Hi Doug--On the issue of seeking US Govt funding for research, I've also
been concerned about pushing SRM research before the US Govt (including
Congress) has committed to real emissions cutbacks. We were at least
close to that point with Obama Admin, but not with the current
situation, so I do agree with your concern. That Europe seems to have
made the pledge to cut GHG emissions to zero--perhaps not fast enough,
but at least on that path, so supporting research by those nations seems
much less likely to encounter the slippery slope issue--gives me some hope.
As for proceeding, while the Federal Government is embarrassingly
lagging, many states and cities are pushing hard and the pace of
technology development may even be accelerating, so it seems to me that
the international community pushing for as much efficiency, mitigation
and CDR as feasible and then enough SRM to keep things from getting
worse is a reasonable approach during the period when SRM research goes
on, quite likely funded by other nations as it is in their interest as well.
Best, Mike
On 11/6/17 9:22 AM, Douglas MacMartin wrote:
Hi Mike,
I agree that the situation is far from black and white. Ultimately it's a bit of a judgment call, weighing
the risks of what we don't know about solar geo against what we don't know about climate change, and more
importantly perhaps, what we don't know about how people will behave differently. I admit that my "20
years" might have more to do with my perceived timeframe for when (a) the impacts of climate change will
be much more obvious and (b) where we're headed in terms of stabilizing the climate through mitigation will
be much more obvious, and less to do with what we actually learn about solar geoengineering - but given that
I think (a) and (b) could easily push "us" (who "us" is is a separate conversation) into
wanting to do it in ~20 years, I'd rather be prepared. We'd better make a lot more progress over the next 10
years than we have over the last 10 (that isn't a dig against the research, but against the funding levels).
My hesitation with telling the House Science Committee on Wednesday that they
should urgently fund a goal-oriented strategic research program is primarily
that I don't trust them not to use this as an excuse not to mitigate, and IMHO
not mitigating is even worse than not pursuing research urgently. (And a fair
argument to make would be that nothing I say is likely to influence how much
mitigation the US does, but might influence how much research is done.)
doug
-----Original Message-----
From: Michael MacCracken [mailto:[email protected]]
Sent: Sunday, November 05, 2017 10:46 PM
To: [email protected]; [email protected]; 'geoengineering'
<[email protected]>
Subject: On when it might make sense for intervention to begin
Hi Doug--In response to your Nov 4 post below, I am all for learning, but the
problem with waiting and waiting is that the Earth will keep warming and
warming and impacts will keep growing and growing--including especially ones
that are or near irreversible, such as to biodiversity and commitment to sea
level rise.
If the goal were, during this 20-year learning time, only to reduce or offset
year-by-year warming as might be done, based on our understanding of volcanic
effects, using quite small annual increments to the stratospheric sulfur
loading, and basically iterating as we go on something like 5-year running
averages, we would very likely be in a much more favorable situation to
evaluate how to proceed, both having better model analyses and having some
experience to work with. If we find the 20-year accumulation is worse than
ongoing global warming with GHGs or that mitigation is working particularly
well, the stratospheric injection level could be gradually reduced instead of
continuing with ongoing augmentation. While there would of course be
uncertainties, it is not really clear that they would be more serious than the
increasing changes and impacts that are occurring. It just seems to me that to
do nothing while continuing with research just lets the situation get worse and
then the cure having to be so much stronger than deployment itself could be
problematic.
If, as Santer et al suggest, early 21st century rate of warming was slowed by
the cooling influences of small volcanic eruptions that injected amounts that
were barely noticeable even with advanced instruments and really not at all
noticeable by the general public, I'd suggest that we actually have a natural
analog of the type of influence that I am suggesting be pursued. And, in that
we will be learning along the way through the 20-year research program (let's
assume that the research is funded), so it just seems, as noted above, that the
uncertainties associated with such an approach would not be less than the
impacts and uncertainties of deferring all intervention efforts until some
probably pretty arbitrary level of understanding in the future.
Regarding my favoring of regionally focused alterations, I would make that a research
priority, but I'd suggest that the earlier one started injecting enough sulfur to offset
each year's forcing increment or so, the better--just thinking that, in the type of
relative risk framing that I view as appropriate to the situation given where we are,
that, with mitigation ramping up virtually everywhere (and the US doing somewhat well
despite the Administration's mistaken actions), starting very modestly with stratospheric
aerosol climate intervention could really help in making sure that the situation is not
so bad by the time we learn enough to "make reasonably informed decisions"
(whatever that
means) that we will be unable to avoid significant overshoot of the global
average temperature without such aggressive intervention that we'll be
suffering from both the growing impacts and then the supposed cure.
At the very least, I would think a good case could be made for such an effort.
Best regards, Mike MacCracken
On 11/4/17 11:43 AM, Douglas MacMartin wrote:
Both SAI and MCB probably need of order of 20 years of research before
we could make reasonably informed decisions; both have a long list of
unknowns. (In the case of MCB, we don't even really know if it
"works" in any meaningful sense of the word, because cloud-aerosol
interactions are too uncertain today, so we really don't know whether
there is a useful fraction of cloud meteorological conditions in which
the albedo is significantly enhanced. We should all really really
hope that it doesn't work very well, because if it doesn't, that means
the indirect aerosol effect is smaller than current best guess and
climate sensitivity will be on the low end...)
(And, of course, at the current level of worldwide funding, that "20"
above is probably off by a few orders of magnitude.)
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Michael Hayes
Sent: Saturday, November 04, 2017 10:00 AM
To: geoengineering <[email protected]>
Subject: Re: [geo] Can anyone offer a CE perspective on this SLR article?
Holly and List,
The use of sulfur needs proper polar field level testing. Testing is planned
yet may not be done in areas prone to Polar Stratospheric Cloud formation. Time
of the season is also of the essence for testing.
Until that is done, SAI has a large question to answer; in general terms.
MCB, used in key areas, is a critical first step. There should be no deflection
at that engineering level. Once MCB paves the way, other marine capable systems
can gain traction.
What marine engineering minded person or institution would not give Steven's
word heavy weight? This is a marine issue.
--
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