800,000 Hiroshima Bombs per Day

[jai mitchell]

I posted this today over at the Daily Kos, http://www.dailykos.com/story/2015/03/15/1370965/-The-World-is-Set-for-Rapid-Warming

In February 2012, renowned climate scientist James Hansen gave a TED talk.  In it he shocked the world by explaining how global warming was heating planet Earth on a scale that was equal to 400,000 Hiroshima atomic bombs every day!  However, recent work by several scientists has shown that his estimates were significantly understated.  And the heat rate is going up much faster than we thought!

In it I assert that our current top of atmosphere radiative energy imbalance is now 1.2 Watts per Meter squared.  This is double the amount estimated by Hansen and Sato in 2010 for an average value that was reached sometime around 2007 (see attached graphic).

Please review the diary and let me know what you think.  I am certain that we will be experiencing rapid warming in the near future and that even this rapid warming will not be enough to reduce the trajectory of the top of atmosphere heat accumulation. 

This is especially true once the arctic summer sea ice is melted out completely and economic collapse and/or Chinese pollution controls reduce the cooling effect of the atmospheric aerosol loading forcing factor by 50%

[wili]

Thanks for this, jm. In the first paragraph after the Chinese video you say: "The studies show that the cooling factor from Chinese smokestack pollution could be as much as 800,000 ANTI-Hiroshima bombs per day!"

Did you mean "400,000 Anti-Hiroshima bombs"? If not, I don't follow your maths.

And when you say we're still back in 2007 as far as realized warming, I wonder if you need to be a  bit clearer on what that means.

[jai mitchell]

Thank you for your response Wili!

800,000 Hiroshima bombs per day is the equivalent of 1.2 Watts per meter squared Top of Atmosphere energy imbalance.

According to the AR5 forcing diagram, the potential negative forcing from Aerosols is -2.1 Watts per Meter Squared. 

I am taking a very strong stance that the East Asian aerosol effects are driving most of the change we have been seeing in the last 5 years with regard to regional pattern shifts.  Mostly due to regional influence on the West Pacific, inducing a negative PDO phase, but also the blocking pattern in Northern California, leading to cloudier and more turbulent arctic activity as well as the standing wave pattern that makes the Eastern Half of the U.S. so cold this winter.

note: as well as influencing cloudiness patterns in the arctic and reducing early melt pond formation and suppressing sea ice loss recently, as shown on this thread:  https://forum.arctic-sea-ice.net/index.php/topic,784.0.html

Now these observations are not wholly due to Chinese aerosols, they are also due to the increased (locked-in) forcing from about 10 years ago as CO2 emissions began to ramp up at three times its previous rate in 2003.  So the regional negative effect from Chinese Aerosols is around -1.2 watts per meter squared or 800,000 ANTI-Hiroshima nuclear bombs per day!



the 2007 effect is due to the slow increase in secondary forcing effects of CO2 emissions, such as increased water vapor feedbacks.  The CO2 forcing parameter is only about 10% of the total emissions related forcing per unit of CO2, as CO2 warms the earth then other things happen causing additional forcing. 

According to the Caldeira paper I quoted the peak forcing effect is not reached until about 10 years after the emissions.   Since there is some ramp up associated with reaching the peak, I estimate that our current forcing effects are responding at the 2007 level of GHG abundances.  So the forcing parameters will continue to increase and every amount of SO2 that China scrubs from their smokestacks, refines out of their liquid fuels (they are currently VERY dirty) and any reduction in the amount of  sulfate-laden coal, either due to economic slowdown or fuel switching, will lead to additional increased forcing.  If ALL Chinese aerosols suddenly stopped being emitted, the effect on the earth would be to DOUBLE the current radiative forcing parameter experienced at the Top of Atmosphere (to 1,600,000 Hiroshima bombs per day, or 4 times Hansen & Sato's 2010 estimate, or 2.4 Watts per meter squared TOA, whichever you prefer.

[wili]

Thanks, jai, but I'm still confused:

"800,000 Hiroshima bombs per day is the equivalent of 1.2 Watts per meter squared Top of Atmosphere energy imbalance.

