Conservative Scientists & its Consequences

[AbruptSLR]

The linked reference indicates that current climate models over-estimate the influence of DMS on climate response.  In order to correct for this over-estimation future models will likely need to increase the effectiveness of aerosol forcing and feedback.  If so this would imply that climate scientists have once again erred on the side of least drama with regard to the impacts on climate change as aerosol emissions are reduced:

Erik Hans Hoffmann, Andreas Tilgner, Roland Schrödner, Peter Bräuer, Ralf Wolke and Hartmut Herrmann (November 2016), "An advanced modeling study on the impacts and atmospheric implications of multiphase dimethyl sulfide chemistry", PNAS, vol. 113 no. 42,  11776–11781, doi: 10.1073/pnas.1606320113

http://www.pnas.org/content/113/42/11776

Abstract: "Oceans dominate emissions of dimethyl sulfide (DMS), the major natural sulfur source. DMS is important for the formation of non-sea salt sulfate (nss-SO42−) aerosols and secondary particulate matter over oceans and thus, significantly influence global climate. The mechanism of DMS oxidation has accordingly been investigated in several different model studies in the past. However, these studies had restricted oxidation mechanisms that mostly underrepresented important aqueous-phase chemical processes. These neglected but highly effective processes strongly impact direct product yields of DMS oxidation, thereby affecting the climatic influence of aerosols. To address these shortfalls, an extensive multiphase DMS chemistry mechanism, the Chemical Aqueous Phase Radical Mechanism DMS Module 1.0, was developed and used in detailed model investigations of multiphase DMS chemistry in the marine boundary layer. The performed model studies confirmed the importance of aqueous-phase chemistry for the fate of DMS and its oxidation products. Aqueous-phase processes significantly reduce the yield of sulfur dioxide and increase that of methyl sulfonic acid (MSA), which is needed to close the gap between modeled and measured MSA concentrations. Finally, the simulations imply that multiphase DMS oxidation produces equal amounts of MSA and sulfate, a result that has significant implications for nss-SO42− aerosol formation, cloud condensation nuclei concentration, and cloud albedo over oceans. Our findings show the deficiencies of parameterizations currently used in higher-scale models, which only treat gas-phase chemistry. Overall, this study shows that treatment of DMS chemistry in both gas and aqueous phases is essential to improve the accuracy of model predictions."

[Theta]

New paper that states that earth could warm up to 7C within human lifetimes

https://forum.arctic-sea-ice.net/index.php?action=post;topic=1053.1550;last_msg=93367

Global mean surface temperatures are rising in response to anthropogenic greenhouse gas emissions. The magnitude of this warming at equilibrium for a given radiative forcing—referred to as specific equilibrium climate sensitivity (S)—is still subject to uncertainties. We estimate global mean temperature variations and S using a 784,000-year-long field reconstruction of sea surface temperatures and a transient paleoclimate model simulation. Our results reveal that S is strongly dependent on the climate background state, with significantly larger values attained during warm phases. Using the Representative Concentration Pathway 8.5 for future greenhouse radiative forcing, we find that the range of paleo-based estimates of Earth’s future warming by 2100 CE overlaps with the upper range of climate simulations conducted as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Furthermore, we find that within the 21st century, global mean temperatures will very likely exceed maximum levels reconstructed for the last 784,000 years. On the basis of temperature data from eight glacial cycles, our results provide an independent validation of the magnitude of current CMIP5 warming projections.

Also, news sources stating that with this, we could end up with Venus Syndrome type warming if we don't stop with our emmissions (economic difficulties will put a stop to them, but with the self-reinforcing feedbacks set in, I'd say Venus is already baked in and most likely this decade or century))

http://www.independent.co.uk/news/science/climate-change-game-over-global-warming-climate-sensitivity-seven-degrees-a7407881.html

But, if leading scientists writing in one of the most respected academic journals are right, planet Earth could be on course for global warming of more than seven degrees Celsius within a lifetime.

And that, according to one of the world’s most renowned climatologists, could be “game over” – particularly given the imminent presence of climate change denier Donald Trump in the White House.

[AbruptSLR]

New paper that states that earth could warm up to 7C within human lifetimes

Further to this point, the linked reference indicated that the projected GMSTA range could be between 4.78C to 7.36C by 2100, based on one set of calculations (see the attached image).

Tobias Friedrich, Axel Timmermann, Michelle Tigchelaar, Oliver Elison Timm and Andrey Ganopolski (09 Nov 2016), "Nonlinear climate sensitivity and its implications for future greenhouse warming", Science Advances, Vol. 2, no. 11, e1501923, DOI: 10.1126/sciadv.1501923

http://advances.sciencemag.org/content/2/11/e1501923

Extract: "Global mean surface temperatures are rising in response to anthropogenic greenhouse gas emissions. The magnitude of this warming at equilibrium for a given radiative forcing—referred to as specific equilibrium climate sensitivity (S)—is still subject to uncertainties. We estimate global mean temperature variations and S using a 784,000-year-long field reconstruction of sea surface temperatures and a transient paleoclimate model simulation. Our results reveal that S is strongly dependent on the climate background state, with significantly larger values attained during warm phases. Using the Representative Concentration Pathway 8.5 for future greenhouse radiative forcing, we find that the range of paleo-based estimates of Earth’s future warming by 2100 CE overlaps with the upper range of climate simulations conducted as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Furthermore, we find that within the 21st century, global mean temperatures will very likely exceed maximum levels reconstructed for the last 784,000 years. On the basis of temperature data from eight glacial cycles, our results provide an independent validation of the magnitude of current CMIP5 warming projections."

[AbruptSLR]

Further to this point, the linked reference indicated that the projected GMSTA range could be between 4.78C to 7.36C by 2100, based on one set of calculations (see the attached image).

The linked article helps to clarify how higher the paleo-based climate sensitivity that Friedrich et al (2016) found vs CMIP5 (see attached image):

http://www.sciencealert.com/scientists-say-it-could-already-be-game-over-for-climate-change

Extract: "Scientists are now saying it might already be too late to avoid a temperature rise of up to 7.36 degrees Celsius (13.25 degrees Fahrenheit) above pre-industrial levels by 2100.
That's way above the upper limit of 4.8 degrees Celsius (8.6 degrees Fahrenheit) predicted by the Intergovernmental Panel on Climate Change (IPCC) in 2014, and to make matters worse, a new study suggests that we're underestimating just how sensitive Earth is to greenhouse gases.
…
From this data, they concluded that Earth becomes more sensitive to warming in interglacial warming phases (periods between ice ages), like the one we're now in.
The researchers also calculated there will be a "likely" temperature increase of between 4.78 and 7.36 degrees Celsius (8.6 and 13.25 degrees Fahrenheit) above pre-industrial levels over the next 85 years if greenhouse gas emissions continue at their current rate,.
That means it's absolutely vital that we get those emissions down as quickly as possible.
Because a 7.36-degree Celsius (13.25-degree Fahrenheit) rise would effectively be "game over" for the planet as we know it, climatologist Michael Mann from Penn State University, who wasn't involved in the research, told Ian Johnston at The Independent."

[AbruptSLR]

The linked article further clarifies that the Friedrich et al (2016) study indicates that for current conditions the effective ECS may be about 5C:

http://www.thefosterlab.org/blog/2016/11/12/future-relevant-climate-sensitivity-part-deux

Extract: "The Friedrich et al (2016) study used a new empirical estimate of Surface Air Temperature (SAT) based on a compilation of Sea Surface Temperatures (as did Snyder recently) and a complete assessment of the processes “forcing” climate change over the last ~800 thousand years (e.g. CO2, land-ice albedo, and dust) to identify that climate sensitivity changed as a function of climate state: they found it was ~1.8 K per CO2 doubling when the Earth was substantially colder than today and ~5K per doubling when the Earth was only a little bit colder than the pre-industrial."

See also & the associated image:

von der Heydt, A.S., Dijkstra, H.A., van de Wal, R.S.W. et al. (2016), "Lessons on Climate Sensitivity From Past Climate Changes", Curr Clim Change Rep 2: 148. doi:10.1007/s40641-016-0049-3

http://link.springer.com/article/10.1007/s40641-016-0049-3
&
http://download.springer.com/static/pdf/124/art%253A10.1007%252Fs40641-016-0049-3.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs40641-016-0049-3&token2=exp=1478975776~acl=%2Fstatic%2Fpdf%2F124%2Fart%25253A10.1007%25252Fs40641-016-0049-3.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs40641-016-0049-3*~hmac=9ccae885f2cf370659bc3f7efb5b35f12c353a316b3e4ece1e7d2f9d1eb56221

Abstract: "Over the last decade, our understanding of climate sensitivity has improved considerably. The climate system shows variability on many timescales, is subject to non-stationary forcing and it is most likely out of equilibrium with the changes in the radiative forcing. Slow and fast feedbacks complicate the interpretation of geological records as feedback strengths vary over time. In the geological past, the forcing timescales were different than at present, suggesting that the response may have behaved differently. Do these insights constrain the climate sensitivity relevant for the present day? In this paper, we review the progress made in theoretical understanding of climate sensitivity and on the estimation of climate sensitivity from proxy records. Particular focus lies on the background state dependence of feedback processes and on the impact of tipping points on the climate system. We suggest how to further use palaeo data to advance our understanding of the currently ongoing climate change."


Caption for the attached image, Figure 2: "Schematic of the phase diagram of a climate model with two stable coexisting climate states. The shape of the S curve follows closely that discussed in [62–64]; see also [65]. The climate sensitivity parameter S is defined on each of the stable branches as the local slope of the global mean surface temperature T versus the (logarithm of) atmospheric pCO2 (cf. Eq. 8 ). Type I state dependence: When starting at point A (e.g. the pre-industrial climate), the temperature increase after a doubling of pCO2 (point B) is smaller than when starting from a colder climate (point C) on the same branch. Type II state dependence: When the initial pCO2 is the same as in point A, but the climate is initially on the cold branch (point D), a doubling of pCO2 results in a smaller temperature increase (point E) than if starting from point A and ending in point B. S becomes undefined at the transition points (open squares) between the two branches. The conditional climate sensitivity is equal to S for small perturbations (going from points D to E), but largely increases if the perturbation in CO2 is large enough to move the system from point D beyond the bifurcation point (blue open square) and jumps to the warm branch. Note that S is generally defined as a local gradient, while the 2xCO2 definition in the ECS may involve a perturbation too large for the linear assumption along the branch to be applicable"

[jai mitchell]

 
Thank you for laying this one on the table for us ASLR.  The Paleosens work of 2012 http://www.nature.com/nature/journal/v491/n7426/full/nature11574.html  Clearly showed that this was the case as they had to rule out erratic non-linear response rates for S in their work to get the IPCC 'correct' range of ECS. 

This, in my understanding, is complete justification for the long work you (and a much smaller degree I) have done on this thread.  Unfortunately, certain impacts have not been incorporated in this paleoclimate analysis since the change of CO2 forcing is so much greater than the paleo analogs.

For example, the impacts of a sudden ocean acidification on the production rates of dimethylsulfide is not comparative, the increased warming due to this impact likely did not occur in previous interglacials, additionally, a rapid collapse of tropical peat and tropical rainforests, the sudden release of CO2 from rapidly warming soils and the rapid disassociation of permafrost is also not comparable to these much slower events.

Finally, any attempt at modeling future climate responses, not taking into account the much slower warming rates of the world's oceans, must understand that the long-wave emissions from the worlds oceans during the early Pleistocene when CO2 was last at 400 ppmv and CH4 emissions rates were comparable to today's was much higher, that the oceans won't reach temperature equilibrium for another 2,000 years or so, and that the land and air temperatures will have to compensate by warming that much more to reach thermal equilibrium with the increased radiative forcing and ESS responses to this rapidly warmed climate.

Indeed, only a WWII total societal mobilization response will produce the rapid reductions in emissions necessary to give us even a slim chance of maintaining our modern society.

please see:  www.theclimatemobilization.org

[jai mitchell]

By the way, I don't want to toot my own horn, but my second post on this forum was talking about this very same thing.

