Conservative Scientists & its Consequences

[Michael Hauber]

you don't even understand what I mean by carbon cycle feedbacks, you don't remember what kind of feedback parameters ASLR has shown you and you don't have a clue what I am talking about with regard to waiting 10 years before mitigation actions are taken.

I understand you don't really understand this stuff.

I see you are resorting to pointless insults which have no actual content.

The 10-year comment isn't about how much the earth might warm between now and then, it is about how much more locked-in warming we will secure by the time we make adequate emissions reduction cuts.  The earth operates on a 10-year lag of warming just due to thermal inertia, the water vapor feedbacks associated with today's co2 emissions won't kick in for another 10 years.  Add onto that the negative forcing of anthropogenic aerosols and you find that the water vapor feedback has not even begun for all of the co2 emissions that have been released since about the mid 1990s.

so we have about 2.5 C of additional warming locked in at current atmospheric abundances.

Ok I did forget to consider the difference between transient and equilibrium climate response.  Current Co2 growth is roughly 2.5pppm/year.  Current concentration is 400ppm.  So 10 years growth is roughly 6% of a doubling.  If you go with Hansen's estimate of earth system sensitivity at 6 degrees, this is an extra 0.38 degrees of warming.  The additional warming for earth system sensitivity will take thousands to tens of thousands of years to realise.

[AbruptSLR]

  Mauritsen & Stevens (2015) take the CERES data and run it through a climate model that filters out weather driven signals [such as Trenberth et al (2015) identified] and then inappropriately derive a biased climate sensitivity.

They run the CERES data through a linear regression.  They do not run it through a climate model.

And what do you mean a weather driven signal and how is it not included in climate models?  Climate models certainly include 'weather' as I understand it.

What climate models do not include is detailed simulation of clouds.  Trenberth does not address this issue at all (not the purpose of his paper).  Mauritsen references a new model that performs detailed simulation of convection, and finds that this model shows evidence of convective clustering that can contribute to this IRIS effect.

Due to their coarse horizontal resolution, present day climate models must parameterize deep convection (see: Storer, R. L., Griffin, B. M., Höft, J., Weber, J. K., Raut, E., Larson, V. E., Wang, M., and Rasch, P. J. (2015), "Parameterizing deep convection using the assumed probability density function method", Geosci. Model Dev., 8, 1-19, doi:10.5194/gmd-8-1-2015).

Thus while Mauritsen & Stevens (2015) consider deep convention, the parameterization in their coarse grid model filters out the positive feedback mechanism identified by Trenberth et al (2015); who can identify the signal for this vapor related positive feedback mechanism because they are working with raw, un-filtered, data.


Furthermore, the extract from the linked interview of Kate Marvel confirms (also working with raw unfiltered CERES data) that particularly tropical thunderheads due to deep convection near the topical equator are increasing in altitude due to anthropogenic global warming since at least the 1980's (ie since the satellite era began):

http://degreeofsatisfaction.blogspot.com/2015/03/kate-marvel-physicist-climate-scientist.html
Extract: "At least in a couple data sets, you can see clouds rising, which is what’s predicted under global warming conditions.

What do you mean, you can see them rising?

So we’ve got cloud satellites dating back to the early 80’s, and in the satellite data, you can basically see the fingerprint of human-caused climate change in the cloud records, which is really surprising, because they’re so noisy, and so difficult to get anything out of. But you can really start to see all of these patterns emerging and it’s amazing how coherent everything is.

So you mean the typical height of the clouds above the land is changing?

Yeah. So I mean the height of high clouds is changing. So these big thunderheads that you would see, like convective clouds in the tropics, those are rising, those are going higher in ways that are predicted very robustly by a lot of the climate models and some of the physics underlying them, which is incredible."


See also:
http://www.mpimet.mpg.de/fileadmin/atmosphaere/WCRP_Grand_Challenge_Workshop/Ringberg_2015/Talks/Geoffroy_25032015.pdf


http://marvelclimate.blogspot.com/

http://www.ess.uci.edu/~wenchay/journals/jc.html

[jai mitchell]

I understand you don't really understand this stuff.

I see you are resorting to pointless insults which have no actual content.

That is because you think that frozen soils are considered part of the carbon cycle feedback components.  That can be easily misunderstood if you haven't taken the time to look into it.  The carbon cycle feedback is predominately due to increased rates of soil decomposition and heat/drought stress on plants. 

http://www.scientificamerican.com/article/higher-temperatures-lessen-plants-ability-to-store-co2/

Ok I did forget to consider the difference between transient and equilibrium climate response.  Current Co2 growth is roughly 2.5pppm/year.  Current concentration is 400ppm.  So 10 years growth is roughly 6% of a doubling.  If you go with Hansen's estimate of earth system sensitivity at 6 degrees, this is an extra 0.38 degrees of warming.  The additional warming for earth system sensitivity will take thousands to tens of thousands of years to realise.

I am not talking about ESS.  I am talking about the near term climate feedbacks that will occur between now and 2100 and on into 2150. 

These feedbacks, which you keep forgetting to acknowledge or understand, as shown by ASLR are:

• Reduction in Ocean DMS production - .4C
• Reduction in Lowngwave IR emissivity of ice in arctic - .13C
• Loss of the Amazon Forest - .5C
• Accelerated loss of permafrost due to sea ice loss (with microbial decomposition) - .7C by 2100
• Loss of boreal forest and boreal peat - .4C in black carbon and GHG
• Decreased arctic ocean albedo due to algae increase - .3C
• total loss of arctic summer solstice sea ice by 2065 - 1.8C

in case you don't have a calculator these feedback parameters result in 4.23C of additional warming on top of the GHG equivalent forcing parameters.

These feedbacks are all documented here, mostly with referenced papers published by ASLR.  Do you dispute any of them individually?  They are listed as what their impacts would be under BAU through 2050 or so.  These feedbacks on their own have been produced by independent study and analysis and are not a complete list as CARBON CYCLE feedbacks may produce as much warming as RCP 6.0 on its own.

--------

I already told you, it isn't about the decadal radiative forcing it is about how far past the tipping points that we turn in future emissions.  It is about how much damage we allow to happen and lock-in to the future before we are finally able to get to zero and then negative net emissions. 

I can't believe you are seriously advocating that we do nothing between now and 2025, or that you think this action would be insignificant somehow.  You have been shown over and over about these compounding feedbacks but you will  ALWAYS state the least value ECS and pretend that this is what we would expect for future warming. 

if the ocean clathrates suddenly go (at 7C) we will see 12-14C within 60 years.  hows THAT for a carbon cycle feedback?

[Michael Hauber]

Due to their coarse horizontal resolution, present day climate models must parameterize deep convection (see: Storer, R. L., Griffin, B. M., Höft, J., Weber, J. K., Raut, E., Larson, V. E., Wang, M., and Rasch, P. J. (2015), "Parameterizing deep convection using the assumed probability density function method", Geosci. Model Dev., 8, 1-19, doi:10.5194/gmd-8-1-2015).

Thus while Mauritsen & Stevens (2015) consider deep convention, the parameterization in their coarse grid model filters out the positive feedback mechanism identified by Trenberth et al (2015); who can identify the signal for this vapor related positive feedback mechanism because they are working with raw, un-filtered, data.

[/quote]

The models Mauritsen use have a finer resolution than the analysis Trenberth performs.  Trenberth performs an analysis on the planet as a whole, and captures the impact of small scale feedbacks on average.

In the same way Mauritsen performs an analysis of the CERES data to determine what the effect of small scale feedbacks are on average.  The average effects of these small scale feedbacks are then included in Mauritsen's model.

[Michael Hauber]

That is because you think that frozen soils are considered part of the carbon cycle feedback components.  That can be easily misunderstood if you haven't taken the time to look into it.  The carbon cycle feedback is predominately due to increased rates of soil decomposition and heat/drought stress on plants. 

The frozen soil issues were the primary issue being discussed while I was participating in this thread.  If the soil/plant feedback issues have been discussed its while I was taking a break from this thread. 

I am not talking about ESS.  I am talking about the near term climate feedbacks that will occur between now and 2100 and on into 2150. 

These feedbacks, which you keep forgetting to acknowledge or understand, as shown by ASLR are:

• Reduction in Ocean DMS production - .4C
• Reduction in Lowngwave IR emissivity of ice in arctic - .13C
• Loss of the Amazon Forest - .5C
• Accelerated loss of permafrost due to sea ice loss (with microbial decomposition) - .7C by 2100
• Loss of boreal forest and boreal peat - .4C in black carbon and GHG
• Decreased arctic ocean albedo due to algae increase - .3C
• total loss of arctic summer solstice sea ice by 2065 - 1.8C

And what does that have to do with the amount of extra warming for ten years.

Also adding up individual feedbacks is a poor way to determine climate sensitivity, and is an approach that I have never seen a serious climate scientist use.  That is because the errors for individual feedbacks will accumulate as you add them together resulting in such a large error that the final result is worthless.