According to the AR5 forcing diagram, the potential negative forcing from Aerosols is -2.1 Watts per Meter Squared. "

Shouldn't that mean that the earth should be undergoing net cooling??

[jai mitchell]

No, 

The top of atmosphere imbalance is the net value.  the current 800,000 value is what is left over after subtracting the 800,000 from china. 

understand?

if not

http://edberry.com/SiteDocs/2011/01/Bryce3.jpg

[wili]

No, I'm still not following.

To get 800,000 after subtracting 800,000, you have to have started at 1,600,000.

But I don't see that figure in your essay.

I don't want to belabor it, but may I just suggest that if I am having a bit of trouble following your logic and maths, others may find it hard to do so, too. (Of course, it is always possible that I am just the dullest damn tool in the whole darn shed!  )

 Something to consider if you are going to publish your insights elsewhere.

[Laurent]

I don't understand either if that can reassure you wili. 

[jai mitchell]

hmmm

This is interesting, I suppose that I could say something like:

The balance of energy being received by the earth and leaving the earth can be measured at the surface boundary of the atmosphere.  Just as with any object, if more energy enters the boundary than leaves the boundary, that object will heat up.   If we neglect the heat energy produced by natural radioactivity and waste heat from human activities (both negligibly small in comparison to global warming) we have 3 primary forces that control the amount of energy reaching the boundary surface of the atmosphere.  These three forces are the sun (incoming energy) and reflected sunlight and infrared radiation (both leaving the earth). 

Currently, the amount of additional reflected energy from Chinese aerosol emissions, the high altitude haze and extra reflectivity of clouds that the tiny aerosol particulates cause, is reflecting an additional 1.2 Watts per meter squared over the surface of the entire earth, however, the majority of these effects are measured in the northern hemisphere with measurements taken in the late 1990's in china showing a reduction of 30 watts per meter squared in the north east.  (their pollution levels have tripled since then) 

So then, the amount of actual heat energy that would be measured at the top of the atmosphere if there was NO Chinese pollution would be 2.4 watts per meter squared, averaged over the entire surface of the earth.  this is equal to 1,600,000 Hiroshima bombs going off every day!  This is twice the amount that is currently being felt by the earth (since the other half is being reflected away) and 4 times the amount that James Hansen claimed to be going into the earth at the top of the atmosphere during his 2012 TED talk (when he related the average value of warming that was occurring based on his measurements in Hansen & Sato (2010) which had an average value date of 2007.

better?

[Buddy]

Yes.....better. 

[crandles]

Clearer, but perhaps you might not want to appear to say Hansen got it so far wrong as a factor of 4.

To what extent are you saying he got it right at the time but forcing has increased since then versus  to what extent was there an underestimate at the time versus any change in basis of the calculation?

Otherwise you end up with a reaction of: OMG 4 times the value, climate scientists don't know what they are doing, we shouldn't listen to them type of reaction.

[jai mitchell]

Hmmm


I think I see what is going on here.  I posted the graph and it isn't as clear as it should be.

I suppose a better way to say it would be

China has significantly increased its smokestack pollution this last decade and that pollution is working to cool the planet.  In 2012 James Hansen stated that, in 2007, the amount of global warming was equal to 400,000 Hiroshima bombs per day.

Since we have not slowed down our carbon emissions since then, and due to a 10-year lag time for the heating of CO2 to take effect, the amount of global warming today is much higher than it was in 2007.  In fact, recent work by climate scientists has shown that it may be as high as 800,000 Hiroshima bombs per day!

However, due to the unprecedented economic expansion of China this last decade, the amount of cooling pollution grew at an incredible rate.  This pollution only lasts in the atmosphere for a few weeks an must be continually replenished if it is to keep the earth from warming up rapidly.  The amount of pollution that China puts into the air is so great that the 800,000 Hiroshima bombs that we are experiencing today could very well be over 1,600,000 bombs within about 8 weeks, if China suddenly stopped emitting pollution (smog) into the atmosphere. 