(copied from the 2013 Short and medium term sea ice condition thread)

This shows the intense permafrost melt associated with accelerated sea ice loss.
http://www.colorado.edu/geography/class_homepages/geog_4271_f10/readings/week_10_lawrence_et_al_2008.pdf

This shows how the loss of sea ice leads to a massive increase in the global temperature sensitivity to more carbon dioxide during the peak of prior interglacials.

http://www.iac.ethz.ch/people/knuttir/papers/rohling12nat.pdf

--sorry if this is very much off topic.

The link to Knuttir website was originally a link to the Paleosense ECS paper that I showed above, as shown by Chris Reyold's response:

Jai,

It's the loss of ice in the last ten days that has caused 2013 to have had such a large loss. I await with great interest the rest of June...

Thanks for the Paleosense Team paper.

[AbruptSLR]

jai,
Thanks for reminding readers that our current rate of radiative forcing is unprecedented in the paleo record.  This is supported by the fact that some ESM projections indicate effective climate sensitivities this century higher than 5C (see attached for a 2010 ESLD NASA PDF for ECS climate sensitivity).  That said the following summarizes selected considerations [including: (1) transient masking factors, (2) misinterpretations of paleo & observed climate sensitivities, (3) misinterpretations of the stability of the WAIS and (4) underestimates of the likeliness of continued high anthropogenic radiative forcing] as to why our climate change situation is more dire than the IPCC AR5 consensus (which represents scientism)  currently acknowledges:

1. Masking mechanisms which allow scientists to match model results to paleo & observed conditions while calibrating for relatively low climate response (while either ignoring many masking mechanisms [such as paleo-dust & paleo-SOA], or diminishing their effectiveness in the models); and which allow decision makers to procrastinate in exactly the timeframe when it was critical that they take immediate action. 

Hodzic, A., Kasibhatla, P. S., Jo, D. S., Cappa, C. D., Jimenez, J. L., Madronich, S., and Park, R. J.: Rethinking the global secondary organic aerosol (SOA) budget: stronger production, faster removal, shorter lifetime, Atmos. Chem. Phys., 16, 7917-7941, doi:10.5194/acp-16-7917-2016, 2016.

http://www.atmos-chem-phys.net/16/7917/2016/

W.R.T. GMSTA: Specific masking mechanisms include:

(a) Temporary (observed at least from roughly 1998 to 2013) atmospheric conditions in the Tropical Pacific that not only temporarily increased the frequency of lower level cloud cover with negative feedback, but also above average La Nina-like conditions and generally negative PDO values; which, accelerated the sequestration of heat in the ocean, which was partially release during the 2015-16 El Nino. 

(b) The temporary acceleration of anthropogenic aerosol emissions (largely associated with coal-fired power plants in both in China and elsewhere) that temporarily induced both negative forcing & negative feedback.

(c) A temporary acceleration of the absorption of carbon dioxide by land-based plants associate both with higher atmospheric carbon dioxide concentrations, and with global warming.

i. Keenan et. al. (2016) "Recent pause in the growth rate of atmospheric CO₂ due to enhanced terrestrial carbon uptake", Nature Communication, doi:10.1038/ncomms13428.

http://www.nature.com/articles/ncomms13428

Erik Hans Hoffmann, Andreas Tilgner, Roland Schrödner, Peter Bräuer, Ralf Wolke and Hartmut Herrmann (November 2016), "An advanced modeling study on the impacts and atmospheric implications of multiphase dimethyl sulfide chemistry", PNAS, vol. 113 no. 42,  11776–11781, doi: 10.1073/pnas.1606320113

http://www.pnas.org/content/113/42/11776

(d) Decadal scale thermal inertia fluctuations associated the ocean, atmosphere and cryosphere.
 
(f) A probable underestimation of both natural and anthropogenic negative aerosol forcing and feedback.

W.R.T. SLR: Specific masking consideration include:

(a) The tidal gauges around the world are located so as to be biased against the Greenland Ice Sheet, GIS, fingerprint contribution, likely underestimating SLR;

(b) In 2011 atypical atmospheric river event deposited large quantities of snow in Eastern Antarctica, thus underestimating SLR trends.

(c) Isostatic rebound associate with ice mass loss in the WAIS can mask the true ice mass loss measured by either gravity (GRACE) or ice surface elevation.

(d) If the WAIS is a major contributor to SLR this century, then due to the fingerprint effect this contribution could be increased by up to 40% in the NH.

W.R.T. Anthropogenic Bias: Other masking issues relate to the phrase "To err is human" in that AR5's projections contain so many caveats that it obfuscates the seriousness of our climate change challenge.  Specific anthropogenic masking factors include:

(a) The referenced standards for reporting observed GMST have been demonstrated to be biased on the low side.

(b) Anthropogenic forcing began earlier than assumed in AR5. 

(c) Common use of old values for GMSTA above pre-industrial.

(d) Common use radiative forcing scenarios that err too far on the side of least drama.

(e) Focus on linear Frequentist theory thereby underreporting the findings of chaos theory, of Bayesian analysis; of non-linear theory and of preliminary research that does yet meet the Frequentist confidence levels for evidence.

(f) Organized intimidation of climate scientists by denialists have contributed to ESLD reporting.

2. The TCR, ECS and ESS are all likely higher than consensus science is willing to currently acknowledge, due to a combination of:

(a) Masking factors biasing the recent observed climate change. 

(b) A misinterpretation of paleo-data with regard both the role of negative forcing from paleo dust and the role of Lorenz strange attractors in progressively ratcheting Earth Systems into higher states (such as an early albedo flip for the Arctic; and increased frequencies for strong El Nino events).

(c) The synergistic acceleration of non-liner positive feedback mechanisms (including Polar Amplification and permafrost degradation).

3. Instability of the WAIS could lead to a rapid acceleration of Hansen's ice-climate feedback mechanism within coming decades.  The likely earlier than expected collapse of key portions of the WAIS are due to reasons such as:

(a) The formation of the ozone hole over Antarctica accelerated the westerly winds over the Southern Ocean that together with the Coriolis effect drove warm circumpolar deep water, CDW, to the exposed ice of many key marine glaciers and associated ice shelves.

(b) The likelihood that GMSTA will approach (or exceed) 2.7C above pre-industrial conditions which per DeConto (2016) should trigger hydrofracturing and cliff failures of key WAIS marine glaciers.

(c) The rapid ocean heat uptake by the Southern Ocean's CDW (which is partially related to a climate change related increase in intense ENSO events).

4.  Anthropogenic radiative forcing would continue at higher than advisable levels, and for a longer than expected periods, due to such trends as:

(a) The transfer of industry from first world to third world countries (thus allowing high emissions to continue for some decades to come).

(b) An increase in fracking and farming led to an increase in methane emission rates.

(c) The domination of US policy by the GOP (soon including by Donald Trump) and their protection of the fossil fuel industry.

(d) The relatively rapid decline of the coal industry (particularly in China) that has accelerated aerosol forcing.

Best regards,
ASLR

[AbruptSLR]

To get a better handle of the "fat-tailed" risk discounted by Andy Skuce (& reticent science); the second linked reference discusses paleodata to indicate that climate sensitivity increased from 3.3 - 5.6 (mean of 4.45k) at the beginning of the PETM up to 3.7 - 6.5 K (mean of 5.1K) near the peak of the PETM.  The second attached image compare this to ECS values for the Last Glacial Maximum, LGM, Modern Day, MD, Late Pleistocene, LP, and the Paleocene-Eocene Thermal Maximum, PETM. The caption for the second attached image is: "Paleo climate sensitivity study reconstructs global warming 56 million years ago and suggests future global warming could be even worse than expected. This graphic shows climate sensitivity at different global temperatures in the atmosphere. The figure shows from the right estimates for the past warm period, the PETM 56 million years ago, the period before the PETM and for the present. On the left the figure shows estimates for the Last Glacial Maximum. Courtesy: Gary Shaffer and Roberto Rondanelli"

Gary Shaffer, Matthew Huber, Roberto Rondanelli & Jens Olaf Pepke Pedersen (23 June 2016), "Deep-time evidence for climate sensitivity increase with warming", Geophysical Research Letters, DOI: 10.1002/2016GL069243


http://onlinelibrary.wiley.com/doi/10.1002/2016GL069243/full

Next, the third linked reference presents paleo evidence about the Eocene.  While the authors emphasize that their findings support the IPCC interpretation for climate sensitivity, when looking at the third attached image of Fig 4 panel f, it appears to me that this is only the case if one averages ECS over the entire Eocene; while if one focuses on the Early Eocene Climate Optimum (EECO) which CO₂ levels were higher than in current modern times, it appear that ECS was higher (around 4C) than the IPCC AR5 assumes (considering that we are increasing CO2 concentrations faster now that during the EECO this gives me concern rather than reassurance).

Eleni Anagnostou, Eleanor H. John, Kirsty M. Edgar, Gavin L. Foster, Andy Ridgwell, Gordon N. Inglis, Richard D. Pancost, Daniel J. Lunt & Paul N. Pearson (2016), "Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate", Nature, doi:10.1038/nature17423


http://www.nature.com/nature/journal/vaop/ncurrent/full/nature17423.html

Next, the fourth linked reference indicates that corrected recent observations indicate that the most likely value of ECS may be as high as 4.6C (see fourth attached plot of the time dependent curve); which is much higher than Andy Skuce acknowledges for recent observations:

Kyle C. Armour  (27 June 2016), "Projection and prediction: Climate sensitivity on the rise", Nature Climate Change, doi:10.1038/nclimate3079

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3079.html


A pdf of Armour 2016 can be found at the following link:

http://www.nature.com/articles/nclimate3079.epdf?author_access_token=LNQKgwEONy5YVJSvlubB29RgN0jAjWel9jnR3ZoTv0PPTNF_sOIeFx9myJ_U10XLsj8_p1lqjx0RRDTJbTTc78eupvudlmNtEiNXnWHNhr4crt8ZuOmLA66TNpMu_PUg

The caption for the fourth image is: "Climate sensitivity estimated from observations1 (black), and its revision following Richardson et al. (blue) then following Marvel et al. (green), and in red the revision for the time dependence (Armour). The grey histogram shows climate model values."

Finally, for this post, I believe that by the time reasonably accurate projections are available circa 2032 we will have passed a tipping point leading to global socio-economic collapse (in the 2045 to 2060 timeframe) driving substantially by non-linear climate change related impacts.  As published projections from a ACME-Phase 4 climate model will not be available for something like 16-years, and as reticent science hides risk in the "tall grass" of uncertainty, I recommend that risk managers use Scenario Based Hazard Assessment, SBHA (guided by both Bayesian methodology & information theory), to get a better handle on the poorly defined risks that are currently heavily discounted by reticent science.  Then the findings of such SBHA efforts could be used in Robust Decision Making, RDM, to better adapt to the coming consequences of the Anthropocene era.

Furthermore, as most of the area of concern is associated with "fat-tailed" risk, I further propose the SBHA be used to identify Maximum Credible Events, MCE, which we many need to adapt to (even if that adaptation includes presenting numerous Darwin Awards).  In my next post, I plan to present a scenario for a MCE illustrating how PETM-like conditions might be reached at early at 2100, rather than several centuries in the future as assumed by reticent science.

Edit: Finally, the following four linked references all indicate that consideration of chaos theory's strange attractors in paleo-eras demonstrate that climate sensitivity is higher than traditional (AR5) climate modeling projections have assumed.  Thus while it has not finally been determined how quickly global temperatures will increase, I provide the following list (with a hat tip to Robert Scribbler) of atmosphere CO₂ concentrations vs long-term (paleo) global temperature increases.

