Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
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 andrew.lock...@gmail.com 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 euggor...@comcast.net 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: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of John Nissen Sent: Saturday, July 23, 2011 6:46 PM To: kcalde...@stanford.edu Cc: em...@lewis-brown.net; 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 johnnissen2...@gmail.com 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
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
List, Andrew, John , David , Ken Andrew - I have re-read the paper you have cited below and decided to try to put the numbers there into the context of the paper by Dr. David Wasdell that you alerted us to on the 20th - which I also. found fascinating. For others, I am referring to a large body of work on climate feedbacks that can be found at http://www.apollo-gaia.org/. The specfic one of most pertinence to this discussion and comparison to the Davis-Caldeira Science article (that you cite below) is at: http://www.apollo-gaia.org/Climate%20Sensitivity.pdf Using the numbers from the recent (Science-Davis-Caldeira) cite, I find (from the right hand sides of their figure 1 C (for ppm CO2) and figure 1d - for temperature rise, presumably above the 280 ppm level), those three points fall slightly below the straight line that Dr. Wasdell terms the Charney sensitivity. Dr. Hansen would be about 2.5 times higher in predicted temperature and Dr. Wasdell about 3 times higher (both including positive feedbacks that I believe all would agree are not included in the Davis-Caldeira pape)r. This is not meant to be a criticism of theDavis Caldeira paper - as they clearly stated which model they were employing to come to their conclusions - and there are many valuable conclusions there. But I do think it important in the current discussion (see the thread title) on Hansen to point out this factor of 2.5 - which (by Dr.Wasdell) could be a factor of 3. Everyone seems convinced that the current breed of models is leaving out a lot - and apparently mostly of the positive freedback character. I don't believe that message is being heard at all clearly by the general population (which is what Andrew is betting his $100 on). For those who have not read the Wasdell analysis, his higher curve is justified by experimental (not theoretical) results attributed to three publications of other investigators besides Dr. Hansen - namely (in shorthand) Engelbeen (Vostok), Pagani (Paleo), and Kiehl (100 Ma history). They together validate (amazingly closely) his climate senstivity proposal of 7.8 degrees at 560 ppm (doubling). Davis-Caldeira are at about 2.5; Hansen at 6 degrees. Also need to point out that Dr. Hansen sees about a 50 ppm drop from geoengineering only with 100 Gt C of new forests -which can be amplified a good bit when combined with Biochar. I include John Nissen as a cc - as this Wasdell approach strongly supports his proposal to move faster generally because of the positive feedback that is surely not being considered in the Davis-Caldeira model - but is so apparent already in the Arctic. ANd is the reason for this thread. I hope someone closer to this than myself can explain how slow the missing feedbacks might be - and why. From what I have read there have been some pretty dramatic quick flips in the past. Ron - Original Message - From: Andrew Lockley andrew.lock...@gmail.com To: John Nissen johnnissen2...@gmail.com Cc: geo-engineering grp geoengineering@googlegroups.com Sent: Monday, July 25, 2011 11:49:48 AM Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise 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
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
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 kcalde...@gmail.com 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 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira On Sat, Jul 23, 2011 at 12:08 AM, John Nissen johnnissen2...@gmail.comwrote: 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 kcalde...@gmail.comwrote: 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
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 johnnissen2...@gmail.comwrote: 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 kcalde...@gmail.com 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 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira On Sat, Jul 23, 2011 at 12:08 AM, John Nissen johnnissen2...@gmail.comwrote: 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 kcalde...@gmail.comwrote: 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
RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
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: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of John Nissen Sent: Saturday, July 23, 2011 6:46 PM To: kcalde...@stanford.edu Cc: em...@lewis-brown.net; 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 johnnissen2...@gmail.com 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 kcalde...@gmail.com 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 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira On Sat, Jul 23, 2011 at 12:08 AM, John Nissen
