Agree with the analysis presented. As to the impact from geoengineering, the solar radiation management schemes, while not directly reducing emissions of CO2 could indirectly reduce them via less use of AC in temperate and tropical climates and by slowing feedback driven emissions from permafrost. To date, however, I am not aware of any specific calculations as to the possible benefits from this aspect of solar radiation management on coral, even though the indirect benefits would certainly prevent some CO2 from being absorbed into the ocean by keeping it locked up. About half of sulfuric acid aerosol will descend as sulfuric acid and the rest as various sulfate species. Evidence from past volcanic eruptions and from calculations suggest that there would not be an increase in either ocean acidity (well buffered with respect to sulfate) or over at risk land areas from large scale use of stratospheric aerosols. More calculations and modeling are needed on targeted deployment in the Arctic, but again, past eruptions in Alaska have apparently had no effect on ecosystems.
----- Original Message ----- From: "Alex D. Rogers" <alex.rog...@ioz.ac.uk> To: "John Nissen" <j...@cloudworld.co.uk> Cc: <dan.wha...@gmail.com>; "geoengineering" <geoengineering@googlegroups.com>; "Alvia Gaskill" <agask...@nc.rr.com>; "Stephen Salter" <s.sal...@ed.ac.uk> Sent: Tuesday, July 21, 2009 4:45 AM Subject: Re: Protecting the corals > Hi John, > > I am travelling at present but will give you some short answers now and > then send you our technical document when it is ready. > > The situation is that high temperatures associated with CO2 emissions and > combined with natural environmental variation have led to a new > phenomenon known as mass coral bleaching. Here, the symbiotic algae > living in coral tissue go into overdrive produce too many reactive oxygen > species toxic to the coral host. They are ejected from the coral tissue > leading to the White appearance known as bleaching. This began in the > late 1970s as a time lagged response to a CO2 level of about 320 ppm. In > 1998 there was a very severe event killing 16% of all corals. There have > been further severe events regionally and at current temperatures we are > expect the next el niño to be a critical event. > > Acidification is a direct affect of the absorption of CO2 by seawater. It > produces carbonic acid altering the carbonate equilibrium and reducing > aragonite. In preindustrial times 98% of coral reefs occurred in waters > 3.5 x saturated in aragonite. Now corals in many areas are in waters with > a lower saturation and by 2030 only 8% of corals will be in waters 3.5x > saturation. Observations indicate a 14 % decrease in growth rates of > corals already in the GBR probably partially a result of acidification. > If this continues all reefs will become erosional certainly by the end of > the century. > > Sea level rise is not necessarily such a problem for corals. Larvae can > colonise submerged hard substrata. > > We need large cuts in emissions of the order of 50-85% by 2050 based on > 2000 levels coupled with CO2 draw down where I suspect geoengineering may > be required. There have been suggestions of CO2 draw down through the > burying of charcoal or other schemes using burial of wood. Carbon can of > course be locked up through woodland, peat bogs and wetlands as well. > > Solar radiation management could slow down the rate of temperature > increase but will not cure the acidification problem and indeed any > geoengineering scheme should be carefully considered as to whether it > will be significant in terms of CO2 draw down at a global scale and > whether or not it increases the acidification problem (could sulphate for > example get converted to sulphuric acid?). > > Best wishes > > Alex > > Dr Alex David Rogers, > Marine Biologist, > Institute of Zoology, > Regent's Park, > London, > NW1 4RY > > Phone 0044 (0)20 7449 6669 > Mobile 0044 (0)7590 356209 > > On 20 Jul 2009, at 14:49, "John Nissen" <j...@cloudworld.co.uk> wrote: > >> >> Dear Dr Rogers, >> >> The plight of corals has been highlighted by the Guardian article (see >> forwarded below). I'm not an expert on corals, but there seem to be at >> least three major threats: >> * ocean acidification >> * warming sea surface temperatures >> * rapid sea level rise >> >> 1. As regards ocean acidification, you seem to suggest that the current >> level of CO2 is already too high. How long have we got to get it down >> to 350 ppm? >> >> 2. How much effect does the warming have? Since warmer water can hold >> less CO2, it is therefore less acidic, so this must to some extent >> negate the increase in CO2. >> >> 3. About 14,000 years ago there was a meltwater event with sea level >> rise around 20 metres in 400 years [1]. Hansen is worried that, with >> current emissions trajectory, we could have a metre or even metres of >> sea level rise this century. Indeed, if Greenland and West Antarctic >> ice sheets (GIS/WAIS) were both to disintegrate, we'd get about 15 >> metres. There has been bad news from Greenland recently [2] [3] and >> Antarctic [4]. >> >> The possibility of geoengineering arises, both to remove CO2 from the >> atmosphere and to for solar radiation management (SRM). It has been >> proposed to use SRM to cool the Arctic and save the Arctic sea ice [5]. >> There are currently two principle candidates for SRM - stratospheric >> sulphate aerosols and marine cloud brightening [6]. Could the latter be >> used for local cooling and help to save particular coral reefs? >> >> Kind regards, >> >> John Nissen, >> Chiswick, London W4 >> >> >> [1] James Hansen, e.g. in: >> http://climateandcapitalism.com/?p=148 >> >> [2] >> http://www.earth-stream.com/Earth/Continents/Japan/Massive-Greenland-Glacier-Melting-At-Troublesome-Pace_18_197_681_182823.html >> [3] >> http://www.newscientist.com/article/dn17465-arctic-glacier-to-lose-manhattansized-tongue.html?DCMP=OTC-rss&nsref=environment >> >> [4] For example see "recent glacier acceleration" in: >> http://en.wikipedia.org/wiki/Pine_Island_Glacier >> >> [5] See "Part C" in the open letter to Dr Pachauri: >> http://geo-engineering.blogspot.com/2009/03/open-letter-to-dr-pachauri.html >> >> [6] See special issue of Phil Trans of Royal Society, A, referenced >> here: >> http://en.wikipedia.org/wiki/List_of_proposed_geoengineering_projects >> >> --- >> >> Alvia Gaskill wrote: >>> Here it is from the Guardian. He appears to be referring to measures >>> to remove the legacy CO2, but isn't specific. >>> >>> http://www.guardian.co.uk/environment/2009/jul/07/coral-attenborough >>> >>> Coral condemned to extinction by CO2 levels, warns Attenborough >>> Coral is the canary in the cage as damage can be seen most quickly, >>> veteran naturalist tells Royal Society >>> >>> a.. Alok Jha >>> >>> b.. guardian.co.uk, Tuesday 7 July 2009 11.02 BST >>> >>> A coral seen off Jarvis Island in the Pacific Ocean. Photograph: Jim >>> Maragos/AP >>> >>> >>> David Attenborough joined scientists yesterday to warn that carbon >>> dioxide in the atmosphere is already above the level which condemns >>> coral reefs to extinction in the future, with catastrophic effects for >>> the oceans and the people who depend upon them. >>> >>> >>> Coral reefs support a quarter of all marine life including more than >>> 4,000 species of fish. They also provide spawning, nursery, refuge and >>> feeding areas for creatures such as lobsters, crabs, starfish and sea >>> turtles. This makes them crucial in supporting a healthy marine >>> ecosystem upon which more than 1bn people depend for food. Reefs also >>> play a crucial role as natural breakwaters, protecting coastlines from >>> storms. >>> >>> >>> Attenborough said the world had a "moral responsibility" to save >>> corals. >>> >>> >>> He was speaking yesterday at the Royal Society in London, following a >>> meeting of marine biologists. At the current rate of increase of >>> atmospheric CO2, they said, coral would become extinct within a few >>> decades. >>> >>> >>> "A coral reef is the canary in the cage as far as the oceans are >>> concerned," said Attenborough. "They are the places where the damage is >>> most easily and quickly seen. It is more difficult for us to see what >>> is happening in, for example, the deep ocean or the central expanses of >>> ocean." >>> >>> >>> "Anybody's who's had the privilege of diving on a coral reef will have >>> seen the natural world at its most glorious, diverse and beautiful," >>> said Attenborough. "[There is a] moral responsibility one has to the >>> natural world. Also you have responsibility to future generations, to >>> your future grandchildren and great grandchildren." >>> >>> >>> Increasing carbon dioxide in the atmosphere has a double effect on >>> coral. Global warming means warmer seas, which causes the corals to to >>> bleach, where the creatures lose the symbiotic algae they need to >>> survive. Carbon dioxide also makes seas more acidic, which means the >>> corals find it difficult to prevent their exoskeletons from dissolving. >>> >>> >>> "We've already passed a safe threshold for coral reef ecosystems in >>> terms of climate change. We believe that a safe level for CO2 is below >>> 350 parts per million," said Alex Rogers of the Zoological Society of >>> London and International Programme on the State of the Ocean, who >>> helped organise yesterday's meeting. >>> >>> >>> Carbon dioxide in the atmosphere has risen from 280 ppm before the >>> industrial revolution to around 387ppm today. Environmentalists say >>> that any new global deal on climate must restrict the growth of CO2 >>> levels to 450ppm, though more pessimistic scientists say that the world >>> is heading for 550ppm or even 650ppm. >>> >>> >>> "When we get up to and above 450ppm, that really means we're into the >>> realms of catastrophic destruction of coral reefs and we'll be moving >>> into a planetary-wide global extinction," said Rogers. >>> >>> >>> "The only way to get to 350ppm or below is not only to have major cuts >>> in CO2 emissions but also to draw CO2 out of the atmosphere through >>> measures such as geo-engineering." >>> >>> >>> Attenborough said the plight of the corals was another example of why >>> the control of carbon was so important to the world's inhabitants. >>> "Each ecological disaster or problem traces its cause back to carbon. >>> To quibble about this is really fiddling while Rome burns. If we do not >>> control the emission of carbon, this world is heading for a major >>> catastrophe and this is one of the first to be staring us straight in >>> the face." >>> >>> ----- Original Message ----- From: "DW" <dan.wha...@gmail.com> >>> To: "geoengineering" <geoengineering@googlegroups.com> >>> Sent: Friday, July 17, 2009 6:54 PM >>> Subject: [geo] Re: david attenborough >>> >>> >>> >>> Can we get a link or a scan of the article? >>> >>> Dan >>> >>> On Jul 17, 12:13 pm, "John Gorman" <gorm...@waitrose.com> wrote: >>> >>>> from the widely read UK weekly The Week a quote from Sir David >>>> Attenborough >>>> >>>> "we're going to have to use geoengineering techniques" !!!! >>>> >>>> JOhn G >>>> >> >> >> This message has been scanned for viruses by MailControl - >> www.mailcontrol.com >> >> Click https://www.mailcontrol.com/sr/wQw0zmjPoHdJTZGyOCrrhg== to report >> this email as spam. > > > The Zoological Society of London is incorporated by Royal Charter > Principal Office England. Company Number RC000749 > Registered address: Regent's Park, London, England NW1 4RY > Registered Charity in England and Wales no. 208728 > _________________________________________________________________________ > This e-mail has been sent in confidence to the named addressee(s). > If you are not the intended recipient, you must not disclose or distribute > it in any form, and you are asked to contact the sender immediately. > Views or opinions expressed in this communication may not be those > of The Zoological Society of London and, therefore, The Zoological > Society of London does not accept legal responsibility for the contents > of this message. 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