1) Jones, R. N. and Ricketts, J. H.: Reconciling the signal and noise of atmospheric warming on decadal timescales, Earth Syst. Dynam. Discuss., doi:10.5194/esd-2016-35, in review, 2016.

http://www.earth-syst-dynam-discuss.net/esd-2016-35/
&
http://www.earth-syst-dynam-discuss.net/esd-2016-35/esd-2016-35.pdf

2) Roger Neville Jones & James Henry Ricketts (2016), "Atmospheric warming 1997–2014: hiatus, pause or regime?"

https://www.researchgate.net/publication/305989994_Atmospheric_warming_1997-2014_hiatus_pause_or_regime

3) Ragone, F., Lucarini, V. & Lunkeit, F. (2016), "A new framework for climate sensitivity and prediction: a modelling perspective", Clim Dyn, 46: 1459. doi:10.1007/s00382-015-2657-3

http://link.springer.com/article/10.1007/s00382-015-2657-3

4) Anna S. von der Heydt, Peter Ashwin (Submitted on 12 Apr 2016), "State-dependence of climate sensitivity: attractor constraints and palaeoclimate regimes",  arXiv:1604.03311


http://arxiv.org/abs/1604.03311
&
http://arxiv.org/pdf/1604.03311v1.pdf

[AbruptSLR]

As it can be tiresome looking back over this thread, I the following selected 28 references [not including either von der Heydt et. al. 2016 nor Friedrich et al (2016)] that either directly, or indirectly, indicate that climate sensitivity is most likely significantly higher than the range summarized by AR5:

1. The linked reference analyses the CMIP3&5 results to conclude the ECS is likely 3.9C +/- 0.45C:

Chengxing Zhai, Jonathan H. Jiang & Hui Su (2015), "Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity", Geophysical Research Letters, DOI: 10.1002/2015GL065911


http://onlinelibrary.wiley.com/doi/10.1002/2015GL065911/full

2. The linked reference provides findings from CMIP5 of the continued poleward expansion of the Hadley Cell with continued global warming; which in-turn supports the idea that ECS is greater than 3C:

Lijun Tao, Yongyun Hu & Jiping Liu (May 2016), "Anthropogenic forcing on the Hadley circulation in CMIP5 simulations", Climate Dynamics, Volume 46, Issue 9, pp 3337-3350 DOI: 10.1007/s00382-015-2772-1

http://rd.springer.com/article/10.1007%2Fs00382-015-2772-1

3. The linked reference presents new paleo evidence about the Eocene.  While the authors emphasize that their findings support the IPCC interpretation for climate sensitivity, when looking at the attached Fig 4 panel f, it appears to me that this is only the case if one averages ECS over the entire Eocene; while if one focuses on the Early Eocene Climate Optimum (EECO) which CO₂ levels were higher than in current modern times, it appear that ECS was higher (around 4C) than the IPCC AR5 assumes (considering that we are increasing CO2 concentrations faster now that during the EECO this gives me concern rather than reassurance).

Eleni Anagnostou, Eleanor H. John, Kirsty M. Edgar, Gavin L. Foster, Andy Ridgwell, Gordon N. Inglis, Richard D. Pancost, Daniel J. Lunt & Paul N. Pearson (2016), "Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate", Nature, doi:10.1038/nature17423


http://www.nature.com/nature/journal/vaop/ncurrent/full/nature17423.html

4. Tan et al (2016) indicates that ECS may well be between 5.0 and 5.3C.

Ivy Tan, Trude Storelvmo & Mark D. Zelinka (08 Apr 2016), "Observational constraints on mixed-phase clouds imply higher climate sensitivity", Science, Vol. 352, Issue 6282, pp. 224-227, DOI: 10.1126/science.aad5300


http://science.sciencemag.org/content/352/6282/224

5. According to the IPCC AR5 report: "The transient climate response is likely in the range of 1.0°C to 2.5°C (high confidence) and extremely unlikely greater than 3°C"; however, the linked reference uses only observed data to indicate that TCR is 2.0 +/- 0.8C.  Thus AR5 has once again erred on the side of least drama.


T. Storelvmo, T. Leirvik, U. Lohmann, P. C. B. Phillips & M. Wild (2016), "Disentangling greenhouse warming and aerosol cooling to reveal Earth’s climate sensitivity", Nature Geoscience, doi:10.1038/ngeo2670


http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2670.html

6. The linked reference reassesses ECS from CMIP3 &5 and find an ensemble-mean of 3.9C, and I note that CMIP3&5 likely err on the side of least drama as they ignore several important non-linear slow feedbacks that could be accelerated by global warming:

Chengxing Zhai, Jonathan H. Jiang, Hui Su (2015), "Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity", Geophysical Research Letters, DOI: 10.1002/2015GL065911

http://onlinelibrary.wiley.com/doi/10.1002/2015GL065911/full

7. The linked reference could not make it more clear that paleo-evidence from inter-glacial periods indicates that ECS is meaningfully higher than 3C and that climate models are commonly under predicting the magnitude of coming climate change.

Dana L. Royer (2016), "Climate Sensitivity in the Geologic Past", Annual Review of Earth and Planetary Sciences, Vol. 44


http://www.annualreviews.org/doi/abs/10.1146/annurev-earth-100815-024150?src=recsys

8. Thompson indicates that ECS has a 95%CL range of from 3C to 6.3C, with a best estimate of 4C, and Sherwood (2014) has a higher value still:

Climate sensitivity by Roy Thompson published by Earth and Environmental Science Transactions of the Royal Society of Edinburgh, DOI: 10.1017/S1755691015000213

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10061758&fileId=S1755691015000213


9. Tian (2015) indicates that the double-ITCZ bias constrains ECS to its high end (around 4.0C):

Tian, B. (2015), "Spread of model climate sensitivity linked to double-Intertropical Convergence Zone bias", Geophys. Res. Lett., 42, doi:10.1002/2015GL064119.


http://onlinelibrary.wiley.com/doi/10.1002/2015GL064119/abstract

10. 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

11. The linked reference studies numerous climate models and finds that: "… those that simulate the present-day climate best even point to a best estimate of ECS in the range of 3–4.5°C."
Reto Knutti, Maria A. A. Rugenstein (2015), "Feedbacks, climate sensitivity and the limits of linear models", Philosophical Transactions of the Royal Society A, DOI: 10.1098/rsta.2015.0146

http://rsta.royalsocietypublishing.org/content/373/2054/20150146

12.  The linked reference indicates that the cloud feedback from tropical land is robustly positive.  As AR5 did not know whether this contribution to climate sensitivity was positive or negative, this clearly indicates that AR5 errs on the side of least drama with regard to both TCR & ECS:

Youichi Kamae, Tomoo Ogura, Masahiro Watanabe, Shang-Ping Xie and Hiroaki Ueda (8 March 2016), "Robust cloud feedback over tropical land in a warming climate", Atmospheres, DOI: 10.1002/2015JD024525

http://onlinelibrary.wiley.com/doi/10.1002/2015JD024525/abstract

13.  Graeme L. Stephens, Brian H. Kahn and Mark Richardson (5 May, 2016), "The Super Greenhouse effect in a changing climate", Journal of Climate, DOI: http://dx.doi.org/10.1175/JCLI-D-15-0234.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0234.1

14. The linked reference assumes different degrees of nonlinearity for climate feedback mechanisms and concludes that such nonlinearity for positive feedback represents a Black Swan risk that linear climate models cannot recognize:

Jonah Bloch-Johnson, Raymond T. Pierrehumbert & Dorian S. Abbot (24 June 2015), "Feedback temperature dependence determines the risk of high warming", Geophysical Research Letters, DOI: 10.1002/2015GL064240

http://onlinelibrary.wiley.com/doi/10.1002/2015GL064240/full


15.  While the linked (open access) reference has many appropriate qualifying statements and disclaimers, it notes that the AR5 paleo estimates of ECS were linear approximations that change when non-linear issues are considered.  In particular the find for the specific ECS, S[CO2,LI], during the Pleistocence (ie the most recent 2 million years) that:
"During Pleistocene intermediate glaciated climates and interglacial periods, S[CO2,LI] is on average ~ 45 % larger than during Pleistocene full glacial conditions."

Therefore, researchers such as James Hansen who relied on paleo findings that during recent full glacial periods ECS was about 3.0C, did not know that during interglacial periods this value would be 45% larger, or 4.35C.

Köhler, P., de Boer, B., von der Heydt, A. S., Stap, L. B., and van de Wal, R. S. W. (2015), "On the state dependency of the equilibrium climate sensitivity during the last 5 million years", Clim. Past, 11, 1801-1823, doi:10.5194/cp-11-1801-2015.


http://www.clim-past.net/11/1801/2015/cp-11-1801-2015.html
http://www.clim-past.net/11/1801/2015/cp-11-1801-2015.pdf

16.  The linked reference implies that climate sensitivity (ESS) could be much higher than previously assumed:

Jagniecki,Elliot A. et al. (2015), "Eocene atmospheric CO2from the nahcolite proxy", Geology, http://dx.doi.org/10.1130/G36886.1


http://geology.gsapubs.org/content/early/2015/10/23/G36886.1

17.  The linked open access reference identifies three constraints on low cloud formation that suggest that cloud feedback is more positive than previously thought.  If verified this would mean that both TCR and ECS (and ESS) are larger than previously thought:

Stephen A. Klein and Alex Hall (26 October 2015), "Emergent Constraints for Cloud Feedbacks", Climate Feedbacks (M Zelinka, Section Editor), Current Climate Change Reports, pp 1-12, DOI 10.1007/s40641-015-0027-1

http://link.springer.com/article/10.1007%2Fs40641-015-0027-1

18.  The linked article indicates that values of TCR based on observed climate change are likely underestimated:

J. M. Gregory, T. Andrews and P. Good (5 October 2015), "The inconstancy of the transient climate response parameter under increasing CO₂", Philosophical Transactions of the Royal Society A, DOI: 10.1098/rsta.2014.0417


http://rsta.royalsocietypublishing.org/content/373/2054/20140417

19.  The linked reference indicates that most current climate models underestimate climate sensitivity:

J. T. Fasullo, B. M. Sanderson & K. E. Trenberth (2015), "Recent Progress in Constraining Climate Sensitivity With Model Ensembles", Current Climate Change Reports, Volume 1, Issue 4, pp 268-275, DOI 10.1007/s40641-015-0021-7

http://link.springer.com/article/10.1007/s40641-015-0021-7?wt_mc=email.event.1.SEM.ArticleAuthorOnlineFirst

20.  The linked reference indicates that studies that assuming linearity of climate sensitivity likely underestimate the risk of high warming.

