Equilibrium Climate Sensitivity

[StudentOfClimatology]

I certainly have heard from the outside that Columbia's L-D crowd is home to strong and vibrant personalities with strong, vibrant opinions on this issue in particular

I've been fortunate enough to meet a number of the "gods" in this field..it's truly a humbling experience, especially when you know that you'll never compare to them.

I'll try to get a few paleoclimatologists to post on this site in the near future.

As of right now, the most unbiased source on the YD is actually Wikipedia. Their current piece on the YD pretty much sums up the state of the science, at this time:

http://en.m.wikipedia.org/wiki/Younger_Dryas

[StudentOfClimatology]

Also, I want to mention that some of the heat-transfer parameterizations by Chiang et al 2009 are highly suspect. We barely understand the dynamics and forcings behind the MJO and Rossby Wave train now. Assuming we know how those dynamics behaved during the YD is a huge stretch given we still have conflicting SST proxies.

[Isotherm]

Regarding feedbacks, this is an interesting paper concerning the possibility of a significant positive bias in feedbacks:

 

http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2253.1

 

 

Another one on feedbacks and climate sensitivity:

 

 

http://webcache.googleusercontent.com/search?q=cache:3b7otVla9qgJ:www-eaps.mit.edu/faculty/lindzen/236-Lindzen-Choi-2011.pdf+&cd=1&hl=en&ct=clnk&gl=us

[bluewave]

Hopefully, the sensitivity values are toward the lower end of the scale since we have

a way to go before transitioning off carbon based energy as a primary source.

 

http://oilprice.com/Latest-Energy-News/World-News/Newly-Built-CO2-Emitting-Plants-Outpace-Closings.html

 

Newly Built CO2-Emitting Plants Outpace Closings

 

 

Governments around the world may be enacting measures to reduce greenhouse gas emissions, but the energy industry isn’t on board with those goals, according to a new report from researchers at Princeton University and the University of California at Irvine (UCI).

Their report, published in the journal Environmental Research Letters, says existing power plants fired by coal and gas will generate more than 300 billion tons of atmosphere-clogging carbon dioxide over the next 40 years.

They calculate that “committed” emissions – those coming from plants already in operation – will rise by about 4 percent each year as industry builds even more coal and gas fired plants. Their study is the first to quantify the rate at which such emissions grow.

The report estimates that just the new plants built around the world in 2012 will emit 19 billion tons of carbon dioxide during their expected four decades of operation. That’s significantly more than the 14 billion tons of CO2 emissions produced by all the plants operating worldwide built before 2012.

The only way to reverse the trend is “retiring more fossil fuel-burning facilities than we build,” said Steven Davis, assistant professor of Earth system science at UCI and a co-author of the study.

The report explains that the United Nations, which keeps track of global carbon emissions, ignores capital investments in future power plants that commit to billions of tons of CO2 emissions over several decades.

“We are flying a plane that is missing a crucial dial on the instrument panel,” says Robert Socolow, a professor emeritus of mechanical and aerospace engineering at Princeton. “[T]he only dial on our plane tells us about current emissions, not the emissions that current capital investments will bring about in future years.”

The Princeton-UCI report says the number of new power plants is outpacing the old ones being retired. Worse, it says, total remaining commitments in the worldwide power sector haven’t been reduced in a single year since 1950; in fact, they grew at an average rate of 4 percent per year between 2000 and 2012.

The main culprits are developing countries like China, India, and Indonesia. Power plants in China and India will be responsible for 42 percent and 8 percent respectively of committed future emissions.

Caps on emissions in the western countries, meanwhile, are producing benefits, the report says. The United States, once the world’s leading polluter, is now responsible for only 11 percent of committed future emissions; in Europe, the figure is only 9 percent.

By Andy Tully of Oilprice.com

[nflwxman]

Bluewave thats an interesting article.  Thank you for posting.  The TCR and ECS debate is interesting in the sense that we truly don't know much about what consequences each degree temperature rise brings.  On one hand, you'd like climate sensitivity to be on the lower end, but if climate sensitivity is low, that could also indicate that the major paleoclimatic shifts of the past came with a lower temperature threshold. 

