Regional SRM experiment

[Hawkins, Dave]

Climatic effects of 1950–2050 changes in US anthropogenic aerosols – Part 2: Climate response 

http://www.atmos-chem-phys.net/12/3349/2012/acp-12-3349-2012.pdf

Reduction in air pollution from coal fired power stations due to environmental regulations since the 1980s has increased regional global warming in the Central and Eastern United States. Climate scientists from the Harvard School of Engineering and Applied Sciences (SEAS) found that particulate pollution, particularly from coal fired power stations, caused a global warming hole, or a large cold patch reducing temperatures by up to 1 degree C in the region, particularly lowering maximum temperatures in Summer and Autumn.

Since I have spent a good deal of the past several decades advocating for rapid deployment of particle reducing techniques, I guess I can be tagged as an inadvertent geoengineer.

:>)

Sent from my iPad

[Mike MacCracken]

Hi David—Very interesting, and just why it might be possible to do something to limit warming in an area like the Arctic, which, as was documented over and over again at the Montreal IPY meeting last week, is changing very fast.

Mike MacCracken

********

On 4/28/12 10:06 AM, "David Hawkins" <dhaw...@nrdc.org> wrote:

Climatic effects of 1950–2050 changes in US anthropogenic aerosols – Part 2: Climate response
http://www.atmos-chem-phys.net/12/3349/2012/acp-12-3349-2012.pdf


Reduction in air pollution from coal fired power stations due to environmental regulations since the 1980s has increased regional global warming in the Central and Eastern United States. Climate scientists from the Harvard School of Engineering and Applied Sciences (SEAS) found that particulate pollution, particularly from coal fired power stations, caused a global warming hole, or a large cold patch reducing temperatures by up to 1 degree C in the region, particularly lowering maximum temperatures in Summer and Autumn.

[Hawkins, Dave]

The largest insight I draw from this paper is the reminder that there are fairly large-scale activities going on right now that might provide useful information regarding SRM if we had systems set up to monitor resulting changes. 

This paper documents one of them – the large reversal of sulfate loadings in the eastern half of the US, mostly occurring since the 1990 Clean Air Act was passed.  And those reductions will continue.  Rules promulgated by EPA in the

last six months will required millions of tons more of SO2 and NOx reductions over the next 3-5 years.

It would be nice to do a rapid assessment of what additional instrumentation might produce even more useful information, relevant to the many unanswered questions  about SRM.  To be sure, most of these reductions are

occurring in the troposphere and so may not be directly applicable to SRM in the stratosphere.  Still, I imagine there could be useful information to be gathered.  It might be much easier to get governments to devote some

money to such an enhanced measurement effort than to try to stand up some new “geoengineering program.”

--
You received this message because you are subscribed to the Google Groups "geoengineering" group.
To post to this group, send email to geoengi...@googlegroups.com.
To unsubscribe from this group, send email to geoengineerin...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.

[Nathan Currier]

Hi, David -

I fully agree with that, and actually used that same MIT paper in something
I wrote up for the group AMEG recently. In fact, if you look at table 3.3 in this - 

http://www.findthatfile.com/search-19564999-hPDF/download-documents-4876_powerplant_airemission_en.pdf.htm

you'll also see that of the top 10 highest SO2-producing
power plants in the US - and these are the only US plants that put out
over 100,000 mt SO2/yr each (and their inputs get smaller pretty quickly as
the sizes decrease) -  7 of the 10 are just in Penn & OH alone.
On the "dot map" of US SO2 emissions in the attached, these two states are
almost invisible, being swallowed up by a big dot for all the SO2 there.
I don't have a figure for the average loading of the two states, but it
could be roughly ascertained pretty easily by EPA's SO2 trends map.

Anyhow, just a study of the SO2 in these two states, Penn and Ohio, would
be the most helpful, and in fact possibly even more useful *because* it's
in the troposphere, I feel. But it needs to be done very soon, as the new 

CAIR program rules are apparently going to reduce all of this a good deal 

more in the next 3-4 yrs, I believe.

All best,

Nathan

To post to this group, send email to geoengineering@googlegroups.com.
To unsubscribe from this group, send email to geoengineering+unsubscribe@googlegroups.com.