Jonah Bloch-Johnson, Raymond T. Pierrehumbert and Dorian S. Abbot (June 2015), "Feedback temperature dependence determines the risk of high warming", Geophysical Research Letters, DOI: 10.1002/2015GL064240

http://onlinelibrary.wiley.com/doi/10.1002/2015GL064240/abstract

21. The linked reference indicates that new research (from PlioMIP2) demonstrates that the climate sensitivity for the Pliocene was higher than previously believed (from PlioMIP1):

Kamae, Y., Yoshida, K., and Ueda, H.: Sensitivity of Pliocene climate simulations in MRI-CGCM2.3 to respective boundary conditions, Clim. Past, 12, 1619-1634, doi:10.5194/cp-12-1619-2016, 2016.

http://www.clim-past.net/12/1619/2016/

http://www.clim-past.net/12/1619/2016/cp-12-1619-2016.pdf


22. The linked reference indicates that corrected recent observations indicate that the most likely value of ECS may be as high as 4.6C (see attached plot of the time dependent curve):

Kyle C. Armour  (27 June 2016), "Projection and prediction: Climate sensitivity on the rise", Nature Climate Change, doi:10.1038/nclimate3079

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3079.html

23. The linked reference indicates that the climate responses (climate sensitivities) projected by advanced climate models generally match observations when apple to apple comparisons are made.  This is a useful finding as advanced climate models generally indicate that climate sensitivity values are towards the high end of the IPCC climate sensitivity range:

Mark Richardson, Kevin Cowtan, Ed Hawkins & Martin B. Stolpe (2016), "Reconciled climate response estimates from climate models and the energy budget of Earth", Nature Climate Change, doi:10.1038/nclimate3066

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3066.html

24. The linked reference discusses paleodata to indicate that climate sensitivity increased from 3.3 - 5.6 (mean of 4.45k) at the beginning of the PETM up to 3.7 - 6.5 K (mean of 5.1K) near the peak of the PETM; and that if we burn only the easily accessible carbon reserves then GMST could increase by about 10C.  I note these climate sensitivity values are much higher than those inherent in the CMIP5 projections:

Gary Shaffer, Matthew Huber, Roberto Rondanelli & Jens Olaf Pepke Pedersen (23 June 2016), "Deep-time evidence for climate sensitivity increase with warming", Geophysical Research Letters, DOI: 10.1002/2016GL069243

http://onlinelibrary.wiley.com/doi/10.1002/2016GL069243/full


25. The linked Reuters article notes that NASA reported that a new satellite-based method have located 39 unreported sources of anthropogenic emissions that, when accounted for, increase our previously estimated amount of sulfur dioxide by about 12 percent of all such anthropogenic emissions from 2005 to 2014.  This indicates that the CMIP5 projections also underestimated the impact of this negative forcing source; which raises the prospect that climate sensitivity (ECS) is likely higher than the CMIP5 models indicate, and the linked Zhai et al (2015) reference analyses of the CMIP3&5 results conclude that the ECS is likely 3.9C +/- 0.45C:

Chengxing Zhai, Jonathan H. Jiang & Hui Su (2015), "Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity", Geophysical Research Letters, DOI: 10.1002/2015GL065911

http://in.reuters.com/article/us-nasa-pollution-idINKCN0YO1PW

26. The linked reference uses an information-theoretic weighting of climate models by how well they reproduce the satellite measured deseasonlized covariance of shortwave cloud reflection, indicates a most likely value of ECS of 4.0C; which indicates that AR5 errs on the side of least drama:

Florent Brient & Tapio Schneider (2016), "Constraints on climate sensitivity from space-based measurements of low-cloud reflection", Journal of Climate, DOI: http://dx.doi.org/10.1175/JCLI-D-15-0897.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0897.1


27. The linked article indicates that the contribution of sea-ice loss to Arctic Amplification is regulated by the PDO and that in positive PDO phases (like we are in now) there should be less Arctic Amplification.  Thus the fact that we are currently experiencing high Arctic Amplification during a period of highly positive PDO values gives cause for concern that climate sensitivity may be higher than considered by AR5:

James A. Screen & Jennifer A. Francis (2016), "Contribution of sea-ice loss to Arctic amplification is regulated by Pacific Ocean decadal variability", Nature Climate Change, DOI: 10.1038/nclimate3011


http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3011.html


28. The linked reference uses an information-theoretic weighting of climate models by how well they reproduce the satellite measured deseasonlized covariance of shortwave cloud reflection, indicates a most likely value of ECS of 4.0C.  As this satellite data is certainly biased by the recent acceleration of natural aerosol emissions associated with the increasing atmospheric CO2 concentration, the actually ECS is likely higher than 4.0C, as will become apparent if climate change reduces future plant activity.  Unfortunately, the envisioned upgrades to the Paris Pact do not have any contingency for addressing such high values (4 to 4.5C) of ECS (including accelerting NET):

Florent Brient & Tapio Schneider (2016), "Constraints on climate sensitivity from space-based measurements of low-cloud reflection", Journal of Climate, DOI: http://dx.doi.org/10.1175/JCLI-D-15-0897.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0897.1

[AbruptSLR]

As indicated in numerous news sources including the linked Global Carbon Project site, the CO₂ anthropogenic (fossil fuel & cement) emissions in 2016 are projected to increase slightly above that for 2016 (see the first image); which keep these emissions on the low side of the RCP 8.5 scenario (see the second image).  Unfortunately, the total atmospheric CO₂ concentration at Mauna Loa remain at record high levels (see the third image), and these figures do not address total GHG CO₂-eq emissions; which are running high:

http://www.globalcarbonproject.org/carbonbudget/index.htm
&
http://www.globalcarbonproject.org/carbonbudget/16/files/GCP_budget_2016_v1.0_FinalRelease.pdf

[AbruptSLR]

The linked reference presents evidence that the polar vortex has weakened progressively over the past three decades which leads to a "Warm Arctic Cold Continent" pattern.  This pattern should lead to the Arctic warming more rapidly than projected by AR5, resulting in a faster rate of Arctic Amplification than consensus scientists are admitting publically.


Jiankai Zhang et. al. (2016), “Persistent shift of the Arctic polar vortex towards the Eurasian continent in recent decades”, Nature Climate Change, doi:10.1038/nclimate3136

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3136.html


Abstract: “The wintertime Arctic stratospheric polar vortex has weakened over the past three decades, and consequently cold surface air from high latitudes is now more likely to move into the middle latitudes. However, it is not known if the location of the polar vortex has also experienced a persistent change in response to Arctic climate change and whether any changes in the vortex position have implications for the climate system. Here, through the analysis of various data sets and model simulations, we show that the Arctic polar vortex shifted persistently towards the Eurasian continent and away from North America in February over the past three decades. This shift is found to be closely related to the enhanced zonal wavenumber-1 waves in response to Arctic sea-ice loss, particularly over the Barents–Kara seas (BKS). Increased snow cover over the Eurasian continent may also have contributed to the shift. Our analysis reveals that the vortex shift induces cooling over some parts of the Eurasian continent and North America which partly offsets the tropospheric climate warming there in the past three decades. The potential vortex shift in response to persistent sea-ice loss in the future, and its associated climatic impact, deserve attention to better constrain future climate changes.”

The associate linked article is entitled: “Climate change playing role in late-winter shift in polar vortex”. 


http://www.accuweather.com/en/weather-blogs/climatechange/climate-change-playing-role-in/61124223

Extract: “New research published in the journal Nature Climate Change has found that the wintertime Arctic stratospheric polar vortex has weakened over the past three decades.
The result of this weakening is an increased probability of cold surface air from the high latitudes shifting southward into the middle latitudes.”

Edit: The first attached global ice area plot by Wipneus indicates that this value is currently about 10 sigma below the recent mean, and even after considering the current weak La Nina this plot raises concerns about how fast polar amplification may occur with global warming.  The second attached plot issued today by the DMI shows the daily mean temperature north of 80 degrees north through Nov 16, 2016; which also hints at high Arctic Amplification.

[AbruptSLR]

The linked reference discusses the impacts of climate change from genes to biomes to people, and they are typically worse than previously expected:

Brett R. Scheffers, et. al. (11 Nov 2016), "The broad footprint of climate change from genes to biomes to people", Science, Vol. 354, Issue 6313, DOI: 10.1126/science.aaf7671

http://science.sciencemag.org/content/354/6313/aaf7671

Accumulating impacts: "Anthropogenic climate change is now in full swing, our global average temperature already having increased by 1°C from preindustrial levels. Many studies have documented individual impacts of the changing climate that are particular to species or regions, but individual impacts are accumulating and being amplified more broadly. Scheffers et al. review the set of impacts that have been observed across genes, species, and ecosystems to reveal a world already undergoing substantial change. Understanding the causes, consequences, and potential mitigation of these changes will be essential as we move forward into a warming world."

[AbruptSLR]

While I have just posted this in the Science folder, in the "Southern Ocean Venting CO₂" thread, due to its likely masking implication, I also post it here:

http://forum.arctic-sea-ice.net/index.php/topic,888.50.html#lastPost


The linked article discusses both the reality and consequences of the changing nature of CO₂ absorption/release and heat uptake by the Southern Ocean.  The extracts below only focus on the risks that the Southern Ocean may soon start venting more CO₂ than it is absorbing.

Jeff Tollefson (17 November 2016), "How much longer can Antarctica’s hostile ocean delay global warming?", Nature, Volume: 539, Pages: 346–348, doi:10.1038/539346a

http://www.nature.com/news/how-much-longer-can-antarctica-s-hostile-ocean-delay-global-warming-1.20978

The waters of the Southern Ocean have absorbed much of the excess heat and carbon generated by humanity.
…
Although controversial when she encountered it back in 1994, this powerful upwelling is now recognized as a hallmark of the Southern Ocean, a mysterious beast that swirls around Antarctica, driven by the world’s strongest sustained winds. The Southern Ocean absorbs copious amounts of carbon dioxide and heat from the atmosphere, which has slowed the rate of global warming. And its powerful currents drive much of the global ocean circulation.
…
Already, initial data from an array of ocean floats suggest that upwelling waters could be limiting how much CO2 the Southern Ocean absorbs each year. This raises new questions about how effective these waters will be as a brake on global warming in decades to come.

“The Southern Ocean is doing us a big climate favour at the moment, but it’s not necessarily the case that it will continue doing so in the future,” says Michael Meredith …
…
Indirect evidence suggests that the Southern Ocean is a net carbon sink and has absorbed as much as 15% of the carbon emissions emitted by humanity since the industrial revolution. But at some times of year and in specific places in this region, carbon-rich surface waters release CO2 into the atmosphere.

Now, researchers are getting some of their first glimpses in near-real time of what happens in the Southern Ocean, particularly in winter. “Right off the bat, we are seeing CO2 fluxes into the atmosphere that are much greater than we had estimated before,” Sarmiento says. “It’s just revolutionary.”

The unpublished analysis is based on just 13 floats that have been in the water for at least a year, so the question now is whether the higher CO2 emissions during winter represent larger trends across the entire Southern Ocean.

“It’s pretty tantalizing,” says Alison Gray, a postdoctoral researcher at Princeton who is leading the study. “It would imply that potentially there is a much weaker carbon sink in the Southern Ocean than has been estimated.”

Hints of something similar have been seen before. In 2007, a team led by Corinne Le Quéré, now director of the Tyndall Centre for Climate Change Research in Norwich, UK, published a study in Science indicating that the rate of carbon uptake by the Southern Ocean decreased between 1981 and 2004. The authors blamed the changes on the winds that encircle the Antarctic continent. The speed of those winds had increased during that time, probably as a result of the hole in the stratospheric ozone layer over Antarctica and possibly because of global warming. Stronger winds are better able to pull up deep, ancient water, which releases CO2 when it reaches the surface. That would have caused a net weakening of the carbon sink.

If that trend were to continue, atmospheric CO2 levels would rise even faster in the future. However, a study in Science last year found that the carbon sink started to strengthen in the early 2000s (see ‘The unreliable sink’).

Le Quéré says it’s unclear whether that rise in CO2 absorption is a return to normal or a deviation from the long-term weakening of the sink. Regardless, she says, it’s now clear that the Southern Ocean might be much more fickle than scientists thought."

[AbruptSLR]

The linked article is entitled: "Climate study explores link between Arctic warming and extreme weather".  Not only is it likely that climate sensitivity is higher than expected, but it appears likely that the weather responses to global warming may likely be greater than once thought:

http://phys.org/news/2016-11-climate-explores-link-arctic-extreme.html

Extract: "According to several studies (the most recent of which was published in Nature Climate Change in October 2016), a warming Arctic can, in fact, lead to prolonged periods of severe weather and cold spells in the mid-latitudes.

The impacts of severe weather on commerce and infrastructure can be significant, so having adequate tools to predict when and how severe weather systems will affect Europe, Asia and North America is vital to inhabitants of these regions. The APPLICATE project is bringing together an international team of experts in weather and climate prediction to improve climate and weather forecasting models to work on improving prediction tools while expanding and improving observational capabilities in the Arctic."

[AbruptSLR]

In the first linked essay, James Annan offers a defense of the consensus position on climate sensitivity.  I suspect that such defenses downplay the importance of correctly accounting for masking factors when estimating climate sensitivity:

http://julesandjames.blogspot.co.uk/2016/11/apocalpyse-now.html

Extract: "To cut a long story short, it's not silly - the authors are entirely respectable and the work is interesting - but I don't think it is really that credible in terms of overturning established consensus."

