...

[skierinvermont]

Who said there would be an out of the ordinary OHC response to Pinatubo? I said the exact opposite. Surface temperatures, including SSTs, changed fast enough to bring us most of the way into equilibrium very quickly which is exactly why no large changes in OHC were observed. Yes it would take many centuries for 'pefect' equilibrium to be reached and all the feedbacks to play out. But the majority of equilibrium is achieved very quickly by rapid surface response (due to slow mixing). You're just proving my point. 

 

So, given the nearly 1C of surface warming since 1900, can you please give us a plausible explanation, other than positive radiative forcing, for why the earth is not losing heat at a rate of 3W/m2?

[skierinvermont]

You can't have it both ways. From 1946-1976, global temperatures dropped slightly despite increasing anthropogenic forcing, urban expansion, and an active solar component. If equilibrium were as rapid as you suggest, that should not have occurred. It can, however, be explained by an increase in oceanic mixing.

 

1. If the cause of the slight cooling in this period were increased ocean mixing there would have been an acceleration in the rate of OHC increase. The evidence points to the exact opposite. This period had the slowest rate of OHC increase in the 20th century.

 

2. Most reconstructions point to near-flat radiative forcing over this period due to a combination of increased volcanic activity, anthropogenic aerosols, and a weak solar cycle in the 70s.

[StudentOfClimatology]

Who said there would be an out of the ordinary OHC response to Pinatubo? I said the exact opposite. Surface temperatures, including SSTs, changed fast enough to bring us most of the way into equilibrium very quickly which is exactly why no large changes in OHC were observed. Yes it would take many centuries for 'pefect' equilibrium to be reached and all the feedbacks to play out. But the majority of equilibrium is achieved very quickly by rapid surface response. You're just proving my point.

Apparently I'm doing a poor job explaining this. Try reading the Cess/Goldenburg et al paper: The effect of ocean heat capacity upon global warming due to increasing atmospheric carbon dioxide

Here: http://onlinelibrary.wiley.com/doi/10.1029/JC086iC01p00498/abstract;jsessionid=DC048DFAED6BF27B7B67B223681535F4.f01t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false

So, given the nearly 1C of surface warming since 1900, can you please give us a plausible explanation, other than positive radiative forcing, for why the earth is not losing heat at a rate of 3W/m2?

No I can't? Radiative forcing is the reason for the warming we've seen, there is a scientific consensus here. I hope you're not one of those folks who thinks the Earth's core is to blame..

[StudentOfClimatology]

1. If the cause of the slight cooling in this period were increased ocean mixing there would have been an acceleration in the rate of OHC increase. The evidence points to the exact opposite. This period had the slowest rate of OHC increase in the 20th century.

We had essentially no viable measurement system during the early decades. So it's not really possible to draw that conclusion.

Furthermore, it was a period of very rapid sea level rise..suggesting the OHC measurements may be faulty.

2. Most reconstructions point to near-flat radiative forcing over this period due to a combination of increased volcanic activity, anthropogenic aerosols, and a weak solar cycle in the 70s.

Global sulfur emissions have increased and are a possible explanation for the recent warming slowdown, but production actually peaked in the early 1990s.

http://www.sciencedirect.com/science/article/pii/S1465997201000204

[skierinvermont]

We had essentially no viable measurement system during the early decades. So it's not really possible to draw that conclusion.

 

Global sulfur emissions have actually increased and are a possible explanation for the recent warming slowdown.

http://www.sciencedirect.com/science/article/pii/S1465997201000204

 

Most reconstructions of OHC go back to 1955 and we see there was very little increase in OHC from 1955-1975. In addition, sea level rise is a rough proxy for OHC and we know this was a period of slower SLR than the first half of the 20th century.

 

 

I am aware that recent increases in sulfur emissions are a possible cause of the current slowdown. We were discussing the period 1946-1976. What is the relevance of this?

 

Flat radiative forcing (due to aerosols, volcanoes, and TSI), not increased ocean mixing, are primarily responsible for the flat lie in global temperature 1946-76.

[skierinvermont]

Apparently I'm doing a poor job explaining this. Try reading the Cess/Goldenburg et al paper: The effect of ocean heat capacity upon global warming due to increasing atmospheric carbon dioxide

Here: http://onlinelibrary.wiley.com/doi/10.1029/JC086iC01p00498/abstract;jsessionid=DC048DFAED6BF27B7B67B223681535F4.f01t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false

No I can't? Radiative forcing is the reason for the warming we've seen, there is a scientific consensus here. I hope you're not one of those folks who thinks the Earth's core is to blame..