China is currently working hard to clean up their air.  New laws have been passed and they are also beginning to reduce their coal consumption.  In addition, they are requiring new, cleaner fuels for vehicles and new emissions controls on diesel trucks that will also work to reduce this pollution.  The combination of these two effects, the increasing warming from current and future CO2 levels coupled with a reduction in the cooling effect of China's air pollution, will soon lead to the world reaching 1,000,000 Hiroshima bombs per day worth of warming.  And this accelerated warming will continue at a pace much greater than any that has ever been witnessed by humanity.

[JimD]

jai

Not to derail your post but let me run with something a bit here. 

There may be a silver lining here (of a sort).

A big percentage of the increase in carbon emissions was due to the rapid growth of China's industrial capacity (building for the US and EU so they are our emissions so to say).  Following the US/EU economic meltdown of 2009 we saw a stagnation in US emissions due to the drop in economic activity.  No such drop in China because, as the rest of the world stumbled, the Chinese turned on the stimulus spigots and started their massive overbuilding boom.  This resulted in continued strong growth and rapidly rising emissions now related to 'their' boom and put them in the position of now being responsible for rising/continuing high emissions in the commodity supplying countries around the world.  Thus a series of years of record emissions thru 2014. 

China is now slowing dramatically and along with them virtually the entire world is slowing, stagnant or in decline in economic terms.  China could very likely experience a dramatic economic slowdown and possibly worse in the near future (lots on that in the other threads).  That would tip a lot of other countries into serious slowdown and outright recession.  The US economic situation is steadily weakening and we are the sole growth driver globally right now. 

So when this likely big slowdown in China happens there is not likely going to be anyone left standing to pull the growth lever for some time.  Commodities are already cheap and getting cheaper by the day.  The developed countries are pretty tapped out on debt and in the strong grip of austerity. 

So a long way of getting to this...When China really slows down.

Global emissions are likely to fall some or at least stagnate.  There will be no growth engine to pick up the slack this time.  This is good, but it will not have much to do with the growth of renewables (though one can bet that will be claimed) but due to declining economic activity.  This will trigger your scenario above.

In the ensuing period the struggling economies of the world will be tapped out financially and will be forced to resort to the absolute cheapest methods of making do.  So a stagnation in green investments and a dependency on much cheaper fossil fuels (which require no further investment).    Thus no progress on global renewables on a significant percentage basis.  Plus the increased poverty will result in a growth of the use of inappropriate fuels by the very poor.

Rising temperatures, stagnation in green technology growth of large scale capacities, economics forcing the continued use of large amounts of fossil fuels, continued significant growth in CO2 levels will all result. And where does that leave us?

It is not out of line to consider this one of the stair step downs talked about in collapse mechanics.  Our ability to use (steal) the wealth of the future is permanently reduced as our our options for trying to mitigate climate change and carrying capacity effects.  This situation "should" or "could" be sufficient to finally trigger our short term subconscious 'pattern recognition' immanent threat response.  And people will FINALLY start to panic and do something meaningful.

Or maybe I am just lost in wishful thinking.

btw I thought your explanation was pretty good lol.   I do find it kind of ironic that we are talking about China turning off their geo-engineering cooling project and things getting worse.  I am very confident that all geo-engineering projects will be made of such two edged swords (and that is why I oppose them and prefer safer solutions).

[ccgwebmaster]

Global emissions are likely to fall some or at least stagnate.  There will be no growth engine to pick up the slack this time.  This is good, but it will not have much to do with the growth of renewables (though one can bet that will be claimed) but due to declining economic activity.  This will trigger your scenario above.

I think history also highlights the distinct possibility that a global depression that cannot be stimulated back from is likely to lead us down the path to a large war at some point. Not in a single step of course, but nonetheless, war provides an engine for growth and the means by which to channel the anger of the people away from their immediate rulers, not to mention the increasing pressure to compete for key resources?

I don't see that there are any nice endings left as "likely".

[jai mitchell]

Jim,

The point of this thread is that china will reduce its SO2 emissions either through pollution controls, economic slowdown, or both and that the residual warming effect of CO2 emissions over the last 10 years, which has not yet been felt by the earth's atmosphere, due to the slow feedbacks associated with forcing, will lead to a rapid surge in warming rates all over the globe.  To a potentially catastrophic level in the next 10 years.

