Where am I being naive?

Of course, CO2 is still an unhealthy pollutant

Which is why I've never liked the climate change argument for CO2 reduction; it distracts from the fact that CO2 is a harmful pollutant.

The fact that...

Do you have data to support the claim or just a mindless doctrinal response?

Patent Nonsense

This argument is often made by scientifically naive persons and it is patent nonsense. If you want the facts go read “The Grand View: 4 Billion Years Of Climate Change” posted some time ago on this blog. In that article you will find that CO2 has been present in Earth's atmosphere for more than 4 billion years, almost always in significantly higher concentrations than today. In our book The Resilient Earth we stated: “Life extracts carbon from the environment in order to build organic molecules... Carbohydrates (starches and sugars), lipids (fats), nucleic acids (DNA and RNA), and proteins are all based on carbon. Carbon is the stuff of life.” Much of that extracted carbon comes from CO2 and is extracted by plants. As many others have noted, CO2 is plant food and life as we know it would not exist without it.

Can carbon dioxide be unhealthy, even life threatening? Yes, in concentrations higher than 5%, which is 130 times higher than today's atmospheric levels. The concentration of CO2 must be over about 2% before most people are even aware of its presence and then it only causes more frequent and deeper respiration. Does that make it an “unhealthy pollutant”? Pure oxygen at twice atmospheric pressure is toxic, is O2 an unhealthy pollutant? How about water? A couple of inches of H2O can kill you, does that make water a dangerous and unhealthy pollutant? Such statements are pure balderdash and would never be uttered by someone with even the most rudimentary scientific knowledge.

Unhealthy concentration

It might be worth noting here that the US Navy's standard for CO2 concentration on submarines (where air is recycled and precious) is 8000 ppm, or roughly 20 times current ambient. And the Navy is not in the business of poisoning its sailors.

... Interesting to see what a spider plant would do aboard a sub. Just with ambient CO2, my wife's seem to take over the whole house...

EPA

Which is why the EPA uttered them; lacking scientific knowledge, it admits it relied on the IPCC and its PR statements when making a determination which blows a huge hole in the hull of the nation's economy.

al gore

as you know Al Gore will not be happy to hear he is wrong.

Consequences

When I look at the picture "solar irradiance variation" vs time, I see that there must be a lag in reaction of the temperature to the irradiance. There was still a cooling until the 70ies even the irradiance increased.
The second conclusion is, that we might expected more warming in the next few years (?)

Sun spot warming

The last time there was a period of very few/no sunspots was in 1913. The next two years were very much warmer and led to a resultant 0.6C rise in global average temps from 1917 to 1944 (GISS). Surely this won't happen again?

The true cause of climate change

[ Post deleted by the Administrator: The post that previously appeared here, "A Compilation of the Arguments that Irrefutably Prove that Climate Change is driven by Solar Activity and not by CO2 Emission" by Dr. Gerhard Löbert, has been deleted because no corroboration can be found for the "facts" stated therein. This same post has been made to a number of other websites and is widely suspected of being a fringe science hoax, a position strengthened by its appearance on several fringe websites (specifically zero-point energy and super-Einstein theory sites). While we try to keep an open mind and do not wish to suppress scientific debate, the use of the word "irrefutably" should set of alarm bells in any true skeptic's head. ]

Doug and Anonymous

Doug and Anonymous

Doug, you give the answer I expected. A further comment could be that we are only having the discussion because so much money has been sunk in GCMs, probably more than $5 billion, with little or no result. This money might have been better invested in looking at the actual climate rather than fantasising about it. So the result of this work is an interesting stick with which to beat the warmists but still may have little to say about what happens in reality, much as I would like to believe in anything that undermines the hoax that is AGW.

A. Of course models have application, especially in engineering. However, man in his desire to deal with uncertainty has invested too much faith in what are simply vast numbers of equations that can be solved more rapidly by modern computers. What has happened with the Credit Crunch is one example. In my own business, catastrophe modelling is now de riguer for all insurers although most underwriters know how poor the results can be. E.g Katrina and the UK's summer 2007 floods.

Doug, I read the book but lost patience with the last two chapters which seemed to contradict all that had gone before. Of course we need to conserve energy and find alternatives to oil. But this will not be done through the misdirection of billions and trillion of dollars in wind and tidal power for example.

A lot less money could be better spent on improving efficiency, better insulation and getting clean water and electricicty to poor Africans.