 

Good. So we finally agree. Surface and OHC observations over the 20th century necessarily demonstrate rising radiative forcing.

 

This was my original statement. 

 

To which you responded "not necessarily."

[StudentOfClimatology]

Good. So we finally agree. Surface and OHC observations over the 20th century necessarily demonstrate rising radiative forcing.

This was my original statement.

To which you responded "not necessarily."

I said the radiative forcing is not required to be "ever increasing" in trend. There just has to be an imbalance between incoming and outgoing radiation.

[skierinvermont]

I said the radiative forcing is not required to be "ever increasing" in trend. There just has to be an imbalance between incoming and outgoing radiation.

 

And if surface temperatures rose 1C (which they did) this balance would be reversed and become strongly negative. Which it did not. Which indicates that radiative forcing continued to increase. 

[StudentOfClimatology]

Most reconstructions of OHC go back to 1955 and we see there was very little increase in OHC from 1955-1975. In addition, sea level rise is a rough proxy for OHC and we know this was a period of slower SLR than the first half of the 20th century.

The peer reviewed reconstructions I know of suggest a rapid rise from 1940-1960:

http://academics.eckerd.edu/instructor/hastindw/MS1410-001_FA08/handouts/2008SLRSustain.pdf

http://m.geology.gsapubs.org/content/37/12/1115.abstract

http://www.ocean-sci.net/5/193/2009/os-5-193-2009.pdf

http://www.pol.ac.uk/psmsl/author_archive/jevrejeva_etal_1700/2008GL033611.pdf

http://onlinelibrary.wiley.com/doi/10.1029/2009GL038720/abstract

http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2985.1

[StudentOfClimatology]

And if surface temperatures rose 1C (which they did) this balance would be reversed and become strongly negative.

Which it did not. Which indicates that radiative forcing continued to increase.

We won't know what the actual imbalance is until the RAVAN project is launched in 2015. We can interpolate from the CERES/AIRS data, but that is far from conclusive.

[skierinvermont]

The peer reviewed reconstructions I know of suggest a rapid rise from 1940-1960:

http://academics.eckerd.edu/instructor/hastindw/MS1410-001_FA08/handouts/2008SLRSustain.pdf

http://m.geology.gsapubs.org/content/37/12/1115.abstract

http://www.ocean-sci.net/5/193/2009/os-5-193-2009.pdf

http://www.pol.ac.uk/psmsl/author_archive/jevrejeva_etal_1700/2008GL033611.pdf

http://onlinelibrary.wiley.com/doi/10.1029/2009GL038720/abstract

http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2985.1

 

Except the cut off is 1946 and much of the SLR occurred 1940-1946. SLR 1946-1976 is slower than 1976-present and slower than than 1920-1946. If radiative forcing was rising 1946-76 at the same rate it was before and after, and increased ocean mixing were responsible for the absence of surface temperature increase, then the rate of OHC uptake (and thus SLR) should have doubled or tripled in this period. It did not. The evidence we have points to the opposite (a slower increase). And the evidence also points to a lack of increase in radiative forcing in this period. Two independent lines of evidence point to a lack of increase in radiative forcing during this period. Both independent lines of evidence (slow OHC increase and radiative forcing calculations) point against ocean overturning (the PDO) being the primary driver of surface cooling in this period. 

[skierinvermont]

We won't know what the actual imbalance is until the RAVAN project is launched in 2015. We can interpolate from the CERES/AIRS data, but that is far from conclusive.

 

Numerous peer reviewed papers, largely based on OHC, already estimate the imbalance near .5W/m2 with a high degree of confidence. RAVAN is not necessary to estimate the net energy balance. Perhaps it can yield an even more precise/accurate estimate, but I am not familiar with it. 

 

Again, I repeat, the 1C of surface temperature increase and positive energy imbalance demonstrate that there has been ever increasing radiative forcing. If there were not, the current energy imbalance would be -3W/m2 and the oceans and atmosphere would be cooling rapidly (losing net heat at a rate of 24 hiroshima bombs per second). 

 

OHC and surface temperatures cannot rise without ever increasing radiative forcing. This was my original statement and it is a valid one.