I do not agree with your assessment on renewables, nor do I believe in the catastrophic collapse that you seem somewhat fixated on.  The price curves of renewables prove that solar and solar with storage will soon be cheaper than retail electricity in all cases.

what concerns me the most is a step change in arctic ice loss leading to 8-16C spiking regional anomalies and rapid disassociation of permafrost as well as super heat waves in northern india, Ukraine and the U.S. Midwest.  I am sure you understand.

[JimD]

jai

I understand the point of your post.  No problem.  I will leave the topic.

I do not, of course, agree at all with your implications of what the renewable projections actually mean and what the real result will be.  We will see who is right on that if I live long enough.

I must say though that this ...

..what concerns me the most is a step change in arctic ice loss leading to 8-16C spiking regional anomalies and rapid disassociation of permafrost as well as super heat waves in northern india, Ukraine and the U.S. Midwest. ...

occurring in the next 10 years is far less likely to occur than my projections on collapse.  But we will see on that as well and I should be around for that.

[jai mitchell]

occurring in the next 10 years is far less likely to occur than my projections on collapse.  But we will see on that as well and I should be around for that.

FYI  the heat waves are already starting, once the sea ice is completely lost we WILL see the regional warming spike and massive increases in arctic ocean heat content increases, this will lead to even wilder swings in the jet stream resulting in all kinds of cascading environmental impacts.

THEN we might get our act together with regard to mitigation and adaption/resiliency issues.  This will lead to a massive increase in white elephant spending all over the globe, a giant increase in wealth equality and a fundamental redistribution of wealth and resources as distributed energy generation and food projection become the new working models.

Either that, or your dystopian future projections become more fully realized.

[AbruptSLR]

jai,
What do you make of the following researchers claim that the forcing associated with anthropogenic aerosols cannot be more negative than  −1.0 W m−2?


Bjorn Stevens (2015), "Rethinking the lower bound on aerosol radiative forcing", Journal of Climate; doi: http://dx.doi.org/10.1175/JCLI-D-14-00656.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00656.1


Abstract: "Based on research showing that in the case of a strong aerosol forcing, this forcing establishes itself early in the historical record, a simple model is constructed to explore the implications of a strongly negative aerosol forcing on the early (pre 1950) part of the instrumental record. This model, which contains terms representing both aerosol-radiation and aerosol-cloud interactions well represents the known time history of aerosol radiative forcing, as well as the effect of the natural state on the strength of aerosol forcing. Model parameters, randomly drawn to represent uncertainty in understanding, demonstrates that a forcing more negative than −1.0 W m−2 is implausible, as it implies that none of the approximately 0.3 K temperature rise between 1850 and 1950 can be attributed to northern-hemispheric forcing. The individual terms of the model are interpreted in light of comprehensive modeling, constraints from observations, and physical understanding, to provide further support for the less negative ( −1.0 W m−2 ) lower bound. These findings suggest that aerosol radiative forcing is less negative and more certain than is commonly believed."

Best,
ASLR

[JimD]

FYI  the heat waves are already starting, once the sea ice is completely lost we WILL see the regional warming spike and massive increases in arctic ocean heat content increases, this will lead to even wilder swings in the jet stream resulting in all kinds of cascading environmental impacts.

Well I have real doubts about whether you have this right, but I accept you think so.  But what I find interesting in your post is the below...

THEN we might get our act together with regard to mitigation and adaption/resiliency issues.  This will lead to a massive increase in white elephant spending all over the globe, a giant increase in wealth equality and a fundamental redistribution of wealth and resources as distributed energy generation and food projection become the new working models.

Either that, or your dystopian future projections become more fully realized.

Now I know you don't like the words I use, but you just did a pretty good job of articulating an unstated desire for a giant adverse climate impact which would trigger the very collapse dynamic I am always describing and, therefore, result in that dramatic change I am always advocating for.  Looks like we are on the same boat.  I would point out that one could interpret this also as an apparent desire for people to have to suffer just as folks assume for many of my statements (Wrongly in my case. And I presume so also in yours?).   

[jai mitchell]

jai,
What do you make of the following researchers claim that the forcing associated with anthropogenic aerosols cannot be more negative than  −1.0 W m−2?