[Hawkins, Dave]

Nathan,

The CEC report you link to was useful but is now dated.  Much more current information on SO2 emissions (up to and including 4^th quarter 2011 for the power sector) is available thanks to the 1990 Clean Air Act, which required SO2 continuous emission monitors on all coal power plants in the 48 contiguous states of the US.

A handy spreadsheet of national SO2 emission trends from 1980 to 2010 can be found here:

http://www.epa.gov/airmarkets/progress/ARPCAIR_downloads/CAIR_ARP_2010_data_1.xls

This spreadsheet also includes data disaggregated by state and by month.

Other pages at the airmarkets link above will get you access to hourly emissions and operational data from all significant US coal power plants.  (FWIW, getting the rules in place to require these data to be reported at all, much less to be reported electronically and accessible to anyone, required quite a lot of persistent advocacy.)

The national SO2 trends are informative as to the scale of the reductions from more than 17 million tons of SO2 from the power sector in 1980 to about 5.2 million tons in 2010.  The combination of EPA’s new transport rule and toxics rule will cut the load further to about 2 million tons in the 2015-2016 time frame.  http://www.epa.gov/ttn/ecas/regdata/RIAs/matsriafinal.pdf, Table 3-4.

But the additional instrumentation I was referring to in  my email was not emission monitoring data (as the above information indicates, we now have that pretty well in place in the US for the power sector).  Rather, I am thinking of high resolution data of the characteristics of the atmosphere that might change as these additional emission reduction occur.  I don’t know enough to have anything in particular in mind but I imagine there are some on this list who could identify the data sets they would like to have to fully characterize the forcing and other aspects of the changes brought about by the large SO2 reductions from 1980 to date and from the large additional percentage reductions that will occur over the next 3-5 years.  For example, how linear or nonlinear are the forcing responses to a given tonnage reduction in fine particle precursors or a given ppm change in fine particle concentrations.  My hunch is that the localized impacts will differ depending on the baseline atmospheric conditions on which the emission changes are imposed.  Knowing more about that might be nice to help improve modeling estimates of the local/regional impacts of SRM experiments.

David

To post to this group, send email to geoengi...@googlegroups.com.
To unsubscribe from this group, send email to geoengineerin...@googlegroups.com.

For more options, visit this group at

http://groups.google.com/group/geoengineering?hl=en.

--

You received this message because you are subscribed to the Google Groups "geoengineering" group.

To view this discussion on the web visit https://groups.google.com/d/msg/geoengineering/-/PRIGiFXTufkJ.
To post to this group, send email to geoengi...@googlegroups.com.
To unsubscribe from this group, send email to geoengineerin...@googlegroups.com.

[David Keith]

Folks

 

I am not getting this, and yet I am close to it. My office is down the hall from the GEOS-Chem group that produced these papers. We collaborate in that Debra Weisenstein works with me and with that group is doing  modeling for geoengineering and looking into improvements to the GEOS-Chem stratospheric chemistry.

 

1. Can someone tell me exactly what would be tested here? Climate response? Aerosol radiative forcing?

 

2. Is there a sensible reason why you one would prefer troposphere SO2 for geoengineering if one wanted to do it? Recall that trop SO2 now is linked to about 1 million air pollution deaths per year globally as well as acid rain etc.

 

3. The idea that cutting tropospheric SO2 pollution is a form of geoengineering would seem to me to extend the definition of geoengineering to mean, in effect, “any human action that may alter the climate”. I doubt this definition will help clarify debate.

 

Yours,

On 4/28/12 10:06 AM, "David Hawkins" <

MailScanner has detected a possible fraud attempt from "dhaw...@nrdc.org" claiming to be dhaw...@nrdc.org> wrote:

[Hawkins, Dave]

Hi David,

My thoughts on your points:

 

On 1.  I am wondering more about the opportunity to do measuring of phenomena than testing.  Others will have to say which phenomena would be the most interesting to observe and whether current instrumentation is adequate.  But I assume that more detailed observations on the fine points aerosol forcing and second+ order effects would be the most likely targets.

 

On 2.  I sure hope no one is thinking of tropospheric SO2 injection for the reason you mention.

