date: 26 Jun 2007 12:42:52 -0400 from: Gavin Schmidt subject: Re: Armstrong to: Phil Jones I'll try and go to the presentation on thursday if I can sneak into their conference... I suspect a mere publicity stunt for an upcoming book. With respect to Keenan, he is clearly a man on a mission. So engaging him and trying to appeal to his more rational side is a waste of time. Other than that, I'm not sure what to recommend... gavin On Mon, 2007-06-25 at 09:04, Phil Jones wrote: > Gavin, > Just quickly read an awful paper by Armstrong. Have got a quick > response from Kevin Trenberth. Kevin says you may run with this > on RC? Might be worthwhile. He seems to have got some > bad advice somewhere, or he's a republican. Kevin's response > is on the button. > > By the way - on Keenan - I have spoken to Pascal. According to > Pascal, though, he's gone further than he went with him (grapes) on this > Chinese urbanization issue. > > Cheers > Phil > > Gavin, > I see CA has some threads about GISS ModelE. The discussion > just shows how little they know. Models are verified against obs > data and parameterizations changed/improved. Do they not realize > that any parameterization will likely affect most grid boxes and > not just ones they are looking at! > Nice to know that the GISS ModelE has some 91K lines of code! > Also they on the ball with Kenneth Trenberth! > > I see that CA is taking adverts. I have seen a few times, one for > the MSc Climate Change course at the University of Exeter. Maybe > if you deign to reply (I wouldn't but on RC some time) you should > suggest some of them take the course! > > On teaching, we are experiencing a massive upsurge in applications > to do our MSc on Climate Change. We have made offers to over 80 > people. Based on a conversion rate from past years of 50%, we may > likely have about twice as many people doing course cf previous > years. It doubled to about 20 only 3 years ago from 10 during 1998-2004. > > Cheers > Phil > > > At 23:32 22/06/2007, you wrote: > >It would indeed be nice if they would do something constructive like > >write an actual paper, but it's extremely unlikely that they'll bother. > >As we've discussed before, this isn't really about the science - it's > >more of a way to shift the topic of conversation away from physics and > >on to perfidious scientists, totalitarian bureaucracies and freedom of > >speech. Those subjects resonate with a lot of people who are looking for > >reasons not to want to trust the IPCC. > > > >Keenan is extremely unpleasant - much more so than McIntyre. Ask Pascal > >Yiou the next time you see him! > > > >There is unfortunately no good way to deal with this micro-parsing - but > >don't let anything you do allow them to shift the focus onto 'hiding' > >data etc. > > > >regards, > > > >gavin > > > >On Thu, 2007-06-21 at 03:58, Phil Jones wrote: > > > Gavin, > > > So you do look at CA occasionally! Yes nice emails > > > welcomed all the time. CRU gets a number of emails each > > > week from interested amateurs (the public). I'm much more > > > careful how I reply to these. > > > I won't be replying to CA. McIntyre's email wasn't too bad. > > > The really awful one with threats came from Douglas Keenan. > > > The only issue I can see they are complaining about is that > > > we said we used 84 sites (42 rural and 42 urban) and that > > > we chose those with the fewest site changes. They have found > > > site histories for some of them and there are site moves! They > > > have yet to look at the temperature data that I sent them! So > > > their claim is nothing about the analysis in the paper! > > > They don't seem to realise that when you spend ages doing all > > > the site adjustments they only make differences locally. At > > > large scales they tend to cancel each other out. In > > > Brohan et al. (2006) Figure 4 you can see a histogram of > > > adjustments - the average of which is close to zero! > > > Adjusting is useful as it improves the continuity of spatial > > > patterns. > > > The real issues are the biases like urbanization, buckets > > > and the exposure issues from pre-Stevenson screen days. > > > Jim will have realized this ages ago, as I did around the > > > mid-1980s. > > > > > > If only they would write a paper, then I'd know what to deal > > > with. I reckon they are trying this new tack now (blogs, > > > personal attacks and maybe complaints to our employers) > > > as they realize they can't write papers (the MM ones re MBH > > > were poor), and they see their new approach as being more > > > productive for them. > > > > > > So more nice emails