[chubbs]

Per this article,  the oil industry is running pretty hard just to maintain current  production. Even today's high price of oil can't justify exploration expense. The long-term availability and relative economics of fossil fuels is just as uncertain as ESS or TCR. 

 

STAVANGER, Norway, Aug 27 (Reuters) - The rate of oil discoveries continues to disappoint after a record low last year and firms could even cut their exploration budgets to save on costs, a risk to long-term supplies and prices, industry executives said.

 

http://www.reuters.com/article/2014/08/27/norway-oil-conference-exploration-idUSL3N0QW31K20140827

[nflwxman]

It's amazing that papers like this (some apparently peer reviewed) exist on the blogosphere with ECS estimates of under 1 degree C.

 

http://wattsupwiththat.com/2014/10/14/yet-another-significicant-paper-finds-low-climate-sensitivity-to-co2-suggesting-there-is-no-global-warming-crisis-at-hand/

 

In order to believe in a ECS of less than 1.0 degree Celcius, you would have to assume that we would undergo some real flatlining and/or cooling of global temperatures over the next several decades.  We've already warmed approximately 0.8-0.9 from pre-industrial times. I seriously have no idea how estimates like this can ever be taken seriously and/or become peer reviewed.  Looks at some of these asinine estimates below:

 

 

 

Lindzen & Choi [2011]: 0.7 C

Spencer & Braswell: 0.62 C

Bjornbom: 0.67 C

 

Eschenbach: 0.2 C 

Levitus 2012 = 0.39 C

 

Douglass & Knox [2012]: 0.16 * 1.3 = 0.21 C

Lindzen & Giannitsis: 0.67 C

Douglass et al [2005]: .22 * 1.3 = 0.29 C

 

Bogdanov: .41*1.3 = 0.53 C

Chylek: .385*1.3 = 0.50 C

 

Monckton: .12 * 3.7 * 1.3 = 0.58 C

Paltridge: .1 - .3 (based on NCEP trends, figure 10) (ave .2)*1.3 = 0.26 C

Schwartz: 0.3 * 1.3 = 0.39 C

Bengtsson: 2C with lower bound 1.167C

The Hockey Schtick: 0.28C [to doubling of man-made CO2 emissions]

The Hockey Schtick [alternate method]: 0.25C [to doubling of CO2 levels]

Harde: 0.43C

Norden: 0.8 C

Lewis & Curry: 1.3C Transient Climate Sensitivity, 1.6C Equilibrium Climate Sensitivity

[ORH_wxman]

 

It's amazing that papers like this (some apparently peer reviewed) exist on the blogosphere with ECS estimates of under 1 degree C.

 

http://wattsupwiththat.com/2014/10/14/yet-another-significicant-paper-finds-low-climate-sensitivity-to-co2-suggesting-there-is-no-global-warming-crisis-at-hand/

 

In order to believe in a ECS of less than 1.0 degree Celcius, you would have to assume that we would undergo some real flatlining and/or cooling of global temperatures over the next several decades.  We've already warmed approximately 0.8-0.9 from pre-industrial times. I seriously have no idea how estimates like this can ever be taken seriously and/or become peer reviewed.  Looks at some of these asinine estimates below:

 

 

 

Lindzen & Choi [2011]: 0.7 C

Spencer & Braswell: 0.62 C

Bjornbom: 0.67 C

 

Eschenbach: 0.2 C 

Levitus 2012 = 0.39 C

 

Douglass & Knox [2012]: 0.16 * 1.3 = 0.21 C

Lindzen & Giannitsis: 0.67 C

Douglass et al [2005]: .22 * 1.3 = 0.29 C

 

Bogdanov: .41*1.3 = 0.53 C

Chylek: .385*1.3 = 0.50 C

 

Monckton: .12 * 3.7 * 1.3 = 0.58 C

Paltridge: .1 - .3 (based on NCEP trends, figure 10) (ave .2)*1.3 = 0.26 C

Schwartz: 0.3 * 1.3 = 0.39 C

Bengtsson: 2C with lower bound 1.167C

The Hockey Schtick: 0.28C [to doubling of man-made CO2 emissions]