 

On 3. My initial comment about fine particle pollution reduction being inadvertent geoengineering was most tongue in cheek.  But there is an underlying question that I am interested in getting expert views on: can we learn anything useful about forcing and second+ order effects by gathering data on changes to the atmosphere in a region like the eastern US that are associated with these recent and projected changes in particle loadings?  If so and there are gaps in instrumentation, it would be a good idea to come up with a proposal for such instrumentation improvements.

David

[Mike MacCracken]

Hi David H and David K—For purposes of debate, I’ll venture an alternative viewpoint on point 2.

The approach, however, would not be to inject the SO2 as it is now injected nor where it is injected, but to do it in a way that would greatly reduce the adverse impacts while getting much more benefit from the emissions.

1. The key problem with current SO2 emissions comes from their location and link to coal-fired power plants. If both links can be broken, then it seems to me there are some possibilities.
2. Putting the SO2 out from power plants puts the emissions mostly where people are (so health effects—some suggest probably more from the other pollutants that come out along with the SO2, which may be more a proxy than the culprit). In any case what one would want to do is to have emissions where can have maximum effect on solar radiation, and this would be at low latitudes where sun is at maximum and over the oceans so one has a dark surface below for maximum albedo contrast. One would also want the emissions put up into the free troposphere to lengthen their lifetime, and not at surface where people are (at those altitudes, use the sea salt approach of Salter and Latham).
3. Power plants also put out SO2 when there is need for electricity—ideally, one would put the SO2 out when weather and chemistry is favorable for extended lifetime (so could use a few fixed locations for injection and let winds carry the SO2/sulfate over broader areas). Emissions need not be steady in time as we are aiming at cumulative effect.
4. So, I would suggest that having lower loadings over larger areas such as the remote (and largely unpopulated) areas of the low albedo Indian and Pacific Oceans (and above the boundary layer so not generally exposing people) could allow much more effect for a given emissions amount than the present SO2 emissions that are concentrated where people are and where sun angle is low for much of the year.
5. Yes, there could still be impacts when sulfate got carried over land areas and deposited. But main deposition impacts on ecological systems was when accumulated on snow during winters (low light periods that really serve little purpose for SRM) and when got deposition in dew (again, not something that would be likely with proposed strategy above). And do note that in some areas farmers add sulfur to the soils, so sulfur deposition is not a problem everywhere. In any case, the concentration would be lower as would be much more spread out. And, it could be that one could go to another material than SO2 if impacts were large—or go to sea salt.
6. As to comparisons with other approaches:
   
   1. Cloud brightening would require a good bit more effort for injection as CCN lifetime is pretty short, but then effect on cloud albedo is likely more significant than having aerosols above the boundary layer. For free troposphere injection, would likely get a bit greater clear sky effect. Yes, an impact is reduced visibility—but how does that compare to other benefits?
   2. Compared to stratospheric SRM, this would not have problem of turning direct to diffuse radiation over all land areas, so not affecting direct solar technologies, would not have the stratospheric ozone depletion problem, could more quickly be terminated in event of major volcanic eruption, and would not require the effort of stratospheric injection as might be able to do from some elevated hills, etc.--or at least much lower altitude balloon held pipes.
   3. I would also suggest that tropospheric sulfate would allow a more targeted effect than possible with stratospheric sulfate and does not require ocean access, so might be useful for regionally focused types of interventions, such as to limit Arctic warming.
      
7. Thus, I would not rule it out so fast. It seems to me, given that reducing emissions from coal-fired power plants and for air pollution clean-up, that the cooling offset of existing SO2 emissions is going to go down, and the question is how best to offset this plus the continuing rise in the CO2 concentration even despite mitigation and adaptation. It seems to me that governance issues might be easier with tropospheric rather than stratospheric emissions, largely due to familiarity (as David Hawkins other points suggest, there is a lot of learning possible from what has been done to date and what is going on). Even though the amount of the emissions needs to be higher than for the stratosphere due to shorter lifetime, the amounts are likely still less than what world has been putting out, and the design of effort would greatly reduce adverse impacts. So, what is needed in my view is a comprehensive relative risk and cost evaluation—cavalierly dismissing the possibility seems to me premature.
   

