geoengineering Google Group

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering AND did you get that right?

2009-11-22T17:32:40Z

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering AND did you get that right?Hi Mike

Don't think so. Rereading my message I see that I did not omit to mention both the deposit and withdrawl mechanisms for the "biosphere carbon bank" i.e. photosynthesis for deposit into the biosphere 'bank' and decay for withdrawl from it. The gross flows of about 110 Gt each into ocean and terrestrial biosphere are netted off in the numbers I quoted, with about 50Gt respired immediately by plant life and about as much released by warm oceans as is absorbed in cold ocean regions (more exact numbers at Fig 4 [3?] of the RS geo-engineering report that I don't have to hand).

Practical hardware for stratospherics

2009-11-22T16:23:31Z

Peter

Thank you for your cockle-warming words.

Work on the mechanical design of most difficult inside bits of the spray
vessels has reached a point where little more can be done without some
money for test rigs. I can give you part numbers for bearings, seals,
and tell you the temperature of the cooling water. It would be a mistake

Re: [geo] A simple argument for SRM geoengineering, again.

2009-11-22T07:27:53Z

Re: [geo] A simple argument for SRM geoengineering, again.I used sulphate as an example because my understanding is that this is the only SRM technology that we are confident would work. I think your interesting recent paper confirms that view, although it mentions a number of other technologies that look very interesting.

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering AND did you get that right?

2009-11-21T19:00:52Z

Be aware that that formulation of Vaughn and Lenton is a simplification and
that 20% asymptotic value and 40% is probably a better estimate for
cumulative releases on the scale of conventional fossil fuel resources.

See attached paper for discussion.

______________________________ _____________________

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering AND did you get that right?

2009-11-21T18:40:19Z

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering AND did you get that right?From Lenton and Vaughn (2009):

"First we consider the calculation of effects on atmospheric
CO2 (deltaCatm) over time. Adding CO2 to the atmosphere or

removing CO2 from the atmosphere triggers responses from

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering AND did you get that right?

2009-11-21T13:56:14Z

Hi Peter‹Problem with your analysis is that biosphere also gives off
something like 60 GtC as well. Preindustrial with steady CO2, as much was
being taken up and given off. The net uptake, driven by the gradient created
by emissions is now something like 1 GtC/yr and would equilibrate well
before all of the perturbation is removed for this net uptake is occurring

Re: [geo] A simple argument for SRM geoengineering, again.

2009-11-21T10:57:58Z

*Hi John,*

I have said that your train of logic is just what we would be needing
today. Go for your *manifesto,* I am all for it !

We have been talking about long term solutions for too long, let's act on
the immediate term solution from *John * -- this might even buy us time to
come up with a set of really good long term solutions, too.

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering AND did you get that right?

2009-11-21T08:20:59Z

RE: [geo] Re: Rejected - a simple argument for SRM geoengiI must be off the map somewhere I guess, but in my view you guys have got it wrong

This is because the calculations pertain exclusively to atmospheric physics/chemistry.

In fact the biosphere fixes about 60 Gt C annually plus another 20 including oceanic photosynthesis

Re: [geo] A simple argument for SRM geoengineering, again.

2009-11-21T07:24:19Z

John

If it is to impact on policy -- I guess policy-makers are the intended audience but how to get the message to them is another question -- it is important to realise there are quite likely a fair number of deniers out there. It is no good just saying [or implying] they are wrong since confrontation is not good conflict resolution.

Re: [geo] A simple argument for SRM geoengineering, again.

2009-11-21T06:08:51Z

John,

In my experience, the best way to develop a broad sign-on letter is for
someone to write a first draft, and then assemble a small core group to
carefully hone the message, and then send it out to a broader group with a
simple yes/no offer to sign on (unless some egregious or easily corrected

Re: [geo] A simple argument for SRM geoengineering, again.

2009-11-21T04:56:56Z

John - Sorry I haven't responded earlier. I think I can speak for
quite a few others in the "Biochar tribe" when I offer below some
comments on what you have written. I do wholeheartedly agree with the
thrust that we are not doing enough today.

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering

2009-11-21T00:17:59Z

Dear all,

How important is methane? This is not a simple question to answer.

But in my attached 1998 paper I conclude that 100-yr GWPs **underestimate**
its importance by a factor of 3.

GWPs are seriously flawed. See the papers below, but there are others
by other authors (Harvey, Shine, ...)

A simple argument for SRM geoengineering, again.

2009-11-20T23:43:54Z

Hi Jim,

I want to follow up on your email of 15th November.

So far, nobody has challenged the logic of my argument. So we all seem
to be in agreement! It's not what we'd like to believe, but the
conclusion is clear.

Why are most academics among us so reticent? Jim Hansen has noticed

RE: [geo] Re: Rejected - a simple argument for SRM geoengineering

2009-11-20T23:00:26Z

David et al:

True, Jim Kasting's work on the long-term carbon cycle as impacted by
human fossil fuel CO2 emissions is decades old. But brilliant though
Jim is, he was not the first. See, e.g., the attached paper published
in 1974 when it first dawned on me and others at NASA/GISS that we
might be on to something important with the fossil fuel O2

Re: [geo] Re: Rejected - a simple argument for SRM geoengineering

2009-11-20T22:38:07Z

The other problem with 100-year GWPs is that they tend to hide all that can
be done with the short-lived species (black carbon, methane, ozone
precursors), so what we really need to do is to use both 20 and 500+ year
GWPs. Use of 100-year GWPs covers up both of the important tails.

Mike