See also:

https://andthentheresphysics.wordpress.com/2016/11/15/non-linear-climate-sensitivity/

Extract: "Essentially it uses proxies and models to reconstruct temperatures and forcings over the past 784000 years. Their key result is probably that the climate sensitivity is state dependent; higher in warm climates than in cold. They conclude that in warm climates, the equilibrium climate sensitivity (ECS) is 4.88 ± 0.57 K, which only just overlaps with the IPCC’s likely range (1.5 – 4.5K). What’s maybe more interesting is that they also try to estimate the transient climate response (TCR) which, using paleo data, requires a model of ocean heat uptake. They conclude that it is 2.74K with a likely range from 2.23 to 3.43K. This, again, only just overlaps the IPCC’s likely range (1 – 2.5K)."

[AbruptSLR]

The linked article indicates that the expansion of the Antarctic sea ice extent from 2000 to 2014 may have been associated with a negative phase of the IPO, and thus this negative phase of the IPO may have acted as a temporary masking factor hiding Antarctic Amplification.  Since 2014 the IPO has been positive and the Antarctic sea ice extent is currently well below its seasonal mean, thus we may be moving in to a phase of accelerating polar amplification.

Gerald A. Meehl, Julie M. Arblaster, Cecilia M. Bitz, Christine T. Y. Chung, and Haiyan Teng (2016), "Antarctic sea-ice expansion between 2000 and 2014 driven by tropical Pacific decadal climate variability", Nature Geoscience, DOI: 10.1038/NGEO2751

http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo2751.html

Abstract: "Antarctic sea-ice extent has been slowly increasing in the satellite record that began in 1979. Since the late 1990s, the increase has accelerated, but the average of all climate models shows a decline. Meanwhile, the Interdecadal Pacific Oscillation, an internally generated mode of climate variability, transitioned from positive to negative, with an average cooling of tropical Pacific sea surface temperatures, a slowdown of the global warming trend and a deepening of the Amundsen Sea Low near Antarctica that has contributed to regional circulation changes in the Ross Sea region and expansion of sea ice. Here we show that the negative phase of the Interdecadal Pacific Oscillation in global coupled climate models is characterized by anomalies similar to the observed sea-level pressure and near-surface 850 hPa wind changes near Antarctica since 2000 that are conducive to expanding Antarctic sea-ice extent, particularly in the Ross Sea region in all seasons, involving a deepening of the Amundsen Sea Low. These atmospheric circulation changes are shown to be mainly driven by precipitation and convective heating anomalies related to the Interdecadal Pacific Oscillation in the equatorial eastern Pacific, with additional contributions from convective heating anomalies in the South Pacific convergence zone and tropical Atlantic regions."

https://www2.ucar.edu/atmosnews/news/121622/expanding-antarctic-sea-ice-linked-natural-variability

Extract: "The new study finds that when the IPO changes phase, from positive to negative or vice versa, it touches off a chain reaction of climate impacts that may ultimately affect sea ice formation at the bottom of the world.
When the IPO transitions to a negative phase, the sea surface temperatures in the tropical eastern Pacific become somewhat cooler than average when measured over a decade or two. These sea surface temperatures, in turn, change tropical precipitation, which drives large-scale changes to the winds that extend all the way down to Antarctica."

[AbruptSLR]

The linked reference confirms that there is (& will continue to be) a positive feedback loop between retreating Arctic sea ice and Arctic cloud cover that contributes to Arctic Amplification:

Abe, M., Nozawa, T., Ogura, T., and Takata, K.: Effect of retreating sea ice on Arctic cloud cover in simulated recent global warming, Atmos. Chem. Phys., 16, 14343-14356, doi:10.5194/acp-16-14343-2016, 2016.


http://www.atmos-chem-phys.net/16/14343/2016/
&
http://www.atmos-chem-phys.net/16/14343/2016/acp-16-14343-2016.pdf


Abstract. This study investigates the effect of sea ice reduction on Arctic cloud cover in historical simulations with the coupled atmosphere–ocean general circulation model MIROC5. Arctic sea ice has been substantially retreating since the 1980s, particularly in September, under simulated global warming conditions. The simulated sea ice reduction is consistent with satellite observations. On the other hand, Arctic cloud cover has been increasing in October, with about a 1-month lag behind the sea ice reduction. The delayed response leads to extensive sea ice reductions because the heat and moisture fluxes from the underlying open ocean into the atmosphere are enhanced. Sensitivity experiments with the atmospheric part of MIROC5 clearly show that sea ice reduction causes increases in cloud cover. Arctic cloud cover increases primarily in the lower troposphere, but it decreases in the near-surface layers just above the ocean; predominant temperature rises in these near-surface layers cause drying (i.e., decreases in relative humidity), despite increasing moisture flux. Cloud radiative forcing due to increases in cloud cover in autumn brings an increase in the surface downward longwave radiation (DLR) by approximately 40–60 % compared to changes in clear-sky surface DLR in fall. These results suggest that an increase in Arctic cloud cover as a result of reduced sea ice coverage may bring further sea ice retreat and enhance the feedback processes of Arctic warming.

[jai mitchell]

This document previously posted shows the impact of dimethyl sulifde on the atmosphere and global cooling impacts from current high-density forest regions.

http://digital.csic.es/bitstream/10261/117629/1/jgrd51980.pdf

This study shows the pollen records of previous interglacials showing what primoridal interglacials looked like from a forest biomass perspective.

http://centaur.reading.ac.uk/40025/1/cpd-11-1031-2015.pdf

This study shows that previous interglacial periods experience significantly increased temperature response to CO2 than the glacial periods.  It is my assertion that the cause of this increased response is due to much higher temperature sensitivities to cloudcover fractions at lower latitudes and more rapid shifts of cloudcover regimes to the further northern latitudes during interglacials with increases in temperature, leading to rapid and significant albedo declines, increased solar absorption and increased temperatures.

http://advances.sciencemag.org/content/2/11/e1501923.full

note that the expected ECS value for this study is closer to 5C.

Also supporting the potential for much higher interglacial ECS values is this study looking at a 2Mya global temperature reconstruction.

http://www.nature.com/nature/journal/v538/n7624/abs/nature19798.html

------------------------

In view of this information, with regard to future potential shifts in our climate.  We are running, while blindfolded, carrying scissors. 

We know that interglacial ECS is very likely at the high end (or higher) than the current IPCC range of 1.5C to 4.5C.  We also know that primordial interglacial forest dimethyl sulfide emissions AT MIDLATITUDES was much higher than our currently (relatively) deforested northern hemisphere can produce.

We know that the largest uncertainty with regard to paleoclimate ECS is the aerosol component.

---------

IF my assertion is correct and this increase is due to increased cloud-cover fraction sensitivity during interglacials.

THEN It is possibly the most critical need of the entire body of science to develop an adequate model of primordial forest dimethyl sulfide emissions in the mid latitudes during previous interglacials

SO THAT we can adequately deduce what how our current anthropogenic impacts on mid-latitude forest densities will induce on our modern cloudcover fraction as temperatures increase.

(reposted to science of aerosols thread)

[AbruptSLR]

Further to jai's point (in Reply #1568) about the influence of natural aerosols on masking paleo climate sensitivity, in addition to my discuss on masking factors in Reply #1557, I note that according to the IPCC AR5 report: "The transient climate response is likely in the range of 1.0°C to 2.5°C (high confidence) and extremely unlikely greater than 3°C"; however, the first linked reference uses only observed data (corrected for aerosol effects) to indicate that TCR is 2.0 +/- 0.8C.


T. Storelvmo, T. Leirvik, U. Lohmann, P. C. B. Phillips & M. Wild (2016), "Disentangling greenhouse warming and aerosol cooling to reveal Earth’s climate sensitivity", Nature Geoscience, doi:10.1038/ngeo2670


http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2670.html

Also, in addition to jai's reference on DMS (largely from plankton), I provide the following related references:

- Anoop S. Mahajan, Suvarna Fadnavis, Manu A. Thomas, Luca Pozzoli, Smrati Gupta, Sarah-Jeanne Royer, Alfonso Saiz-Lopez, Rafel Simó, (2015), " Quantifying the impacts of an updated global dimethyl sulfide climatology on cloud microphysics and aerosol radiative forcing", J. Geophys. Res. 120, 6, 2524-2536. DOI: 10.1002/2014JD022687


http://ac2.iqfr.csic.es/es/component/content/category/images/pdf/2008/acp-8-4855-2008.pdf

&

- Daniel T. McCoy, Susannah M. Burrows, Robert Wood, Daniel P. Grosvenor, Scott M. Elliott, Po-Lun Ma, Phillip J. Rasch and Dennis L. Hartmann (17 Jul 2015), "Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo", Science Advances, Vol. 1, no. 6, e1500157, DOI: 10.1126/sciadv.1500157


http://advances.sciencemag.org/content/1/6/e1500157

&
- Weller, R., Schmidt, K., Teinilä, K., and Hillamo, R.: Natural new particle formation at the coastal Antarctic site Neumayer, Atmos. Chem. Phys., 15, 11399-11410, doi:10.5194/acp-15-11399-2015, 2015.

http://www.atmos-chem-phys.net/15/11399/2015/acp-15-11399-2015.html



Further with regard to jai's point about the cooling influence of forests, I provide the following additional references:

- Jasper Kirkby, Jonathan Duplissy, Kamalika Sengupta, Carla Frege, Hamish Gordon, Christina Williamson, Martin Heinritzi, Mario Simon, Chao Yan, João Almeida, Jasmin Tröstl, Tuomo Nieminen, Ismael K. Ortega, Robert Wagner, Alexey Adamov, Antonio Amorim, Anne-Kathrin Bernhammer, Federico Bianchi, Martin Breitenlechner, Sophia Brilke, Xuemeng Chen, Jill Craven, Antonio Dias, Sebastian Ehrhart, Richard C. Flagan, Alessandro Franchin, Claudia Fuchs, Roberto Guida, Jani Hakala, Christopher R. Hoyle, Tuija Jokinen, Heikki Junninen, Juha Kangasluoma, Jaeseok Kim, Manuel Krapf, Andreas Kürten, Ari Laaksonen , Katrianne Lehtipalo, Vladimir Makhmutov, Serge Mathot, Ugo Molteni, Antti Onnela, Otso Peräkylä, Felix Piel, Tuukka Petäjä, Arnaud P. Praplan, Kirsty Pringle, Alexandru Rap, Nigel A. D. Richards, Ilona Riipinen, Matti P. Rissanen, Linda Rondo, Nina Sarnela, Siegfried Schobesberger, Catherine E. Scott, John H. Seinfeld, Mikko Sipilä , Gerhard Steiner, Yuri Stozhkov, Frank Stratmann, Antonio Tomé, Annele Virtanen, Alexander L. Vogel, Andrea C. Wagner, Paul E. Wagner, Ernest Weingartner, Daniela Wimmer, Paul M. Winkler, Penglin Ye, Xuan Zhang, Armin Hansel, Josef Dommen, Neil M. Donahue, Douglas R. Worsnop, Urs Baltensperger, Markku Kulmala, Kenneth S. Carslaw, & Joachim Curtius, et al. (26 May 2016), "Ion-induced nucleation of pure biogenic particles", Nature, Volume: 533, Pages: 521–526, doi:10.1038/nature17953


http://www.nature.com/nature/journal/v533/n7604/full/nature17953.html

&

- Hodzic, A., Kasibhatla, P. S., Jo, D. S., Cappa, C., Jimenez, J. L., Madronich, S., and Park, R. J. (2015), "Rethinking the global secondary organic aerosol (SOA) budget: stronger production, faster removal, shorter lifetime", Atmos. Chem. Phys. Discuss., 15, 32413-32468, doi:10.5194/acpd-15-32413-2015.

http://www.atmos-chem-phys-discuss.net/15/32413/2015/acpd-15-32413-2015.html

&

- Lee, A. K. Y., Abbatt, J. P. D., Leaitch, W. R., Li, S.-M., Sjostedt, S. J., Wentzell, J. J. B., Liggio, J., and Macdonald, A. M. (2015), "Substantial secondary organic aerosol formation in a coniferous forest: observations of both day and night time chemistry", Atmos. Chem. Phys. Discuss., 15, 28005-28035, doi:10.5194/acpd-15-28005-2015.