every now and then. > > > > > > Cheers > > > Phil > > > > > > > > > At 17:21 20/06/2007, you wrote: > > > >yeah, I've been noticing... Well, just let me know if I can do anything > > > >- even if it's just sending the occasionally nice email! > > > > > > > >Gavin > > > > > > > > > > > >On Wed, 2007-06-20 at 05:59, Phil Jones wrote: > > > > > Gavin, > > > > > Thanks. Yours was the nicest email I got overnight. > > > > > Cheers > > > > > Phil > > > > > > > > > > > > > > > At 20:02 19/06/2007, you wrote: > > > > > >Refs for my section - note that the first Goosse reference should be > > > > > >Goosse et al 2006, and the second was in error and shouldn't be there > > > > > >any way. > > > > > > > > > > > > > > > > > >Gavin > > > > > > > > > > > > > > > > > > > > > > > >References > > > > > > > > > > > >Collins, W. D., et al., Radiative forcing by well-mixed greenhouse > > > > > >gases: Estimates from climate models in the Intergovernmental > > > > > > Panel on Climate Change (IPCC) Fourth Assessment Report (AR4), J. > > > > > >Geophys. Res, 111, 2006. > > > > > > > > > > > >Dickinson, R., Solar variability and the lower atmosphere, Bull. Amer. > > > > > >Meteor. Soc., pp. 1240­1248., 1975. > > > > > > > > > > > >Gerber, S., F. Joos, P. P. Bruegger, T. F. Stocker, M. E. Mann, and S. > > > > > >Sitch, Constraining temperature variations over the last > > > > > > millennium by comparing simulated and > > observed atmospheric CO2, Clim. > > > > > >Dyn., 20, 281­299, 2003. > > > > > > > > > > > >Goosse, H., O. Arzel, J. Luterbacher, M. E. Mann, H. Renssen, N. > > > > > >Riedwyl, A. Timmermann, E. Xoplaki, and H. Wanner, The origin > > > > > > of the European "Medieval Warm Period", Climate of the Past, 2, > > > > > >99­113, 2006. > > > > > > > > > > > >Haigh, J. D., The impact of solar > > variability on climate, Science, 272, > > > > > >981­984, 1996. > > > > > > > > > > > >Houghton, J. T., Y. Ding, D. J. Griggs, > > M. Nouger, P. J. van der Linden, > > > > > >X. Dai, K. Maskell, and C. A. Johnson, Climate Change > > > > > > 2001: The scientific basis, Cambridge Univ. Press, New York, 2001. > > > > > > > > > > > >Lean, J., Evolution of the sun's spectral irradiance since the Maunder > > > > > >Minimum, Geophys. Res. Lett., 27, 2425­2428, 2000. > > > > > > > > > > > >LeGrande, A. N., G. A. Schmidt, D. T. > > Shindell, C. Field, R. L. Miller, > > > > > >D. Koch, G. Faluvegi, and G. Hoffmann, Consistent simulations > > > > > > of multiple proxy responses to an > > abrupt climate change event, Proc. > > > > > >Natl. Acad. Sci., 103, 837­842, 2006. > > > > > > > > > > > >Oman, L., A. Robock, G. Stenchikov, G. A. Schmidt, and R. Ruedy, > > > > > >Climatic response to high-latitude volcanic eruptions, J. Geophys. > > > > > > Res., 110, 2005. > > > > > > > > > > > >Ruddiman, W. F., The anthropogenic greenhouse era began thousands of > > > > > >years ago, Clim. Change, 61, 261­293, 2003. > > > > > > > > > > > >Shindell, D. T., G. A. Schmidt, R. L. Miller, and D. Rind, Northern > > > > > >hemisphere winter climate response to greenhouse gas, ozone, > > > > > > solar and volcanic forcing, J. Geophys. Res., 106, 7193­7210, 2001. > > > > > > > > > > > >Shindell, D. T., G. Faluvegi, R. L. > > Miller, G. A. Schmidt, J. E. Hansen, > > > > > >and S. Sun, Solar and anthropogenic forcing of tropical > > > > > > hydrology, Geophys. Res. Lett., 33, 2006. > > > > > > > > > > > > > > > > > > > > > > > >On Tue, 2007-05-29 at 05:55, Phil Jones wrote: > > > > > > > Gavin, > > > > > > > Thanks for this. I'll incorporate this into a revised draft > > > > > > > later this week > > > > > > > and then send around. Gene has sent me something as well. > > > > > > > Can you send the refs if you have them? > > > > > > > > > > > > > > Thorsten will likely send a reminder around as he's being > > > > > > > pressurized by Larry from EPRI. > > > > > > > > > > > > > > Cheers > > > > > > > Phil > > > > > > > > > > > > > > > > > > > > > At 09:51 28/05/2007, you wrote: > > > > > > > > > > > > > > >Hi Phil, sorry for the long delay. > > But here is a first draft of the > > > > > > > >forcings and models section I was supposed to take the lead on. > > > > > > > >Hopefully, we can merge that with whatever Caspar has. > > > > > > > > > > > > > > > >Thanks > > > > > > > > > > > > > > > >Gavin > > > > > > > > > > > > > > > >================ > > > > > > > > > > > > > > > >4 Forcing (GS/CA/EZ) 4-5pp > > > > > > > > > > > > > > > >Histories (CA) > > > > > > > >How models see the forcings, especially wrt aerosols/ozone and > > > > > > > >increasing model complexities (GS) > > > > > > > > > > > > > > > >An