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Tuesday, March 24, 2015

A sensitive climate workshop - and freebies from the Royal Society

Sou | 3:45 AM Go to the first of 2 comments. Add a comment


Some of you will know about the workshop on climate sensitivity that's taking place this week at Ringberg in Germany. The participant list includes some big names in the science world, and will ensure a wide range of views on the subject.

You can read about the workshop at realclimate.org, or visit the website.  You can also follow what's happening on Twitter, by searching #ringberg15. (There are some nuisance denier tweeters, but if you're on Twitter, you can just block or mute them and read what the scientists are tweeting.)

The workshop aims to get a better handle on climate sensitivity (and transient climate response), though I'm not all that optimistic that there'll be agreement on all counts. Here are the questions posed on the website:

I. Is the present range of TCR/ECS too narrow or broad and if so what is the case for changing it?
- physical hypotheses and story lines
- model and observational investigations, underlying mechanisms 
II. How would we expect extremely sensitivities (either high or low ones) to physically manifest themselves?
- in terms of climatology, variability, trends and past changes
- in terms of projections 
III. How strongly can observations (including palaeo) constrain sensitivities? 
- how consistent are different constraints and what can be inferred from multiple constraints?
- do observations suggest models are missing or distorting key processes? 
IV. Outlook
- what are the most promising prospects for reducing uncertainty in estimated ECS/TCR? How to facilitate these?
- any blocking points? Any evidence (or otherwise) that the problem should be addressed differently?
- are there specific ideas or mechanisms to be tested more collectively? Using more exotic models or data? 

I've been reading through the papers - most of them have been made available for the workshop, though not all. They all make interesting reading. I found the upcoming paper by Steve Sherwood et al particularly interesting. It discusses "the new concept of adjustments, which are responses to forcings that are not mediated by the global mean temperature". From the abstract:
This concept, related to the older ones of climate efficacy and stratospheric adjustment, is a more physical way of capturing unique responses to specific forcings. We present a pedagogical review of the adjustment concept, why it is important, and how it can be used. The concept is particularly useful for aerosols, where it helps to organize what has become a complex array of forcing mechanisms. It also helps clarify issues around cloud and hydrological response, transient vs. equilibrium climate change, and geoengineering.
Another paper by Joeri Rogelj et al is about "what to do" and discusses the impact of different sensitivities on risk and policy response. (Answer - not a great deal. We need to act now.)

Then there's the Stevens paper that got deniers and Nic Lewis a bit over-excited, which was suggesting that aerosol forcing may not be as negative as in some climate models and the "best estimate" of the IPCC. (Bjorn Stevens is also a co-author of the Sherwood paper I mentioned above. I suggest reading both papers because they complement each other.)


Click on the >>> to download the papers or go to the abstract.
  • Opens external link in new window>>>  Andrews, T. et al., 2015: The dependence of radiative forcing and ... , J. Climate, 28, 1630-1648
  • Opens external link in new window>>>  Armour, K. C. et al., 2013: Time-varying climate sensitivity from regional feedbacks. J. Climate, 26, 4518-4534  
  • Opens external link in current window>>>  Caldwell, P. M. et al., 2014: Statistical significance of climate sensitivity predictors ... , GRL, 41(5), 1803-1808
  • Opens external link in current window>>>  Feldl, N., and G. H. Roe, 2013: The nonlinear and nonlocal nature of climate feedbacks. J. Climate, 26, 8289-8304
  • Opens external link in current window>>>  Huber, M. and Knutti, R., 2014: Natural variability, radiative forcing and ... , Nature Geoscience
  • Opens external link in current window>>>  Huber, M. et al., 2014: Estimating climate sensitivity and future temperature in ... , GRL
  • Opens external link in current window>>>  Lewis N. and Curry, J. A., 2014: The implications for climate sensitivity of AR5 forcing and ... , Climate Dynamics
  • Opens external link in current window>>>  Marotzke, J. and Forster, P., 2015: Forcing, feedback and internal variability in global temperature trends. Nature
  • Opens external link in current window>>>  Meraner, K., et al., 2013: Robust increase in equilibrium climate sensitivity ..., GRL, 40, 5944–5948  
  • Opens external link in current window>>>  Merlis, T. M., et al., 2014: Constraining transient climate sensitivity using ... , J. Climate, 27, 7781-7795
  • Initiates file download>>>  Millar, R. J., 2015: Model structure in observational constraints on ... , Climatic Change, in press
  • Opens external link in current window>>>  Roe G. H., et al., 2015: The remote impacts of climate feedbacks on regional ... , Nature Geoscience, 8, 135–139
  • Opens external link in current window>>>  Rogelj, J. et al., 2014: Implications of potentially lower climate sensitivity on ... , Environ. Res. Lett.
  • Opens external link in current window>>>  Rose B. E. J., et al., 2014: The dependence of transient climate sensitivity and ... , GRL, 41
  • Opens external link in current window>>>  Schaller, N. et al., 2014: The asymmetry of the climate system's response to solar forcing changes and ... , JGR
  • Opens external link in current window>>>  Sherwood, S. et al., 2015: Adjustments in the forcing-feedback framework for ... , BAMS, in press
  • Opens external link in current window>>>  Shindell, D. T., 2014: Inhomogeneous forcing and transient climate sensitivity. Nature ClimateChange,  4, 274–277
  • Opens external link in current window>>>  Stevens, B. 2015: Rethinking the lower bound on aerosol radiative forcing. J. Climate, in press
  • Opens external link in current window>>>  Qu, X. et al., 2014: On the spread of changes in marine low cloud cover in ..., Climate Dynamics

Royal Society journals free to the end of March


From the Royal Society blog:
So what better way to mark the 350th anniversary of the world’s first science journal than to make all Royal Society content freely available, to everyone?
Yes, you read that right… readers can access our complete collection online, without the need for a subscription, between now and the end of March.

2 comments:

Dan Andrews said...

Thanks for pointing that out, Sou. I downloaded a number of papers dealing with bird migration and climate change (which is my main connection with climate change), that I don't have yet.

Anonymous said...

I thought the Rogelj et al paper was disapointing, because it makes conclusions outside the scope of science, and engages in naive one-eyed politics. It also transparently overplays the implications of ECS relative to TCR, the latter obviously being of greater relevance to policy. The conclusion unfortunately fails to acknowledge the many negative social and envionmental implications of climate policies which entail higher energy costs, and in particular the impacts on poorer countries. Unless this is acknowleged, the scientific case for climate action will continued to be ignored in the rapidly industrialising developing countries, as a secondary issue to growth, jobs, education, health and living standards.