Bjorn Stevens (2015), "Rethinking the lower bound on aerosol radiative forcing", Journal of Climate; doi: http://dx.doi.org/10.1175/JCLI-D-14-00656.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00656.1


Abstract: "Based on research showing that in the case of a strong aerosol forcing, this forcing establishes itself early in the historical record, a simple model is constructed to explore the implications of a strongly negative aerosol forcing on the early (pre 1950) part of the instrumental record. This model, which contains terms representing both aerosol-radiation and aerosol-cloud interactions well represents the known time history of aerosol radiative forcing, as well as the effect of the natural state on the strength of aerosol forcing. Model parameters, randomly drawn to represent uncertainty in understanding, demonstrates that a forcing more negative than −1.0 W m−2 is implausible, as it implies that none of the approximately 0.3 K temperature rise between 1850 and 1950 can be attributed to northern-hemispheric forcing. The individual terms of the model are interpreted in light of comprehensive modeling, constraints from observations, and physical understanding, to provide further support for the less negative ( −1.0 W m−2 ) lower bound. These findings suggest that aerosol radiative forcing is less negative and more certain than is commonly believed."

Best,
ASLR

I read the paper, and have been thinking about it for a bit.  My sense of it is that he used a (admittedly) very simplistic model, one that did not incorporate the relative effects of volcanic activity, PDO and AMO phase impacts, he may have also overestimated the atmospheric loading residence time as early emissions were predominately home fires at the time which had VERY low thermal efficiencies, lower temperatures and left most aerosols in the lower troposphere, vs. todays loading that is injected into the middle and upper troposphere by higher thermal efficiencies.    Also, and this is significant, he likely did not incorporate the decadal lag factor associated with the secondary feedbacks of GHG forcing, (water vapor and lapse rate feedbacks take about 10 years to reach full impact).  I am not sure if this would be enough of an increased uncertainty to ensure that his measurements are artificially low.  I have also considered that there is a possible water vapor feedback dependent effect on Aerosol secondary cloud effect forcing parameters.  As water vapor effects increase then greater dimming and cloud effects occur and aerosol forcing becomes more negative.  It is also very likely that a higher regime of aerosol loading may produce a non-linear response as well, the relative loading for the period that he studied is approximately 1/5th the amount from the 1970's.

Finally, the temperature response to the aerosol loading is likely implemented on a globally homogenous forcing, instead of the loading that would be predominately felt in the northern hemisphere vs. the southern one.   So, I don't think that this can yet be a definitive analysis, there are just too many variables, (e.g. regional forcing parameter effects on PDO and 500Hpa blocking patterns leading to regional cooling/warming effects)

[jai mitchell]

Jim,

Don't confuse my desire for sane public policy and a response to the greatest existential threat that humanity has faces since the TOBA eruption as "wishing" for calamity.  However, I recognize that in much of the world, including and especially the U.S., the mechanisms of governance are so completely broken, the certitude of the scientific community to stand for its beliefs, at potentially personal risk, so lacking that, indeed,

The best lack all conviction, while the worst
     Are full of passionate intensity.

    Surely some revelation is at hand;
     Surely the Second Coming is at hand.
     The Second Coming! Hardly are those words out
     When a vast image out of Spiritus Mundi
     Troubles my sight: a waste of desert sand

http://www.potw.org/archive/potw351.html

and in this circumstance the only solution will be one of desperate response.  Will we engage in time with the fullest resources available to us or will we collapse into neofeudal despotic enclaves suffering under catastrophic global environmental armageddon? 

. . .stay tuned. . .

[AbruptSLR]

jai,
What do you make of the following researchers claim that the forcing associated with anthropogenic aerosols cannot be more negative than  −1.0 W m−2?