http://www.atmos-chem-phys-discuss.net/15/28005/2015/acpd-15-28005-2015.html

&

- Heikki Lihavainen, Eija Asmi, Veijo Aaltonen, Ulla Makkonen and Veli-Matti Kerminen (Published 8 October 2015), "Direct radiative feedback due to biogenic secondary organic aerosol estimated from boreal forest site observations" Environmental Research Letters, Volume 10, Number 10


http://iopscience.iop.org/article/10.1088/1748-9326/10/10/104005/meta

http://iopscience.iop.org/article/10.1088/1748-9326/10/10/104005/pdf

&

- Tuija Jokinen, Torsten Berndt, Risto Makkonen, Veli-Matti Kerminen, Heikki Junninen, Pauli Paasonen, Frank Stratmann, Hartmut Herrmann, Alex B. Guenther, Douglas R. Worsnop, Markku Kulmala, Mikael Ehn, and Mikko Sipilä (June 9, 2015), "Production of extremely low-volatile organic compounds from biogenic emissions: measured yields and atmospheric implications", PNAS, vol. 112 no. 23 7123-7128, doi: 10.1073/pnas.1423977112


http://www.pnas.org/content/112/23/7123

&

- Mikael Ehn, Joel A. Thornton, Einhard Kleist, Mikko Sipilä, Heikki Junninen, Iida Pullinen, Monika Springer, Florian Rubach, Ralf Tillmann, Ben Lee, Felipe Lopez-Hilfiker, Stefanie Andres, Ismail-Hakki Acir, Matti Rissanen, Tuija Jokinen, Siegfried Schobesberger, Juha Kangasluoma, Jenni Kontkanen, Tuomo Nieminen, Theo Kurtén, Lasse B. Nielsen, Solvejg Jørgensen, Henrik G. Kjaergaard, Manjula Canagaratna, Miikka Dal Maso et al (2014), " A large source of low-volatility secondary organic aerosol", Nature, 506, 476–479, doi:10.1038/nature13032


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

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

&
- Paasonen, P., et. al. (2013), "Evidence for negative climate feedback: warming increases aerosol number concentrations,", Nature Geoscience, 6, Pages: 438–442, doi: 10.1038/NGEO1800

http://www.nature.com/ngeo/journal/v6/n6/full/ngeo1800.html

[jai mitchell]

Great Stuff SLR,

The loss of account or even a good model of paleoclimate aerosol values has always been the big 'what if' when trying to determine ECS.  This is especially true in the few (and only correct methodology) studies that look at only previous interglacial periods.

The fact that previous interglacial period studies are returning ECS values > 5.0 and we have significantly reduced the biosphere's abundance of primordial forest and bony fish (as well as the potential of acidification on the production of SOAs from the ocean) indicate that we could very easily breach a modern ECS value that is greater than 6.0 (and this is without looking at near term sea ice impacts)

The most recent study of Pine Island glacier experiencing much earlier retreat (in 1940) is also an indication that our climate response is much greater than our current models hold.

https://www.nsf.gov/news/news_summ.jsp?cntn_id=190473&org=NSF&from=news
New study reveals that West Antarctica's largest glacier may have started retreating as early as the 1940s

NSF's U.S. Antarctic Program contributed to British Antarctic Survey's study

[TeaPotty]

Cross posted from another thread, since it reflects my updated opinion:

I dont support Trump at all, but I am pretty disgusted with this outrage. Good fucking morning ppl.

Where were you when Liberals rigged the primary against a real Leftist, Bernie Sanders, who was a sure bet against Trump and a climate hawk? He was our last great hope, and those with power in the climate movement mostly stayed quiet.

Where was the outrage the past 8 years over the fact that carbon emissions are STILL accelerating and we are STILL on the worse case path (BAU)? Where was the outrage at Obama for making USA the #1 oil producer, sent Hillary to export fracking around the world, and underhanded the entire Paris Climate Agreement?

I see ppl on a crusade to defend renewables, as if they are sufficient or have been funded by anything close to the same scale which fossil fuels are. I see ppl already propagating the ridiculous Liberal talking points that Climate Change will be Trump's fault, as if the ship hasn't long past sailed at stopping CC?

Other than Professor James Hansen and several others, most of those in the scientific establishment and Dem party cheered on as we congratulated ourselves on wasting more time in style.

In fact, Hillary was promising to do even less than Obama to fight CC, and ppl made fools of themselves defending her dirty history of FF peddling & donations. What about her support for TPP, which effectively prevents us from fighting Climate Change? At least maybe Trump stays true to his word and kills the TPP as promised, and thats a big Climate victory.

Hillary is a crook, as proven by Wikileaks info released on her. Did you read the speech where she told Wall St that Climate Activists pushing to stop burning of carbon should "get a life"??

Sure, Trump is an asshole and bigot (I'm dark-skinned btw), but I find it quite amusing that NOW so many ppl are outraged, at a president who hasn't even taken office yet? Sure, he's an asshole and climate denier, but the math shows not much will change in our carbon emissions for better of worse. We are currently STILL on the worst case path, and will remain so during Trump's term just like with Obama or would have been with Hillary.

I will keep doing my part to fight for change, but I really do expect the worst. Both parties are climate deniers, including Liberals. Most of the Climate movement is in denial, most scientists are in denial. Worse, Liberals are like a quack doctor informing their patient his cancer is in remission, when its not. Other than some real Leftists, there is a complete inability to grasp just how far fucked we are and how urgently action is needed.

Welp, its been nice guys.

[AbruptSLR]

While I have repeated noted that I believe that scientists, policymakers and the general public have erred on the side of least drama with regard to the coming climate challenge that we are all facing; I have also come to appreciate that with a current global population of approximately 7.5 billion people, there are the same number of different points of view all having a unique interpretation of their perspective on "the truth".  Some here have pointed-out that the size of the world population is the primary source of our problems and if only everyone else would just accept this "truth" then we would not have a population of approximately 7.5 billion and our problems would be solved.  Others note that if everyone would just consume less then all of our problems would be solved.  Others believe that if we just keep the global economy from running of the tracks long enough then technology will solve our problems.  The permutations are endless, but at the end of the day each one of us needs to make-up our own minds and deal with the consequences of both our own and of our communal actions.

In short it is easy to find fault in others, but it is more effective to first take responsibility for our own actions; which then leads to an understanding of our interconnectedness to others.

[Sigmetnow]

James Spann, an AMS certified meteorologist, writes: "We have to rethink the way we communicate weather information to the public."

A Failure To Communicate
https://medium.com/@spann/a-failure-to-communicate-b3005808ee

[Bruce Steele]

" Welp, it's been nice guys."

I don't know if this means you're signing off TeaPotty ?  I have enjoyed your posts and a little fire in the belly  is a great improvement over staid acceptance . Maybe I am reading something more into your last post than what you intended but if you are leaving I will miss your unforgiving point of view.
Bruce

[Sigmetnow]

Economists agree: economic models underestimate climate change

It's fairly well-established at this point that there's a robust scientific consensus about the threat of climate change. But analysts and journalists often say (or imply) that there's less of an economic consensus, that economists are leery of the actions recommended by scientists because of their cost.

Is it true? It turns out there have been very few systematic surveys of economists' opinions on the subject, and the few that have been done suffer from methodological shortcomings.

Last year, the New York–based Institute for Policy Integrity tried to remedy that situation with just such a large-scale survey of economists who have published work on climate change.

The conclusion? There is broad consensus on some questions, a wider spread on others, but in every case the median opinion of climate economists supports more vigorous action against climate change, sooner. Like scientists, economists agree that climate change is a serious threat and that immediate action is needed to address it.

http://www.vox.com/2015/12/8/9869918/economists-climate-consensus

[AbruptSLR]

The linked article is entitled: "Unprecedented Video Campaign: Scientists Talk About Why Climate Change Matters to Them Personally".  The article, & linked videos, provide personal views of scientists on the frontlines of climate research.  In general this indicates that frontline climate scientists are personally more concerned about climate change than IPCC documents present:

http://www.ecowatch.com/unprecedented-video-campaign-scientists-talk-about-why-climate-change--1882022353.html

[AbruptSLR]

The linked video is entitled: "Climate change and security: Unprecedented impacts, unpredictable risks".  The video highlights the fact that the interconnected impacts of climate raises global risks to unprecedented and unpredictable levels:




Edit: If it is unclear the hand on the right is composed of bullets.

[AbruptSLR]

The linked article is entitled: "Arctic ice melt could trigger uncontrollable climate change at global level".  It looks like an early collapse of Arctic sea ice extent will trigger at least 19 tipping point in the Arctic region alone; which is not appropriately considered by AR5:

https://www.theguardian.com/environment/2016/nov/25/arctic-ice-melt-trigger-uncontrollable-climate-change-global-level?CMP=share_btn_tw

Extract: "Arctic scientists have warned that the increasingly rapid melting of the ice cap risks triggering 19 “tipping points” in the region that could have catastrophic consequences around the globe.

The Arctic Resilience Report found that the effects of Arctic warming could be felt as far away as the Indian Ocean, in a stark warning that changes in the region could cause uncontrollable climate change at a global level."

[TeaPotty]

In short it is easy to find fault in others, but it is more effective to first take responsibility for our own actions; which then leads to an understanding of our interconnectedness to others.

I understand what you mean my friend, but this is different.

I am pointing fault at a president who handicapped the Paris climate agreement and did nothing to actually reduce our accelerating carbon emissions. Tinkering around the margins in the market with tiny investments in renewables is symbolic feel-good PR. Even his regulations border on the edge of insignificance (to climate, not environment). He made USA the #1 oil producer, spread fracking with help of FF shills selling gas as a "bridge fuel". Ultimately, carbon emissions are still accelerating. How does Obama get to claim having a climate legacy?

Then I got upset at the surge in posts blaming Trump already for everything, from ppl who praised Obama his whole presidency. Tribalism has become more important to these ppl than fighting climate change, bc they cant yet recognize that their "side" is blatantly lying to them. Even Hillary was revealed to have told business leaders in a paid speech that climate activists calling to stop burning carbon should "get a life". Many of these same ppl have been in denial at how fucked we are on Climate Change, and now they suddenly have all this concern and outrage bc of Democratic Party tribalistic talking points.

" Welp, it's been nice guys."

I don't know if this means you're signing off TeaPotty ?

What? And miss out learning from all the great minds on this forum?

I just meant that I've given up hope. I could be surprised, but I dont expect to. I don't even talk to my loved ones about it anymore other than small updates on significant research. Just seems depressing and pointless to them since nothing is getting done, and I can't blame them.

I think our best chance is not delaying the inevitable. The quicker things get bad, the better chance we have of ppl waking up and voting. There was so much potential with Bernie, and we really started the most successful & largest grassroots movement in American history. We raised more for Bernie's primary from small donors than Obama did for either of his presidential campaigns. Millennials actually enthusiastic and active to help this wonderful man fight for economic justice and try his best to fight climate change & the FF industry hampering action.

But the combination of election rigging, party favoritism, media collusion, smear campaigns, paid online posters, and a smug apathetic i-got-mine older generation brought that dream down. The movement still exists, so there is some potential here, but we wont see how much of an electoral force it is until next election. The establishment & MSM are busy trying to destroy it through their usual dirty tactics.

I have enjoyed your posts and a little fire in the belly  is a great improvement over staid acceptance.

Thanx buddy, I've always learnt much from your thoughtful posts.

[AbruptSLR]

In short it is easy to find fault in others, but it is more effective to first take responsibility for our own actions; which then leads to an understanding of our interconnectedness to others.

I understand what you mean my friend, but this is different.

...

I have enjoyed your posts and a little fire in the belly  is a great improvement over staid acceptance.

Thanx buddy, I've always learnt much from your thoughtful posts.