important reason for improving > > > > climate reconstructions of the past few > > > > > > > >millenia is that these reconstructions can help us both evaluate > > > > > > > >climate model responses and sharpen our understanding of important > > > > > > > >mechanisms and feedbacks. Therefore, a parallel task to improving > > > > > > > >climate reconstructions is to assess and independently constrain > > > > > > > >forcings on the climate system over that period. > > > > > > > > > > > > > > > >Forcings can generically be described as external effects on a > > > > > > > >specific system. Responses within that system that also themselves > > > > > > > >have an impact on its internal state > > are described as feeebacks. For > > > > > > > >the atmosphere, sea surface temperature changes could > > > > > > > >therefore be considered a forcing, > > but in a coupled ocean-atmosphere > > > > > > > >model they could be a feedback to another external factor or be > > > > > > > >intrinsic to the coupled system. Thus > > > > the distinction between forcings and > > > > > > > >feedbacks is not defined a priori, > > but is a function of the scope of > > > > > > > >the modelled system. This becomes > > especially important when dealing > > > > > > > >with the bio-geo-chemical processes in climate that effect the > > > > > > > >trace gas concentrations (CO2 and CH4) or > > > > > > aerosols. For example, if a model > > > > > > > >contains a carbon cycle, than the CO2 variations as a function of > > > > > > > >climate will be a feedback, but for > > a simpler physical model, CO2 is > > > > > > > >often imposed directly as a forcing > > from observations, regardless of > > > > > > > >whether in the real world it was a > > feedback to another change, or a > > > > > > > >result of human industrial activity. > > > > > > > > > > > > > > > >It is useful to consider the > > pre-industrial period (pre-1850 or so) > > > > > > > >seperately from the more recent past, since the human influence on > > > > > > > >many aspects of atmospheric > > composition has increased dramatically in > > > > > > > >the 20th Century. In particular, aerosol and land use changes are > > > > > > > >poorly constrained prior to the late 20th Century and have large > > > > > > > >uncertainties. Note however, there may > > > > conceivably be a role for human > > > > > > > >activities even prior to the 19th > > Century due to early argiculatural > > > > > > > >activity (Ruddiman, 2003; Goosse et al, 2005). > > > > > > > > > > > > > > > >In pre-industrial periods, forcings can be usefully separated into > > > > > > > >purely external changes (variations of solar activity, volcanic > > > > > > > >eruptions, orbital variation), and > > those which are intrinsic to the > > > > > > > >Earth system (greenhouse gases, aerosols, vegetation etc.). Those > > > > > > > >changes in Earth system elements > > will occur predominantly as feedbacks > > > > > > > >to other changes (whether externally > > forced or simply as a function of > > > > > > > >internal climate 'noise'). In the > > more recent past, the human role in > > > > > > > >affecting atmospheric composition > > (trace gases and aerosols) and land > > > > > > > >use have dominated over natural > > processes and so these changes can, to > > > > > > > >large extent, be considered external forcings as well. > > > > > > > > > > > > > > > >Traditionally, the 'system' that is > > most usually implied when talking > > > > > > > >about forcings and feedbacks are the > > 'fast' components atmosphere-land > > > > > > > >surface-upper ocean system that, not > > coincidentally, corresponds to > > > > > > > >the physics contained within atmospheric > > > > > > general circulation models (AGCMs) > > > > > > > >coupled to a slab ocean. What is not > > > > > > included (and therefore considered as a > > > > > > > >forcing according to our previous > > definition) are 'slow' changes in > > > > > > > >vegetation, ice sheets or the carbon > > cycle. In the real world these > > > > > > > >features will change as a function > > of other climate changes, and in > > > > > > > >fact may do so on relatively 'fast' (i..e multi-decadal) > > > > > > > >timescales. Our choice then of the appropriate 'climate system' is > > > > > > > >thus slightly arbitrary and does not > > give a complete picture of the > > > > > > > >long term sensitivity of the real climate. > > > > > > > > > > > > > > > >These distinctions become important > > because the records available for > > > > > > > >atmospheric composition do not > > record the distinction between feedback > > > > > > > >or forcing, they simply give, for instance, the history of CO2 and > > > > > > > >CH4. Depending on the modelled > > system, those records will either be a > > > > > > > >modelling input, or a modelling target. > > > > > > > > > > > > > > > >While there are good records for > > some factors (particularly the well > > > > > > > >mixed greenhouse gases such as CO2 > > and CH4), records for others are > > > > > > > >either hopelessly incomplete (dust, > > vegetation) due to poor spatial or > > > > > > > >temporal resolution or non-existant > > (e.g. ozone). Thus estimates of > > > > > > > >the magnitude of these forcings can > > only be made using a model-based > > > > > > > >approach. This can be done using > > GCMs that include more Earth system > > > > > > > >components (interactive aerosols, chemistry, dynamic vegetation, > > > > > > > >carbon cycles etc.), but these > > models are still very much a work in > > > > > > > >progress and have not been used extensively for paleo-climatic > > > > > > > >purposes. Some initial attempts have > > been made for select feedbacks > > > > > > > >and forcings (Gerber et al, 2003; Goosse et al 2006) but a > > > > > > > >comprehensive assessment over the millennia prior to the > > > > > > > >pre-industrial does not yet exist. > > > > > > > > > > > > > > > >Even for those forcings for which good records exist, there is a > > > > > > > >question of they are represented within the models. This is not so > > > > > > > >much of an issue for the well-mixed > > greenhouse gases (CO2, N2O, CH4) > > > > > > > >since there is a sophisticated literature and history of including > > > > > > > >them within models (IPCC, 2001) though some aspects, such as minor > > > > > > > >short-wave absorption effects for CH4 and N2O are still not > > > > > > > >universally included > > > > > > > >(Collins et al, 2006). However, solar effects have been treated in > > > > > > > >quite varied ways. > > > > > > > > > > > > > > > >The most straightforward way of > > including solar irradiance effects on > > > > > > > >climate is to change the solar 'constant' (preferably described as > > > > > > > >total solar irradiance - TSI). > > However, observations show that solar > > > > > > > >variability is highly dependent on wavelength with UV bands having > > > > > > > >about 10 times as much amplitude of > > change than TSI over a solar cycle > > > > > > > >(Lean, 2000). Thus including this spectral variation for all solar > > > > > > > >changes allows for a slightly different behaviour (larger > > > > > > > >solar-induced changes in the stratosphere where the UV is mostly > > > > > > > >absorbed for instance). > > Additionally, the changes in UV affect ozone > > > > > > > >production in both the stratosphere and troposphere, and this > > > > > > > >mechanism has been shown to affect > > both the total radiative forcing > > > > > > > >and dynamical responses (Haigh 1996, Shindell et al 2001; > > > > > > > >2006). Within a chemistry climate > > model this effect would potentially > > > > > > > >modify the radiative impact of the > > > > original solar forcing, but could also > > > > > > > >be included as an additional > > (parameterised) forcing in standard GCMs. > > > > > > > > > > > > > > > >There is also a potential effect from the indirect effect of solar > > > > > > > >magnetic variability on the > > sheilding of cosmic rays, which have been > > > > > > > >theorised to affect the production of cloud condensation nuclei > > > > > > > >(Dickinson, 1975). However, there have been no quantitative > > > > > > > >calculations of the magnitude of > > this effect (which would require a > > > > > > > >full study of the relevant aerosol > > and cloud microphysics), and so its > > > > > > > >impact on climate is not (yet) been included. > > > > > > > > > > > > > > > >Large volcanic eruptions produce significant amounts of sulpher > > > > > > > >dioxide (SO2). If this is injected into the tropical stratosphere > > > > > > > >during a particularly explosive > > eruption, the resulting sulphate can > > > > > > > >persist in the atmosphere for a number of years (e.g. Pinatubo in > > > > > > > >1991). Less explosive, but more persistent eruptions (e.g. Laki in > > > > > > > >1789??) can still affect climate > > though in a more regional way and for > > > > > > > >a shorter term (Oman et al, 2005). These aerosols have both a > > > > > > > >shortwave (reflective) and longwave (absorbing) impact on the > > > > > > > >radiation and their local impact on stratospheric heating can have > > > > > > > >important dynamical effects. It