[AbruptSLR]

Due to their coarse horizontal resolution, present day climate models must parameterize deep convection (see: Storer, R. L., Griffin, B. M., Höft, J., Weber, J. K., Raut, E., Larson, V. E., Wang, M., and Rasch, P. J. (2015), "Parameterizing deep convection using the assumed probability density function method", Geosci. Model Dev., 8, 1-19, doi:10.5194/gmd-8-1-2015).

Thus while Mauritsen & Stevens (2015) consider deep convention, the parameterization in their coarse grid model filters out the positive feedback mechanism identified by Trenberth et al (2015); who can identify the signal for this vapor related positive feedback mechanism because they are working with raw, un-filtered, data.

The models Mauritsen use have a finer resolution than the analysis Trenberth performs.  Trenberth performs an analysis on the planet as a whole, and captures the impact of small scale feedbacks on average.

In the same way Mauritsen performs an analysis of the CERES data to determine what the effect of small scale feedbacks are on average.  The average effects of these small scale feedbacks are then included in Mauritsen's model.
[/quote]

First, let me note that the objective the Trenberth et al (2015) paper was different than the objective of the Mauritsen & Stevens (2015), so there was no need for the different teams to use comparable models.

Furthermore, as Trenberth et al were not estimating climate sensitivity, I am not concerned about their model; however Mauritsen & Stevens (2015) do estimate climate sensitivities and thus their models run into the same limits discussed by Jean-Pascal van Ypersele (professor of climatology and environmental sciences at the Université catholique de Louvain in Belgium & the likely new chair of the Intergovernmental Panel on Climate Change (IPCC), to succeed Dr Rajendra Pachauri), in the interview with Carbon Brief below, where he notes that correctly modeling the physics of clouds requires high resolution models, special computer codes and a lot of computer time, as was the case for the CESM-H run.  All of these consideration are not adequately addressed by the Mauritsen & Stevens (2015) model.

Hopefully, the first stage of the ACME program (to be completed in another 2.5 years) will reduce this uncertainty with modeling clouds before society follows a pathway that it comes to regret.


http://www.carbonbrief.org/blog/2015/04/the-carbon-brief-interview-jean-pascal-van-ypersele/

Extract: "CB: So, as a climate scientist, what areas of new research excite you the most, which questions would you like to see more than any others?

JY: Probably one of the key questions is the role of clouds. I mean, the main reason behind, let's face it, the large range in the climate sensitivity, the equilibrium climate sensitivity - sorry for using jargon here, but probably the readers of this will know what we're talking about - climate sensitivity is simply the amount of warming that you get at equilibrium when you double the amount of CO2 in the atmosphere. But the range for the number has been basically [the same] for the last 40 years; 1.5 to 4.5C with some fluctuations. It's a situation with nuances, but basically it's a large range - it's a factor of three. It would make a big difference to reduce that range and to know better if, for a doubling of the concentration, the warming would be 2C, 3C, or 4C. It would make a big difference for policymakers as well when they discuss risk management because the risk would be better known. And the main factor behind that is cloud microphysics and the way clouds interact with other elements in the climate system. And relatively little progress has been made actually. When Charney published in 1975 his first assessment of the range of climate sensitivity, it was 1.5 to 4.5 and it's still the same today. So little progress has been made, and the main factor is the uncertainties around clouds.

CB: So, my understanding of clouds - cloud feedbacks - is that there's quite a lot of evidence that there is a positive feedback, which means it would amplify the warming that you would get just purely for a doubling of carbon dioxide. There are suggestions that it might be a negative feedback, but there isn't a lot of evidence to support that, in fact I'm not sure of any. Having identified clouds as an issue, does that lessen the possibility that's it's at the lower end of that range?

JP: Things are even a little more complicated than that. Because it's true that overall water vapour - and clouds is one of the manifestations of water vapour - increase the warming for an increase in the CO2 concentration, so overall the feedback is positive. But inside that big envelope there are different behaviours for different kinds of clouds. I'm not a cloud expert, but still, I know that, for example, high-level clouds like cirrus, have a warming effect if there's an increase in their number. Low-lying clouds, low in the atmosphere, on the contrary, have a cooling effect because they reflect more sunlight to space, while the upper clouds have a larger greenhouse effect by trapping heat radiation. So, when you talk about clouds, clouds is not just a large cloud - let's use that word! - of water vapour in different forms. The altitude and type of clouds and the microphysics is quite different for different levels in the atmosphere. And to understand the overall effects of clouds and changing cloudiness in warming climates depends on the understanding, the detail of the understanding, of the microphysics of those individual layers of clouds at different layers. For some layers, it's a positive feedback and for some layers it's a negative feedback. And the balance is positive indeed, but how positive? How to quantify that depends on the details of the microphysics of clouds, and there there is still much progress to do. One difficulty being that it's very hard to observe what is happening inside clouds at their level, and the other difficulty - or one other difficulty - is the difficulty to model with high resolution - the high resolution that would be needed to resolve clouds. It's very difficult to do that in climate models because we are limited by computer power, and that's one of the difficulties."

[jai mitchell]

There is high confidence that reductions in permafrost extent due to warming will cause thawing of some currently frozen carbon. However, there is low confidence on the magnitude of carbon losses through CO2 and CH4 emissions to the atmosphere, with a range from 50 to 250 PgC between 2000 and 2100 under the RCP8.5 scenario. The CMIP5 Earth System Models did not include frozen carbon feedbacks. {6.4.3.4, Chapter 12}

https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter06_FINAL.pdf

Therefore, carbon cycle analyses never included frozen soils and the variance in emissions, as large as the TOTAL emissions of RCP 6.0 are based on soil and plant CO2 variability alone.

• Reduction in Ocean DMS production - .4C
• Reduction in Lowngwave IR emissivity of ice in arctic - .13C
• Loss of the Amazon Forest - .5C
• Accelerated loss of permafrost due to sea ice loss (with microbial decomposition) - .7C by 2100
• Loss of boreal forest and boreal peat - .4C in black carbon and GHG
• Decreased arctic ocean albedo due to algae increase - .3C
• total loss of arctic summer solstice sea ice by 2065 - 1.8C

And what does that have to do with the amount of extra warming for ten years.

I answered this question in my previous posts.  read it and then you can stop asking these kinds of questions.

when you say,

adding up individual feedbacks is a poor way to determine climate sensitivity, and is an approach that I have never seen a serious climate scientist use.

I am not trying to find climate sensitivity, I am showing you (some of) the feedback parameters that are not being included in the ECS analysis.  These are the feedbacks that will unleash the runaway warming effect that will be locked in if we take much longer before we stop emitting CO2.

None of these items are interacting with each other in any significant degree.  If you claim otherwise then you are simply arguing for the sake of distorting the discussion on this forum.  In fact, I really don't see a point in talking with you any more.  I should have just ignored your ignorant protests and claims from the outset.   You have absolutely no clue what you are talking about and you keep changing the subject and I have absolutely no doubt that in another few weeks you will again be claiming that a low ECS value is what the temperature projection profile will look like.  You will misrepresent the science to this effect and use this deceitful tactic to attack some other thread on this forum that is showing new and revealing science that indicates that the temperature or earth system response to CO2 is worse than your paltry misunderstanding of the science.

[AbruptSLR]

The linked article indicates that by 2100 the Arctic could be 20% warmer due to phytoplankton blooms, than scientists (including AR5) previously thought:

Jong-Yeon Park, et al (2015), "Amplified Arctic warming by phytoplankton under greenhouse warming", PNAS, doi: 10.1073/pnas.1416884112

http://www.pnas.org/content/early/2015/04/14/1416884112
 
Significance: "One of the important impacts of marine phytoplankton on climate systems is the geophysical feedback by which chlorophyll and the related pigments in phytoplankton absorb solar radiation and then change sea surface temperature. Yet such biogeophysical impact is still not considered in many climate projections by state-of-the-art climate models, nor is its impact on the future climate quantified. This study shows that, by conducting global warming simulations with and without an active marine ecosystem model, the biogeophysical effect of future phytoplankton changes amplifies Arctic warming by 20%. Given the close linkage between the Arctic and global climate, the biologically enhanced Arctic warming can significantly modify future estimates of global climate change, and therefore it needs to be considered as a possible future scenario."

Abstract: "Phytoplankton have attracted increasing attention in climate science due to their impacts on climate systems. A new generation of climate models can now provide estimates of future climate change, considering the biological feedbacks through the development of the coupled physical–ecosystem model. Here we present the geophysical impact of phytoplankton, which is often overlooked in future climate projections. A suite of future warming experiments using a fully coupled ocean−atmosphere model that interacts with a marine ecosystem model reveals that the future phytoplankton change influenced by greenhouse warming can amplify Arctic surface warming considerably. The warming-induced sea ice melting and the corresponding increase in shortwave radiation penetrating into the ocean both result in a longer phytoplankton growing season in the Arctic. In turn, the increase in Arctic phytoplankton warms the ocean surface layer through direct biological heating, triggering additional positive feedbacks in the Arctic, and consequently intensifying the Arctic warming further. Our results establish the presence of marine phytoplankton as an important potential driver of the future Arctic climate changes."