Mike

http://www.epa.gov/airmarkets/progress/ARPCAIR_downloads/CAIR_ARP_2010_data_1.xls <http://www.epa.gov/airmarkets/progress/ARPCAIR_downloads/CAIR_ARP_2010_data_1.xls>

On 4/28/12 10:06 AM, "David Hawkins" <

MailScanner has detected a possible fraud attempt from "dhaw...@nrdc.org" claiming to be dhaw...@nrdc.org <http://dhaw...@nrdc.org> > wrote:

Climatic effects of 1950–2050 changes in US anthropogenic aerosols – Part 2: Climate response

http://www.atmos-chem-phys.net/12/3349/2012/acp-12-3349-2012.pdf <http://www.atmos-chem-phys.net/12/3349/2012/acp-12-3349-2012.pdf>

Reduction in air pollution from coal fired power stations due to environmental regulations since the 1980s has increased regional global warming in the Central and Eastern United States. Climate scientists from the Harvard School of Engineering and Applied Sciences (SEAS) found that particulate pollution, particularly from coal fired power stations, caused a global warming hole, or a large cold patch reducing temperatures by up to 1 degree C in the region, particularly lowering maximum temperatures in Summer and Autumn.

Since I have spent a good deal of the past several decades advocating for rapid deployment of particle reducing techniques, I guess I can be tagged as an inadvertent geoengineer.
:>)

Sent from my iPad

--
You received this message because you are subscribed to the Google Groups "geoengineering" group.
To post to this group, send email to geoengi...@googlegroups.com.

To unsubscribe from this group, send email to geoengineerin...@googlegroups.com <mailto:geoengineering%2Bunsu...@googlegroups.com> .

For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.

[Hawkins, Dave]

Mike,

We have evidence of long-distance transport of sulfur-laden plumes (see, eg, http://www.atmos-chem-phys.net/9/4729/2009/acp-9-4729-2009.pdf).  What confidence do we have that sulfur injection at a scale that achieves meaningful reductions in forcing will not reach populated areas?

David

[Mike MacCracken]

Hi David—I would suggest that the attached paper might be interpreted to give support to the idea that the approach might well work. The plume described in the paper you attached came from a pretty concentrated source region so the concentrations were high and the proposal for tropospheric sulfate engineering would have emissions much more dispersed. What is interesting in the paper is that the plume stays aloft and the paper (at least the abstract) does not indicate any impact on human activity except a mid-tropospheric reduction in visibility. And the lifetime is pretty long, again indicating that the amount injected can be relatively limited compared to surface injections.

All approaches are going to require some trade-offs, and it seems to me mid-level visibility might well be worth the benefits of limiting warming. That is just the type of comprehensive evaluation that needs to be done.

Mike

[RAU greg]

"Richard S. Lindzen, a professor of meteorology at the Massachusetts Institute of Technology, is the leading proponent of the view that clouds will save the day. His stature in the field — he has been making seminal contributions to climate science since the 1960s — has amplified his influence.

"Dr. Lindzen says the earth is not especially sensitive to greenhouse gases because clouds will react to counter them, and he believes he has identified a specific mechanism. On a warming planet, he says, less coverage by high clouds in the tropics will allow more heat to escape to space, countering the temperature increase."

more here:

http://www.nytimes.com/2012/05/01/science/earth/clouds-effect-on-climate-change-is-last-bastion-for-dissenters.html?emc=tnt&tntemail0=y

[Ken Caldeira]

Also, much is made of teleconnections and the idea that you cannot affect one area without having effects of comparable magnitude elsewhere.  I think this sort of study provides (perhaps weak) evidence that teleconnections are likely to be much smaller in magnitude than the proximate regional effect.

This could be relevant to regional application of the Latham could-whitening proposal.

[Mike MacCracken]

A couple of comments (also see http://www.climatesciencewatch.org/2007/05/12/maccracken-on-lindzen’s-misleading-newsweek-op-ed/):

If the climate sensitivity is as low as Lindzen suggests, it becomes virtually impossible to explain how the Cretaceous could be about 6 C warmer than at present and how the peak glacial period could be 6 C colder than present. Basically, Lindzen argues that warming leads to less water vapor and cirrus in the upper troposphere, so with the Cretaceous, there must be none there at all, and for the glacial, it must be very wet there—but then one cannot get the temperature change. Lindzen once responded in the past to this critique that the climate sensitivity is low for relatively smooth changes in forcings (i.e., GHGs) and much higher for forcings with strong horizontal gradients. If this is the case, then the sulfate aerosol forcing that is very regional should be causing a very large (presumably) cooling influence that would seem likely to overwhelm the warming influence of GHGs. But we don’t see this. A critical issue for both the GHG and climate engineering analyses is whether the climate sensitivity really varies a lot or a little between forcings; where there do appear to be some differences is between forcings that affect the IR balance of the convectively coupled troposphere and those like black carbon that absorb solar radiation aloft .

