For an alternative perspective on committed warming, note the following: Comment in SciAm http://www.scientificamerican.com/article.cfm?id=guaranteed-global-warming-with-existing-fossil-fuel-infrastructure Paper in Science http://www.sciencemag.org/content/329/5997/1330.abstract
"Slowing climate change requires overcoming inertia in political, technological, and geophysical systems. Of these, only geophysical warming commitment has been quantified. We estimated the commitment to future emissions and warming represented by existing carbon dioxide–emitting devices. We calculated cumulative future emissions of 496 (282 to 701 in lower- and upper-bounding scenarios) gigatonnes of CO2 from combustion of fossil fuels by existing infrastructure between 2010 and 2060, forcing mean warming of 1.3°C (1.1° to 1.4°C) above the pre-industrial era and atmospheric concentrations of CO2 less than 430 parts per million. Because these conditions would likely avoid many key impacts of climate change, we conclude that sources of the most threatening emissions have yet to be built. However, CO2-emitting infrastructure will expand unless extraordinary efforts are undertaken to develop alternatives." The authors note the pending expansion of infrastructure. I can't access the paper, so I can't see the assumptions used. However, I strongly suspect that it won't include Schaeffer's methane estimates (see summary comment on Climate Progress http://thinkprogress.org/romm/2011/02/17/207552/nsidc-thawing-permafrost-will-turn-from-carbon-sink-to-source-in-mid-2020s-releasing-100-billion-tons-of-carbon-by-2100/). I also suspect that it won't be using the carbon cycle feedback and consequential sensitivity estimates recently exchanged on this list. Even so, it comes out at just under 1.5C warming. The sociological and secondary committed technology is also critical. Half built plants need to be counted, as does the industrial output of carbon guzzling factories which are build, being built, or committed in the planning process. You can't only count the cars on the road, but also the ones that you can be reasonably sure will be built. If you consider the following graph http://www.unep.org/dewa/Portals/67/pdf/Black_Carbon.pdf (figure 3, P12) you can see that even with methane and black carbon controls, we're still set on exceeding 1.5C, (and that is without assumptions on methane release and other advanced carbon-cycle feedback work being incorporated, I suspect). There's also the bunker fuel sulphur controls, which have yet to feed properly into ANY climate modelling which I'm aware of. I've also looked at the Hare paper, which is already the best part of a decade out of date, and thus doesn't consider most of the new work on feedbacks, or the alarming rise in emissions. In fact, it's based on models which are in many cases considerably older than the paper itself. http://www.pik-potsdam.de/research/publications/pikreports/.files/pr93.pdf I can't express any confidence in this at the present time, for the reasons above. Furthermore, as there has been a history of underestimating emissions, I'd suggest that a mid-level emissions trajectory would be a 'best case' scenario. Even with all the above missing, I still note that the warming graphed in their 'feasible' scenario again exceeds the 1.5C danger level. Overall, I find it very frustrating that there is such a sense of 'playing catchup' in this field. The modelling of emissions controls needed seems to be a generation behind the earth system science. The world is therefore looking at a political landscape based on science which is largely out of date. Notably, AR4 contained very little of the non-linear change work. I'm looking forward to AR5, but it can't come soon enough. If the process of previous years is repeated, it will again be based on science that is essentially obsolete, even on the day of it's released. There's necessarily a lag process, but we aren't talking about tweaks, here - these are huge chasms between the state of the science for politicians and that for earth scientists. The arctic thaw is an example of the consequences of this. We've badly messed up the predictions. I maintain that with CO2 controls only, we have no possible way of preventing dangerous climate change without geoengineering. Either people agree, or maybe they don't read my posts or don't trust me with 100USD. A On 24 July 2011 18:42, John Nissen <[email protected]> wrote: > Hi Andrew, > > Well spoken. I just want to add to the challenge of anybody who want to > contradict you, with two points: > > 1. The evidence for the severity of our position now points to a much worse > situation than it seemed to be only 12 months ago: > > a) the sea-ice volume trend has emerged, indicating a likely date of 10% > end-summer sea ice at around 2016 +/- 3 years; > > b) a vast quantity of Arctic methane is in a critical condition such that it > could be released into the Arctic atmosphere over the next decade or two, > sufficient to cause more global warming than CO2; > > c) the sensitivity of the climate to radiative forcing appears to be much > great than previously thought - which emphasises the importance of retaining > the sea ice and preventing a methane excursion. > > 2. If you take into account the threat of ocean acidification, then the CDR > (carbon dioxide removal) is required as well as SRM. > > Cheers, > > John > > --- > > On Sun, Jul 24, 2011 at 2:14 PM, Andrew Lockley <[email protected]> > wrote: >> >> Well I think that the scientific evidence is clear. Considering population >> effects, current social change (urbanization, industrialization) and >> technology/political lag, I say that we cannot avoid dangerous climate >> change of 2C or higher without geoengineering - specifically SRM. ( less >> than 5% chance) And that is without considering the chronic apathy of the >> worlds governments on the issue. Even 2C is probably not safe. >> >> Prior work on the issue tends to underestimate feedbacks, societal lag >> times and current emissions trajectories. We have been conning ourselves for >> far too long. >> >> Shoot me down if you can, but I'll put a hundred dollars on me being >> right. >> >> And if I am right, we better have our ships and planes ready when it all >> kicks off, because otherwise we'll be the shepherds who should have cried >> wolf. >> >> I get sick of all this pussy-footing. We need to be clear. We can already >> be highly confident that geoengineering is needed. We therefore need to be >> building knowledge and capacity right now. >> >> Who will step up and challenge me? Etc group? Any other takers? >> >> A >> >> On 24 Jul 2011 12:50, "Eugene Gordon" <[email protected]> wrote: >> > I support John Nissen’s view with some slight modification of the >> > wording, but not the theme. I like his use of the expression, ‘appears to >> > be >> > likely happening’ and want to amplify that. I don’t like Ken’s use of ‘I am >> > confident’. As scientists we can express conviction but not certainty until >> > it has been achieved following the Scientific Method. The current climate >> > observations are highly suggestive of a continuing pattern that will have >> > increasingly disastrous effects. I emphasize there is no certainty. >> > However, >> > if what we are observing is mostly caused by anthropogenic CO2 emissions >> > then it is probably too late to rely on reducing such emissions. Yes, we >> > must no doubt do it out of respect for the current understanding and for >> > potential future benefits, but reducing CO2 emissions will probably not >> > save >> > the day. In parallel, and with comparable conviction, we espouse various >> > geoengineering means for halting the perceived, impending disaster. It is >> > highly likely we can design and put in place limited experiments to test >> > the >> > ability to mitigate or delay. Why do we talk about full implementation >> > rather than careful, limited, experimental tests with minimal risk? >> > Implementation is a threat to some. Careful, limited testing is far more >> > benign. >> > >> > >> > >> > -gene >> > >> > >> > >> > >> > >> > From: [email protected] >> > [mailto:[email protected]] On Behalf Of John Nissen >> > Sent: Saturday, July 23, 2011 6:46 PM >> > To: [email protected] >> > Cc: [email protected]; geo-engineering grp; John Nissen >> > Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise >> > >> > >> > >> > reference [1] >> > http://unfccc.int/essential_background/convention/background/items/1355.php >> > >> > On Sat, Jul 23, 2011 at 11:43 PM, John Nissen <[email protected]> >> > wrote: >> > >> > >> > Ken, >> > >> > We all like to be optimistic - it is a human characteristic. But if you >> > accept what is happening to the Earth System, as being discovered by people >> > like Hansen, Wadhams and Shakhova (on climate sensitivity, sea ice retreat >> > and Arctic methane respectively), then the situation is dire for every >> > human >> > on this planet. This is not a question of perspective, but an appreciation >> > of what appears to be very likely happening, as argued by scientists >> > working >> > in the field, looking at the data - and not clouding their judgement by >> > wishful thinking. None of us wants to see this. It is very difficult to >> > believe that it's happening to us. You look out at our beautiful planet, >> > and >> > enjoy the fruits (mulberries today!), and it's almost impossible to believe >> > that this could all change - if we do not act very quickly and effectively, >> > on several fronts. >> > >> > As for geoengineering perhaps not working as well as expected, this is >> > all the more reason for starting sooner, and starting on several different >> > methods in parallel. Any of the methods being proposed can easily be >> > stopped, if it's not having the required effect - or an adverse effect is >> > too great. The greatest danger is being too late - and then who we have to >> > blame but ourselves - us, who have seen the facts of the situation. >> > >> > Most importantly we must inform our political leaders. If the situation >> > is acknowledged by any country as the emergency, even without 100% >> > scientific certainty, then they are obliged to take action for the sake of >> > their own citizens, according the UNFCCC Article 3 [1]. It's our duty, as >> > people who understand what is happening to the Earth System, not to shelter >> > under misplaced optimism, but come into the open and declare the emergency >> > - >> > if that's the conclusion from what is being discovered. >> > >> > John >> > >> > --- >> > >> > >> > >> > On Sat, Jul 23, 2011 at 3:36 PM, Ken Caldeira <[email protected]> >> > wrote: >> > >> > John, >> > >> > I have no doubt that, from the perspective of many extant species and >> > less-fortunate humans, we