[StudentOfClimatology]

Numerous peer reviewed papers, largely based on OHC, already estimate the imbalance near .5W/m2 with a high degree of confidence. RAVAN is not necessary to estimate the net energy balance. Perhaps it can yield an even more precise/accurate estimate, but I am not familiar with it.

That has been rendered pure speculation, as the most recent publications on this matter fail to reach a conclusion..read below.

Recently published papers offering very different conclusions in this arena:

http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2637.1

Toward Optimal Closure of the Earth's Top-of-Atmosphere Radiation Budget

Norman G. Loeb,* Bruce A. Wielicki,* David R. Doelling,ast; G. Louis Smith,+ Dennis F. Keyes,# Seiji Kato,* Natividad Manalo-Smith,# and Takmeng Wong*

[...]

Despite recent improvements in satellite instrument calibration and the algorithms used to determine reflected solar (SW) and emitted thermal (LW) top-of-atmosphere (TOA) radiative fluxes, a sizeable imbalance persists in the average global net radiation at the TOA from satellite observations. This imbalance is problematic in applications that use earth radiation budget (ERB) data for climate model evaluation, estimate the earth’s annual global mean energy budget, and in studies that infer meridional heat transports. This study provides a detailed error analysis of TOA fluxes based on the latest generation of Clouds and the Earth’s Radiant Energy System (CERES) gridded monthly mean data products [the monthly TOA/surface averages geostationary (SRBAVG-GEO)] and uses an objective constrainment algorithm to adjust SW and LW TOA fluxes within their range of uncertainty to remove the inconsistency between average global net TOA flux and heat storage in the earth–atmosphere system. The 5-yr global mean CERES net flux from the standard CERES product is 6.5 W m−2, much larger than the best estimate of 0.85 W m−2 based on observed ocean heat content data and model simulations. The major sources of uncertainty in the CERES estimate are from instrument calibration (4.2 W m−2) and the assumed value for total solar irradiance (1 W m−2). After adjustment, the global mean CERES SW TOA flux is 99.5 W m−2, corresponding to an albedo of 0.293, and the global mean LW TOA flux is 239.6 W m−2. These values differ markedly from previously published adjusted global means based on the ERB Experiment in which the global mean SW TOA flux is 107 W m−2 and the LW TOA flux is 234 W m−2.

Another paper below:

Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty

Norman G. Loeb, John M. Lyman, Gregory C. Johnson, Richard P. Allan, David R. Doelling, Takmeng Wong, Brian J. Soden & Graeme L. Stephens

http://www.nature.com/ngeo/journal/v5/n2/full/ngeo1375.html

Global climate change results from a small yet persistent imbalance between the amount of sunlight absorbed by Earth and the thermal radiation emitted back to space1. An apparent inconsistency has been diagnosed between interannual variations in the net radiation imbalance inferred from satellite measurements and upper-ocean heating rate from in situ measurements, and this inconsistency has been interpreted as ‘missing energy’ in the system2. Here we present a revised analysis of net radiation at the top of the atmosphere from satellite data, and we estimate ocean heat content, based on three independent sources. We find that the difference between the heat balance at the top of the atmosphere and upper-ocean heat content change is not statistically significant when accounting for observational uncertainties in ocean measurements3, given transitions in instrumentation and sampling. Furthermore, variability in Earth’s energy imbalance relating to El Niño-Southern Oscillation is found to be consistent within observational uncertainties among the satellite measurements, a reanalysis model simulation and one of the ocean heat content records. We combine satellite data with ocean measurements to depths of 1,800 m, and show that between January 2001 and December 2010, Earth has been steadily accumulating energy at a rate of 0.50±0.43 Wm−2 (uncertainties at the 90% confidence level). We conclude that energy storage is continuing to increase in the sub-surface ocean.

Here are the details of the RAVAN project:

http://www.sciencedaily.com/releases/2013/12/131210113317.htm

http://www.jhuapl.edu/newscenter/pressreleases/2013/131210.asp

RAVAN to Help Solve an Earth Science Mystery

A new, low-cost cubesat mission led by the Johns Hopkins Applied Physics Laboratory in Laurel, Md. will demonstrate technology needed to measure the absolute imbalance in Earth's radiation budget for the first time, giving scientists valuable information to study our climate.

RAVAN will use a small, accurate radiometer, developed at L-1 Standards and Technology and not much larger than a deck of cards, to measure the strength of Earth's outgoing radiation across the entire spectrum of energy -- from the ultraviolet to the far infrared. "ERI is too small to be measured by previous, current, or planned future space assets," says co-investigator Warren Wiscombe, a climate scientist at Goddard.