See also:
http://www.climatecentral.org/news/algae-accelerate-arctic-warming-18929

[Michael Hauber]

There is high confidence that reductions in permafrost extent due to warming will cause thawing of some currently frozen carbon. However, there is low confidence on the magnitude of carbon losses through CO2 and CH4 emissions to the atmosphere, with a range from 50 to 250 PgC between 2000 and 2100 under the RCP8.5 scenario. The CMIP5 Earth System Models did not include frozen carbon feedbacks. {6.4.3.4, Chapter 12}

https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter06_FINAL.pdf

Therefore, carbon cycle analyses never included frozen soils and the variance in emissions, as large as the TOTAL emissions of RCP 6.0 are based on soil and plant CO2 variability alone.

You make it look like the The CMIP5 Earth System Models did not include frozen carbon feedbacks is a direct quote from the IPCC report.  I performed a search for the phrase and the result was 'result not found'.  If you actually read the report you will find a table showing the feedbacks for permafrost for various models.

Your presentation of this quote is dishonest.

Friedlingstein et al does an analysis of what climate sensitivity would be with all carbon cycle feedbacks in the CMIP5 models.  This increases temperature change in 2100 from 3.7 to 3.9 degrees.  Also note that CMIP5 models overestimate the amount of carbon in the atmosphere currently, so even this value may be too high. 

• Reduction in Ocean DMS production - .4C
• Reduction in Lowngwave IR emissivity of ice in arctic - .13C
• Loss of the Amazon Forest - .5C
• Accelerated loss of permafrost due to sea ice loss (with microbial decomposition) - .7C by 2100
• Loss of boreal forest and boreal peat - .4C in black carbon and GHG
• Decreased arctic ocean albedo due to algae increase - .3C
• total loss of arctic summer solstice sea ice by 2065 - 1.8C

I am not trying to find climate sensitivity, I am showing you (some of) the feedback parameters that are not being included in the ECS analysis. 

loss of Arctic sea ice by summer 2065 is not included in ECS analysis?  IPCC predict ice free artic by 2050.

None of these items are interacting with each other in any significant degree.  If you claim otherwise then you are simply arguing for the sake of distorting the discussion on this forum.

Four of them all involve the loss of Arctic sea ice.  This is a clear interaction.

[Michael Hauber]

First, let me note that the objective the Trenberth et al (2015) paper was different than the objective of the Mauritsen & Stevens (2015), so there was no need for the different teams to use comparable models.

Furthermore, as Trenberth et al were not estimating climate sensitivity, I am not concerned about their model;

So Mauritsen and Trenberth perform basically the same analysis, but because they have different objectives and make different use of the results one analysis is wrong and the other correct?

where he notes that correctly modeling the physics of clouds requires high resolution models, special computer codes and a lot of computer time, as was the case for the CESM-H run.  All of these consideration are not adequately addressed by the Mauritsen & Stevens (2015) model.

Mauritsen does not attempt to model the phsyics of the clouds.  Mauritsen calculates the properties of the clouds using the same technique as Trenberth to obtain a parameter, and then includes this parameter in the model to represent the average effects of clouds in the model

[AbruptSLR]

MH,

The incoming chair of the IPCC says: "And to understand the overall effects of clouds and changing cloudiness in warming climates depends on the understanding, the detail of the understanding, of the microphysics of those individual layers of clouds at different layers. For some layers, it's a positive feedback and for some layers it's a negative feedback. And the balance is positive indeed, but how positive?"

This is essentially what Trenberth et al say, which is what I am saying; so I will let lobby your case for an iris effect with the IPCC for the up-coming AR6.

[jai mitchell]

https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter06_FINAL.pdf

You make it look like the The CMIP5 Earth System Models did not include frozen carbon feedbacks is a direct quote from the IPCC report.  I performed a search for the phrase and the result was 'result not found'.  If you actually read the report you will find a table showing the feedbacks for permafrost for various models.

Your presentation of this quote is dishonest.

page 468 of the linked document second paragraph from the end of the page.

Four of them all involve the loss of Arctic sea ice.  This is a clear interaction.

And they all work to compound that driving force, when you asserted that they might somehow reduce each other's impacts.  Well, that is a completely unfounded statement. 

I don't know if you are doing this intentionally or simply out of lack of understanding or if you have an emotional denial response that makes you want to jump around like you do and make assertions about things that are not true.  I want you to know if it is the latter that there is still hope.  It is just going to take a very whole much of a lot of collective effort from every decision maker and stakeholder on this planet.  We have locked in so much death and destruction for humanity and the earth's biosphere, but we may yet prevail and save what is left.

[jai mitchell]

loss of Arctic sea ice by summer 2065 is not included in ECS analysis?  IPCC predict ice free artic by 2050.

Summer solstice loss of arctic sea ice is different from loss of summer sea ice.

I expect loss of summer sea ice within the next 10 years, perhaps within the next 3 pending Chinese aerosol reduction efforts and positive PDO.

loss of all sea ice by June 21 I see will happen by 2065 under BAU to collapse scenario.

With regard to ECS calculations  Sea Ice is indeed a forcing parameter, however, the earlier loss of sea ice is not modeled, as well as the fact that the impacts of the loss of sea ice were severely underestimated.

Here is a 2009 paper on the subject
http://people.earth.yale.edu/sites/default/files/files/Pagani/1_2009%20Pagani_NatureGeosci.pdf


more recent work helps to nail down the sea ice contribution to ECS.  Now, if this does happen in 2010 as opposed to 2050 then a much accelerated forcing (and more rapid warming) will occur than is previously modeled.  This is evident in Caldiera & Cvijanovic (2014)

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00042.1

Abstract

The response of sea ice to climate change affects Earth’s radiative properties in ways that contribute to yet more climate change. Here, a configuration of the Community Earth System Model, version 1.0.4 (CESM 1.0.4), with a slab ocean model and a thermodynamic–dynamic sea ice model is used to investigate the overall contribution to climate sensitivity of feedbacks associated with the sea ice loss. In simulations in which sea ice is not present and ocean temperatures are allowed to fall below freezing, the climate feedback parameter averages ~1.31 W m−2 K−1; the value obtained for control simulations with active sea ice is ~1.05 W m−2 K−1, indicating that, in this configuration of CESM1.0.4, sea ice response accounts for ~20% of climate sensitivity to an imposed change in radiative forcing. In this model, the effect of sea ice response on the longwave climate feedback parameter is nearly half as important as its effect on the shortwave climate feedback parameter. Further, it is shown that the strength of the overall sea ice feedback can be related to 1) the sensitivity of sea ice area to changes in temperature and 2) the sensitivity of sea ice radiative forcing to changes in sea ice area. An alternative method of disabling sea ice response leads to similar conclusions. It is estimated that the presence of sea ice in the preindustrial control simulation has a climate effect equivalent to ~3 W m−2 of radiative forcing.

[Michael Hauber]

MH,

The incoming chair of the IPCC says: "And to understand the overall effects of clouds and changing cloudiness in warming climates depends on the understanding, the detail of the understanding, of the microphysics of those individual layers of clouds at different layers. For some layers, it's a positive feedback and for some layers it's a negative feedback. And the balance is positive indeed, but how positive?"

This is essentially what Trenberth et al say, which is what I am saying; so I will let lobby your case for an iris effect with the IPCC for the up-coming AR6.

Its also the same as what Thorsten et al says.  Its just that the question of balance is slightly less positive then previous analysis has found.

AR6 will undoubtedly consider this paper, and more importantly what papers are written in response and whether they strengthen or weaken this result.

[AbruptSLR]

As Mauritsen & Stevens (2015) managed to get published in a peer reviewed journal, I imagine that it will indeed be evaluated by AR6.  However, I hope that the ACME model shines more light on this matter in the meantime, so that AR6 does not include inappropriate low values of ECS as AR5 did/does.

[Michael Hauber]

https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter06_FINAL.pdf

You make it look like the The CMIP5 Earth System Models did not include frozen carbon feedbacks is a direct quote from the IPCC report.  I performed a search for the phrase and the result was 'result not found'.  If you actually read the report you will find a table showing the feedbacks for permafrost for various models.

Your presentation of this quote is dishonest.

page 468 of the linked document second paragraph from the end of the page.

I apologise for that error.  As well as my haste this was contributed to by the fact that I opened the document to page 514, which has a heading 'Carbon Cycle Feedbacks in Climate Modelling
Intercomparison Project Phase 5 Models' and shortly following on the next page is a diagram with feedbacks which includes frozen permafrost.  Reading the fine print and chasing the reference evidently these are calculated elsewhere then in CMIP 5.  So when the document you link too dumps me straight into a page which seems to say the exact opposite (presumably it opened at that location as that was the last thing I looked at last time I opened that document) and as a precaution I do a text search which presumably failed as the entire document wasn't loaded into my computer....

The question then is how much extra feedback from the perma-frost.  According to Shur et al it is between 0.13 and 0.27 extra degrees by 2100.

Four of them all involve the loss of Arctic sea ice.  This is a clear interaction.

And they all work to compound that driving force, when you asserted that they might somehow reduce each other's impacts.  Well, that is a completely unfounded statement. 