are indeed in dire straits. >> > >> > If I were convinced that stratospheric aerosols would work as advertised >> > and that there would be no unforeseen or unanticipated repercussions, and >> > that some sort of democratic process could be devised to give the overall >> > effort political legitimacy, then I would be in favor of early deployment >> > of >> > such schemes. >> > >> > However, I am confident that were such systems deployed, there would be >> > surprises. Maybe the surprise would be how well it works and how everyone >> > the world over greets the project with such a high degree of appreciation. >> > On the other hand, the surprise could be that things go rather wrong, >> > exacerbating international friction, leading to economic disruption, wars, >> > etc. >> > >> > Before such systems would be deployed, I would hope that the >> > risk-benefit balance would be very clearly tipped in the direction of >> > benefit. I just do not think we are there yet. >> > >> > Best, >> > >> > Ken >> > >> > >> > ___________________________________________________ >> > Ken Caldeira >> > >> > Carnegie Institution Dept of Global Ecology >> > 260 Panama Street, Stanford, CA 94305 USA >> > +1 650 704 7212 [email protected] >> > http://dge.stanford.edu/labs/caldeiralab @kencaldeira >> > >> > >> > >> > >> > >> > On Sat, Jul 23, 2011 at 12:08 AM, John Nissen <[email protected]> >> > wrote: >> > >> > Hi Ken, >> > >> > You take a fundamentally different view of the Earth System and >> > geoengineering. I see the Earth System as in an extremely precarious state >> > and geoengineering as absolutely necessary to nudge the system back into a >> > state that allows continued habitation of the planet by ourselves and our >> > offspring. Do you really think that we can survive the century simply by >> > reducing carbon emissions? If we wait for some dramatic event, like >> > disappearance of Arctic sea ice, as an "emergency" sufficient to justify >> > geoengineering, don't we risk leaving geoengineering too late? >> > >> > For me, geoengineering is like chemotherapy when a vital organ has >> > cancer, or like fire-fighting when parts of the burning building contain >> > explosives. You start tackling the problem as quickly as you possibly can, >> > concentrating on the critical parts. >> > >> > John >> > >> > --- >> > >> > >> > >> > On Fri, Jul 22, 2011 at 4:02 PM, Ken Caldeira <[email protected]> >> > wrote: >> > >> > Two points: >> > >> > >> > >> > I am not opposed to scientists making prescriptive statements in their >> > roles as citizens. >> > >> > >> > >> > However, I am opposed to prescriptive statements (statements about what >> > we should do) in peer-reviewed scientific papers. >> > >> > >> > >> > I think science is about establishing objective facts about the world. >> > As citizens, we take these facts and our values and make judgments about >> > what we should do. >> > >> > >> > >> > I am 100% in favor of Jim Hansen making prescriptive statements. I would >> > just prefer that he not do it in the context of a peer-reviewed scientific >> > paper. >> > >> > >> > >> > Science cannot tell us what to do. It can give us information which we >> > can use to make decisions. >> > >> > >> > >> > If the science gets mixed up with politics in peer-reviewed scientific >> > publications, I think it ends up weakening the credibility of the entire >> > scientific publication process (since statements whose truth value cannot >> > be >> > empirically established are obviously getting past reviewers). >> > >> > >> > >> > I should say that the worst in this respect are the economists, who >> > insist that they should be regarded as a science while simultaneously >> > trying >> > to tell us what we should be doing. >> > >> > >> > >> > --- >> > >> > >> > >> > On deployment of some sort of solar reflection system: all of our model >> > results indicate that a high co2 world with deflection of some sunlight >> > would be more similar to a low co2 world than is a high co2 world without >> > deflection of sunlight. >> > >> > >> > >> > So, do I think that direct environmental damage from greenhouse gases >> > could be diminished by deploying such a system? Yes, probably although I am >> > not 100% certain of this. >> > >> > >> > >> > Do I think near-term deployment will reduce overall risk and improve >> > long-term well-being? Of this I am less certain, as it is hard to predict >> > the various sociopolitical, as well as environmental, repercussions that >> > might occur. >> > >> > >> > Ken Caldeira >> > >> > [email protected] >> > >> > +1 650 704 7212 <tel:1%20650%20704%207212> >> > >> > http://dge.stanford.edu/labs/caldeiralab >> > >> > >> > >> > Sent from a limited-typing keyboard >> > >> > >> > On Jul 22, 2011, at 16:38, John Nissen <[email protected]> wrote: >> > >> > >> > >> > >> > Dear Ken, >> > >> > I've already looked at this interesting paper [1], from Jim Hansen and >> > Mikiko Sato - but I'd not read before of his conjecture about rate of ice >> > mass loss doubling per decade, producing many metres of sea level rise this >> > century. But the implication is that the situation can be saved simply by >> > reducing fossil fuel emissions! Is that the prescription that you are >> > complaining about? Wouldn't a well-considered prescription be welcome from >> > somebody as eminent as Prof Hansen? Geoengineering for example! I don't see >> > a