The Hockey Schtick [alternate method]: 0.25C [to doubling of CO2 levels]

Harde: 0.43C

Norden: 0.8 C

Lewis & Curry: 1.3C Transient Climate Sensitivity, 1.6C Equilibrium Climate Sensitivity

 

 

 

 

You're viewing the latest paper wrong...your assumption in the bolded is that 100% of the warming is attributable to AGW. The latest paper attributed over half of the warming to solar so it's not going off the assumption that 0.8C of warming is from AGW. Now there's very good reason to doubt that as a large majority of the literature does not support such an attribution to solar, but it's not as simple as saying they expect no additional net warming going forward.

 

I would also not describe the Lewis estimate of 1.6C or the Bengtsson estimate of 2C as "asinine"...there's plenty of support in the literature for values near those estimates whether you personally accept them or not. I do agree the stuff under 1C are very outlandish and not supported by the majority of mainstream literature.

[nflwxman]

You're viewing the latest paper wrong...your assumption in the bolded is that 100% of the warming is attributable to AGW. The latest paper attributed over half of the warming to solar so it's not going off the assumption that 0.8C of warming is from AGW. Now there's very good reason to doubt that as a large majority of the literature does not support such an attribution to solar, but it's not as simple as saying they expect no additional net warming going forward.

 

I would also not describe the Lewis estimate of 1.6C or the Bengtsson estimate of 2C as "asinine"...there's plenty of support in the literature for values near those estimates whether you personally accept them or not. I do agree the stuff under 1C are very outlandish and not supported by the majority of mainstream literature.

I did say "some" not all of the papers were asinine.  The Curry and Lewis paper is certainly on the lower end of the mainstream, but is not wildly off base like some of the ones mentioned above.

 

Assuming the solar activity continues to slump, some of those climate sensitivities mentioned above would require some type of "leveling off" or dropping in the next few decades.  Especially if the attribution of solar activity in temperature change is that high with to begin with.  Would you disagree?  I believe I was looking at it the same way you were, but was trying to take into account the fact that solar has began to slump.

[ORH_wxman]

I did say "some" not all of the papers were asinine.  The Curry and Lewis paper is certainly on the lower end of the mainstream, but is not wildly off base like some of the ones mentioned above.

 

Assuming the solar activity continues to slump, some of those climate sensitivities mentioned above would require some type of "leveling off" or dropping in the next few decades.  Especially if the attribution of solar activity in temperature change is that high with to begin with.  Would you disagree?

 

 

No, no disagreement there. The solar brigade absolutely has to have a significant temperature response in the next 10-15 years if they want to continue to claim that the influence is on the same level as GHG concentration.

 

I don't think they will get it though.

[chrisf97212]

No, no disagreement there. The solar brigade absolutely has to have a significant temperature response in the next 10-15 years if they want to continue to claim that the influence is on the same level as GHG concentration.

 

I don't think they will get it though.

 

I would expect some type of solar response in less time than that.  The problem, as with CO2, is that there are so many moving components that offsetting occurs.  What's the current consensus on which GCM is best?

[PhillipS]

From a cursory reading of the translation, this seems to be a rehash of the soundly debunked 'saturation' argument.  I"m sure the pseudo-skeptics and denialists will eat it up - but I don't see that it adds anything to the discussion.

[Isotherm]

From a cursory reading of the translation, this seems to be a rehash of the soundly debunked 'saturation' argument.  I"m sure the pseudo-skeptics and denialists will eat it up - but I don't see that it adds anything to the discussion.

 

 

Do you have a scientific paper that directly responds to / refutes the one you're referencing?

[PhillipS]

The OP paper hasn't been out long enough to have a formal rebuttal yet - and it's so weak that serious  climate scientists lakely won't waste time on it.  But here is a column on Realclimate.org [link] on an earlier attempt to make the same argument that CO2 is saturated.  An excerpt:

 

Some people have been arguing that simple physics shows there is already so much CO2 in the air that its effect on infrared radiation is "saturated"— meaning that adding more gas can make scarcely any difference in how much radiation gets through the atmosphere, since all the radiation is already blocked. And besides, isn’t water vapor already blocking all the infrared rays that CO2 ever would?