The secret to RAVAN's precise measurements is a "forest" of carbon nanotubes, grown at APL, that serve as the radiometer's light absorber. "The carbon nanotubes are a very deep black across the energy spectrum, which will let the radiometer gather virtually all the light reflected and emitted from the planet," says Swartz.

RAVAN represents the first step toward a constellation of cubesats, each no larger than a loaf of bread, that would provide global coverage of Earth's total outgoing radiation throughout the day and night, and data to answer long-standing questions about Earth's climate future.

This will essentially be an ARGO-style cube-sat constellation. We will know exactly what the contributing factors to the imbalance are, and will be able to determine feedback responses as well.

Again, I repeat, the 1C of surface temperature increase and positive energy imbalance demonstrate that there has been ever increasing radiative forcing. If there were not, the current energy imbalance would be -3W/m2 and the oceans and atmosphere would be cooling rapidly (losing net heat at a rate of 24 hiroshima bombs per second).

Yes, a radiative imbalance is required. The forcing behind it does not have to be "ever increasing".

http://onlinelibrary.wiley.com/doi/10.1029/JC086iC01p00498/abstract;jsessionid=DC048DFAED6BF27B7B67B223681535F4.f01t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false

Time-dependent global warming due to increasing levels of atmospheric carbon dioxide has been estimated by employing an ocean-land global climate model. Ocean heat capacity is incorporated by means of a global ocean model having a 70 m deep mixed layer, with heat being transported from the mixed layer to deeper waters by eddy diffusion. The time-dependent increase in atmospheric CO2, from 1860 to 2025, is taken from carbon-cycle models. The model results suggest that ocean heat capacity will produce a lag in CO2-induced global warming of about 2 decades. For example, without inclusion of ocean heat capacity the model predicts that an increase in global surface temperature of 1°C, relative to 1860, will occur by 1988. But when ocean heat capacity is included, the 1°C warming is delayed until 2006–2012, this range of times corresponding to no land-ocean advective coupling (2006) and complete land-ocean coupling (2012). By 2025, when the assumed atmospheric CO2 content is twice the 1860 value, the model predicts global warming of 1.5°–1.8°C, in contrast to 3.1°C when ocean heat capacity is neglected.

OHC and surface temperatures cannot rise without ever increasing radiative forcing. This was my original statement and it is a valid one.

No, it isn't.

[StudentOfClimatology]

Except the cut off is 1946 and much of the SLR occurred 1940-1946. SLR 1946-1976 is slower than 1976-present and slower than than 1920-1946. If radiative forcing was rising 1946-76 at the same rate it was before and after, and increased ocean mixing were responsible for the absence of surface temperature increase, then the rate of OHC uptake (and thus SLR) should have doubled or tripled in this period. It did not. The evidence we have points to the opposite (a slower increase). And the evidence also points to a lack of increase in radiative forcing in this period. Two independent lines of evidence point to a lack of increase in radiative forcing during this period. Both independent lines of evidence (slow OHC increase and radiative forcing calculations) point against ocean overturning (the PDO) being the primary driver of surface cooling in this period.

Please read the peer-reviewed research paper(s) I linked to you:

http://www.nature.com/nclimate/journal/v1/n7/abs/nclimate1229.html

Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods

There was no statistically significant reduction in SLR between 1946-1976. The SLR data is much more reliable during the 1946-1976 period than the OHC recons, for obvious reasons. We had no measurement system capable of adequately analyzing OHC or the TOA radiation budget during that time period. I'm not sure how much clearer I can make this.

I also don't see how the PDO is relevant here. I personally don't believe it has anything to do with climate change.

[skierinvermont]

 

Yes, a radiative imbalance is required. The forcing behind it does not have to be "ever increasing".
 

 

 

 

Except if surface temperatures rise, which they did, then the radiative imbalance would be eliminated. If surface temperatures rise, which they did, there must be a further increase in radiative forcing to maintain the "radiative imbalance."

 

If the surface temperature of the earth increases even just .1C and all else remains constant, the earth radiates energy to space at a much faster rate. This would cause the net energy imbalance to revert to zero (or become negative) unless there was a further increase in radiative forcing to cause the next .1C of warming.. and the next .1C .. and the next.