is therefore better to include the > > > > > > > >aerosol absorber directly in the > > radiative transfer code. However, in > > > > > > > >less sophisticated models, the impact of the aerosols has been > > > > > > > >parameterised as the equivalent > > decrease in TSI. For extreme eruptions > > > > > > > >it has been hypothesised that > > sulphate production might saturate the > > > > > > > >oxidative capacity of the > > stratosphere leaving significant amounts of > > > > > > > >residual SO2. This gas is a > > greenhouse gas and would have an opposite > > > > > > > >effect to the cooling aerosols. This > > effect however has not yet been > > > > > > > >quantified. > > > > > > > > > > > > > > > >Land cover changes have occured both > > due to deliberate modification by > > > > > > > >humans (deforestation, imposed fire > > regimes, arguculture) as well as a > > > > > > > >feedback to climate change (the > > desertification of the Sahara ca. 5500 > > > > > > > >yrs ago). Changing vegetation in a > > standard model affects the seasonal > > > > > > > >cycle of albedo, the surface roughness, the impact of snow, > > > > > > > >evapotranspiration (through > > different rooting depths) etc. However, > > > > > > > >modelling of the yearly cycle of > > crops, or incorporating the effects > > > > > > > >of large scale irrigation are still very much a work in > > > > > > > >progress. > > > > > > > > > > > > > > > >Aerosol changes over the last few milllenia are very poorly > > > > > > > >constrained (if at all). These might have arisen from climatically > > > > > > > >or human driven changes in dust emissions, ocean biology feedbacks > > > > > > > >on circulation change, or climate impacts on the emission volatile > > > > > > > >organics from plants (which also have an impact on ozone > > > > > > > >chemistry). Some work on modelling a subset of those effects has > > > > > > > >been done for the last glacial maximum or the 8.2 kyr event > > > > > > > >(LeGrande et al, 2006), but there have been no quantitative > > > > > > > >estimates for the late Holocene (prior to the industrial period). > > > > > > > > > > > > > > > >Due to the relative expense of doing millennial simulations with > > > > > > > >state-of-the-art GCMs, exisiting > > simulations have generally done the > > > > > > > >minimum required to include relevant solar, GHG and volcanic > > > > > > > >forcings. Progress can be expected relatively soon on more > > > > > > > >sophisticated treatments of those forcings and the first > > > > > > > >quantitative estimates of additional effects. > > > > > > > > > > > > > > > >============= > > > > > > > > > > > > > > > > > > > > > > > >*------------------------------------ > > --------------------------------* > > > > > > > >| Gavin > > Schmidt NASA/Goddard Institute for Space Studies | > > > > > > > >| 2880 > > Broadway | > > > > > > > >| Tel: (212) 678 5627 New > > York, NY 10025 | > > > > > > > >| > > | > > > > > > > >| > > gschmidt@giss.nasa.gov http://www.giss.nasa.gov/~gavin | > > > > > > > >*------------------------------------ > > --------------------------------* > > > > > > > > > > > > > > Prof. Phil Jones > > > > > > > Climatic Research Unit Telephone +44 (0) 1603 592090 > > > > > > > School of Environmental Sciences Fax +44 (0) 1603 507784 > > > > > > > University of East Anglia > > > > > > > Norwich Email p.jones@uea.ac.uk > > > > > > > NR4 7TJ > > > > > > > UK > > > > > > > > > > > > > > > > > > > ---------------------------------------------------------------------------- > > > > > > > > > > > > > > > > > > > > > > > Prof. Phil Jones > > > > > Climatic Research Unit Telephone +44 (0) 1603 592090 > > > > > School of Environmental Sciences Fax +44 (0) 1603 507784 > > > > > University of East Anglia > > > > > Norwich Email p.jones@uea.ac.uk > > > > > NR4 7TJ > > > > > UK > > > > > > > > > > > ---------------------------------------------------------------------------- > > > > > > > > > > > > > > > > > > > > Prof. Phil Jones > > > Climatic Research Unit Telephone +44 (0) 1603 592090 > > > School of Environmental Sciences Fax +44 (0) 1603 507784 > > > University of East Anglia > > > Norwich Email p.jones@uea.ac.uk > > > NR4 7TJ > > > UK > > > > > ---------------------------------------------------------------------------- > > > > > > > > > > Prof. Phil Jones > Climatic Research Unit Telephone +44 (0) 1603 592090 > School of Environmental Sciences Fax +44 (0) 1603 507784 > University of East Anglia > Norwich Email p.jones@uea.ac.uk > NR4 7TJ > UK > ---------------------------------------------------------------------------- > >