For those interested in the equivalence of different forcing agents, the following Kravitz et al paper may be of interest.
http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00663.1 I've bcc Ben, in the hope that he may be able to explain in more depth how his methodology could be applied - to establish the equivalence between a certain mass of sulphur and a tonne CO2 A On 26 August 2015 at 01:15, Maggie Zhou <[email protected]> wrote: > I just want to emphasize the distinction, that "incentive" does not equal > "carbon credit". I have no objection per se to using incentives as a > possible policy tool to encourage increasing albedo of the built environment > - if there is strong evidence for benefit and little potential harm > (environmental toxicity of paint material?), but "carbon credits" have a > very specific meaning, and consequence: In a mandatory carbon market, using > SRM to create carbon credits enables more carbon emissions beyond what was > set under the "cap" of a cap-and-trade scheme (a very ineffective scheme in > itself that benefits Wall Street, not much the climate). > > Similarly, it's one thing to use a permit system to reduce black carbon > emissions (which is great), quite another to "create a market for credits > from such projects". I wish that scientists involved in these research and > implementation projects can get over the idea that somehow everything needs > to work through a market - please realize that it's really only the Wall > Street who benefits from and are intensely interested in commodifying > everything, creating a market for everything, and they don't have the best > interest of the planet in mind. > > > Maggie Zhou, PhD > https://www.facebook.com/maggie.zhou.543 > > > > > On Sunday, August 23, 2015 4:09 PM, Mike MacCracken <[email protected]> > wrote: > > > Actually, working input from an advisory committee organized by V. > Ramanathan and on which I served, the Gold Standard Foundation (which > certifies projects) has promulgated a new standard for BC, etc. from > cookstoves (basically, what one would need to do to be a certified project) > and it uses the GWP-20 for BC and other species. There is also an effort > underway trying to figure out how best to create a market for credits from > such projects (and possibly other short-lived species projects). That > limiting short-lived species has so many co-benefits (indeed, health effects > may be the main reason for cutting BC and climate change is a co-benefit of > that), so it may be that if some countries use a permit system type approach > to improve air quality, it might well be that a market could be developed. > > Also, the new lifecycle assessment approach being developed for ANSI > consideration also is set up for using GWPs with shorter time durations > other than 100 years, basically set for the time period from emission to > some fixed date (so, say 2050—one just integrates the same equations out > over the period of interest)--so what one gets out are relative > contributions out to the time. This choice does mean that effects of these > species after that time don’t count in the rankings, and so is best used for > considering how to get a response in the near-term. For the long-term, CO2 > overwhelms everything else, so to limit long-term change the focus has to be > to cut CO2 emissions (something well-know and the roles of other species > just aren’t all that important). > > I’d also note that to be complete, all forcings need to be accounted for, > so, for example, tropospheric sulfate is included as a cooling influence in > the ANSI draft, and so cutting its emissions as coal use is cut does count > as a warming influence (if one accounts only for the Kyoto basket of > long-lived GHGs, that is just not an adequate approximation to how models > would respond to the change—remember that GWPs are only approximations of > what is done by models, models don’t use GWPs). So, conceptually, it would > be possible to include SRM in the set of forcings, but one also has to > consider another change in this new type of analysis, and that is not to be > looking at results for a unit emission in just one year, but to be looking > at operations out over time, so one focuses on what is causing what change, > etc. So, one would not look at some unit SRM for one year, but at the > relative influence of a planned implementation of SRM over some time period. > I’d also note that what matters about SRM is more than the temperature > response (e.g., changes in precipitation patterns), so just treating its > temperature aspects would be pretty limited [again, remember, all this GWP > formalism is merely a way to approximate what full model simulations would > provide as a result—and for an intervention scenario, I would think one > would really want to get beyond just an approximation of the temperature > response]. > > So, there is movement on all of this, but ... > > Mike MacCracken > > > On 8/21/15, 10:43 AM, "Geoengineering" <[email protected]> > wrote: > > I agree with David and Olivier. Let's also remember that black carbon etc > are not part of carbon credit schemes exactly because they're not GHGs, even > though they have effect on global warming, and there are scientifically > valid reasons for calculating some kind of equivalence like GWP for some > purposes, awarding SRM with carbon credit is completely wrong. > > As to the possible, if temporary, negative feedback on terrestrial carbon > emission from SRM, since fossil fuel carbon emissions and required carbon > credits are never computed with consideration of their subsequent positive > feedback on the earth system in terms of warming and further emissions, any > secondary effect of SRM, even if real and long lasting, could not come into > carbon credit computation either. > > > Maggie Zhou, PhD > https://www.facebook.com/maggie.zhou.543 > > > > > > > > On Friday, August 21, 2015 9:39 AM, David Morrow <[email protected]> > wrote: > > > > > Andrew, > > I take it that you're thinking about the recent research showing that SRM > could actually reduce the amount of CO2 in the atmosphere by reducing the > amount of carbon released from (or not absorbed by) terrestrial sinks. (At > least, I think that's the mechanism people find in the simulations -- if > not, someone please correct me!). > > I agree with Olivier that there's no straightforward answer to the question > about how much carbon a "unit" of SRM removes/keeps out of the atmosphere, > both for the reason Olivier cited and because I take it the magnitude of the > carbon reduction depends on background conditions (e.g., atmospheric > concentrations and temperatures), which would evolve over time -- especially > at the time scales needed to say that SRM has actually prevented carbon > release, rather than delaying it. > > I also agree with Maggie that this isn't just a physics/earth science > question. A carbon credit is a social creation. SRM isn't worth any carbon > credits unless the relevant decision-making bodies say it is. And I think it > would be a very bad idea for them to say so. > > So, in short, I'd say the answer to your question is: Currently, SRM is not > worth any carbon credits; and it should stay that way, regardless of SRM's > effects on atmospheric carbon concentrations. > > David > > > On Thursday, August 20, 2015 at 7:47:40 PM UTC-4, Maggie Zhou wrote: > > Hi Andrew, > > Firstly, there is no sound answer to the question posed in terms of physics > /earth science, exactly because SRM is not a true substitute of removing > carbon, it does not confer the same effect in terms of duration of effect, > and effect on many other aspects of the earth system other than the > reduction of heat while the aerosol is in the air. So it is scientifically > flawed to ignore all of that, in order to render a carbon credit equivalent > so as to be able to monitize SRM, just like everything else is driven to be > monitized under the insane capitalist system. > > Secondly, in a non-voluntary system that requires carbon credits in order to > emit GHGs, SRM generated credits will simply add to the annual emissions > cap, which is what I pointed out in my last email. In a voluntary system > where people/corporations simply purchase carbon credits to feel better or > use as a PR tool, SRM generated credits allow them to justify their > emissions which they otherwise would be under greater pressure to reduce, > and for those emissions outside of their direct control, SRM generated > credits won't help reduce anyway. In fact they would feel even less > responsible to change agricultural emissions (advocating for better agri > practices, etc), or what their government is doing in their name. > > It's amusing, if not also sad, that you considered what I discussed in the > last email as from a "political angle", i.e., not "science proper". I'd > suggest that what I discussed there is simply science as applied to the > physical reality of this earth, not some abstract concept that draws an > artificial equivalence of SRM = C removal. > > Peace. > > > Maggie Zhou, PhD > https://www.facebook.com/ maggie.zhou.543 > <https://www.facebook.com/maggie.zhou.543> > > > > > > > > On Thursday, August 20, 2015 7:00 PM, Andrew Lockley > <[email protected]> wrote: > > > > > Maggie (and list), > Thanks for your response. However, there are a couple of problems with the > stance you take. > Firstly, I'm simply looking to answer a physics / earth science question. > The answer will be true whether we want it to be, or not. The world deals > with many other distasteful comparisons, such as how much is a life worth in > cost-benefit analyses. > Secondly, even if we engage with the political angle you discuss, your logic > doesn't necessarily bear scrutiny. People may choose to offset only the > components of their emissions they have no control over, eg agriculture, > government sector, etc. I'd suggest that those buying carbon credits are > probably more prone to taking mitigation action than demographically matched > controls. > I'd welcome further dialogue. > Thanks > Andrew Lockley > On 20 Aug 2015 23:49, "Maggie Zhou" <[email protected]> wrote: > > "How many carbon credits is a tonne of SRM worth?" > > Seriously? This is precisely what geoengineering proponents promised that > it won't be used for - as a substitute in any way, shape or form to carbon > emission mitigation. To get acceptance for the idea of even funding > research into SRM or other geoengineering schemes in response to global > warming, the repeated promise was that it is not meant to replace emission > reductions, only a backup to buy us some time... > > Using SRM to generate carbon credits is EXACTLY to generate EXTRA carbon > emissions allowances - even though all SRM could do, at best, is masking the > true impact of the current GHG levels on warming while the spraying is > ongoing, without ever removing a single atom of carbon from the atmosphere > for which it's to claim carbon credit. In short, SRM will lead to even MORE > emissions, not less, and due to the masking and the lack of public awareness > that it's the masking that's keeping the temperatures from shooting up even > higher even quicker, it just helps keeping business-as-usual longer, on top > of ocean acidification, acid rain, potential disruption of regional climate > patterns, etc etc. > > > > Maggie Zhou, PhD > https://www.facebook.com/ maggie.zhou.543 > <https://www.facebook.com/maggie.zhou.543> > > > > > > > > On Thursday, August 20, 2015 4:15 AM, Andrew Lockley > <[email protected]> wrote: > > > > > How many carbon credits is a tonne of SRM worth? > We could work this out as watts cooling or weight sulphur for weight carbon. > Doesn't really matter. > Thanks > Andrew > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/d/optout. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