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
Dear Ken: I love your sentence about economists. The problem is that they are often consulted by the press as experts whether or not they are, and they don't always caveat their statements to indicate they are not scientists. The best, Bill On Jul 22, 2011, at 11:03 AM, Ken Caldeira kcalde...@gmail.commailto:kcalde...@gmail.com 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 mailto:kcalde...@carnegie.stanford.edukcalde...@carnegie.stanford.edumailto:kcalde...@carnegie.stanford.edu +1 650 704 7212 http://dge.stanford.edu/labs/caldeiralabhttp://dge.stanford.edu/labs/caldeiralab Sent from a limited-typing keyboard On Jul 22, 2011, at 16:38, John Nissen mailto:johnnissen2...@gmail.comjohnnissen2...@gmail.commailto:johnnissen2...@gmail.com 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 http://arxiv.org/ftp/arxiv/papers/1105/1105.0968.pdf http://arxiv.org/ftp/arxiv/papers/1105/1105.0968.pdf Abstract here:
RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
Have you been wondering, why the North Pole's sea ice is looking like this today? http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png Cryosphere Today has reported a phenomenal North Pole melting: North Pole's Ice Cap currently melts away at a phenomenal weekly rate of: 14.9%. Melting figures of the Arctic Ocean for the last 7 days are: 17.07.2011: ice area 5,456,000 km2 - melting 98,000 km2 18.07.2011: ice area 5,383,000 km2 - melting 73,000 km2 19.07.2011: ice area 5,283,000 km2 - melting 100,000 km2 20.07.2011: ice area 5,083,000 km2 - melting 200,000 km2 - 24 hour ice area reduction: 3.93% 21.07.2011: ice area 4,931,000 km2 - melting 152,000 km2 - 24 hour ice area reduction: 3.08% 22.07.2011: ice area 4,843,000 km2 - melting 88,000 km2 23.07.2011: ice area 4,726,000 km2 - melting 117,000 km2 - 24 hour ice area reduction: 2.48% At the start of the week, 16.07.2011 the ice area was 5,554,000 km2. A daily sea ice melting rate 77,000 km2 could melt all ice from the North Pole by the autumn equinox. The current rate of disappearing sea ice is much higher. This suggests that the open seas are increasing solar energy absorption at higher rates than the shortening of daylight hours are reducing the sunlight supply. A return of cold weather and clouds can break this vicious circle. The fact that the North Pole Sea Ice Cap is able to lose 10.5% of its size in just over the last 4 days is a matter of immense concern to me as our train may have already lost its breaks... WattsUpWithThat.com suggests the sun has entered a more intense phase in its sun-spot cycle and the sea ice is now melts. They now say the sea ice melting intensifies over the next few years until solar activity peaks, after that the sunspots disappear and the Arctic Oceans sea ice cover recovers. The concern over melting sea ice is alarmism as it is all due to a recent change in solar weather, the increasing radiation drives global warming and, therefore, North Pole's sea ice is now melting. However, this contradicts their own sea ice area outlook projection: http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/july_panarctic_fig1.png In June WattsUpWithThat.com forecasted the second largest sea ice area in September with ice area recovery to 5,100,000 km2. WattsUpWithThat.com forecasting logic apparently expects the Arctic Ocean to be freezing 374,000 km2 by September. We should change our Googlrgroup's name to: Geoengineering Now! Kind regards, Albert From: wf...@utk.edu To: kcalde...@gmail.com CC: johnnissen2...@gmail.com; em...@lewis-brown.net; geoengineering@googlegroups.com; j...@cloudworld.co.uk Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise Date: Sun, 24 Jul 2011 19:05:59 + Dear Ken: I love your sentence about economists. The problem is that they are often consulted by the press as experts whether or not they are, and they don't always caveat their statements to indicate they are not scientists. The best, Bill On Jul 22, 2011, at 11:03 AM, Ken Caldeira kcalde...@gmail.com 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 kcalde...@carnegie.stanford.edu +1 650
RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
The world is full of economic experts. Little good it is doing; the economies of most countries are disasters. It is easy to take a swing at economists. My choice for bums of the year are the politicians. From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Fulkerson, William Sent: Sunday, July 24, 2011 3:06 PM To: kcalde...@gmail.com Cc: John Nissen; em...@lewis-brown.net; geo-engineering grp; John Nissen Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise Dear Ken: I love your sentence about economists. The problem is that they are often consulted by the press as experts whether or not they are, and they don't always caveat their statements to indicate they are not scientists. The best, Bill On Jul 22, 2011, at 11:03 AM, Ken Caldeira kcalde...@gmail.com 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 kcalde...@carnegie.stanford.edu +1 650 704 7212 http://dge.stanford.edu/labs/caldeiralab Sent from a limited-typing keyboard On Jul 22, 2011, at 16:38, John Nissen johnnissen2...@gmail.com 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
RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
Albert: No! Geoengineering Yesterday. In any case it is interesting that sunspots are now getting attention. Most climate scientists have ignored sunspots despite excellent perfect correlation back to the year 1500. So much for the science! -gene From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Veli Albert Kallio Sent: Sunday, July 24, 2011 4:23 PM To: wf...@utk.edu; kcalde...@gmail.com Cc: John Nissen; em...@lewis-brown.net; Geoengineering FIPC; John Nissen; Peter Wadhams Subject: RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise Have you been wondering, why the North Pole's sea ice is looking like this today? http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png Cryosphere Today has reported a phenomenal North Pole melting: North Pole's Ice Cap currently melts away at a phenomenal weekly rate of: 14.9%. Melting figures of the Arctic Ocean for the last 7 days are: 17.07.2011: ice area 5,456,000 km2 - melting 98,000 km2 18.07.2011: ice area 5,383,000 km2 - melting 73,000 km2 19.07.2011: ice area 5,283,000 km2 - melting 100,000 km2 20.07.2011: ice area 5,083,000 km2 - melting 200,000 km2 - 24 hour ice area reduction: 3.93% 21.07.2011: ice area 4,931,000 km2 - melting 152,000 km2 - 24 hour ice area reduction: 3.08% 22.07.2011: ice area 4,843,000 km2 - melting 88,000 km2 23.07.2011: ice area 4,726,000 km2 - melting 117,000 km2 - 24 hour ice area reduction: 2.48% At the start of the week, 16.07.2011 the ice area was 5,554,000 km2. A daily sea ice melting rate 77,000 km2 could melt all ice from the North Pole by the autumn equinox. The current rate of disappearing sea ice is much higher. This suggests that the open seas are increasing solar energy absorption at higher rates than the shortening of daylight hours are reducing the sunlight supply. A return of cold weather and clouds can break this vicious circle. The fact that the North Pole Sea Ice Cap is able to lose 10.5% of its size in just over the last 4 days is a matter of immense concern to me as our train may have already lost its breaks... WattsUpWithThat.com suggests the sun has entered a more intense phase in its sun-spot cycle and the sea ice is now melts. They now say the sea ice melting intensifies over the next few years until solar activity peaks, after that the sunspots disappear and the Arctic Oceans sea ice cover recovers. The concern over melting sea ice is alarmism as it is all due to a recent change in solar weather, the increasing radiation drives global warming and, therefore, North Pole's sea ice is now melting. However, this contradicts their own sea ice area outlook projection: http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/july_panarctic_fig1.png http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/july_panarctic_fig1.png In June WattsUpWithThat.com forecasted the second largest sea ice area in September with ice area recovery to 5,100,000 km2. WattsUpWithThat.com forecasting logic apparently expects the Arctic Ocean to be freezing 374,000 km2 by September. We should change our Googlrgroup's name to: Geoengineering Now! Kind regards, Albert _ From: wf...@utk.edu To: kcalde...@gmail.com CC: johnnissen2...@gmail.com; em...@lewis-brown.net; geoengineering@googlegroups.com; j...@cloudworld.co.uk Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise Date: Sun, 24 Jul 2011 19:05:59 + Dear Ken: I love your sentence about economists. The problem is that they are often consulted by the press as experts whether or not they are, and they don't always caveat their statements to indicate they are not scientists. The best, Bill On Jul 22, 2011, at 11:03 AM, Ken Caldeira kcalde...@gmail.com 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
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
As I understand it from scientific presentations at the IUGG conference in Melbourne, recent reconciliation of US and European satellite observations of solar irradiance give a quiet sun value of 1360.8 W/m2 (so average over the Earth of 340.2 W/m2 before about 30% reflected)--two years ago the baseline values of the instruments differed by about 5 W/m2, although their variations were in excellent agreement. Apparently, some stray light was found to be leaking in, and correcting for this has brought observations of the baseline into agreement. The variation over solar cycles is really quite small compared to the magnitude of the greenhouse forcing. Asserting that the accelerating melting back of Arctic sea ice is due to the sunspot cycle is, given that the relative magnitude of the GHG induced changes, is thus really unsubstantiated wishful thinking. Mike MacCracken PS to Gene--Excellent correlation of what--and how accurate are each of the records. Suggesting something is perfect would really mean no room for any volcanic effects or anything else--just not a scientific statement. On 7/24/11 4:33 PM, esubscript...