John,
Can you repost a link to that primer -- the one in your post 404s. Or if you can post the doc, that would be greatly appreciated, as well. I would also like to know how strong the evidence is that 3C is the threshold for a runaway effect (assuming that's what is meant in your fourth summary bullet). Given how much greater impacts have been relative to the amount of warming so far, including at least hints of methane being awakened, trying to pinpoint where things go off the rails seems to be exceedingly difficult. Again, I refer to the early 1970s UN effort, the one I call the proto-IPCC, that said +/- 2C was the difference between a new ice age or a catastrophic ice-free age. (See the book Only One Earth, p. 192.) Given that the amount of warming we've locked in already (realized warming, current thermal disequilibrium, warming from continued wind down of emissions, additional warming from the loss of cooling aerosols) is perilously close to 2C, it's hard to see how the answer to "can the world be saved without geoengineering" could possibly be "yes". On Monday, December 2, 2013 11:58:57 PM UTC-5, John Nissen wrote: > > Hi all, > > > > Did anybody go to this debate on the question: “Can geoengineering save > the world?” I would put the question the other way round: “Can the world > be saved without geoengineering?” > > > > I suspect there is an enormous gap between the commonly held view of a > slowly changing world, where we can take time over taking measures, and the > reality of a rapidly changing world, where we have to act quickly to head > off catastrophe. Hulme comes out with this: > > *“I am mystified by your faith that solar climate engineering is an > effective way of achieving this. More direct and assured methods would be > to invest in climate adaptation measures—a short-term gain—and to invest in > new clean energy technologies—a long-term gain.”* > > Let us unpick this position statement, the elements of which are held by > many scientists as well as non-scientists. > > > > First of all he pours doubt on the *effectiveness of climate engineering*, > implying that “geoengineers live in a fantasy world”. Yet geoengineers > have produced papers showing techniques which are sufficient to counter a > doubling of CO2 – a concentration of 560 ppm with a climate forcing of > around 4 W/m2 or 2 petawatts total. Geoengineering could work in the > real world. And, with good modelling, we can check out techniques both > before and after initial deployment for any major unwanted side-effects, > predicted or observed respectively. > > > Secondly, Hulme assumes that *adaptation *is a sensible option for the > short-term as if it won’t be required in the long term. Does he have any > concept of how bad it could get if no action is taken to prevent climate > change? > > > > I am reminded of Rex Tillerson, the CEO of Exxon, who has admitted that we > are heading for 4°C global warming by the end of the century as if we can > adapt to it. Read what was said by Climate Code Red in 2011 about adapting > to four degrees! It hasn't got any easier since then! > > http://www.climatecodered.org/2011/02/4-degrees-hotter-adaptation-trap.html > > [Quote] > > > So what does 4 degrees feel and look like? In a new > primer<http://www.climateactioncentre.org/sites/default/files/4-degrees-hotter.pdf>, > > the Climate Action Centre has surveyed some of the literature. In a > nutshell, it is one in which: > > - The world would be warmer than during any part of the period in > which modern humans evolved, and the rate of climate > change<http://www.newscientist.com/article/mg20126971.700-how-to-survive-the-coming-century.html>would > be faster than any previously experienced by humans. The world's > sixth mass extinction would be in full swing. In the oceans, acidification > would have rendered many calcium-shelled organisms such as coral and many > at the base of the ocean food chain artefacts of history. Ocean ecosystems > and food chains would collapse. > - Half of the world would be uninhabitable. Likely population > capacity: under one billion > people<http://news.scotsman.com/latestnews/Warming-will-39wipe-out-billions39.5867379.jp>. > > Whilst the loss will be exponential and bunch towards the end of the > century, on average that is a million human global warming deaths every > week, every year for the next 90 years. The security implications need no > discussion > - Paleoclimatology tells us that the last time temperatures were 4C > above pre-industrial (during the Oligocene 30 million years ago), there > were no large ice-sheets on the > planet<http://pubs.giss.nasa.gov/docs/2007/2007_Hansen.pdf>and sea levels > were 65–70 metres higher than today. Whilst ice sheets take > time to lose mass, and the rise to 2100 may be only 1–2 metres (or > possibly > a couple more according to James Hansen), the world would be on the way to > 65–70 metres. > - 3C may be the “tipping > point”<http://www.columbia.edu/%7Ejeh1/2008/StateOfWild_20080428.pdf>where > global warming could be driven by positive feedbacks, leaving us > powerless to intervene as planetary temperatures soared. James Hansen says > warming has brought us to the "precipice of a great tipping point”. If we > go over the edge, it will be a transition to “a different planet”, an > environment far outside the range that has been experienced by humanity. > There will be "no return within the lifetime of any generation that can be > imagined, and the trip will exterminate a large fraction of species on the > planet". > > And we are talking about how we might adapt to a 4-degree warmer world? > Have we gone mad? > > [End quote] > > > > Thirdly Hulme suggests that investment in *clean energy technology* is > going to provide the answer in the long term. Does he understand that, > even with zero carbon energy generation and zero CO2 emissions globally, > the legacy CO2 would continue to warm the planet beyond 2 degrees, which > according to Prof Hansen is well beyond a safe limit? Has he considered > the carbon budget of AR5, which is liable to be exhausted within 15 to 25 > years, according to Lord Stern, former World Bank chief economist and > author of the Stern Review (see Guardian, 30th September)? > > > > This is a very strong argument for CDR geoengineering. Yet there may be > an even stronger argument that the atmospheric concentration of CO2 needs > to be reduced within a few decades to reduce the risk of *catastrophic > ocean acidification*, since this has already become an extremely serious > problem. > > > > Finally, Hulme neglects *what is happening in the Arctic*. Admittedly > the AR5 models suggest that the sea ice will last for decades, but there is > a clear exponential trend for September sea ice to reach below the 1 > million km2 mark this decade and the latest modelling from the US Navy > shows that it could reach this mark as soon as 2016. > > > > The albedo loss is growing each year as the sea ice retreats further in > the summer, which means that each year more heat is absorbed by the ocean. > The record retreat in 2012 produced the equivalent to about 20 years of > CO2 forcing, according to the sea ice expert, Professor Peter Wadhams of > Cambridge University. And Dr Jennifer Francis of Rutgers University has > pointed out that the sea ice retreat and warming Arctic has disrupted the > polar jet stream, with consequences for weather extremes, crop failures and > a rising food price index (now above the crisis level at which food riots > break out in many countries). And methane is bubbling out the Arctic > seabed in ever increasing quantities. > > > > So, strong evidence points to the urgent requirements to reduce CO2 level > in the atmosphere and to cool the Arctic sufficient to save the sea ice and > subdue the methane. These requirements necessarily involve CDR and SRM > geoengineering respectively. > > > > Perhaps it is us advocates of geoengineering who live in the real world, > and it is those who deny the urgent requirement for geoengineering who live > in a fantasy world. > > > > Cheers, > > > > John > > > On Fri, Nov 29, 2013 at 10:12 PM, Andrew Lockley > <andrew....@gmail.com<javascript:> > > wrote: > >> >> http://www.theguardian.com/sustainable-business/blog/climate-science-geoengineering-save-world >> >> Climate science: can geoengineering save the world? >> >> Climate professors Mike Hulme and David Keith go head to head over >> whether climate engineering could provide a solution to climate change >> >> Friday 29 November 2013 18.02 >> >> Geoengineering means artificially modifying the Earth's climate. Is this >> a dangerous folly or one of our great hopes? >> >> Geoengineering. It's not the sexiest sounding topic, but a small group of >> scientists say it just might be able to save the world. >> >> The basic idea behind geonengineering (or climate engineering) is that >> humans can artificially moderate the Earth's climate allowing us to control >> temperature, thereby avoiding the negative impacts of climate change. There >> are a number of methods suggested to achieve this scientific wizardry, >> including placing huge reflectors in space or using aerosols to reduce the >> amount of carbon in the air. >> >> It's a hugely controversial theory. One of the main counter-arguments is >> that promoting a manmade solution to climate change will lead to inertia >> around other efforts to reduce human impact. But the popularity of >> geoengineering is on the rise among some scientists and even received a nod >> from the IPCC in its recent climate change report. >> >> In a fast-flowing and sometimes heated head-to-head climate professors >> David Keith and Mike Hulme set out the for and against. Keith, a >> geoengineering advocate, doesn't believe that this science is a solve-all >> but says "it could significantly reduce climate impacts to vulnerable >> people and ecosystems over the next half century." While Hulme sets out his >> stall in no uncertain terms: "Solar climate engineering is a flawed