All I said was that they will interact because four of them involve Arctic ice.  Obviously 7 is going to promote 6 and 4, but once all the ice is gone the effect of 2 will become 0, so at least one of these factors will counteract another factor.

[Michael Hauber]

loss of Arctic sea ice by summer 2065 is not included in ECS analysis?  IPCC predict ice free artic by 2050.

Summer solstice loss of arctic sea ice is different from loss of summer sea ice.

There is about 9 million km2 of Arctic sea ice in June to be lost.  Losses so far are about 2 million.  Loss of NH snow so far is about 5 million.

So up to now we have lost about 7 million km2 of NH ice and the global temperature has gone up by about 0.8 degrees.  Much of the temperature increase to date is due to factors other than loss of NH ice.  I cannot see how the loss of a further 9 million km2 of NH sea ice could lead to 1.8 degrees of extra warming beyond whatever the IPCC include for what will still be quite substantial losses of ice in June by 2050.

[AbruptSLR]

I note that the linked (open access) reference discusses advances in CESM/CAM5.1; and that CESM (and its modules) is the foundation software for the ACME project.

Jian He, Yang Zhang, Tim Glotfelty, Ruoying He, Ralf Bennartz, John Rausch, & Karine Sartelet (2015), "Decadal simulation and comprehensive evaluation of CESM/CAM5.1 with advanced chemistry, aerosol microphysics, and aerosol-cloud interactions", JAMES, DOI: 10.1002/2014MS00036


http://onlinelibrary.wiley.com/doi/10.1002/2014MS000360/full


Abstract: "Earth system models have been used for climate predictions in recent years due to their capabilities to include biogeochemical cycles, human impacts, as well as coupled and interactive representations of Earth system components (e.g., atmosphere, ocean, land, and sea ice). In this work, the Community Earth System Model (CESM) with advanced chemistry and aerosol treatments, referred to as CESM-NCSU, is applied for decadal (2001–2010) global climate predictions. A comprehensive evaluation is performed focusing on the atmospheric component—the Community Atmosphere Model version 5.1 (CAM5.1) by comparing simulation results with observations/reanalysis data and CESM ensemble simulations from the Coupled Model Intercomparison Project phase 5 (CMIP5). The improved model can predict most meteorological and radiative variables relatively well with normalized mean biases (NMBs) of −14.1 to −9.7% and 0.7–10.8%, respectively, although temperature at 2 m (T2) is slightly underpredicted. Cloud variables such as cloud fraction (CF) and precipitating water vapor (PWV) are well predicted, with NMBs of −10.5 to 0.4%, whereas cloud condensation nuclei (CCN), cloud liquid water path (LWP), and cloud optical thickness (COT) are moderately-to-largely underpredicted, with NMBs of −82.2 to −31.2%, and cloud droplet number concentration (CDNC) is overpredictd by 26.7%. These biases indicate the limitations and uncertainties associated with cloud microphysics (e.g., resolved clouds and subgrid-scale cumulus clouds). Chemical concentrations over the continental U.S. (CONUS) (e.g.,  , Cl−, OC, and PM2.5) are reasonably well predicted with NMBs of −12.8 to −1.18%. Concentrations of SO2,  , and PM10 are also reasonably well predicted over Europe with NMBs of −20.8 to −5.2%, so are predictions of SO2 concentrations over the East Asia with an NMB of −18.2%, and the tropospheric ozone residual (TOR) over the globe with an NMB of −3.5%. Most meteorological and radiative variables predicted by CESM-NCSU agree well overall with those predicted by CESM-CMIP5. The performance of LWP and AOD predicted by CESM-NCSU is better than that of CESM-CMIP5 in terms of model bias and correlation coefficients. Large biases for some chemical predictions can be attributed to uncertainties in the emissions of precursor gases (e.g., SO2, NH3, and NOx) and primary aerosols (black carbon and primary organic matter) as well as uncertainties in formulations of some model components (e.g., online dust and sea-salt emissions, secondary organic aerosol formation, and cloud microphysics). Comparisons of CESM simulation with baseline emissions and 20% of anthropogenic emissions from the baseline emissions indicate that anthropogenic gas and aerosol species can decrease downwelling shortwave radiation (FSDS) by 4.7 W m−2 (or by 2.9%) and increase SWCF by 3.2 W m−2 (or by 3.1%) in the global mean."

[jai mitchell]

I cannot see how the loss of a further 9 million km2 of NH sea ice could lead to 1.8 degrees of extra warming beyond whatever the IPCC include for what will still be quite substantial losses of ice in June by 2050.

Open ocean in september is much much different than open ocean in mid June with regard to absorbed solar energy.

[Michael Hauber]

I cannot see how the loss of a further 9 million km2 of NH sea ice could lead to 1.8 degrees of extra warming beyond whatever the IPCC include for what will still be quite substantial losses of ice in June by 2050.

Open ocean in september is much much different than open ocean in mid June with regard to absorbed solar energy.

All figures I quoted were for June. 

[jai mitchell]

All figures I quoted were for June.

going from 90% albedo (ice)

to 26% albedo (algae laden open ocean)

at 90'N  during the summer solstice looks like this.

[AbruptSLR]

The two following linked articles discuss how looking at all of the available data points towards the reality of higher climate sensitivities; while denalists (like Nic Lewis & Judith Curry) focus on a limited subset of studies to support their agenda to promote the acceptance of low climate sensitivity values by policy makers (many of which are in power because of their support by the fossil fuel industry).  Such denalists are emboldened by the success that they experience in getting AR5 to accept likely values for ECS as low as 1.5C; and they are actively working to repeat this successful formula to try to get AR6 to also acknowledge inappropriately low values for climate sensitivity.

http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/apr/30/overlooked-evidence-global-warming-may-proceed-faster-than-expected


https://www.skepticalscience.com/overlooked-evidence-gw-may-proceed-faster-than-expected.html

[Michael Hauber]

All figures I quoted were for June.

going from 90% albedo (ice)

to 26% albedo (algae laden open ocean)

at 90'N  during the summer solstice looks like this.

Yes I know that the sun shines a lot in June.  That has nothing to do with my argument that 1.8 degrees is far too high a number.

[Michael Hauber]

The two following linked articles discuss how looking at all of the available data points towards the reality of higher climate sensitivities; while denalists (like Nic Lewis & Judith Curry) focus on a limited subset of studies to support their agenda to promote the acceptance of low climate sensitivity values by policy makers (many of which are in power because of their support by the fossil fuel industry).  Such denalists are emboldened by the success that they experience in getting AR5 to accept likely values for ECS as low as 1.5C; and they are actively working to repeat this successful formula to try to get AR6 to also acknowledge inappropriately low values for climate sensitivity.

http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/apr/30/overlooked-evidence-global-warming-may-proceed-faster-than-expected


https://www.skepticalscience.com/overlooked-evidence-gw-may-proceed-faster-than-expected.html

From the guardian article:

Real Skeptics Consider all the Evidence

True skepticism requires considering all available evidence. While some studies suggest that climate sensitivity is on the low end of the estimated range, other studies suggest it’s on the high end. As Andrew Dessler told me,

    There certainly is some evidence that climate sensitivity may be below 2°C. But if you look at all of the evidence, it’s hard to reconcile with such a low climate sensitivity. I think our best estimate is still around 3°C for doubled CO2.

If the above is true and reasonable, then this also must be true and reasonable:

True skepticism requires considering all available evidence.  While some studies suggest that climate sensitivity is on the high end of the estimated range, other studies suggest it's on the low end.  As Andrew Dessler might have said,

There is certainly some evidence that climate sensitivity may be above 4°C.  But if you look at all of the evidence, it's hard to reconcile with such a high climate sensitivity.  (And as he did say)  I think our best estimate is still around 3°C for doubled CO2

[Michael Hauber]

While many studies have found that the recent pause is consistent with moderate projections of climate change, a new study in nature by Brown et al again finds that the pause is consistent with moderate projections of climate change.  But it also finds that the pause is not consistent with the high end projections of climate change.

But is there a way to make the high a high end sensitivity consistent with observations?  It cannot be a higher water vapor or cloud feedback, that would make the inconsistency bigger.  A stronger aerosol forcing could work, however another recent study finds evidence against a stronger than normally accounted for aerosol forcing.

Probably the best candidate would be perma-frost feedback.  This can reconcile a higher climate sensitivity with historical slow warming due to possibly strongly non linear effects which mean that the impact on temperature is low in the past, but much higher in the future.  Recent papers I have pointed to are finding that the permafrost feedback is only likely to add much less than 1 degree by 2100, but this seems to be an area with a great deal of uncertainty and things could still change.

[AbruptSLR]

If the above is true and reasonable, then this also must be true and reasonable:

If everything that Gavin Schmidt says "is true and reasonable, then" his estimate of the likely range for ECS of 2 to 5C as cited at the linked RealClimate web article below, indicates that the most reasonable value for ECS is 3.5C.


http://www.realclimate.org/index.php/archives/2015/04/reflections-on-ringberg/

Unfortunately, scientists do not issue warranties with their projections, and they feel free, even obligated, to change their projections whenever they have gathered sufficient data to do so.  Furthermore, as the great majority of times true scientists err on the side of least drama, thus when they revise their projections they typically move up, say from 3.5 to 4C for ECS (not to mention albedo, and ESS mechanisms not included in ECS).