 

The arguments do sound good, so good that in fact they helped to suppress research on the greenhouse effect for half a century. In 1900, shortly after Svante Arrhenius published his pathbreaking argument that our use of fossil fuels will eventually warm the planet, another scientist, Knut Ångström, asked an assistant, Herr J. Koch, to do a simple experiment. He sent infrared radiation through a tube filled with carbon dioxide, containing somewhat less gas in total then would be found in a column of air reaching to the top of the atmosphere. That’s not much, since the concentration in air is only a few hundred parts per million. Herr Koch did his experiments in a 30cm long tube, though 250cm would have been closer to the right length to use to represent the amount of CO₂ in the atmosphere. Herr Koch reported that when he cut the amount of gas in the tube by one-third, the amount of radiation that got through scarcely changed. The American meteorological community was alerted to Ångström’s result in a commentary appearing in the June, 1901 issue of Monthly Weather Review, which used the result to caution "geologists" against adhering to Arrhenius’ wild ideas.

 

Still more persuasive to scientists of the day was the fact that water vapor, which is far more abundant in the air than carbon dioxide, also intercepts infrared radiation. In the infrared spectrum, the main bands where each gas blocked radiation overlapped one another. How could adding CO₂ affect radiation in bands of the spectrum that H₂O (not to mention CO₂ itself) already made opaque? As these ideas spread, even scientists who had been enthusiastic about Arrhenius’s work decided it was in error. Work on the question stagnated. If there was ever an “establishment” view about the greenhouse effect, it was confidence that the CO₂ emitted by humans could not affect anything so grand as the Earth’s climate.

Nobody was interested in thinking about the matter deeply enough to notice the flaw in the argument. The scientists were looking at warming from ground level, so to speak, asking about the radiation that reaches and leaves the surface of the Earth. Like Ångström, they tended to treat the atmosphere overhead as a unit, as if it were a single sheet of glass. (Thus the “greenhouse” analogy.) But this is not how global warming actually works.

 

What happens to infrared radiation emitted by the Earth’s surface? As it moves up layer by layer through the atmosphere, some is stopped in each layer. To be specific: a molecule of carbon dioxide, water vapor or some other greenhouse gas absorbs a bit of energy from the radiation. The molecule may radiate the energy back out again in a random direction. Or it may transfer the energy into velocity in collisions with other air molecules, so that the layer of air where it sits gets warmer. The layer of air radiates some of the energy it has absorbed back toward the ground, and some upwards to higher layers. As you go higher, the atmosphere gets thinner and colder. Eventually the energy reaches a layer so thin that radiation can escape into space.

 

What happens if we add more carbon dioxide? In the layers so high and thin that much of the heat radiation from lower down slips through, adding more greenhouse gas molecules means the layer will absorb more of the rays. So the place from which most of the heat energy finally leaves the Earth will shift to higher layers. Those are colder layers, so they do not radiate heat as well. The planet as a whole is now taking in more energy than it radiates (which is in fact our current situation). As the higher levels radiate some of the excess downwards, all the lower levels down to the surface warm up. The imbalance must continue until the high levels get hot enough to radiate as much energy back out as the planet is receiving.

 

Any saturation at lower levels would not change this, since it is the layers from which radiation does escape that determine the planet’s heat balance. The basic logic was neatly explained by John Tyndall back in 1862: "As a dam built across a river causes a local deepening of the stream, so our atmosphere, thrown as a barrier across the terrestrial [infrared] rays, produces a local heightening of the temperature at the Earth’s surface."

 

Remember, the paper in the OP uses an overly simplistic two layer model - one layer for land adn ocean, one layer for atmosphere.  As I said earlier, this paper is junk.