idea >> seeking an illusory solution to the wrong problem". >> >> Enjoy the debate and do add your comments at the end. >> >> David Keith: Gordon McKay professor of applied physics (SEAS) and >> professor of public policy at Harvard Kennedy School >> >> Deliberately adding one pollutant to temporarily counter another is a >> brutally ugly technical fix, yet that is the essence of the suggestion that >> sulphur be injected into the stratosphere to limit the damage caused by the >> carbon we've pumped into the air. >> >> I take solar geoengineering seriously because evidence from atmospheric >> physics, climate models, and observations strongly suggest that it could >> significantly reduce climate impacts to vulnerable people and ecosystems >> over the next half century. >> >> The strongest arguments against solar geoengineering seem to be the fear >> that it is a partial fix that will encourage us to slacken our efforts to >> cut carbon emissions. This is moral confusion. It is our responsibility to >> limit the impact that our cheap energy has on our grandchildren >> independently of the choices we make about temporary solar >> geoengineering.Were we faced with a one-time choice between making a total >> commitment to a geoengineering programme to offset all warming and >> abandoning geoengineering forever, I would choose abandonment. But this is >> not the choice we face. Our choice is between the status quo—with almost no >> organised research on the subject—and commitment to a serious research >> program that will develop the capability to geoengineer, improve >> understanding of the technology's risks and benefits, and open up the >> research community to dilute the geo-clique. Given this choice, I choose >> research; and if that research supports geoengineering's early promise, I >> would then choose gradual deployment. >> >> Mike Hulme: professor of climate and culture in the School of Social >> Science & Public Policy at King's College London >> >> David, your ambition to significantly reduce future climate impacts is >> one of course we can share along with many others. But I am mystified by >> your faith that solar climate engineering is an effective way of achieving >> this. More direct and assured methods would be to invest in climate >> adaptation measures—a short-term gain—and to invest in new clean energy >> technologies—a long-term gain.My main argument against solar engineering is >> not the moral hazard argument you refer to. It is twofold. First, all >> evidence to date—from computer simulations and from the analogies of >> explosive volcanic eruptions—is that deliberately injecting sulphur into >> the stratosphere will further destabilise regional climates. It may reduce >> globally-averaged warming, but that it not what causes climate damage. It >> is regional weather that does that—droughts in the US, floods in >> Pakistan, typhoons in Philippines. Solar climate engineering in short is a >> zero-sum game: some will win, some will lose.Which leads me to my second >> argument. The technology is ungovernable. Even the gradual deployment you >> propose will have repercussions for all nations, all peoples and all >> species. All of these affected agents therefore need representation in any >> decisions made and over any regulatory bodies established. But given the >> lamentable state in which the conventional UN climate negotiations linger >> on, I find it hard to envisage any scenario in which the world's nations >> will agree to a thermostat in the sky.Solar climate engineering is a flawed >> idea seeking an illusory solution to the wrong problem.DK - You are correct >> that climate impacts are ultimately felt at the local scale as changes in >> soil moisture, precipitation or similar quantities. No one feels the global >> average temperature. Precisely because of this concern my group has studied >> regional responses to geoengineering.In the first quantitative look at the >> effectiveness of solar geoengineering we found—to our surprise—that it can >> reduce changes in both temperature and precipitation on a region-by-region >> basis. This work has now been replicated by much larger study using a whole >> set of climate models led by Alan Robock one of the more skeptical >> scientist working on the topic, and they got the same result. While there >> are claims in the popular press that it will "destabilise regional >> climates"—presumably meaning that it will increase local variability—I know >> of no scientific paper that backs this up.I have no faith in >> geoengineering. I have some faith in empirical science and reasoned >> argument. It's true that we don't have mechanisms for legitimate governance >> of this technology. Indeed in the worse case this technology could lead to >> large-scale conflict. This exactly why I and others have started efforts to >> engage policy makers from around the world to begin working on the >> problem.MH - David, The point here is how much faith we can place in >> climate models to discern these types of regional changes. As the recent >> report from the UN's Intergovernmental Panel on Climate Change has shown, >> at sub-continental scales state-of-the-art climate models do not robustly >> simulate the effects of greenhouse gas accumulation on climate.What you are >> claiming then is that we can rely upon these same models to be able to >> ascertain accurately the additional effects of sulphur loading of the >> stratosphere. Frankly, I would not bet a dollar on such results, let alone >> the fate of millions.You may say that this is exactly why we need more >> research—bigger and better climate models. I've been around the climate >> research scene long enough to remember 30 years of such claims. Are we to >> wait another 30 years? What we can be sure about is that once additional >> pollutants are injected into the skies, the real climate will not behave >> like the model climate at scales that matter for people.As for getting >> political scientists to research new governance mechanisms for the global >> thermostat - you again place more faith in human rationality than I. We >> have had more than 20 years of a real-world experiment into global climate >> governance: it's called the UN Framework Convention on Climate Change. It's >> hardly been a roaring success! You must be a supreme optimist to then >> expect a novel system of global governance can be invented and sustained >> over the time periods necessary for solar climate engineering to be >> effective.DK: You made a very strong claim that geoengineering is zero-sum. >> If true, I would oppose any further work on the technology. I responded >> that results from all climate models strongly suggest that this is not the >> case. Your response was to dismiss climate models. Assume for the moment >> that climate models tell us nothing about regional climate response, on >> what then do you base your claim that solar geoengineering is zero sum - >> that is, that is just shuffles winners and losers?When climate skeptics >> rubbish models I defend science by agreeing if all we had was complex >> models I too would be a doubter; but, I then argue, that we base our >> conclusions on a breath of evidence from basic physics and a vast range of >> observations to simple—auditable—models as well as the full-blow three >> dimensional climate models. Models of atmospheric circulation and aerosols >> developed for earth make good predictions of the climates of other planets. >> This is a triumph of science.The same science that shows us that carbon >> dioxide will change the climate shows that scattering a bit more sunlight >> will reduce that climate change. How you do you accept one and reject the >> other? >> >> On the other points: I am not exited by an endless round of climate model >> improvements nor do it think that political scientist will solve this. We >> need less theory and more empiricism. >> >> MH: David, I agree that we need less theory and more empiricism. This is >> one of the reasons why I am skeptical that climate models are able to >> reveal confidently what will happen to regional climates—especially >> precipitation—once sulphur is pumped into the stratosphere.I don't dismiss >> climate models, but I discriminate between what they are good for and what >> they are less good for. Having spent nearly half of my professional life >> studying their ability to simulate regional and local rainfall—by comparing >> simulations against observations, empiricism if you will—I have little >> faith in their skill at the regional and local scales.But let's assume for >> a moment that climate models were reliable at these scales. Another >> argument against intentional solar climate engineering is that it will >> introduce another reason for antagonism between nations. There are those >> who claim that their models are good enough to precisely attribute specific >> local meteorological extremes—and ensuing human damages—to greenhouse gas >> emissions. There will be nations who will want to claim that any damaging >> weather extreme following sulphur injection was aerosol-caused rather than >> natural- or greenhouse gas-caused. The potential for liability and >> counter-liability claims between nations is endless.I am against solar >> climate engineering not because some violation of nature's integrity - the >> argument used by some. I am against it because my reading of scientific >> evidence and of collective human governance capabilities suggests to me >> that the risks of implementation greatly outweigh any benefits. There are >> surer ways of reducing the dangers of climate change. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "geoengineering" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to geoengineerin...@googlegroups.com <javascript:>. >> To post to this group, send email to geoengi...@googlegroups.com<javascript:> >> . >> Visit this group at http://groups.google.com/group/geoengineering. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
