Hi Sam,

Excellent posting.  Two matters arising:

Firstly, on the matter of Stephen Salter's "cooling ships", we could start 
with a sea-side installation on some suitable NE Atlantic island, (e.g. 
Faeroes?) to provide infrastructure - easy access for power, people, 
maintenance, etc.  We badly need funds to jump start this technology.  Any 
suggestions?

Secondly, thanks for the great idea of an open letter to the forthcoming 
international climate forum.  Can it be the same letter as sent to Dr 
Pachauri?
http://geo-engineering.blogspot.com/2009/03/open-letter-to-dr-pachauri.html

If possible I'd like to include an argument for the urgency for Part C 
action in the Arctic, as has been suggested we might discuss in this 
geoengineering forum over the next week.  How should we balance the risks of 
geoengineering against the risks of not geoengineering, or delaying action? 
What is the optimum ramp up speed for candidate techniques?

Also we should point out the rediculously low cost of Part C type 
geoengineering, in relation to potential cost and life saving if it manages 
to prevent Arctic tipping points tipping.

BTW, who should the open letter be addressed to, at the forum?

Here it gives the date as April 27-28:
http://www.france24.com/en/20090328-obama-climate-change-denmark-un-summit

AFP - President Barack Obama Saturday launched a Major Economies Forum on 
Energy and Climate to give a boost to a historic agreement on climate change 
facilitated by the UN.

Leaders from the 16 major economies are to participate in a "preparatory 
session" on April 27-28 in Washington to "help generate the political 
leadership" for successful climate change negotiations December in 
Copenhagen, the White House said in a statement.

The forum, the White House added, would encourage "a candid dialogue" 
between developing and industrialized countries and help "advance the 
exploration of concrete initiatives and joint ventures that increase the 
supply of clean energy while cutting greenhouse gas emissions."

Denmark, which is hosting a UN meeting in December to create a new agreement 
on global warming to replace the Kyoto Protocol, and the United Nations were 
also invited.

The preparatory sessions would conclude with the Major Economies Forum 
Leaders' summit, to be hosted in July by Italian Prime Minister Silvio 
Berlusconi in La Maddalena, Italy.

The 17 major economies are Australia, Brazil, Canada, China, the European 
Union, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, 
South Africa, South Korea, the United Kingdom and the United States.

UN talks were to resume in Bonn on Sunday with some 190 countries 
participating to reach a new pact for curbing greenhouse gases beyond 2012, 
when Kyoto Protocol provisions expire.

The climate treaty was rejected by the US Congress in 1997 because it did 
not impose commitments on developing countries.

Obama's announcement came ahead of a Group of 20 economic crisis summit in 
London on April 2, for which he would embark on his first major foreign trip 
as president, with other stops planned in France and Germany for a NATO 
summit, the Czech Republic for an EU/US summit and an onward trip to Turkey.

----

Cheers,

John



----- Original Message ----- 
From: "Sam Carana" <[email protected]>
To: "Geoengineering" <[email protected]>
Sent: Wednesday, April 01, 2009 2:49 PM
Subject: [geo] Re: the limits of geoengineering?



Andrew,

Looking at global historic data of warming, one might at first glance
conclude that only a relatively small amount of global warming did
cause the arctic melting we're witnessing now. So, the conclusion
would then be that we similarly needed to reflect just a small amount
of sunshine back into space to have the reverse effect.

However, what complicates things is that global warming is amplified
in specific areas, notably around the North Pole. East Siberia was at
times 7°C warmer than normal during the summer of 2007 and the East
Siberian permafrost region alone contains 500 billion tonnes of
carbon. So, we would need to achieve much more cooling there to avoid
further melting. In other words, it's going to be hard to come up with
exact amounts of water vapor or aerosols that needed to be released to
achieve the same amount of cooling worldwide.

And of course, we don't need to achieve the same amount of cooling
everywhere. What is most urgent is the arctic melting of sea-ice and
permafrost. Therefore, I suggest to make a start by getting ships as
proposed by Stephen Salter to cruise as close to the arctic as
possible.