@montgomerycountymd.gov euggor...@comcast.net wrote: Albert: No! Geoengineering Yesterday. In any case it is interesting that sunspots are now getting attention. Most climate scientists have ignored sunspots despite excellent perfect correlation back to the year 1500. So much for the science! -gene From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Veli Albert Kallio Sent: Sunday, July 24, 2011 4:23 PM To: wf...@utk.edu; kcalde...@gmail.com Cc: John Nissen; em...@lewis-brown.net; Geoengineering FIPC; John Nissen; Peter Wadhams Subject: RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise Have you been wondering, why the North Pole's sea ice is looking like this today? http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png Cryosphere Today has reported a phenomenal North Pole melting: North Pole's Ice Cap currently melts away at a phenomenal weekly rate of: 14.9%. Melting figures of the Arctic Ocean for the last 7 days are: 17.07.2011: ice area 5,456,000 km2 - melting 98,000 km2 18.07.2011: ice area 5,383,000 km2 - melting 73,000 km2 19.07.2011: ice area 5,283,000 km2 - melting 100,000 km2 20.07.2011: ice area 5,083,000 km2 - melting 200,000 km2 - 24 hour ice area reduction: 3.93% 21.07.2011: ice area 4,931,000 km2 - melting 152,000 km2 - 24 hour ice area reduction: 3.08% 22.07.2011: ice area 4,843,000 km2 - melting 88,000 km2 23.07.2011: ice area 4,726,000 km2 - melting 117,000 km2 - 24 hour ice area reduction: 2.48% At the start of the week, 16.07.2011 the ice area was 5,554,000 km2. A daily sea ice melting rate 77,000 km2 could melt all ice from the North Pole by the autumn equinox. The current rate of disappearing sea ice is much higher. This suggests that the open seas are increasing solar energy absorption at higher rates than the shortening of daylight hours are reducing the sunlight supply. A return of cold weather and clouds can break this vicious circle. The fact that the North Pole Sea Ice Cap is able to lose 10.5% of its size in just over the last 4 days is a matter of immense concern to me as our train may have already lost its breaks... WattsUpWithThat.com suggests the sun has entered a more intense phase in its sun-spot cycle and the sea ice is now melts. They now say the sea ice melting intensifies over the next few years until solar activity peaks, after that the sunspots disappear and the Arctic Oceans sea ice cover recovers. The concern over melting sea ice is alarmism as it is all due to a recent change in solar weather, the increasing radiation drives global warming and, therefore, North Pole's sea ice is now melting. However, this contradicts their own sea ice area outlook projection: http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/ju ly_panarctic_fig1.png http://www.arcus.org/files/search/sea-ice-outlook/2011/07/images/pan-arctic/j uly_panarctic_fig1.png In June WattsUpWithThat.com forecasted the second largest sea ice area in September with ice area recovery to 5,100,000 km2. WattsUpWithThat.com forecasting logic apparently expects the Arctic Ocean to be freezing 374,000 km2 by September. We should change our Googlrgroup's name to: Geoengineering Now! Kind regards, Albert From: wf...@utk.edu To: kcalde...@gmail.com CC: johnnissen2...@gmail.com; em...@lewis-brown.net; geoengineering@googlegroups.com; j...@cloudworld.co.uk Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise Date: Sun, 24 Jul 2011 19:05:59 + Dear Ken: I love your sentence about economists. The problem is that they are often consulted by the press as experts whether
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
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 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira On Sat, Jul 23, 2011 at 12:08 AM, John Nissen johnnissen2...@gmail.comwrote: 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 kcalde...@gmail.com 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 kcalde...@carnegie.stanford.edu +1 650 704 7212 http://dge.stanford.edu/labs/caldeiralab Sent from a limited-typing keyboard On Jul 22, 2011, at 16:38, John Nissen johnnissen2...@gmail.com 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
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