TeaPotty,

While I appreciate your logic (which is one reason that I have made so many posts in this thread that you created); in this world that we all live in often one must choose the lesser of two evils, in much the same way that moving towards the light is better than moving towards darkness even if one still remains in the dark.

Bruce,

If the note about "staid acceptance" refers to my efforts to get people to acknowledge the actual probabilities that we are headed towards socio-economic collapse within decades; lets just say that I am alarmed without trying to be alarmist because it is easy for the public to ignore an alarmist; while it is more difficult to ignore someone who is actually (& consistently) pointing at smoke coming from the approaching fire. 

That said, it definitely gets my blood boiling to think of the current, on-going, 6th Extinction and the billions of men, women and children who will likely suffer/die before the end of this century due both to the lack of wisdom from both our leaders and from most of the public.  Again, acknowledging that suffering exists is much different than promoting, or accepting, suffering; but if we are going to reduce (or eliminate) suffering thrashing around mindlessly is not the right way to move in the right direction.

Best,
ASLR

[Bruce Steele]

Abrupt, "staid acceptance" was in no way in reference to you. I have carried the climate change conversation into the public realm and some of the responses have been " extinctions  have happened before " or  " the arctic has melted before ".  I think TeaPottys response better matches the current situation although it is generally socially frowned on to show raw emotions. " Staid " reactions are going to run us all collectively off the cliff.  A little pissed off is appropriate and for me anyhow I would like to see more people pissed off and willing to confront BAU.
 What we are suppose to do about all this is also important and once you do get someone willing to listen I think having some appropriate suggestions about responses is also important.

[AbruptSLR]

What we are suppose to do about all this is also important and once you do get someone willing to listen I think having some appropriate suggestions about responses is also important.

Bruce,

While I am sure that you have lots of ideas of what to do about climate change (carbon tax, legal action, regulation, investment in sustainable technologies, divestment, boycotts, etc.), I provide a linked to a Climate Analytics article entitled: "The ten most important short-term steps to limit warming to 1.5°C":

http://climateanalytics.org/latest/the-ten-most-important-short-term-steps-to-limit-warming-to-15c

Extract: "All key sectors—energy generation, road transport, buildings, industry, forestry and land use, and commercial agriculture—have to begin major efforts to cut emissions by, latest, 2020. By 2025 they should have accelerated these efforts in order to reach globally aggregated zero carbon dioxide emissions by mid-century, and zero greenhouse gas emissions overall roughly in the 2060s."

Best,
ASLR

[TeaPotty]

While I appreciate your logic (which is one reason that I have made so many posts in this thread that you created); in this world that we all live in often one must choose the lesser of two evils, in much the same way that moving towards the light is better than moving towards darkness even if one still remains in the dark.

We agree on that my friend. But things have changed. Liberals are no longer the "lesser evil", or more correctly they have been blackmailing us by offering the minimum they could sell in pretty packaging. We have proof that for the past ~30 years they are the bigger enemy than the Conservatives, both from their own actions when in power, and from leaks revealed by Snowden or Wikileaks. They are much like someone who pretends to be your friend only to keep backstabbing you without your knowledge. Liberals have undermined any political efforts to help the working class, while quietly acting in favor of the 1%.

lets just say that I am alarmed without trying to be alarmist because it is easy for the public to ignore an alarmist; while it is more difficult to ignore someone who is actually (& consistently) pointing at smoke coming from the approaching fire.

I think the 1%-controlled media likes to make a joke out of those who are openly alarmist. Its part of their tactics to dissuade climate action. Unfortunately, I don't think humans will act if they are not alarmed. The past 20 years of climate activism is surely proof that non-alarmism is a failed tactic - which is why the 1% push us toward that stance. Its no coincidence that many establishment scientists are anti-alarmists - they earned their positions bc they were team players. Do you think history will look favorably upon them?

That said, it definitely gets my blood boiling to think of the current, on-going, 6th Extinction and the billions of men, women and children who will likely suffer/die before the end of this century due both to the lack of wisdom from both our leaders and from most of the public.

Damn right.

Again, acknowledging that suffering exists is much different than promoting, or accepting, suffering; but if we are going to reduce (or eliminate) suffering thrashing around mindlessly is not the right way to move in the right direction.

Thats what we've been doing till now. More of the same tactics will not result in any significant climate action. Leftists have spoken for decades about the root of all our problems, that nothing will get done without flipping the table on the 1%. They were right.

This election saw the biggest grassroots uprising in American history raise more money from small donors for Bernie Sanders in the Dem party primary than any candidate ever has even for the general election. The movement focused on economic justice and climate change, and the majority were independents & millennials. Wikileaks confirmed Hillary & the Dem establishment's disdain for the movement and its agenda, employing tactics like McCarthyism, race-baiting, hiring of online trolls to falsely smear 24/7, collusion among party elites, use of the state party branches to create a pyramid scheme circumventing max donation limits, collusion with media/journalists on their smear campaigns and fake scandals. They worked tirelessly to take the movement down and destroy it as the threat to the monied interests that it is. Just like Obama did to Occupy Wall St too, destroyed by gov operatives. Ultimately, they still had to rig the polls to barely win with a candidate who was already polling as losing to Trump a year before the gen election, with historic unpopularity (especially among independents, who Trump polled well with do to his fake economic populism).

After all the ridiculing and attacking of Bernie Sanders and our movement, the   numbers showed a loss of ~11% of independents & Millennials, nearly half of those which voted for Trump so Hillary would lose. Those key votes in the swing states lose Hillary the election, by ppl who are economically ruined and see the so-called "working ppl party" working with the Repubs against them. Truth is, the Dem establishment prefers to lose with Hillary than win with Bernie. That is their job.

Of course, Trump is highly unlikely to improve the lives of working ppl much, and our coalition can easily sweep in a real Leftist willing to take urgent action. The media's narratives are meaningless now, about half of voters dont trust a word of their propaganda. The same propaganda as all the climate optimism and "progress" published... nothing more than a marketing campaign to deceive & capture voters. Too many older adults accepted the Dem party's corruption, not realizing that their "lesser evilism" proved a slippery slope as both parties marched rightward. For example, Nixon was to the left of Obama economically.

The biggest problem now is who our 2020 candidate will be. Bernie is too old by then, and most Democrats are electoral poison now. The establishment Dem are irredeemable, bc they are not on our side. They dont intend to fight climate change. They are not the lesser evil. They lost this election bc we cannot take over the Dem party with them in power.

[AbruptSLR]

Of course, Trump is highly unlikely to improve the lives of working ppl much, and our coalition can easily sweep in a real Leftist willing to take urgent action.

As the first image indicates: "There is no sense in crying over spilt milk".  We most likely are stuck with Trump for four years and I believe that any improvements that he makes will be short-lived at best and will most likely make matters worse in the long-term.  As far as your "coalition can easily sweep in a real Leftist willing to take urgent action", I refer to the second image to quote Frederick Douglass that: "Power concedes nothing without a demand.  It never did and it never will."

I imagine that we are headed for turbulent times, and remember that the 1% have been planning the 4th Industrial Revolution for some time now & it will be interesting to see what the populist response is to the 4th Industrial Revolution.

http://www.cnbc.com/2016/11/18/elon-musk-says-robots-will-push-us-to-a-universal-basic-income-heres-how-it-would-work.html

Extract: "A 2013 study by Oxford University's Carl Frey and Michael Osborne estimates that 47 percent of U.S. jobs will potentially be replaced by robots and automated technology in the next 10 to 20 years. Those individuals working in transportation, logistics, office management and production are likely to be the first to lose their jobs to robots, according to the report.
In less developed countries, the potential for job loss is more severe. A 2016 analysis from the World Bank estimated that roughly two-thirds of all jobs in developing nations around the globe are susceptible to replacement by automation."

[TeaPotty]

As the first image indicates: "There is no sense in crying over spilt milk".  We most likely are stuck with Trump for four years and I believe that any improvements that he makes will be short-lived at best and will most likely make matters worse in the long-term.

So, pretty much like every other president before him.

As far as your "coalition can easily sweep in a real Leftist willing to take urgent action", I refer to the second image to quote Frederick Douglass that: "Power concedes nothing without a demand.  It never did and it never will."

Exactly. I never understood why anyone believed the fossil fuel industries would just allow their empire to be toppled. Its clear now we are at war with the 1% through both major parties.

I imagine that we are headed for turbulent times, and remember that the 1% have been planning the 4th Industrial Revolution for some time now & it will be interesting to see what the populist response is to the 4th Industrial Revolution.

At the very least, it will be interesting. I do hope UBI becomes a reality.

[AbruptSLR]

I do hope UBI becomes a reality.

For those who do not know what UBI is:

http://hubio.com/leading-the-revolution/

Extract: "... technologies such as usage-based insurance (UBI) enhance existing digital capabilities, with data and analytics playing key roles in safety, maintenance and consumer engagement."

[Andre]

I do hope UBI becomes a reality.

For those who do not know what UBI is:

http://hubio.com/leading-the-revolution/

Extract: "... technologies such as usage-based insurance (UBI) enhance existing digital capabilities, with data and analytics playing key roles in safety, maintenance and consumer engagement."

Wasnt UBI refering to Universal Basic Income in this context?

Maybe I misunderstood.

[TeaPotty]

I do hope UBI becomes a reality.

For those who do not know what UBI is:

http://hubio.com/leading-the-revolution/

Extract: "... technologies such as usage-based insurance (UBI) enhance existing digital capabilities, with data and analytics playing key roles in safety, maintenance and consumer engagement."

Wasnt UBI refering to Universal Basic Income in this context?

Maybe I misunderstood.

Yup, I referred to Universal Basic Income as AbruptSLR linked to in the article.

[AbruptSLR]

The linked reference (& associated articles) provides evidence that the positive feedback from soil carbon emissions is stronger than previously appreciated by consensus science:

T. W. Crowther et al (2016), "Quantifying global soil carbon losses in response to warming", Nature, DOI: 10.1038/nature20150

http://www.nature.com/nature/journal/v540/n7631/full/nature20150.html

Abstract: "The majority of the Earth’s terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming. Despite evidence that warming enhances carbon fluxes to and from the soil, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12–17 per cent of the expected anthropogenic emissions over this period. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon–climate feedback that could accelerate climate change."

See the linked article entitled: "Losses of soil carbon under global warming might equal US emissions".

http://phys.org/news/2016-11-losses-soil-carbon-global-equal.html

Extract: "A new Yale-led study in the journal Nature finds that warming will drive the loss of at least 55 trillion kilograms of carbon from the soil by mid-century, or about 17% more than the projected emissions due to human-related activities during that period. That would be roughly the equivalent of adding to the planet another industrialized country the size of the United States.
Critically, the researchers found that carbon losses will be greatest in the world's colder places, at high latitudes, locations that had largely been missing from previous research. In those regions, massive stocks of carbon have built up over thousands of years and slow microbial activity has kept them relatively secure."


See also, the linked article is entitled: "Ground beneath our feet is poised to make global warming much worse, scientists find".

http://www.newsminer.com/news/alaska_news/ground-beneath-our-feet-is-poised-to-make-global-warming/article_f88d5ae6-b752-11e6-8414-b7838e99bb70.html

Extract: "In a massive new study published Wednesday in the influential journal Nature, no less than 50 authors from around the world document a so-called climate system "feedback" that, they say, could make global warming considerably worse over the coming decades.

That feedback involves the planet's soils, which are a massive repository of carbon due to the plants and roots that have grown and died in them, in many cases over vast time periods (plants pull in carbon from the air through photosynthesis and use it to fuel their growth). It has long been feared that as warming increases, the microorganisms living in these soils would respond by very naturally upping their rate of respiration, a process that in turn releases carbon dioxide or methane, leading greenhouse gases.

It's this concern that the new study validates. "Our analysis provides empirical support for the long-held concern that rising temperatures stimulate the loss of soil C to the atmosphere, driving a positive land C-climate feedback that could accelerate planetary warming over the twenty-first century," the paper reports."