Bjorn Stevens (2015), "Rethinking the lower bound on aerosol radiative forcing", Journal of Climate; doi: http://dx.doi.org/10.1175/JCLI-D-14-00656.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00656.1


Abstract: "Based on research showing that in the case of a strong aerosol forcing, this forcing establishes itself early in the historical record, a simple model is constructed to explore the implications of a strongly negative aerosol forcing on the early (pre 1950) part of the instrumental record. This model, which contains terms representing both aerosol-radiation and aerosol-cloud interactions well represents the known time history of aerosol radiative forcing, as well as the effect of the natural state on the strength of aerosol forcing. Model parameters, randomly drawn to represent uncertainty in understanding, demonstrates that a forcing more negative than −1.0 W m−2 is implausible, as it implies that none of the approximately 0.3 K temperature rise between 1850 and 1950 can be attributed to northern-hemispheric forcing. The individual terms of the model are interpreted in light of comprehensive modeling, constraints from observations, and physical understanding, to provide further support for the less negative ( −1.0 W m−2 ) lower bound. These findings suggest that aerosol radiative forcing is less negative and more certain than is commonly believed."

Best,
ASLR

I read the paper, and have been thinking about it for a bit.  My sense of it is that he used a (admittedly) very simplistic model, one that did not incorporate the relative effects of volcanic activity, PDO and AMO phase impacts, he may have also overestimated the atmospheric loading residence time as early emissions were predominately home fires at the time which had VERY low thermal efficiencies, lower temperatures and left most aerosols in the lower troposphere, vs. todays loading that is injected into the middle and upper troposphere by higher thermal efficiencies.    Also, and this is significant, he likely did not incorporate the decadal lag factor associated with the secondary feedbacks of GHG forcing, (water vapor and lapse rate feedbacks take about 10 years to reach full impact).  I am not sure if this would be enough of an increased uncertainty to ensure that his measurements are artificially low.  I have also considered that there is a possible water vapor feedback dependent effect on Aerosol secondary cloud effect forcing parameters.  As water vapor effects increase then greater dimming and cloud effects occur and aerosol forcing becomes more negative.  It is also very likely that a higher regime of aerosol loading may produce a non-linear response as well, the relative loading for the period that he studied is approximately 1/5th the amount from the 1970's.

Finally, the temperature response to the aerosol loading is likely implemented on a globally homogenous forcing, instead of the loading that would be predominately felt in the northern hemisphere vs. the southern one.   So, I don't think that this can yet be a definitive analysis, there are just too many variables, (e.g. regional forcing parameter effects on PDO and 500Hpa blocking patterns leading to regional cooling/warming effects)

Thanks jai,

Per the following link, the Sentinel-5 precursor satellite will be launched in 2015 will carry the Dutch TROPOspheric Monitoring Instrument (TROPOMI); which will make daily global observations of key atmospheric constituents, including ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, methane, formaldehyde and aerosol properties. 

Therefore, soon we will have much better direct data about aerosols.

http://www.tropomi.nl/?lang=en

Best,
ASLR

[AbruptSLR]

Thanks jai,

Per the following link, the Sentinel-5 precursor satellite will be launched in 2015 will carry the Dutch TROPOspheric Monitoring Instrument (TROPOMI); which will make daily global observations of key atmospheric constituents, including ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, methane, formaldehyde and aerosol properties. 

Therefore, soon we will have much better direct data about aerosols.

http://www.tropomi.nl/?lang=en


Best,
ASLR

I forgot to mention (for the benefit of other readers) that if jai is correct that Bjorn Stevens model is too simplistic then this increases the probability that the modern Equilibrium Climate Sensitivity, ECS, is likely well above 3C (and may well be between 4 & 4.5C), and that the 0.3 K temperature increase between 1850 and 1950 was not greater because the negative aerosol forcing (possibly including a natural component from volatile organic compounds (VOCs) emitted by forests, see first set of links below) was actually more negative than -1 Wm-2.

For those not familiar with this topic the IPCC AR5 5-95% range for aerosol forcing was -0.1 to -1.9 Wm-2 (see the third link below).  Furthermore, as discussed at "…and Then There's Physics" (see fourth link below) if Bjorn Stevens is correct then the ECS would fall outside of the range accepted by AR5, which adds support to jai's position that Bjorn Stevens has used overly simplistic thinking.


For VOC references see:

http://www.nature.com/nature/journal/v506/n7489/full/nature13032.html

http://www.bbc.com/news/science-environment-26340038

For the AR5 analysis of aerosols see:

https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter08_FINAL.pdf

…and Then There's Physics link:

https://andthentheresphysics.wordpress.com/2015/03/20/aerosol-forcing/

[JimD]

Jim,

Don't confuse my desire for sane public policy and a response to the greatest existential threat that humanity has faces since the TOBA eruption as "wishing" for calamity.  .....