It would probably help the public if IPCC scientist more clearly stated upper bound bounds on their projected values such as the 9.6C ESS Pliocene value given by Pagani et al 2009:

Mark Pagani, Zhonghui Liu, Jonathan LaRiviere, Ana Christina Ravelo (2009), "High Earth-System Climate Sensitivity determined from Pliocene CO2 Concentrations", Nature geoscience, doi:10.1038/NGEO724

http://people.earth.yale.edu/sites/default/files/files/Pagani/1_2009%20Pagani_NatureGeosci.pdf

Extract from Pagani et al 2009: "Data and modelling for the middle Pliocene (~3–3.3 Myr) indicate that the global mean temperature was 2.4–2.9 ^oC warmer than preindustrial conditions, and ~4 ^oC warmer during the early Pliocene (3.4–4.2 Myr; ref. 5). If changes in carbon dioxide and associated feedbacks were the primary agents forcing climate over these timescales, and estimates of global temperatures are correct, then our results imply a very high Earth-system climate sensitivity for the middle (3.3 Myr) to early (4.2 Myr) Pliocene ranging between 7.1 ± 1.0 ^oC and 8.7 ± 1.3 ^oC per CO2 doubling, and 9.6±1.4 ^oC per CO2 doubling, respectively."

[jai mitchell]

Yes I know that the sun shines a lot in June.  That has nothing to do with my argument that 1.8 degrees is far too high a number.

based on what, exactly?

http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-14-00042.1
 Ivana Cvijanovic, Ken Caldeira
Estimating the Contribution of Sea Ice Response to Climate Sensitivity in a Climate Model

(note: this paper only addresses arctic sea ice)

It is estimated that the presence of sea ice in the preindustrial control simulation has a climate effect equivalent to ~3 W m−2 of radiative forcing.

Losing the sea ice in June of 2065 (as opposed to only barely reaching september ice free as is currently modeled)  represents a significant portion of this 3 watts per meter squared (globally averaged!) forcing of course, the regional effects will be much, much higher (as shown by the insolation graph above).

Still, with ECS of 4.5C the 1.8C warming factor, (again globally averaged), that is produced from this additional forcing that is on the scale of a doubling of CO2 (~3.2 Watts/m^2) is a conservative estimate.

do you have a better study or analysis that provides you a scientific basis for your assertions? (no? I didn't think so!)

by the way, in this very thread now you have been shown this paper TWICE already.

http://forum.arctic-sea-ice.net/index.php/topic,1053.msg44760.html#msg44760
where Lennart van der Linde tries to educate you

and
http://forum.arctic-sea-ice.net/index.php/topic,1053.msg45073/topicseen.html#msg45073
where Michael Hauber decides to ignore the study's implications for future rapid sea ice loss because current model results of arctic sea ice extent is "reasonably close" to what is modeled for the CMIP5 (in his mind).

but this is my favorite:

http://forum.arctic-sea-ice.net/index.php/topic,1053.msg44772.html#msg44772

"where there is troll-like behavior, there may well be a troll."
+1

"Mike is a warmist.  just get over him."

+2

[AbruptSLR]

While many studies have found that the recent pause is consistent with moderate projections of climate change, a new study in nature by Brown et al again finds that the pause is consistent with moderate projections of climate change.  But it also finds that the pause is not consistent with the high end projections of climate change.

But is there a way to make the high a high end sensitivity consistent with observations?  It cannot be a higher water vapor or cloud feedback, that would make the inconsistency bigger.  A stronger aerosol forcing could work, however another recent study finds evidence against a stronger than normally accounted for aerosol forcing.

Probably the best candidate would be perma-frost feedback.  This can reconcile a higher climate sensitivity with historical slow warming due to possibly strongly non linear effects which mean that the impact on temperature is low in the past, but much higher in the future.  Recent papers I have pointed to are finding that the permafrost feedback is only likely to add much less than 1 degree by 2100, but this seems to be an area with a great deal of uncertainty and things could still change.

So MH,

In view of the uncertainties associated with climate change projections, do you recommend that society stay on a BAU pathway, until we reach a lower level of uncertainty (more in line with policy maker's fiduciary responsibility to safeguard the public purse)?

ASLR

[Neven]

While many studies have found that the recent pause is consistent with moderate projections of climate change, a new study in nature by Brown et al again finds that the pause is consistent with moderate projections of climate change.  But it also finds that the pause is not consistent with the high end projections of climate change.

What pause? What is pausing? You're confusing me.

Or do you mean the slowdown?

[Michael Hauber]

Yes I know that the sun shines a lot in June.  That has nothing to do with my argument that 1.8 degrees is far too high a number.

based on what, exactly?

I already said based on what:  the loss of Arctic ice in June is about the same amount of NH albedo loss as we have already experienced so far to date once you add in the loss of snow cover.  As this amount of albedo loss was associated with a temperature loss much lower than 1.8, and other factors contributed substantially to the warming (like CO2) this is obviously an overestimate.

http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-14-00042.1
 Ivana Cvijanovic, Ken Caldeira
Estimating the Contribution of Sea Ice Response to Climate Sensitivity in a Climate Model

(note: this paper only addresses arctic sea ice)

It is estimated that the presence of sea ice in the preindustrial control simulation has a climate effect equivalent to ~3 W m−2 of radiative forcing.

Losing the sea ice in June of 2065 (as opposed to only barely reaching september ice free as is currently modeled)  represents a significant portion of this 3 watts per meter squared (globally averaged!) forcing of course, the regional effects will be much, much higher (as shown by the insolation graph above).

Still, with ECS of 4.5C the 1.8C warming factor, (again globally averaged), that is produced from this additional forcing that is on the scale of a doubling of CO2 (~3.2 Watts/m^2) is a conservative estimate.

do you have a better study or analysis that provides you a scientific basis for your assertions? (no? I didn't think so!)

Loss of all sea ice = 3 w/m2

Half lost since 1850 = 1.5 w/m2 cryosphere today
Half of that is included in IPCC models = 0.75 w/m2 (My guess, feel free to find a better number)
doubling of Co2 = 3.7 w/m2 wikipedia
transient climate sensitivity is about 2 degrees skeptical science
Therefore we are talking about 0.2 of a doubling, which gives about 0.4 degrees of extra warming by by 2065 if we lose all the sea ice throughout the period the sun shines strongly, which is not just June, but May and some of April.

[Michael Hauber]

So MH,

In view of the uncertainties associated with climate change projections, do you recommend that society stay on a BAU pathway, until we reach a lower level of uncertainty (more in line with policy maker's fiduciary responsibility to safeguard the public purse)?

ASLR

No.  I recommend that society take action to mitigate against the low possibility of a high sensitivity, and that only when a higher certainty of a moderate (of if we are lucky enough) a low sensitivity is achieved should we consider reducing the amount of action.

[Michael Hauber]

While many studies have found that the recent pause is consistent with moderate projections of climate change, a new study in nature by Brown et al again finds that the pause is consistent with moderate projections of climate change.  But it also finds that the pause is not consistent with the high end projections of climate change.

What pause? What is pausing? You're confusing me.

Or do you mean the slowdown?

Whatever it is called Brown et al finds that it is not consistent with a high estimate of climate sensitivity.  I like pause as a term because it implies that it is only temporary.  What tamino shows is that the 'thing' did not start around 1998.  We had some hot years from 2002 to 2006, and then some cooler years afterwards, particularly in 2008, and 2011.  In my opinion the 'thing' started in 2008 and was mostly associated with two strong multi-year La Nina events, with maybe a little help from low solar and/or volcanic aerosols.

[Csnavywx]

It starts getting very sticky when we start talking about losing sea ice earlier in the summer, namely because of the annual heat loss in the fall. There's a significant difference between the broken or thin (but still intact) summer ice cover that we have today and a scenario where we lose all ice cover by say.. the end of July. Saturation vapor pressure increases rapidly with temperature. In fact, saturated mixing ratios double between 0 and 10C. Mixed layer ocean temperatures increase rapidly with the total loss of ice under full sun, helping push up near-surface temperatures quite quickly. That will inevitably lead to a marked increase in low-level instability and convective cloudiness in autumn.

There's a reason we see extensive forests in the high Arctic during previous interglacials in the paleo record.

[jai mitchell]

Yes I know that the sun shines a lot in June.  That has nothing to do with my argument that 1.8 degrees is far too high a number.

based on what, exactly?

I already said based on what:  the loss of Arctic ice in June is about the same amount of NH albedo loss as we have already experienced so far to date once you add in the loss of snow cover.  As this amount of albedo loss was associated with a temperature loss much lower than 1.8, and other factors contributed substantially to the warming (like CO2) this is obviously an overestimate.

prove it.

Tell me how NH snow anomalies from 1985 to today are equal to 10 million square kilometers, in addition, since the lower latitude snow cover anomalies receive lower solar insolation AND it has a much lower albedo than sea ice (as well as bare earth with a higher albedo than ocean water!) so increase the snow anomaly by at least 30% to find the arctic sea ice June 21 equivalent. what do you get?