Values and norms do and must guide what questions we ask, but they cannot be allowed to influence our scientific answers. Scientific papers should contain empirical statements and not value-based judgments. On Sat, Jul 23, 2011 at 4:44 PM, Jerome Whitington jwhiting...@dartmouth.edu wrote: Hi All - Forgive me for joining in - I am a newcomer on this list. Georges Canguilhem, who analyzed the French medical sciences, argued that the objectivity of medicine in fact requires its normative component. Research is not only motivated by goals like curing disease, but is organized toward those aims in all its detail. He shows that the positive agenda of a non-normative physiology, which sought to build up an understanding of normal functions in their totality, remained an allusive dream. But for Canguilhem this normative dimension hardly undermines medicine's claim to objectivity - on the contrary. The science of the normal body needs pathology in order to exist. It strikes me that ecological sciences also have an undeniable clinical aspect, at least in a great many research contexts. It is not only that we are motivated by goals of repairing the earth - or even just making policy-relevant conclusions - but that the research is actually organized in such a way. The normative dimension is inescapable, but this doesn't mean the methodological basis of research isn't robust. Like medicine, climate science implies intervention, and our understanding of climate would be hardly as developed were it not so. Incidentally, Canguilhem attributed this polarized condition of normative judgment as an essential element of life itself. Living bodies inherently are involved in polarized judgments - inside versus outside, up versus down, pain versus pleasure. If life is this normative activity, it means that disease is not a strictly objective condition (say, loss of funtionality), but also a 'subjective' judgment about that condition (that the loss of function is bad). This also helps clarify why people use medical sciences to manipulate their bodies in unconventional ways (augmentation, performance enhancing drugs). And of course these sciences are also organized around normative goals. Regards, Jerome Whitington Dartmouth College / NUS On Fri, Jul 22, 2011 at 6:08 PM, John Nissen johnnissen2...@gmail.comwrote: 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 kcalde...@gmail.comwrote: 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
RE: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
Deploy has an ominous and fateful ring. What about some careful, well thought through, limited experiments in order to decide about the value and risk of deployment? I think that is entirely possible with stratospheric aerosols. I think this group is entirely capable if defining and proposing limited experiments. From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Ken Caldeira Sent: Saturday, July 23, 2011 10:37 AM To: John Nissen Cc: em...@lewis-brown.net; geo-engineering grp; John Nissen Subject: Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise 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 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira On Sat, Jul 23, 2011 at 12:08 AM, John Nissen johnnissen2...@gmail.com 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 kcalde...@gmail.com 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 kcalde...@carnegie.stanford.edu +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 johnnissen2...@gmail.com wrote: Dear Ken, I've
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
I sure wish he would avoiding putting prescriptive statements in ostensibly scientific papers. Scientific papers should contain descriptive, not prescriptive, statements. That said, I think he is right about long-term climate sensitivity being higher than the century-scale sensitivity inferred from climate models and analysis of historical data. On Thu, Jul 21, 2011 at 11:07 PM, Emily em...@lewis-brown.net 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=** 0ebaeb14fdbf5dc65289113c1id=**fbefcc8464e=60a7483168http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1id=fbefcc8464e=60a7483168 A__'popular science' summary http://columbia.us1.list-**manage.com/track/click?u=** 0ebaeb14fdbf5dc65289113c1id=**d3b93e0894e=60a7483168http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1id=d3b93e0894e=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 geoengineering@googlegroups.**comgeoengineering@googlegroups.com . To unsubscribe from this group, send email to geoengineering+unsubscribe@* *googlegroups.com geoengineering%2bunsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/** group/geoengineering?hl=enhttp://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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
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 em...@lewis-brown.net 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=0ebaeb14fdbf5dc65289113c1id=fbefcc8464e=60a7483168 A__'popular science' summary http://columbia.us1.list-manage.com/track/click?u=0ebaeb14fdbf5dc65289113c1id=d3b93e0894e=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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at
Re: [geo] Jim Hansen : 1 to 2DegC and 20m sea level rise
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 kcalde...@carnegie.stanford.edu +1 650 704 7212 http://dge.stanford.edu/labs/caldeiralab Sent from a limited-typing keyboard On Jul 22, 2011, at 16:38, John Nissen johnnissen2...@gmail.com 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 em...@lewis-brown.net 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:
