How much brighter is the sun than it used to be? On Dec 11, 9:40 pm, Sam Carana <[email protected]> wrote: > What is the risk of catastrophe? Many will argue that, even if the > best proposals currently being negotiated in Copenhagen would be > implemented, it's virtually certain that we're facing catastrophic > droughts, wildfires, flooding, extinction of species, etc. Most > worrying is the risk of a runaway greenhouse effect. > > Let there be no doubt that scientists acknowledge the risks. As far > back as at least 1991, the possibility of runaway greenhouse effect > was recognized by climatologists. In December 1991, Greenpeace asked > 400 climate scientists if they thought the greenhouse effect might > reach the point of no return in the near future. Of the 113 scientists > who returned their questionnaires, almost half thought a runaway > greenhouse effect is possible, and 13 per cent thought it > probable.http://www.newscientist.com/article/mg13318081.600 > > Extensive research has been done by James Hansen, who said in an AGU > lecture on December 17, 2008: > Now the danger that we face is the Venus syndrome. There is no escape > from the Venus Syndrome. Venus will never have oceans again. Given > the solar constant that we have today, how large a forcing must be > maintained to cause runaway global warming? Our model blows up before > the oceans boil, but it suggests that perhaps runaway conditions could > occur with added forcing as small as 10-20 W/m2. > > There may have been times in the Earth’s history when CO2 was as high > as 4000 ppm without causing a runaway greenhouse effect. But the > solar irradiance was less at that time. What is different about the > human-made forcing is the rapidity at which we are increasing it, on > the time scale of a century or a few centuries. It does not provide > enough time for negative feedbacks, such as changes in the weathering > rate, to be a major factor. There is also a danger that humans could > cause the release of methane hydrates, perhaps more rapidly than in > some of the cases in the geologic record. In my opinion, if we burn > all the coal, there is a good chance that we will initiate the runaway > greenhouse effect. If we also burn the tar sands and tar shale > (a.k.a. oil shale), I think it is a dead > certainty.http://www.columbia.edu/%7Ejeh1/2008/AGUBjerknes_20081217.pdf > > In conclusion, there is significant scientific warning that the risk > of a runaway greenhouse effect shouldn't be ignored. What is lacking > is the political resolve to accept that - as a minimum - research is > required into ways to act on the dangers ahead. Such research should > not only focus on the technical aspects of reducing greenhouse gases > and reflecting more sunlight, but should also look at political > issues, the preparation of an action plan, escalation procedures, etc. > . > > I would like to see research that differs from most previous research > in that it: > - focuses on the effectiveness of action, rather than on questioning > whether climate change was taking place; > - takes a multi-disciplinary approach, rather than to approach issues > from a single specialism; > - takes into account wide impacts and context, as opposed to research > done in ivory towers with isolated lab conditions; > - is open, to allow the public insight in progress, as opposed to > research that is hidden to secure economic gain; > - can take on board issues as they come along, as opposed to > predetermined research that focuses on a single outcome. > > Cheers, > Sam Carana > > > > On Sat, Dec 12, 2009 at 4:08 AM, William Fulkerson <[email protected]> wrote: > > Dear John Nissen: > > How important is it to avoid loosing summer sea ice in the Arctic? The bads > > from it include: positive feedback on warming due to albedo lowering and > > increased input of GHG emissions from permafrost melting and hydrate > > decomposition causing some acceleration of the impact of warming on the > > Greenland ice sheet, damage to ecosystems (including iconic species) and > > social systems, possible harmful impact on northern latitude weather > > patterns, and perhaps others that I don’t know about. There are some goods > > to like the Northwest passage I suppose. To your knowledge has anyone or > > any group tried to quantify these bads or do a rough cost/benefit analysis. > > One important part of your arguments, with which I am in agreement, is that > > the bads are pretty bad, and, therefore, there is an urgency to do > > something. If that can be shown unequivocally, then it argues for finding > > out if some form of SRM can reduce the bads; i.e. Initiating an urgent, > > focused and comprehensive RD&D program. Perhaps the first step in the > > program is to do the cost/benefit as best it can be done. > > With best regards, > > Bill > > Bill Fulkerson, Senior Fellow > > Institute for a Secure and Sustainable Environment > > University of Tennessee > > 311 Conference Center Bldg. > > Knoxville, TN 37996-4138 > > [email protected] > > 865-974-9221, -1838 FAX > > Home > > 865-988-8084; 865-680-0937 CELL > > 2781 Wheat Road, Lenoir City, TN 37771 > > - > > > On 12/11/09 11:18 AM, "John Nissen" <[email protected]> wrote: > > > Hi Dave, > > > I'll deal first with John's case from the "back of the envelope" > > calculation, and then with the scientific reticence. > > > The case is even stronger than John Gorman has put it. Even if emissions > > were stopped overnight, the mean annual temperature in the Arctic would > > continue to rise, and with an acceleration, due to the positive feedback of > > the sea ice - as ice (with high albedo) melts it gives way to open water > > (with low albedo) which absorbs most of the sunlight. This albedo effect is > > thought to be part of the basic mechanism of polar amplification. > > > Now for the scientific reticence. > > > It's not quite the entire scientific community who are reticent. There are > > some good folks on this list who have stood out for geoengineering, David > > Keith for one. He gave an excellent presentation on geoengineering, at the > > Royal Geographical Society, here in London. He pointed out the ginormous > > quantity of CO2 mankind had dumped in the atmosphere, and he pointed out > > that some of this CO2 would last thousands of years - worse than nuclear > > waste! It was quite clear that the associated global warming would last a > > time longer than the Arctic sea ice. > > > The fear that academics have of their own peers is quite understandable. > > Paul Crutzen had enormous difficulty in publishing his seminal paper on > > geoengineering with stratospheric sulphate - and then received a lot of > > flack from colleagues after it was published - so much flack that he seems > > to have retired from the scene. > > > The other fear, which is more forgiveable, is that academics, and scientific > > advisers generally, didn't want to disrupt the Copenhagen process. They have > > strained every ounce of intellect to persuade the politicians to get the > > best possible deal at Copenhagen. This has meant that government advisers > > (like ex-IPCC Bob Watson in the UK) who perfectly understand the dangers of > > Arctic sea ice, have been telling the government that cutting emissions is > > the top priority. What the advisers have not acknowledged is the speed of > > retreat of the sea ice - that is until their "Copenhagen Diagnosis" report > > [1]. The sea ice summer extent has been 40% below the IPCC models > > predictions for three years in a row! So the summer sea ice is now expected > > disappear by 2040 - and there is the possibility of it disappearing end > > summer within a few years, especially because of the natural variability of > > Arctic weather. The sea ice is indeed the "elephant in the room". > > > However now that the politicians seem committed to obtaining good Copenhagen > > results, we could see everything change, and scientists will point out that, > > not only do we have to reduce emissions, but we have to do other things to > > save the planet. It is already accepted by some leading climate scientists, > > such as Jim Hansen, that geoengineering will be required to suck CO2 out of > > the atmosphere. It must also be accepted that SRM geoengineering is needed > > to save the Arctic sea ice - since nobody can dispute the argument. > > > Cheers from Chiswick, > > > John > > > [1]http://www.copenhagendiagnosis.org/ > > > --- > > > Hawkins, Dave wrote: > > > Come on folks. There is no reason to dismiss the entire scientific > > community as afraid to publish a paper due to concerns about political > > correctness or impact on careers. I don't buy this slur on an entire > > profession. > > > -----Original Message----- > > From: John Gorman [mailto:[email protected]] > > Sent: Friday, December 11, 2009 3:33 AM > > To: Hawkins, Dave; [email protected]; [email protected] > > Subject: Re: [geo] Population control, emission cuts, but > > geoengineering? > > > this is a case where the correct answer is that "there isnt any peer > > reviewed reference because it wouldnt be politically correct to say it > > and to do so would be to risk ones career" > > However the back of an envelope calculation is simple; The area of sea > > ice has halved in little more than a decade. Whatever scenario one > > takes it will be gone in 30,40,50 years. Even with no further emissions > > from today the CO2 will stay at 380 and the temperature in the arctic > > will stay at 3 or 4 deg C above 50 years ago. The sea ice will continue > > to melt. With any conceivable emissions limitation scenario it will be > > gone much sooner. > > > This is partly why I included that quote from Schumaker in my submission > > to the parliamentary committee. All this talk of tree rings, computers, > > models etc is just stopping us from recognising the obvious. > > Vick Pope would say " can you prove that this will happen?" no of course > > i cant. Its in the future. > > > john Gorman > > ----- Original Message ----- > > From: "Hawkins, Dave" <[email protected]> <mailto:[email protected]> > > To: <[email protected]> > > ... > > read more »- Hide quoted text - > > - Show quoted text -
-- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