way out of our predicament without it. Do you, Ken? >> > >> > Does Hansen accept that 90% sea ice could be gone as soon as at end >> > summer 2016? (BTW, I've another reference to this date we've been arguing >> > about [2].) >> > >> > Hansen seems to dismiss methane as always producing less forcing than >> > CO2: >> > >> > "This sensitivity has the merit that CO2 is the principal GHG forcing >> > and perhaps the only one with good prospects for quantification of its >> > long-term changes." (page 15) >> > >> > However the paper is relevant to the methane issue in several ways. One >> > argument, which I've heard from Jeff Ridley, is that there is no sign of a >> > methane excursion at previous interglacials* such as end-Eemian, when it >> > was >> > hotter, so we don't need to worry about having an excursion now. Hansen >> > shows that it was never hotter than it is now (in Holocene) by more than >> > one >> > degree. >> > >> > Elsewhere Hansen points out that the current rate of global warming is >> > much higher than it has been for millions of years. Andrew Lockley suggests >> > it's higher than even it was at the PETM some 55.8 million years ago, when >> > temperatures rose about 6 C [3]. That rate of change is important, because >> > of methane's short lifetime. The increasing speed of change implied by >> > Hansen's climate sensitivity is thus relevant to methane. >> > >> > A further way that the paper is relevant to methane is because of >> > climate sensitivity to radiative forcing. The paper suggests various >> > alternative values that could be taken - see [1] table 1. If we get over 2 >> > W/m-2 from methane, then that certainly takes us over the danger line of 2 >> > degrees global warming, using his argument. >> > >> > Cheers, >> > >> > John >> > >> > * During the past 800,000 years, methane never rose much above 700 ppb >> > until recently, see [1] figure 2 >> > >> > [1] Full paper http://arxiv.org/ftp/arxiv/papers/1105/1105.0968.pdf >> > >> > Abstract here: >> > http://arxiv.org/abs/1105.0968v3 >> > >> > [2] http://www.bbc.co.uk/news/science-environment-13002706 >> > >> > [3] >> > http://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum >> > >> > --- >> > >> > On Thu, Jul 21, 2011 at 11:07 PM, Emily <[email protected]> wrote: >> > >> > Hi, >> > >> > here is a recent paper from Jim Hansen,including some figures I've read >> > before, which stunned me: >> > >> > "In the early Pliocene global temperature was no more than 1-2°C warmer >> > than today, yet sea level was 15-25 meters (50-80 feet) higher." >> > >> > best wishes, >> > >> > Emily. >> > >> > >> > *Paleoclimate Implications: Accepted Paper and 'Popular Science'* >> > >> > >> > "Paleoclimate Implications for Human-Made Climate Change" has been >> > reviewed, revised in response to the referee's suggestions, and accepted >> > for publication in "Climate Change at the Eve of the Second Decade of >> > the Century: Inferences from Paleoclimate and Regional Aspects: >> > Proceedings of Milutin Milankovitch 130th Anniversary Symposium" (Eds. >> > A. Berger, F. Mesinger and D Šijački), Springer. >> > >> > This final version has also been published in arXiv:1105.0968v3 >> > [physics.ao-ph] >> > >> > <http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1 >> > <http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1&id=fbefcc8464&e=60a7483168> >> > &id=fbefcc8464&e=60a7483168> >> > >> > A__'popular science' summary >> > >> > <http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1 >> > <http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1&id=d3b93e0894&e=60a7483168> >> > &id=d3b93e0894&e=60a7483168> >> > of the paper, intended for lay audience, is available. >> > >> > Thanks especially to reviewer Dana Royer for helpful comments, >> > foundations and NASA program managers for research support, and a number >> > of people for comments on an early draft of the paper, as delineated in >> > the acknowledgements. >> > >> > Jim Hansen >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "geoengineering" group. >> > To post to this group, send email to [email protected]. >> > To unsubscribe from this group, send email to >> > [email protected]. >> > For more options, visit this group at >> > http://groups.google.com/group/geoengineering?hl=en. >> > >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "geoengineering" group. >> > To post to this group, send email to [email protected]. >> > To unsubscribe from this group, send email to >> > [email protected]. >> > For more options, visit this group at >> > http://groups.google.com/group/geoengineering?hl=en. >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "geoengineering" group. >> > To post to this group, send email to [email protected]. >> > To unsubscribe from this group, send email to >> > [email protected]. >> > For more options, visit this group at >> > http://groups.google.com/group/geoengineering?hl=en. >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "geoengineering" group. >> > To post to this group, send email to [email protected]. >> > To unsubscribe from this group, send email to >> > [email protected]. >> > For more options, visit this group at >> > http://groups.google.com/group/geoengineering?hl=en. >> > >> >> -- >> You received this message because you are subscribed to the Google Groups >> "geoengineering" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