Oh I am not confused in the slightest about that.  My point was to demonstrate that your words could easily be misinterpreted that way (deliberately or not) by others - and they will be.  It happens to me all the time when people don't want to listen to me so they misinterpret and attack.

I have exactly the same desire you seem to in that we must have a meaningful response immediately.  That does not imply a desire for calamity but rather a desire to avoid a worse calamity.

[Csnavywx]

The paper is a bit problematic in the respect that it doesn't give adequate treatment to black carbon or low volcanic activity in the 1910-1950 period. It's just kind of brushed off.

I would still lean on Wilcox et. al, 2013.

[jai mitchell]

One other thing that bothers me.

The lag time of CO2 temperature effects from Ricke & Caldeira (2014) would work to even more significantly affect Stevens' (2015) model.  If anything then this indicates that there may be a significant understatement of radiative forcing from GHGs AND that there may also be a longer-period cumulative (time-lagging) aerosol forcing effect.  There is also some anecdotal information to indicate that this may be the case re: the issue with CMIP5 having slight difficulty being able to adequately duplicate stratospheric volcano temperature responses.

Based on new observations, improved satellite retrievals, and reanalysis of older data, Schmidt (2014) discovered that the models overestimated the short-term cooling effect of the Mt Pinatubo eruption in 1991, and underestimated the cooling effect of increased volcanic eruptions, industrial pollution, and weaker-than-expected solar radiation in the 21st century.

http://www.skepticalscience.com/Climate-Models-Show-Remarkable-Agreement-with-Recent-Surface-Warming.html

Indeed, a significant underestimation of aerosol forcing, coupled with additional underestimations in GHG forcing and positive forcing feedbacks would raise TCR, possibly very significantly.

I would be very surprised at this point that ECS is less than 4.5C  Especially when one considers that the loss of summer sea ice would mean a regional increase in forcing of 75 Watts per meter squared.  (Karlsson & Svensson 2013). resulting in an increased frozen soil feedback as well as arctic amplification by over 10C in the summer and winter.

[Steven]

Furthermore, as discussed at "…and Then There's Physics" (see fourth link below) if Bjorn Stevens is correct then the ECS would fall outside of the range accepted by AR5, which adds support to jai's position that Bjorn Stevens has used overly simplistic thinking
...

What you wrote in the above quote is not correct.

In fact, according to this link, Bjorn Stevens will give a talk at a workshop in Ringberg next week, and the title of his talk is: "Some (not yet entirely convincing) reasons why 2.0 < ECS < 3.5". 

That is compatible with the IPCC range (1.5°C < ECS < 4.5°C).

Perhaps you are confusing Bjorn Stevens' results with those of Nic Lewis.

[jai mitchell]

Yes there is banter going on the denialist echo chamber about how Bjorn's work is a tie into the faulty TCR estimations of Lewis and Curry.  Of course they are engaging in shameless confirmation bias and should be completely disregarded.

Don't get me wrong, the term I used, "simplistic" wasn't my analysis of his model, I have not had access to his model, I don't know how simplistic it is.  I used that word because that is the term that HE used:

a simple model is constructed to explore the implications of a strongly negative aerosol forcing

I hope that he puts his talk up on the intertubes.  It will be good to see what he came up with.

[AbruptSLR]

Furthermore, as discussed at "…and Then There's Physics" (see fourth link below) if Bjorn Stevens is correct then the ECS would fall outside of the range accepted by AR5, which adds support to jai's position that Bjorn Stevens has used overly simplistic thinking
...

What you wrote in the above quote is not correct.

In fact, according to this link, Bjorn Stevens will give a talk at a workshop in Ringberg next week, and the title of his talk is: "Some (not yet entirely convincing) reasons why 2.0 < ECS < 3.5". 

That is compatible with the IPCC range (1.5°C < ECS < 4.5°C).

Perhaps you are confusing Bjorn Stevens' results with those of Nic Lewis.

You are correct that I was referring to the work by Nic Lewis et al; but I still suspect that Bjorn Stevens' model is too simple.