 

 

You seem to be hammering on the point that the deep oceans take a very long time (probably hundreds if not thousands of years) to reach equilibrium. As such surface temperatures will not rise 100% and the earth will remain in a net energy imbalance until the oceans have reached equilibrium. I fully understand this rather obvious point, and nothing I have said contradicts it. 

 

Again, you seem to completely fail to grasp the fact that when surface temperatures change, they have a massive impact on the net energy balance of the earth. 

 

Surface temperatures cannot rise simultaneous with rising OHC without ever increasing radiative forcing. Without ever increasing radiative forcing, rising surface temperatures would cause a large increase in surface radiation to space and for the thermal budget of the earth to become negative. 

[StudentOfClimatology]

Except if surface temperatures rise, which they did, then the radiative imbalance would be eliminated. If surface temperatures rise, which they did, there must be a further increase in radiative forcing to maintain the "radiative imbalance."

If the surface temperature of the earth increases even just .1C and all else remains constant, the earth radiates energy to space at a much faster rate. This would cause the net energy imbalance to revert to zero (or become negative) unless there was a further increase in radiative forcing to cause the next .1C of warming.. and the next .1C .. and the next.

You seem to be hammering on the point that the deep oceans take a very long time (probably hundreds if not thousands of years) to reach equilibrium. As such surface temperatures will not rise 100% and the earth will remain in a net energy imbalance until the oceans have reached equilibrium. I fully understand this rather obvious point, and nothing I have said contradicts it.

Again, you seem to completely fail to grasp the fact that when surface temperatures change, they have a massive impact on the net energy balance of the earth.

Surface temperatures cannot rise simultaneous with rising OHC without ever increasing radiative forcing. Without ever increasing radiative forcing, rising surface temperatures would cause a large increase in surface radiation to space and for the thermal budget of the earth to become negative.

You get your atmospheric warming as the planetary surface (land+ocean) warms, and conducts to the atmosphere. Not the other way around. This is why variations in SSTs lead atmospheric temperatures. The atmosphere won't reach equilibrium until the upper oceanic mixing layer has achieved it first. This is a gradual, prolonged response, as is recognized all throughout climate science (see below).

The world of peer reviewed literature reached a consensus on this matter long ago..see below:

http://onlinelibrary.wiley.com/doi/10.1029/90JC02738/abstract

A zonal-averaged model of the ocean's response to climatic change

A new vertical mixing model is described. It combines a box-advection-diffusion model with a bulk mixed layer model, which simulates wind mixing and penetrative convection. It is shown that mixed layer models can have steady periodic solutions if either the mixing decays to zero at depth or vertical advection is included. The latter approach is adopted. This mixing model is applied to a series of latitude bands between 50°N and 50°S. It successfully simulates present-day seasonal cycles of temperature and mixed layer depth. It is then subjected to an additional heat flux resulting from an increase in greenhouse gases. For an equilibrium warming of 3°C for CO2 doubling, the model predicts the following transient response: a 0.5–0.8°C temperature rise from 1850 to 1990, and a 1.5–2.0°C rise from 1850 to 2050. The ocean acts as a thermal buffer, so that the actual warming lags the equilibrium warming by 25–50 years. Mixed layer and deep ocean contribute about equally to this lag. The seasonal cycle of mixed layer depth pumps more heat down to deeper waters, compared to a fixed mixed layer depth model. The heat uptake depends strongly on possible changes in the global thermohaline circulation, which could therefore affect sea level predictions. The climatic warming also leads to a reduction in winter mixing depth in the higher latitudes, whereas the mixing depth in other seasons and latitudes would be mainly affected by wind changes. A scenario for reduced CO2 emissions shows that the surface warming can be slowed dramatically but that a long-term sea level rise from thermal expansion may be inevitable.

http://link.springer.com/article/10.1007%2FBF02919265

Effect of ocean thermal diffusivity on global warming induced by increasing atmospheric CO2

A global mean ocean model including atmospheric heating, heat capacity of the mixed layer ocean, and vertical thermal diffusivity in the lower ocean, proposed by Cess and Goldenberg (1981), is used in this paper to study the sensitivity of global warming to the vertical diffusivity. The results suggest that the behaviour of upper ocean temperature is mainly determined by the magnitude of upper layer diffusivity and an ocean with a larger diffusivity leads to a less increase of sea surface temperature and a longer time delay for the global warming induced by increasing CO2 than that with smaller one. The global warming relative to four scenarios of CO2 emission assumed by Intergovernmental Panel of Climate Change (IPCC) is also estimated by using the model with two kinds of thermal diffusivities. The result shows that for various combinations of the CO2 emission scenarios and the diffusivities, the oceanic time delay to the global warming varies from 15 years to 70 years.