[chrisf97212]

The OP paper hasn't been out long enough to have a formal rebuttal yet - and it's so weak that serious  climate scientists lakely won't waste time on it.  But here is a column on Realclimate.org [link] on an earlier attempt to make the same argument that CO2 is saturated.  An excerpt:

 

Some people have been arguing that simple physics shows there is already so much CO2 in the air that its effect on infrared radiation is "saturated"— meaning that adding more gas can make scarcely any difference in how much radiation gets through the atmosphere, since all the radiation is already blocked. And besides, isn’t water vapor already blocking all the infrared rays that CO2 ever would?

 

The arguments do sound good, so good that in fact they helped to suppress research on the greenhouse effect for half a century. In 1900, shortly after Svante Arrhenius published his pathbreaking argument that our use of fossil fuels will eventually warm the planet, another scientist, Knut Ångström, asked an assistant, Herr J. Koch, to do a simple experiment. He sent infrared radiation through a tube filled with carbon dioxide, containing somewhat less gas in total then would be found in a column of air reaching to the top of the atmosphere. That’s not much, since the concentration in air is only a few hundred parts per million. Herr Koch did his experiments in a 30cm long tube, though 250cm would have been closer to the right length to use to represent the amount of CO₂ in the atmosphere. Herr Koch reported that when he cut the amount of gas in the tube by one-third, the amount of radiation that got through scarcely changed. The American meteorological community was alerted to Ångström’s result in a commentary appearing in the June, 1901 issue of Monthly Weather Review, which used the result to caution "geologists" against adhering to Arrhenius’ wild ideas.

 

Still more persuasive to scientists of the day was the fact that water vapor, which is far more abundant in the air than carbon dioxide, also intercepts infrared radiation. In the infrared spectrum, the main bands where each gas blocked radiation overlapped one another. How could adding CO₂ affect radiation in bands of the spectrum that H₂O (not to mention CO₂ itself) already made opaque? As these ideas spread, even scientists who had been enthusiastic about Arrhenius’s work decided it was in error. Work on the question stagnated. If there was ever an “establishment” view about the greenhouse effect, it was confidence that the CO₂ emitted by humans could not affect anything so grand as the Earth’s climate.

Nobody was interested in thinking about the matter deeply enough to notice the flaw in the argument. The scientists were looking at warming from ground level, so to speak, asking about the radiation that reaches and leaves the surface of the Earth. Like Ångström, they tended to treat the atmosphere overhead as a unit, as if it were a single sheet of glass. (Thus the “greenhouse” analogy.) But this is not how global warming actually works.

 

What happens to infrared radiation emitted by the Earth’s surface? As it moves up layer by layer through the atmosphere, some is stopped in each layer. To be specific: a molecule of carbon dioxide, water vapor or some other greenhouse gas absorbs a bit of energy from the radiation. The molecule may radiate the energy back out again in a random direction. Or it may transfer the energy into velocity in collisions with other air molecules, so that the layer of air where it sits gets warmer. The layer of air radiates some of the energy it has absorbed back toward the ground, and some upwards to higher layers. As you go higher, the atmosphere gets thinner and colder. Eventually the energy reaches a layer so thin that radiation can escape into space.

 

What happens if we add more carbon dioxide? In the layers so high and thin that much of the heat radiation from lower down slips through, adding more greenhouse gas molecules means the layer will absorb more of the rays. So the place from which most of the heat energy finally leaves the Earth will shift to higher layers. Those are colder layers, so they do not radiate heat as well. The planet as a whole is now taking in more energy than it radiates (which is in fact our current situation). As the higher levels radiate some of the excess downwards, all the lower levels down to the surface warm up. The imbalance must continue until the high levels get hot enough to radiate as much energy back out as the planet is receiving.

 

Any saturation at lower levels would not change this, since it is the layers from which radiation does escape that determine the planet’s heat balance. The basic logic was neatly explained by John Tyndall back in 1862: "As a dam built across a river causes a local deepening of the stream, so our atmosphere, thrown as a barrier across the terrestrial [infrared] rays, produces a local heightening of the temperature at the Earth’s surface."

 

Remember, the paper in the OP uses an overly simplistic two layer model - one layer for land adn ocean, one layer for atmosphere.  As I said earlier, this paper is junk.

 

How does the tropospheric temperature record support this?

 

CO2 has increased enough to expect some sort of atmospheric response.