1 millions square kilometers sea ice anomaly in June 21 (lowest year 2012)
and
1 million square kilometers of snow cover anomaly average month of July

http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=7

clearly you are just making this stuff up.

http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-14-00042.1
 Ivana Cvijanovic, Ken Caldeira
Estimating the Contribution of Sea Ice Response to Climate Sensitivity in a Climate Model

(note: this paper only addresses arctic sea ice)

It is estimated that the presence of sea ice in the preindustrial control simulation has a climate effect equivalent to ~3 W m−2 of radiative forcing.

Losing the sea ice in June of 2065 (as opposed to only barely reaching september ice free as is currently modeled)  represents a significant portion of this 3 watts per meter squared (globally averaged!) forcing of course, the regional effects will be much, much higher (as shown by the insolation graph above).

Still, with ECS of 4.5C the 1.8C warming factor, (again globally averaged), that is produced from this additional forcing that is on the scale of a doubling of CO2 (~3.2 Watts/m^2) is a conservative estimate.

do you have a better study or analysis that provides you a scientific basis for your assertions? (no? I didn't think so!)

Loss of all sea ice = 3 w/m2

Half lost since 1850 = 1.5 w/m2 cryosphere today

You are still making stuff up!  This isn't what the paper is saying. I already told you what it said.  you didn't read the paper. . .doh!

Half of that is included in IPCC models = 0.75 w/m2 (My guess, feel free to find a better number)
doubling of Co2 = 3.7 w/m2 wikipedia

I am sorry, you are simply making stuff up, and really don't have a clue what you are talking about.  forget it.  there has been only 1 million km^2 lost by June 21 on the worst year, to compare albedo effects we have to normalize for seasonal solar incident radiation.

transient climate sensitivity is about 2 degrees skeptical science
Therefore we are talking about 0.2 of a doubling, which gives about 0.4 degrees of extra warming by by 2065 if we lose all the sea ice throughout the period the sun shines strongly, which is not just June, but May and some of April.

No, it doesn't say that at all, by the way your simple math indicates that you claim an ECS of 2.0  That is pretty funny.

your a funny funny guy MH.

[Michael Hauber]

prove it.

Tell me how NH snow anomalies from 1985 to today are equal to 10 million square kilometers, in addition, since the lower latitude snow cover anomalies receive lower solar insolation AND it has a much lower albedo than sea ice (as well as bare earth with a higher albedo than ocean water!) so increase the snow anomaly by at least 30% to find the arctic sea ice June 21 equivalent. what do you get?

1 millions square kilometers sea ice anomaly in June 21 (lowest year 2012)
and
1 million square kilometers of snow cover anomaly average month of July

http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=7

clearly you are just making this stuff up.

Go look up what I wrote in my first response on this topic.  I referenced everything there.  I'm not repeating because you are too lazy to read it and simply want to say 'not true, prove it'.
 

Loss of all sea ice = 3 w/m2

Half lost since 1850 = 1.5 w/m2 cryosphere today

You are still making stuff up!  This isn't what the paper is saying. I already told you what it said.  you didn't read the paper. . .doh!

The paper clearly states that it is loss of Arctic sea ice since pre-industrial – which is 1850.  The cryosphere today chart shows that a lot of ice has been lost since 1850 .   This is an important factor which will reduce the amount of warming that we will get between now and 2065 due to loss of the sea ice.  We aren’t losing all of the ice all over again, but only part of it.  I estimate very roughly at 50%.  Feel free to come up with a better number.

Half of that is included in IPCC models = 0.75 w/m2 (My guess, feel free to find a better number)
doubling of Co2 = 3.7 w/m2 wikipedia

I am sorry, you are simply making stuff up, and really don't have a clue what you are talking about.  forget it.  there has been only 1 million km^2 lost by June 21 on the worst year, to compare albedo effects we have to normalize for seasonal solar incident radiation.

You claimed that the 1.8 degrees is in addition to what the IPCC include in their models.  As the IPCC include significant sea ice lost by 2065, this figure must be reduced by what the IPCC include in their model.  Again I estimate that the amount of ice left in the IPCC models in 2065 is roughly half of the sea ice that we have today.  Feel free to come up with a better number.

transient climate sensitivity is about 2 degrees skeptical science
Therefore we are talking about 0.2 of a doubling, which gives about 0.4 degrees of extra warming by by 2065 if we lose all the sea ice throughout the period the sun shines strongly, which is not just June, but May and some of April.

No, it doesn't say that at all, by the way your simple math indicates that you claim an ECS of 2.0  That is pretty funny.

your a funny funny guy MH.

It says:

The TCR is basically how much the planet will immediately warm once we reach the level of doubled CO2.  The IPCC puts the TCR very likely above 1°C and below 3°C, with a most likely immediate warming of about 2°C in response to doubled CO2.p

You are claiming that we should use the equilibrium climate response to estimate the amount of warming by 2065 for losing the sea ice.  That is wrong as it takes thousands of years to reach equilibrium.  The correct calculation is to use the transient climate response (for an estimate at least, more correct is to actually model the thing).  The transient climate response is about 2 degrees.

[jai mitchell]

Go look up what I wrote in my first response on this topic.  I referenced everything there.  I'm not repeating because you are too lazy to read it and simply want to say 'not true, prove it'.

I did look it up, you are claiming that recent northern hemisphere snow cover anomalies are analogous to arctic sea ice losses in 2065.  I have shown you that the total area anomalies for the month of July are about 1/10th of the arctic sea ice loss AND that the albedo effect of snow loss is about 1/3 the effect of sea ice loss.

funny how you don't mention those points. . .

you are claiming that an effect that is 1/30th of the actual impact of June 21 summer sea ice loss is comparable to summer sea ice loss by June 21. 

This is laughable.

what do you think happens to snow anomalies when the summer sea ice is COMPLETELY GONE in June 21, 2065?

[Neven]

Thanks for the edit, jai. 

[Michael Hauber]

Go look up what I wrote in my first response on this topic.  I referenced everything there.  I'm not repeating because you are too lazy to read it and simply want to say 'not true, prove it'.

I did look it up, you are claiming that recent northern hemisphere snow cover anomalies are analogous to arctic sea ice losses in 2065.  I have shown you that the total area anomalies for the month of July are about 1/10th of the arctic sea ice loss AND that the albedo effect of snow loss is about 1/3 the effect of sea ice loss.

funny how you don't mention those points. . .

you are claiming that an effect that is 1/30th of the actual impact of June 21 summer sea ice loss is comparable to summer sea ice loss by June 21. 

This is laughable.

what do you think happens to snow anomalies when the summer sea ice is COMPLETELY GONE in June 21, 2065?

5million sq kilometres lost in June.  2m lost in July.  Average 3.5.  Sea ice lost is 2

So 5.5 m sq kilometers of NH summer ice lost since about 1960. 

0.6 degrees of warming since 1960.  I guess 0.2 is forced, 0.2 is cloud and albedo feedback, and 0.2 is ice feecback.  This gives 0.04 degrees of warming per 1m sq kilometers of ice lost.

Current Arctic sea ice in June = 8m.  So loss of Arctic ice by this rough estimate would be maybe 0.32 degrees.

Now lets pretend I believe your claim that the albedo of snow is so poor that it is only 1/3rd the effect of sea ice.  That would be 3m km2 lost since about 1960.  Lets pretend there is 0 water vapor or cloud feedback, but that climate sensitivity is still 3 degrees, and all the feedbacks are sea ice.  That is 0.4 degrees of warming, or 0.13 ded/sq km.  So we get just over 1 degree of warming for loss of 8m square kilometres of sea ice.  Thats still just barely half of what you claimed.

The figure of 1.8 degrees is nonsense.

[AbruptSLR]

You are claiming that we should use the equilibrium climate response to estimate the amount of warming by 2065 for losing the sea ice.  That is wrong as it takes thousands of years to reach equilibrium.  The correct calculation is to use the transient climate response (for an estimate at least, more correct is to actually model the thing).  The transient climate response is about 2 degrees.

The two attached images from my Reply #636, shows that the temperature increase associated with ECS values are almost fully realized in just over 100 years; while under traditional thinking ESS is almost fully realized within thousands of years (however, many significant ESS feedback mechanisms appear to be accelerating much faster (even within decades) than traditionally believed would be the case, apparently due to the extremely rapid rate of our current anthropogenic radiative forcing pathway).

[Michael Hauber]

You are claiming that we should use the equilibrium climate response to estimate the amount of warming by 2065 for losing the sea ice.  That is wrong as it takes thousands of years to reach equilibrium.  The correct calculation is to use the transient climate response (for an estimate at least, more correct is to actually model the thing).  The transient climate response is about 2 degrees.

The two attached images from my Reply #636, shows that the temperature increase associated with ECS values are almost fully realized in just over 100 years; while under traditional thinking ESS is almost fully realized within thousands of years (however, many significant ESS feedback mechanisms appear to be accelerating much faster (even within decades) than traditionally believed would be the case, apparently due to the extremely rapid rate of our current anthropogenic radiative forcing pathway).