[skierinvermont]

You get your atmospheric warming as the planetary surface (land+ocean) warms, and conducts to the atmosphere. Not the other way around. This is why variations in SSTs lead atmospheric temperatures. The atmosphere won't reach equilibrium until the upper oceanic mixing layer has achieved it first. This is a gradual, prolonged response, as is recognized all throughout climate science (see below).

The world of peer reviewed literature reached a consensus on this matter long ago..see below:

http://onlinelibrary.wiley.com/doi/10.1029/90JC02738/abstract

A zonal-averaged model of the ocean's response to climatic change

A new vertical mixing model is described. It combines a box-advection-diffusion model with a bulk mixed layer model, which simulates wind mixing and penetrative convection. It is shown that mixed layer models can have steady periodic solutions if either the mixing decays to zero at depth or vertical advection is included. The latter approach is adopted. This mixing model is applied to a series of latitude bands between 50°N and 50°S. It successfully simulates present-day seasonal cycles of temperature and mixed layer depth. It is then subjected to an additional heat flux resulting from an increase in greenhouse gases. For an equilibrium warming of 3°C for CO2 doubling, the model predicts the following transient response: a 0.5–0.8°C temperature rise from 1850 to 1990, and a 1.5–2.0°C rise from 1850 to 2050. The ocean acts as a thermal buffer, so that the actual warming lags the equilibrium warming by 25–50 years. Mixed layer and deep ocean contribute about equally to this lag. The seasonal cycle of mixed layer depth pumps more heat down to deeper waters, compared to a fixed mixed layer depth model. The heat uptake depends strongly on possible changes in the global thermohaline circulation, which could therefore affect sea level predictions. The climatic warming also leads to a reduction in winter mixing depth in the higher latitudes, whereas the mixing depth in other seasons and latitudes would be mainly affected by wind changes. A scenario for reduced CO2 emissions shows that the surface warming can be slowed dramatically but that a long-term sea level rise from thermal expansion may be inevitable.

http://link.springer.com/article/10.1007%2FBF02919265

Effect of ocean thermal diffusivity on global warming induced by increasing atmospheric CO2

A global mean ocean model including atmospheric heating, heat capacity of the mixed layer ocean, and vertical thermal diffusivity in the lower ocean, proposed by Cess and Goldenberg (1981), is used in this paper to study the sensitivity of global warming to the vertical diffusivity. The results suggest that the behaviour of upper ocean temperature is mainly determined by the magnitude of upper layer diffusivity and an ocean with a larger diffusivity leads to a less increase of sea surface temperature and a longer time delay for the global warming induced by increasing CO2 than that with smaller one. The global warming relative to four scenarios of CO2 emission assumed by Intergovernmental Panel of Climate Change (IPCC) is also estimated by using the model with two kinds of thermal diffusivities. The result shows that for various combinations of the CO2 emission scenarios and the diffusivities, the oceanic time delay to the global warming varies from 15 years to 70 years.

 

This is well known basic stuff and doesn't contradict anything I've said. 

[StudentOfClimatology]

This is well known basic stuff and doesn't contradict anything I've said.

Then what do we disagree on? The thermal response to a radiative forcing is prolonged due to the thermal inertia of the oceans. It does not take 1-2 years. This is why we already have additional anthropogenic warming "locked in" down the pipeline.

[A-L-E-K]

so it's cool that bethesda boy is back?

[LakeEffectKing]

 

so it's cool that bethesda boy is back?

You are a super sleuth!!! Now, to answer you question....who cares.

[Jonger]

so it's cool that bethesda boy is back?

if so, he must have several unbanned login names.m, because about 4 posters have been link to bethesdaboy in the past year.

[TerryM]

so it's cool that bethesda boy is back?

Soc has a more  authentic ring than BB

Terry

[skierinvermont]

Then what do we disagree on? The thermal response to a radiative forcing is prolonged due to the thermal inertia of the oceans. It does not take 1-2 years. This is why we already have additional anthropogenic warming "locked in" down the pipeline.

 

And I never said otherwise. You were the one who 'disagreed' with me but then never really said anything that contradicted me other than saying "no."

[The_Global_Warmer]

 

You are a super sleuth!!! Now, to answer you question....who cares.