[AbruptSLR]

The linked reference (& associated following article) discuss paleo findings related to variabilities in the carbon-climate feedback during the Miocene Climatic Optimum (MCO); which may have bearing on what climate sensitivities to calibrate to for future climate change projections, as the MCO had atmospheric CO₂ concentrations comparable to today and GMSTA of about 4C.  The presented evidence implies that when the two polar ice caps are absent, or severely restricted, the associated impacts on the oceans likely resulted in significant (& relatively rapid) carbon emissions from the ocean.  Such feedback mechanisms are not included in AR5 projections

Karlos G. D. Kochhann, Ann Holbourn, Wolfgang Kuhnt, James E. T. Channell, Mitch Lyle, Julia K. Shackford, Roy H. Wilkens & Nils Andersen (17 September 2016), "Eccentricity pacing of eastern equatorial Pacific carbonate dissolution cycles during the Miocene Climatic Optimum", Paleoceanography, DOI: 10.1002/2016PA002988


http://onlinelibrary.wiley.com/doi/10.1002/2016PA002988/full

Abstract: "The Miocene Climatic Optimum (MCO; ~16.9 to 14.7 Ma) provides an outstanding opportunity to investigate climate-carbon cycle dynamics during a geologically recent interval of global warmth. We present benthic stable oxygen (δ18O) and carbon (δ13C) isotope records (5–12 kyr time resolution) spanning the late early to middle Miocene interval (18 to 13 Ma) at Integrated Ocean Drilling Program (IODP) Site U1335 (eastern equatorial Pacific Ocean). The U1335 stable isotope series track the onset and development of the MCO as well as the transitional climatic phase culminating with global cooling and expansion of the East Antarctic Ice Sheet at ~13.8 Ma. We integrate these new data with published stable isotope, geomagnetic polarity, and X-ray fluorescence (XRF) scanner-derived carbonate records from IODP Sites U1335, U1336, U1337, and U1338 on a consistent, astronomically tuned timescale. Benthic isotope and XRF scanner-derived CaCO3 records depict prominent 100 kyr variability with 400 kyr cyclicity additionally imprinted on δ13C and CaCO3 records, pointing to a tight coupling between the marine carbon cycle and climate variations. Our intersite comparison further indicates that the lysocline behaved in highly dynamic manner throughout the MCO, with >75% carbonate loss occurring at paleodepths ranging from ~3.4 to ~4 km in the eastern equatorial Pacific Ocean. Carbonate dissolution maxima coincide with warm phases (δ18O minima) and δ13C decreases, implying that climate-carbon cycle feedbacks fundamentally differed from the late Pleistocene glacial-interglacial pattern, where dissolution maxima correspond to δ13C maxima and δ18O minima. Carbonate dissolution cycles during the MCO were, thus, more similar to Paleogene hyperthermal patterns."


See also, the linked article:

Cook, T. (2016), Earth’s carbon-climate feedbacks varied in past warming episodes, Eos, 97, doi:10.1029/2016EO063291. Published on 29 November 2016

https://eos.org/research-spotlights/earths-carbon-climate-feedbacks-varied-in-past-warming-episodes?utm_source=eos&utm_medium=email&utm_campaign=EosBuzz120216


Extract: "Embedded within the Earth’s long-term cooling trend over the past 65 million years are several climate spikes—swift transitions to “hothouse” conditions—that had profound consequences for life. These spikes could serve as analogues for the future of our warming planet.
…
Their new record spans the Miocene Climatic Optimum (MCO), the hothouse interval between about 17 and 15 million years ago. During the MCO, the average global temperature was up to 4°C warmer than today, and carbon dioxide concentrations hovered at about modern levels (400 parts per million).
…
The study also provides strong evidence that the lysocline, the depth in the ocean below which carbonates are much more quickly dissolved, was very dynamic during the MCO, repeatedly fluctuating by up to 600 meters.
…
Notably, episodes of peak carbonate dissolution during the MCO coincided with warmer temperatures (as indicated by the oxygen isotope records), as well as a lightening of carbon isotopes. In contrast, during Pleistocene interglacial warming intervals, periods of higher temperatures (as indicated by the oxygen isotope records) corresponded to records of heavier carbon isotopes. This difference caused the team to conclude that the feedbacks between climate and the carbon cycle during the Miocene differed fundamentally from those at play during the more recent Pleistocene glacial-interglacial cycles.

The authors note that correlation between high temperature and light carbon isotopes, as seen during the MCO, was also observed during the Paleogene, an interval noted for its extremely rapid episodes of global warming and probable lack of ice caps. Therefore, they argue that climate and carbon cycle variability during the MCO, when global warming conditions probably limited ice cover at the poles, corresponded more closely to patterns observed during the Paleogene than those seen during more recent Pleistocene times, when Earth hosted two polar ice sheets."

[Bruce Steele]

Abrupt, The Karlos abstract you linked talks about the lysocline shoaling  during the MCO " repeatedly fluctuated by up to 600 meters. "
I wanted to get an idea about how much carbon was required to get a 600 meter fluctuation in the lysocline. From Zachos et al 2005
 " modeling of a 1200GtC input over 10 ky produces a lysocline shoaling of 300 m ( less in the Pacific )
with a recovery time of 40 ky."



http://www.whoi.edu/cms/files/zachos05sci_133124.pdf


So if the lack of polar ice caps can result in carbon releases capable of causing a lysocline fluctuation of 600 meters then we are talking about carbon releases of somewhere north of 1200GtC that would be added to want ever Antropogenic Carbon  caused the melting in the first place.
 The lysocline is currently shoaling at a rate of two meters a year in the Pacific and four per year in the Atlantic. It would only take 75 years to reach 300 meters of shoaling at the current rate of change.
Because the recovery time may be 40,000 years  any extra carbon released as a result of melting of the ice caps would be additive to total anthropogenic carbon releases. This may indicate a carbon feedback that will equal the anthropogenic contribution.  Something like 1200C plus 1200C ( totally back of napkin ). This would result in the 600 meter fluctuation noted in the abstract.

[jai mitchell]

Please review the video abstract below:



----------------

Scientists have long feared this ‘feedback’ to the climate system. Now they say it’s happening

https://www.washingtonpost.com/news/energy-environment/wp/2016/11/30/the-ground-beneath-our-feet-is-poised-to-make-global-warming-much-worse-scientists-find/?utm_term=.8c246a8e9cd4

The paper therefore found that the biggest losses were in Arctic regions, where soils are warming rapidly and also where they are quite thick — but also that well down through the mid-latitudes, soils were also losing carbon. And the net result for the research plots as a whole was a loss of soil carbon.

The paper then extrapolated these findings for the globe, finding that by the year 2050, the planet could see 55 billion tons of carbon released from soils.

(this correlates to 200 billion tons of additional CO2 added to the atmosphere due to soil feedbacks by 2050) --  Unless. . .



------------------
http://www.nature.com/nature/journal/v540/n7631/full/nature20150.html

Quantifying global soil carbon losses in response to warming

T. W. Crowther et al.

abstract
The majority of the Earth’s terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming1, 2, 3, 4. Despite evidence that warming enhances carbon fluxes to and from the soil5, 6, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12–17 per cent of the expected anthropogenic emissions over this period7, 8. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon–climate feedback that could accelerate climate change.



---its time to act, there is no more time---

note:  ASLR Also posted on this yesterday above, with additional commentary.

[AbruptSLR]

The lysocline is currently shoaling at a rate of two meters a year in the Pacific and four per year in the Atlantic. It would only take 75 years to reach 300 meters of shoaling at the current rate of change.
Because the recovery time may be 40,000 years  any extra carbon released as a result of melting of the ice caps would be additive to total anthropogenic carbon releases. This may indicate a carbon feedback that will equal the anthropogenic contribution.  Something like 1200C plus 1200C ( totally back of napkin ). This would result in the 600 meter fluctuation noted in the abstract.

Bruce,

Thanks for the quick/rough estimates.  If Hansen is correct about the potential for abrupt ice sheet losses & the associated ice-climate interaction, then the effective ESS between 2050 & 2100 could be well be between 5 & 6C.

Best,
ASLR

[AbruptSLR]

The linked Scribbler article is entitled: "Beyond the Point of No Return — Imminent Carbon Feedbacks Just Made the Stakes for Global Warming a Hell of a Lot Higher", and it adds perspective to Replies #1589 & #1592:


https://robertscribbler.com/2016/12/02/beyond-the-point-of-no-return-imminent-carbon-feedbacks-just-made-the-stakes-for-global-warming-a-hell-of-a-lot-higher/

Extract: " For according to new, conservative estimates in a scientific study led by Dr. Thomas Crowther, increasing soil respiration alone is about to add between 0.45 and 0.71 parts per million of CO2 to the atmosphere every year between now and 2050.
…
… we will easily be on track for 5-7 C or worse warming by the end of this Century."

[Sigmetnow]

Instructions:   No. Crying. In. Science.

"From professors like Allison taking students through a guided meditation after a discussion on retreating rainforests to scientists signing up for workshops on compassion and communication to support groups for climatologists, human emotion has wedged itself into every step of the scientific method."

IT'S THE END OF THE WORLD — HOW DO YOU FEEL?
http://www.ozy.com/fast-forward/its-the-end-of-the-world-how-do-you-feel/62757

[Archimid]

human emotion has wedged itself into every step of the scientific method."

Human emotion is inseparable from any human endeavor. Pretending that emotion can be easily separated from logic only blinds science. Scientist that strive for the ultimate truth must acknowledge emotion before they can separate it from logic. Peer review can help, but if all reviewers are trapped by the same emotions then it is useless.

[Archimid]

The user LoomisDove  at reddit posted this quote. I find that it perfectly describes the arguments of the cowardly climate change deniers. I wanted to share it with you, but I didn't know where to put it. This thread seems appropriate.

There is this great quote in Robert Henson's, The Rough Guide to Climate Change (London/New York: Rough Guides, 2008, p. 257) that sums up many of the counter "arguments" against the reality of climate change and the need to do something about it. It goes like this: ”The atmosphere isn’t warming; and if it is, then it’s due to natural variation; and even if it’s not due to natural variation, then the amount of warming is insignificant; and if it becomes significant, then the benefits will outweigh the problems; and even if they don’t, technology will come to the rescue; and even if it doesn’t, we shouldn’t wreck the economy to fix the problem when many parts of the science are uncertain.”

[Andre]

The methane increases over the last years have finally been noticed by the Guardian as well:

https://www.theguardian.com/environment/2016/dec/12/rapid-rise-methane-emissions-10-years-surprises-scientists

[AbruptSLR]

The linked presentation entitled: “HIATUS ON THE UPWARD STAIRCASE OF GLOBAL WARMING”, indicates that their method for filtering out natural internal variability of climate systems indicates that the global mean surface temperature is actually increasing at a higher rate than previously recognized:

https://scripps.ucsd.edu/news/scripps-news-2016-agu-fall-meeting

Measuring Anthropogenic Global Warming in Real Time
A43K-04 • Thursday, Dec. 15, 3:10 p.m. • Moscone West 3008

Description: "A pair of researchers from Scripps Institution of Oceanography at UC San Diego and University of Tokyo have developed a means to track the increase in global mean surface temperature caused by human activities.

The method allows climate modelers to filter out the natural internal variability of climate systems to make society’s impact clearer. Scripps climate scientist Shang-Ping Xie and Yu Kosaka, formerly of Scripps, have used it to estimate that mean surface temperature in this decade is 1.2° C higher than it was in 1900, a greater rate of increase than had previously been thought by climate researchers.

The researchers suggest this methodology allows climate policymakers to more easily access reliable estimates of human-caused climate change as countries look for ways to limit global warming to 2° C above pre-industrial temperatures.

Xie and Kosaka had previously explained the apparent “hiatus” in global warming that had been the subject of controversy in recent years. They did so by identifying the influence of variables such as the cooling of the tropical Pacific Ocean. It was that research, published in 2013, that led to the creation of this methodology."