Such a proposal should be discussed and considered at the Major
Economies Forum on Energy and Climate, set in Washington this month,
followed by a summit in Italy in July. Obama has invited the leaders
of 16 major economies, as well as the secretary general of the United
Nations, to participate in this forum.
http://voices.washingtonpost.com/44/2009/03/28/obama_sets_international_clima.html

This Forum seems to focus only on energy. We should present the forum
with a similar Open Letter that we recently presented to Dr Pachauri,
head of the IPCC, in which we suggested that a comprehensive approach
to global warming should consist of three parts:

Part A: Emissions reduction
Part B: Carbon stock management
Part C: Heat transfer and radiation management

I hope to convince further members of this group to become signatories
to such an Open Letter to this Forum.

Cheers!
Sam Carana



On Wed, Apr 1, 2009 at 8:31 PM, Andrew Lockley <[email protected]> 
wrote:
> I'm not so concerned about the absolute physical limits of the process (as
> in max temperature or forcing reached). What concerns me is the ability to
> avoid dangerous climate change by using geoeng to arrest or reverse
> dangerous effects.
> I'd be really interested to see calculations that show whether geoeng can 
> or
> cannot 're-freeze' the Arctic. If it cannot, then maybe John Nissen is
> right and we have a very short time to act. If it can re-freeze it, then
> the risks of 'full scale' SRM geoeng probably outweigh the benefits by a
> substantial margin at this stage, and for some time to come. (Much further
> research is needed into geoeng and also ice dynamics and carbon cycle
> feedbacks).
> I think that this is one of the most fundamental things we have to
> demonstrate when considering the case for geoeng. Is there anyone on this
> list who'd be willing to bring forward a paper or informal research on the
> interaction between ice-albedo feedback and SRM geoeng.
> A
>
> 2009/4/1 Eugene I. Gordon <[email protected]>
>>
>> As you probably know greenhouse gas is a positive feedback on global
>> surface temperature but saturates when it becomes a black body. As the
>> concentration of greenhouse gas goes up the layer become blacker and 
>> blacker
>> (in the IR that is) As it becomes blacker the amount of radiation sent 
>> back
>> to the Earth's surface saturates. IT IS NOT A REFLECTOR NOR IS THE LAYER
>> GOING TO GET HOTTER AND RADIATE MORE ENERGY BACK AS THE EARTH WARMS UP. 
>> So
>> there is a concentration of CO2, methane, water vapor etc. above which 
>> the
>> greenhouse layer sends back a maximum amount of energy independent of the
>> concentration. The positive feedback saturates. Does anyone know what 
>> that
>> level is and what fraction of the radiation from the surface is currently
>> returned? In any case there is no tipping point and there may be a limit 
>> to
>> how high the surface temperature can go (of course there is a limit, it 
>> is
>> about 24 C). Geoengineering other than CO2 removal controls the forcing
>> function (the sun intensity at the Earth's surface). There is a lot of 
>> loose
>> talk about tipping points that needs to be eliminated.
>> ________________________________
>> From: [email protected]
>> [mailto:[email protected]] On Behalf Of Andrew Lockley
>> Sent: Tuesday, March 31, 2009 6:49 PM
>> To: geoengineering
>> Subject: [geo] the limits of geoengineering?
>>
>> There's been quite a few suggestions on this list that we need to use
>> geoengineering whilst we still can.
>> I'm not convinced by this argument, and I'd like to investigate how long
>> the 'window of opportunity' for geoeng is.
>> Lenton and Vaughan found that Aerosols could counter a doubling of 
>> natural
>> CO2, and space sunshade (if possible) could go much further
>> This seems to suggest that we have quite a while to act. Even in the even
>> of the start of a methane pulse which gives a doubling of co2 equivalent, 
>> we
>> can still ramp up geoengineering intervention quickly if needed. I 
>> suggest
>> that we'd have at least 5yrs or so warning, even of a really sudden 
>> methane
>> pulse from permafrost.
>> However, the big risk, as I see it, is that ice-albedo feedback will be
>> too strong in the arctic to overcome with geoeng. I know that re-freezing
>> will occur in winter, but the thickness of the ice may not be sufficient 
>> to
>> last all year, even with geoeng. If this happens, we may be unable to 
>> stop
>> the methane pulse from permafrost occuring (if it indeed does).
>> I don't have the skills needed to do the complicated sums, nor do I have
>> access to clever computers that can do them for me. Could someone 
>> therefore
>> suggest how long we've got before the 'window of geoengineering 
>> opportunity'
>> closes - if it indeed does?
>> A
>
>
> >
>




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