 

 

If you care about keeping the discussion honest you should.   It's not about him being a "skeptic". He ruins the forum.  Just like Yetterbium. 

[StudentOfClimatology]

And I never said otherwise. You were the one who 'disagreed' with me but then never really said anything that contradicted me other than saying "no."

Weren't you arguing that the ocean-atmosphere system should only take 1-2 years to largely equilibrate to CO2 forcing?

The majority of the surface temperature response to a sudden 1W/m2 forcing would probably take place within a few years.

The peer reviewed literature comes to a different conclusion.

Bao Ning, Zhang Xuehong et al:

Effect of ocean thermal diffusivity on global warming induced by increasing atmospheric CO2: http://link.springer.com/article/10.1007%2FBF02919265

The ocean acts as a thermal buffer, so that the actual warming lags the equilibrium warming by 25–50 years

If I'm misinterpreting your argument, I apologize.

[skierinvermont]

Weren't you arguing that the ocean-atmosphere system should only take 1-2 years to largely equilibrate to CO2 forcing?

The peer reviewed literature comes to a different conclusion.

Bao Ning, Zhang Xuehong et al:

Effect of ocean thermal diffusivity on global warming induced by increasing atmospheric CO2: http://link.springer.com/article/10.1007%2FBF02919265

If I'm misinterpreting your argument, I apologize.

 

The majority (>50%) of the surface temperature response would take place within a couple years. This doesn't mean the earth is in equilibrium or will be any time soon. The earth would still take several hundred years at least to reach an energy balance. 

 

 

A practical example:

 

Say earth is in balance and CO2 is 300ppm. There is a sudden one time increase in CO2 enough to cause 2W/m2 and CO2 is held at this level. On day one the imbalance is 2W/m2. Within a couple years the surface temperature would likely rise maybe .4C thereby cutting the energy imbalance to .7W/m2. Within 10 years maybe the temperature has risen .5C total and the remaining imbalance is .5W/m2. But after that the earth would remain in a very slowly decreasing energy imbalance with very slowly rising surface temperatures as the deep oceans warmed. 

[StudentOfClimatology]

The majority (>50%) of the surface temperature response would take place within a couple years. This doesn't mean the earth is in equilibrium or will be any time soon. The earth would still take several hundred years at least to reach an energy balance. 

 

 

A practical example:

 

Say earth is in balance and CO2 is 300ppm. There is a sudden one time increase in CO2 enough to cause 2W/m2 and CO2 is held at this level. On day one the imbalance is 2W/m2. Within a couple years the surface temperature would likely rise maybe .4C thereby cutting the energy imbalance to .7W/m2. Within 10 years maybe the temperature has risen .5C total and the remaining imbalance is .5W/m2. But after that the earth would remain in a very slowly decreasing energy imbalance with very slowly rising surface temperatures as the deep oceans warmed.

I see what you're saying, and you're correct that the thermal response to a radiative forcing will manifest logarithmically given we're dealing with two coupled fluid bodies. However, the majority of the peer reviewed literature suggests that the initial response will take a few decades, not a few years, when dealing with lower frequency radiation. For the initial response to take 1-2 years, the oceanic mixing layer would have to be exceptionally shallow.

http://m.sciencemag.org/content/308/5727/1431.short

Earth's Energy Imbalance: Confirmation and Implications

http://journals.ametsoc.org/doi/abs/10.1175/1520-0485(1990)020%3C0722:TROAGO%3E2.0.CO%3B2

Transient Response of a Global Ocean-Atmosphere Model to a Doubling of Atmospheric Carbon Dioxide

To answer this question due account must be taken of oceanic thermal inertia effects, which can significantly slow the response of the climate system to external forcing. The main controlling parameters are the effective diffusivity of the ocean below the upper mixed layer (κ) and the climate sensitivity (defined by Δ T 2×). Previous analyses of this problem have considered only limited ranges of these parameters. Here we present a more general analysis of two cases, forcing by a step function change in CO2 concentration and by a steady CO2 increase. The former case may be characterized by a response time which we show is strongly dependent on both κ and Δ T 2×. In the latter case the damped response means that, at any given time, the climate system may be quite far removed from its equilibrium with the prevailing CO2 level. In earlier work this equilibrium has been expressed as a lag time, but we show this to be misleading because of the sensitivity of the lag to the history of past CO2 variations. Since both the lag and the degree of disequilibrium are strongly dependent on κ and Δ T 2×, and because of uncertainties in the pre-industrial CO2 level, the observed global warming over the past 100 years can be shown to be compatible with a wide range of CO2-doubling temperature changes.