The analysis Lindzen did to come to his conclusion was, as I understand it, mainly to look at satellite data for vertical columns, especially out over the Pacific Ocean. What the analysis neglects are the effects of the region’s circulation patterns, such as the monsoon. The analysis seems to basically assume that the cloud-radiation vertical profiles for a given surface temperature will be the profiles as the whole region warms and the locations of the particular temperatures with respect to land-ocean circulations change. It really seems implausible to me.

As far as I know, neither he nor anyone else has been able (over the dozen or so years he has held this position) to put together a global model with a parameterization that gives the result he suggests. In my view, if reporters are going to write stories about his results, they need to be asking him much tougher questions about his claims and not let him get out of facing up to the tough questions. Opting to present one view versus another (even quoting more than one mainline scientist is not enough) is really a cop out.

Mike MacCracken

[Nathan Currier]

I had written this yesterday, but accidentally sent it just to David Keith and not the group..... 

Thanks much. First, in terms of your 3. below, that was from Dave, and not me, so he could take that up further, perhaps.....

In terms of 2., I'm not sure what Dave meant there either, but I could imagine wanting to look

into relations between current aerosol localized radiative forcing in Ohio, say, the current ground level 

SO2 readings there, and then current health statistics there, too, to see, for example, whether the 1 million figure

you cite - which is of course concerning to everyone who cares about the common good - is necessarily relevant, 

given the amount of SO2 that would be needed to get a useful localized -RF effect if emitted at some level of the troposphere

(obviously not in Ohio, however! - quite the contrary, this would be intended for largely unpopulated strategic regions).

In terms of 2. -  which I think is really the most interesting part of this - it seems to me that, 

while it might not in the end work all that well, the idea of a super-pinpointed project to cool the region

with most of the methane hotspots around the Siberian shelf, if their emissions should increase a lot, 

is something that should really be explored. Even if a large emergency non-CO2 program for emissions 

reductions of BC/CH4 were undertaken to grapple with a situation like that (i.e. a great expansion of the 

program the US state Dept recently started, or the GMF, etc), it would probably take at least a few years 

to start showing much effect, so something to locally effect the region in the meantime could be hugely helpful, 

if Gt-scale releases started to take place. Most of the methane hotspots are currently focused within a ~50,000 

sq mile area of the shelf around Tiksi.  

It seems to me that sensible reasons behind this line of thinking include: that tropospheric injections could be 

pinpointed to a specific region much more than stratospheric injections ever could; because the region is small and the 

total injections would consequently be so small (probably less than 1 large US coal plant to achieve ~-5F for the region) , 

the side effects of doing this might in the end turn out to be far less, rather than greater, than using the stratosphere (i.e., 

no global scale perturbation of hydrological cycles, etc.); it demands little new technological development, and would have 

fewer possible surprises, since we have 200 years of experience doing it already; as Mike MacCracken has noted, such a 

program could take advantage of the shorter aerosol lifetime at lower altitudes, to adjust and stop emissions rapidly where any 

harm was being caused; it would not be an expensive program, possibly costing as little as $15 million per year; its governance 

would not be a large multinational issue, since it would be entirely on Russian territorial waters or soil (and the SO2 pollution that 

has been wafting into neighbors like Norway from Russian companies like Norisk Nickel has been far, far greater than this could 

ever be); it should potentially be a legal entity to have it as a corporation (a non-profit) sited in Russia, and the state fees imposed 

through Russian air quality regulations for the SO2 in those quantities would total perhaps only some $50,000/yr. 

The idea, in my thinking, would be to minimize the "geoengineering footprint" and to depend upon emissions reductions as much as 

possible, and while I think it might be counterintuitive that using the troposphere could help with this, I actually think it might, if one 

considers certain locales as having great global strategic importance, like the ESAS and its carbon stores. 

All best,

Nathan