The diagram shows that after 65 years the response is almost exactly 2 degrees, which is the transient climate sensitivity I said should be used for the calculation. 

If ESS feedbacks are being substantially realised on a decade scale then have seen them by now as we have had over a century of Co2 increase.  If we have seen the feedbacks in the last century of warming then they are not all that high, as warming is slightly below what the IPCC project.

As a reminder:  CMIP modelled rate from 1975 to now: 2.3 deg/century.
Observed warming rate from 1975 to now (well before the pause, which Neven correctly points out is significantly overhyped): 1.7 dec/century.

[AbruptSLR]

You are claiming that we should use the equilibrium climate response to estimate the amount of warming by 2065 for losing the sea ice.  That is wrong as it takes thousands of years to reach equilibrium.  The correct calculation is to use the transient climate response (for an estimate at least, more correct is to actually model the thing).  The transient climate response is about 2 degrees.

The two attached images from my Reply #636, shows that the temperature increase associated with ECS values are almost fully realized in just over 100 years; while under traditional thinking ESS is almost fully realized within thousands of years (however, many significant ESS feedback mechanisms appear to be accelerating much faster (even within decades) than traditionally believed would be the case, apparently due to the extremely rapid rate of our current anthropogenic radiative forcing pathway).

The diagram shows that after 65 years the response is almost exactly 2 degrees, which is the transient climate sensitivity I said should be used for the calculation. 

If ESS feedbacks are being substantially realised on a decade scale then have seen them by now as we have had over a century of Co2 increase.  If we have seen the feedbacks in the last century of warming then they are not all that high, as warming is slightly below what the IPCC project.

As a reminder:  CMIP modelled rate from 1975 to now: 2.3 deg/century.
Observed warming rate from 1975 to now (well before the pause, which Neven correctly points out is significantly overhyped): 1.7 dec/century.

This figure also implies that the mean value for model projected ECS is 3.5C (not 3C).  Also, both I & jai have posted hundreds of Replies in this ASI Forum citing evidence for the acceleration of non-ECS feedback factors (observable now); and I hope that the ACME program will be able to better quantify the expected accelerations of these numerous positive feedbacks before we actually observe them in the coming decades.

[Michael Hauber]

This figure also implies that the mean value for model projected ECS is 3.5C (not 3C).  Also, both I & jai have posted hundreds of Replies in this ASI Forum citing evidence for the acceleration of non-ECS feedback factors (observable now); and I hope that the ACME program will be able to better quantify the expected accelerations of these numerous positive feedbacks before we actually observe them in the coming decades.

Are you trying to dispute my claim that 2 degrees (as transient climate sensitivity) is the correct figure to calculate the amount of warming by 2065 for the loss of Arctic sea ice?

If non-ECS feedback factors are observable now then why is the observed temperature increase a little lower than that predicted, and not just for the recent pause/slowdown, but going back to 1975?

[jai mitchell]

So we get just over 1 degree of warming for loss of 8m square kilometres of sea ice.  Thats still just barely half of what you claimed.

The figure of 1.8 degrees is nonsense.

1/3 of 6 is 2 not 3  That changes your calculation to 1.3

And if ECS is actually 4.5+ ? and not 3.0 as you claim? 

My 1.8C is an estimate based on the expected forcing value of summer solstice sea ice loss (about 2.2 Watts per meter squared globally averaged)  and a climate sensitivity of 4.5.  However, once we lose most of the sea ice we will see rapid regional warming as ice melt occurs under a steady state (phase change) temperature of zero. 

Therefore will will see a significant jump in temperatures once the ice is melted.  This is above and beyond your simplistic ice cover analysis (which by the way, only proves my 1.8C value is conservative).

In addition, since you wanted to include snow cover anomaly in your calculation, you neglect to include snow anomalies that would also occur under my scenario, here's a hint, there will be more early snow cover reductions if sea ice is gone by June 21.  Currently average snowcover in April is 28.6 million kilometers.  May is 17 million square kilometers and June is 7 million.  These values will decline significantly under the conditions of 6-7 degrees of additional (from today) regional warming under the 2065 scenario I have laid out.  (note: I said regional warming, this means in the arctic with arctic amplification).

[AbruptSLR]

Are you trying to dispute my claim that 2 degrees (as transient climate sensitivity) is the correct figure to calculate the amount of warming by 2065 for the loss of Arctic sea ice?

If non-ECS feedback factors are observable now then why is the observed temperature increase a little lower than that predicted, and not just for the recent pause/slowdown, but going back to 1975?

While I am not challenging whether a 2C TCR is right or not, I am pointing out that for the CMIP5 projections a 2C TCR roughly corresponds to an ECS of 3.5C.  Furthermore, I make the following points:

First, transient climate response (TCR) is defined as the average temperature response over a twenty-year period centered at CO2 doubling in a transient simulation with CO2 increasing at 1% per year.

Second, equilibrium climate sensitivity (ECS) can be estimated by combining the transient climate sensitivity with the known properties of the ocean reservoirs (this means only the upper ocean) and the surface heat fluxes (which includes the influence of sea ice and snow albedo).  However, if the climate models used to estimate ECS are underestimating changes in sea ice extent and snow coverage, then they may also be underestimating ECS.

Finally, the non-ECS ESS feedback mechanisms are either accelerating slowly, and/or have been masked by various effects including: aerosols, ocean heat uptake, instrument coverage bias, chaotic signals, etc.

[Michael Hauber]

1/3 of 6 is 2 not 3  That changes your calculation to 1.3

You said 1/3rd of the snow, which is 3.5, so divided by 3 is 1.2  Then add 2 million square kilometres of sea ice, which is what I did in the original calculation.

And if ECS is actually 4.5+ ? and not 3.0 as you claim? 

If you want to talk about the amount of warming that will be experienced in 100s or 1000s of years then the equilibrium climate sensitivity is appropriate.  If you want to talk about the warming by 2065 then the transient climate sensitivity of 2 is what should be used.

And its not just me claiming 3.0, it is the consensus of the world's best climate scientists as the best estimate, with an error bar that allows up to 4.5 and as low as 1.5.  What if climate sensitivity is 1.5?

My 1.8C is an estimate based on the expected forcing value of summer solstice sea ice loss (about 2.2 Watts per meter squared globally averaged)  and a climate sensitivity of 4.5.  However, once we lose most of the sea ice we will see rapid regional warming as ice melt occurs under a steady state (phase change) temperature of zero. 

2.2 or 3.0?  The 3.0 figure was what you quoted before, but that was for loss of ice from pre-industrial.  2.2 would seem quite plausible for loss of sea ice from now, but I would be interested in any source for that.

And your calculation does not calculate the amount of warming above what IPCC project between now and 2065 for Arctic sea ice loss.  It calculates the amount of warming compared to maximum sea ice (1850 for the 3.0 figure, not sure what the 2.2 might be based on) that will be experienced when equilibrium is reached.

Therefore will will see a significant jump in temperatures once the ice is melted.  This is above and beyond your simplistic ice cover analysis (which by the way, only proves my 1.8C value is conservative).

Every time we melt a million square kilometres of ice the earths albedo goes down, and the temperature goes up.  Once its all melted there is no more albedo reduction, and so no further reasons for the temperature to go up except lags, so the temperature increase will gradually approach equilibrium.  Your 1.8 calculation is still nonsense.

In addition, since you wanted to include snow cover anomaly in your calculation, you neglect to include snow anomalies that would also occur under my scenario, here's a hint, there will be more early snow cover reductions if sea ice is gone by June 21.  Currently average snowcover in April is 28.6 million kilometers.  May is 17 million square kilometers and June is 7 million.  These values will decline significantly under the conditions of 6-7 degrees of additional (from today) regional warming under the 2065 scenario I have laid out.  (note: I said regional warming, this means in the arctic with arctic amplification).

I included snow cover in my calculation as it is one of the reasons why the world has become warmer in the last 40 years.  I find out how much the world has warmed, and divide it between the reasons why the world became warmer and I estimate the amount of warming for each factor.

You can include snow cover reduction in your calculation if you want for the amount of warming in the future, but then it is no longer amount of warming due to arctic sea ice loss, but amount of warming due to sea ice and snow cover loss.

Mathematics does not work on the concept of fairness - just because I include something doesn't mean its only fair that you include it - it works on the concept of correctness.  My calculation is correct, your is not.

[Lennart van der Linde]

Climate sensitivity under-estimated?
http://onlinelibrary.wiley.com/doi/10.1002/2015GL064119/abstract?utm_content=buffer3428e&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

"Despite decades of climate research and model development, two outstanding problems still plague the latest global climate models (GCMs): The double-intertropical convergence zone (ITCZ) bias and the 2−5°C spread of equilibrium climate sensitivity (ECS). Here we show that the double-ITCZ bias and ECS in 44 GCMs from Coupled Model Intercomparison Project Phases 3/5 are negatively correlated. The models with weak (strong) double-ITCZ biases have high (low) ECS values of ~4.1(2.2)°C. This indicates that the double-ITCZ bias is a new emergent constraint for ECS based on which ECS might be in the higher end of its range (~4.0°C) and most models might have underestimated ECS. In addition, we argue that the double-ITCZ bias can physically affect both cloud and water vapor feedbacks (thus ECS) and is a more easily measured emergent constraint for ECS than previous ones. It can be used as a performance metric for evaluating and comparing different GCMs."