[skierinvermont]

I see what you're saying, and you're correct that the thermal response to a radiative forcing will manifest logarithmically given we're dealing with two coupled fluid bodies. However, the majority of the peer reviewed literature suggests that the initial response will take a few decades, not a few years, when dealing with lower frequency radiation. For the initial response to take 1-2 years, the oceanic mixing layer would have to be exceptionally shallow.

http://m.sciencemag.org/content/308/5727/1431.short

Earth's Energy Imbalance: Confirmation and Implications

http://journals.ametsoc.org/doi/abs/10.1175/1520-0485(1990)020%3C0722:TROAGO%3E2.0.CO%3B2

Transient Response of a Global Ocean-Atmosphere Model to a Doubling of Atmospheric Carbon Dioxide

 

 

This doesn't contradict what I said. And you already quoted a paper which seems to corroborate what I said. Another paper you posted said that the earth can reach 70% of equilibrium within 2-10 years. This seems fairly consistent with reaching >50% of equilibrium within 2 years, as I suggested. 

[StudentOfClimatology]

This doesn't contradict what I said. And you already quoted a paper which seems to corroborate what I said. Another paper you posted said that the earth can reach 70% of equilibrium within 2-10 years. This seems fairly consistent with reaching >50% of equilibrium within 2 years, as I suggested.

I'm not sure what you're quoting, but you initially proposed a thermal response of 95% over 1-2 years. No offense, but that sounds like something an unqualified blogger would write. The peer reviewed literature suggests a gradual response over multiple decades, as a result of the oceans' thermal inertia.

It is physically impossible to warm the oceans to near-equilibrium within a few years. The oceans are 1-2k warmer than the bulk SAT to begin with.

http://m.sciencemag.org/content/307/5716/1766.short

Even if atmospheric composition were fixed today, global-mean temperature and sea level rise would continue due to oceanic thermal inertia. These constant-composition (CC) commitments and their uncertainties are quantified. Constant-emissions (CE) commitments are also considered. The CC warming commitment could exceed 1°C. The CE warming commitment is 2° to 6°C by the year 2400. For sea level rise, the CC commitment is 10 centimeters per century (extreme range approximately 1 to 30 centimeters per century) and the CE commitment is 25 centimeters per century (7 to 50 centimeters per century). Avoiding these changes requires, eventually, a reduction in emissions to substantially below present levels. For sea level rise, a substantial long-term commitment may be impossible to avoid.

http://onlinelibrary.wiley.com/doi/10.1029/2000GL011786/abstract

Committed warming and its implications for climate change

Time lags between changes in radiative forcing and the resulting simulated climate responses are investigated in a set of transient climate change experiments. Both surface air temperature (SAT) and soil moisture responses are examined. Results suggest that if the radiative forcing is held fixed at today's levels, the global mean SAT will rise an additional 1.0K before equilibrating. This unrealized warming commitment is larger than the 0.6K warming observed since 1900. The coupled atmosphere-ocean GCM's transient SAT response for the year 2000 is estimated to be similar to its equilibration response to 1980 radiative forcings— a lag of ∼20 years. Both the time lag and the warming commitment are projected to increase in the future, and depend on the model‧s climate sensitivity, oceanic heat uptake, and the forcing scenario. These results imply that much of the warming due to current greenhouse gas levels is yet to be realized

[skierinvermont]

I'm not sure what you're quoting, but you initially proposed a thermal response of 95% over 1-2 years. No offense, but that sounds like something an unqualified blogger would write. The peer reviewed literature suggests a gradual response over multiple decades, as a result of the oceans' thermal inertia.

It is physically impossible to warm the oceans to near-equilibrium within a few years. The oceans are 1-2k warmer than the bulk SAT to begin with.

http://m.sciencemag.org/content/307/5716/1766.short

http://onlinelibrary.wiley.com/doi/10.1029/2000GL011786/abstract

 

 

I did not say this '95% in 1-2 year'. Please quote. This is a lie.

 

It is not necessary for the oceans to come anywhere near equilibrium temperature in order for surface temperature to become near equilibrium temperature. It is only necessary for SSTs to warm the majority of the way to what they will reach at full equilibrium (which could take many centuries).