Trying again - seems I sent it from the wrong e-mail address at 8.48 ----- Original Message ----- From: Peter Read To: John Nissen ; Stephen Salter ; Pope, Vicky Cc: geoengineering ; [email protected] Sent: Saturday, May 02, 2009 8:48 PM Subject: Re: NOAA release
Sadly the problem may get worse faster than exponentially. Remember the parable of the pond Pond weed grows ~exponentially starting from one corner of the pond but the uncovered portion is (A - b exp(kt)) That is a function that goes to zero rather suddenly There may be an (unknown) limit to how much heat can be absorbed in some crucial part of the earth system (mushiness of the basal regions of ice sheets ??). The thermal input (~CO2e levels?) is rising (~exponentially ?) If "maybe" then a precautionary approach seems to be indicated until it's proven "not so". Any more comments on my proposed 'cumulative heating' metric. ?? Peter ----- Original Message ----- From: John Nissen To: Stephen Salter ; Pope, Vicky Cc: geoengineering ; [email protected] ; Peter Read Sent: Saturday, May 02, 2009 4:08 AM Subject: Re: NOAA release Hi Stephen, It is interesting to see how much appears linear when plotted on a logarithmic scale - hence is rising exponentially with time. Thus problems get worse exponentially, and the difficulty in solving them rises exponentially. A stitch in time saves nine! It's a pity they don't show the growth in CO2e - which takes into account methane and other greenhouse gases. I would like to know the official figure for it - and was hoping for Vicky Pope to say - since the proposed 450 ppm limit is for CO2e, not CO2. But there is some good news. The facts about Agung and Pinatubo suggest that SRM* might actually slow CO2 build up: "The large volcanic eruptions of Mt. Agung (Indonesia) in 1963 and Mt. Pinatubo (Philippines) in 1991 each slowed CO2 buildup for several years. Volcanic emissions cool the lower atmosphere and scatter sunlight. Those changes can both reduce plant respiration, a process that releases carbon dioxide, and boost photosynthesis, which removes carbon dioxide from the air. " However I'm not convinced by the explanation. The reduced respiration could be more or less balanced by reduced photosynthesis. What they don't mention is that cooling land soil and sea will allow them to absorb more CO2. Isn't that a more significant effect? It could be a major plus for your marine cloud brightening technique. Cheers, John * SRM = solar radiation management. ----- Original Message ----- From: "Stephen Salter" <[email protected]> To: "Pope, Vicky" <[email protected]> Cc: "John Nissen" <[email protected]>; "geoengineering" <[email protected]>; <[email protected]>; "Peter Read" <[email protected]> Sent: Friday, May 01, 2009 11:02 AM Subject: NOAA release > Hi All > > There is a useful NOAA release at > > http://www.noaanews.noaa.gov/stories2009/20090421_carbon.html > > They give the Mauna Loa graph extended by ices cores and plotted > together with fuel burn, GDP (now $60 trillion) and population. It was > sensible of them to use a log scale. > > Methane is up over the last two years after a 10 year lull but they > repeat the times 25 factor mistake. Even so they say now that the > methane contribution is now nearly half that of CO2. > > The 1929 depression shows up in the ices core CO2 so let's all be > grateful for the 2009 one and the far-sighted wisdom of our wonderful > bankers. There was also a reduction for WWII but this is maybe not the > most cost effective method. > > Stephen > > Emeritus Professor of Engineering Design > School of Engineering and Electronics > University of Edinburgh > Mayfield Road > Edinburgh EH9 3JL > Scotland > tel +44 131 650 5704 > fax +44 131 650 5702 > Mobile 07795 203 195 > [email protected] > http://www.see.ed.ac.uk/~shs > > > -- > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336. > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