Regards

Paul

Skeptics can also be Ecologists

Our conclusions at the end of The Resilient Earth were basically that AGW was not a threat to nature or humanity. We also said that explosive growth in developing nations would necessarily drive up the cost of fossil fuels world wide. For economic, national security and environmental reasons we should start the process of moving off fossil fuels. Remember that the age of steam didn't end because we ran out of wood and coal to fire steam engines. Transitioning to a new energy source always starts before the previous dominant source is exhausted. Being realists, we expect this process to take about a century, meaning oil, coal and natural gas will be with us for the foreseeable future.

We are skeptics with respect to global warming, we are not blind to how messed up people can make their environment given half a chance. Pollution is real, burning dirty fuels releases particles into the air that darken the skies of many of the world's cities and coal keeps dumping mercury into streams, rivers and lakes to the point that you shouldn't consume any fish caught in them. Most people in the developed world don't remember just how bad pollution was back in the unregulated 1960s, when city dumps spontaneously combusted, rivers caught fire and breathing was hazardous to your health. Not accepting global warming doesn't keep us from being concerned about the environment.

Even so, we specifically spoke out about the injustice of denying energy to the impoverished peoples of the world. A green world filled with poverty, disease and hunger is not a world anyone should desire to create. The technologically advanced nations need to take the lead in developing new, cleaner, more efficient energy sources to replace the dirty technologies of the past—if not out of humanitarian altruism then from enlightened self interest. All of this will be detailed in our next book, which we hope to release in early December.

Pollution

Two points here need to be borne in mind for perspective, though --

  • However bad the pollution was in the 1960s compared to now -- and in most cases I think there is exaggeration, though New York, Los Angeles, London, and so on were indeed terrible -- the pollution in, say, 1890 was infinitely worse. The East was largely deforested for fuel, for example; the reforestation over the last century is due largely to abandonment of "biomass" energy and adoption of coal and oil.
  • Industrial-scale electricity generation by wind and biomass is even in theory impossible, but the current insane fad for "renewables" and the accompanying enormous government subsidies poses the single greatest threat to wilderness and wildlife habitat in the entire developed world.

But people ARE the problem!

To many, that is. With talk of forced abortions, sterilization and other horrendously anti-human ideas, it is apparent that many of the eco-whackos hate their own species - they aren't interested in science, since this is ideology/religion to them. It constantly amazes me that some who believe in the ruthless, merciless process of evolution would bother to worry about those that can't make it in the current evolutionary environment. It is what it is, right?

Atmospheric Solar Heat Amplifier

Doug

I'm no modelling expert. This result from a model only works if you believe that the models work. Since as you argue in your book that there are many reasons why the models do not work, why should we take this work as valid.

Presumably, the models that have been used suffer from the same weaknesses as the others. For example, not delaing with clouds and precipitation. Correlation is not causation.

Regards

Paul

Modeling as a tool

A good and reasonable question, Paul. I have often warned about the overuse of computer models or, more specifically, the miss-use of models. But that does not mean that modeling is totally useless. On the contrary, modeling is an important tool and can actually uncover unsuspected physical phenomena if done correctly. This application is not an attempt to model the whole of Earth's global climate system for 100 years into the future. Instead, the researchers made many modeling runs for restricted periods of time and compared the results against known empirical data. In other words, they used physical reality as a check on their modeling experiment.

This does not mean that their hybrid model should be taken as an exact replication of how the Earth system works, it is not. Likewise, the amount of amplification they calculated should not be taken as fact: it is but an estimate that says “there's something promising to look into here.” As I said in the article, more observations are necessary to confirm if this amplifier effect is really present and to quantify how great a boost it gives the impact of solar variability.

What I do find most encouraging is that, even in the face of negative reaction from the traditional climate change community, this new research has been published in one of the most prestigious scientific journals around. This is a sign that finally scientists are looking for other causes for climate change and not just reflexively blaming CO2 for every upward tick of the thermometer.

Doug

Modeling..

Paul,

Does your skepticism of models also apply to the "Man-Made Global Warming" models?

What modelling does

Modelling extrapolates a particular set of assumptions and guesses into unknown or new areas, preferably ones which can then be tested (at least in representative samples) to see if the assumptions and guesses are logically consistent with observation. If the model fails, we know for sure that some one or more of the assumptions are wrong. If the model matches the new, test observations, we know that the model has not yet been disproven. It can then be tentatively used to predict more situations and conditions, until it is found once again to disagree with reality, at which point a new hunt for the mistaken assumption or guess embedded in it can begin. And so on.

General Semantics' fundamental motto: "The map is not the territory." No statement or model exactly matches the reality it refers to. Some are REALLY far off, other less so. It's only a matter of degree.