[AbruptSLR]

Lennart,

Thank you very much for the link to the Baijun Tian (2015), "Spread of Model Climate Sensitivity Linked to Double-Intertropical Convergence Zone Bias", Geophysical Research Letters, DOI: 10.1002/2015GL064119, paper.

The following linked Wang et al (2015) reference indicates that the cause of the double-ITCZ bias in the CAM5 model is focused on its modeling of the Eastern Tropical Pacific, which may help to explain why Stevens misses the positive cloud feedback signal as he does not give as much significance to the Eastern Tropical Pacific (which is heavily influenced by the ENSO) as do researchers such as Trenberth and Sherwood, who pay particular attention to the Tropical Pacific and the influence of the ENSO.

On the face of it, this evidence seems to strengthen the probability that ECS is relatively close to 4.1C; which would have profound impacts on society moving forward.

Chia-Chi Wang, Wei-Liang Lee, Yu-Luen Chen, and Huang-Hsiung Hsu (2015), "Processes Leading to Double Intertropical Convergence Zone Bias in CESM1/CAM5", J. Climate, 28, 2900–2915, doi: http://dx.doi.org/10.1175/JCLI-D-14-00622.1

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00622.1

"The double intertropical convergence zone (ITCZ) bias in the eastern Pacific in the Community Earth System Model version 1 with Community Atmosphere Model version 5 (CESM1/CAM5) is diagnosed. In CAM5 standalone, the northern ITCZ is associated with inertial instability and the southern ITCZ is thermally forced. After air–sea coupling, the processes on both hemispheres are switched because the spatial pattern of sea surface temperature (SST) is changed.
Biases occur during boreal spring in both CAM5 and the ocean model. In CAM5 alone, weaker-than-observed equatorial easterly in the tropical eastern South Pacific leads to weaker evaporation and an increase in local SST. The shallow meridional circulation overly converges in the same region in the CAM5 standalone simulation, the planetary boundary layer and middle troposphere are too humid, and the large-scale subsidence is too weak at the middle levels. These biases may result from excessive shallow convection behavior in CAM5. The extra moisture would then fuel stronger convection and a higher precipitation rate in the southeastern Pacific.
In the ocean model, the South Equatorial Current is underestimated and the North Equatorial Countercurrent is located too close to the equator, causing a warm SST bias in the southeastern Pacific and a cold bias in the northeastern Pacific. These SST biases feed back to the atmosphere and further influence convection and the surface wind biases in the coupled simulation. When the convection in the tropical northeastern Pacific becomes thermally forced after coupling, the northern ITCZ is diminished due to colder SST, forming the so-called alternating ITCZ bias."

Best,
ASLR

[jai mitchell]

The 3.0 figure was what you quoted before, but that was for loss of ice from pre-industrial.  2.2 would seem quite plausible for loss of sea ice from now, but I would be interested in any source for that.

And your calculation does not calculate the amount of warming above what IPCC project between now and 2065 for Arctic sea ice loss.  It calculates the amount of warming compared to maximum sea ice (1850 for the 3.0 figure, not sure what the 2.2 might be based on) that will be experienced when equilibrium is reached.

http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-14-00042.1

The 3.0 Watts per meter squared is the value from the referenced paper (really, this is the fourth time you have been shown this now!)  It is the value of forcing that occurs if one completely removes all arctic sea ice from the models for a full year.  Since the amount of forcing due to a total loss of sea ice by June 21 is a significant portion of that forcing I estimate the forcing value to be about 2.2 Watts per meter squared.

really, why do I even bother talking to you when you don't bother to read the things I write or the papers that I share with you to show the scientific background to what I am saying?

   

• Reduction in Ocean DMS production - .4C
• Reduction in Lowngwave IR emissivity of ice in arctic - .13C
• Loss of the Amazon Forest - .5C
• Accelerated loss of permafrost due to sea ice loss (with microbial decomposition) - .7C by 2100
• Loss of boreal forest and boreal peat - .4C in black carbon and GHG
• Decreased arctic ocean albedo due to algae increase - .3C
• total loss of arctic summer solstice sea ice by 2065 - 1.8C

you are trying to argue a small portion of this list, which is in itself a small subset of the forcings that are not included in the ECS calculus, you decide to move the goalposts and argue about TCR when you lose the argument about ECS and refuse to acknowledge when you are being corrected in your arguments.  Like when you were shown clearly that frozen soils are not part of what the CMIP5 model runs consider "carbon cycle".

Once its all melted there is no more albedo reduction, and so no further reasons for the temperature to go up except lags, so the temperature increase will gradually approach equilibrium.

And this is really where we have our problem with you.  Place a glass of ice water under a heat lamp.  place a thermometer inside that water glass.

I guarantee you that that glass will be at zero degrees centigrade until the moment the last bit of ice melts.  Then it will start to rise rapidly.

[AbruptSLR]

Climate sensitivity under-estimated?
http://onlinelibrary.wiley.com/doi/10.1002/2015GL064119/abstract?utm_content=buffer3428e&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

"Despite decades of climate research and model development, two outstanding problems still plague the latest global climate models (GCMs): The double-intertropical convergence zone (ITCZ) bias and the 2−5°C spread of equilibrium climate sensitivity (ECS). Here we show that the double-ITCZ bias and ECS in 44 GCMs from Coupled Model Intercomparison Project Phases 3/5 are negatively correlated. The models with weak (strong) double-ITCZ biases have high (low) ECS values of ~4.1(2.2)°C. This indicates that the double-ITCZ bias is a new emergent constraint for ECS based on which ECS might be in the higher end of its range (~4.0°C) and most models might have underestimated ECS. In addition, we argue that the double-ITCZ bias can physically affect both cloud and water vapor feedbacks (thus ECS) and is a more easily measured emergent constraint for ECS than previous ones. It can be used as a performance metric for evaluating and comparing different GCMs."

Needless to say the Baijun Tian (2015) findings that you quote fully support the following findings presented by Sherwood et al (2014), which found that ECS cannot be less than 3C, and is likely currently in the 4.1C range.  Also, everyone should remember that the effective ECS is not a constant, and models project that following a BAU pathway will result in the effective ECS increasing this century:


Sherwood, S.C., Bony, S. and Dufresne, J.-L., (2014) "Spread in model climate sensitivity traced to atmospheric convective mixing", Nature; Volume: 505, pp 37–42, doi:10.1038/nature12829

http://www.nature.com/nature/journal/v505/n7481/full/nature12829.html


Quote from Sherwood (2014): “Climate sceptics like to criticize climate models for getting things wrong, and we are the first to admit they are not perfect, but what we are finding is that the mistakes are being made by those models which predict less warming, not those that predict more,” said Prof. Sherwood.
“Rises in global average temperatures of this magnitude will have profound impacts on the world and the economies of many countries if we don’t urgently start to curb our emissions."

[AbruptSLR]

Are you trying to dispute my claim that 2 degrees (as transient climate sensitivity) is the correct figure to calculate the amount of warming by 2065 for the loss of Arctic sea ice?

If non-ECS feedback factors are observable now then why is the observed temperature increase a little lower than that predicted, and not just for the recent pause/slowdown, but going back to 1975?

While I am not challenging whether a 2C TCR is right or not, I am pointing out that for the CMIP5 projections a 2C TCR roughly corresponds to an ECS of 3.5C.  Furthermore, I make the following points:

First, transient climate response (TCR) is defined as the average temperature response over a twenty-year period centered at CO2 doubling in a transient simulation with CO2 increasing at 1% per year.

Second, equilibrium climate sensitivity (ECS) can be estimated by combining the transient climate sensitivity with the known properties of the ocean reservoirs (this means only the upper ocean) and the surface heat fluxes (which includes the influence of sea ice and snow albedo).  However, if the climate models used to estimate ECS are underestimating changes in sea ice extent and snow coverage, then they may also be underestimating ECS.

Finally, the non-ECS ESS feedback mechanisms are either accelerating slowly, and/or have been masked by various effects including: aerosols, ocean heat uptake, instrument coverage bias, chaotic signals, etc.

The attached image from the linked presentation by Armour at the Ringberg 2015 Workshop, demonstrates: (a) it is very important to cite whether the TCR that one is talking about is at some stated period of time after forcing begins (say 20, 40 or 70 years after forcing begins), because the number increases with time; (b) that a TCR of 2C after 65 years (as MH cited) is indeed close to an ECS value of 3.5C (as I stated); and (c) the Armour analysis does not consider the possibility of other positive feedback factors becoming more active with increasing warming which would further increase the effective ECS this century (beyond the values cited by Armour).

http://www.mpimet.mpg.de/fileadmin/atmosphaere/WCRP_Grand_Challenge_Workshop/Ringberg_2015/Talks/Armour_23032015.pdf