Thank you Rebecca et al. I agree. Not surprisingly, the UNEP is not going to break ranks with conventional wisdom on this issue. From a quick skim, a couple of "glimmers of progress" might be their support for a "risk risk" evaluation, and for small scale research. Interestingly the Montreal Protocol report is cited as a supportive backup source in the interview but that report focused on a spring injection of SAI in Antarctica (where the Ozone hole is largest) and found mixed results. After 20 years of SAI loss of ozone in Antarctica in October close to 1990's loss, but less loss if SAI is started later, and for larger applications enhancement of Ozone in NH midlatitudes:
*Additional ozone depletion due to SAI is simulated in* *spring over Antarctica, with magnitudes dependent onthe injection rate and timing. Simulations of strong SAIshow an increase in total column ozone (TCO) in mid-lat-itudes (40–60°N) in the winter Northern Hemisphere.º For October over Antarctica, SAI simulations that achievea global mean surface cooling of 0.5 °C in the first 20years, show a reduction of TCO of around 58 ± 20 DU,assuming 2020–2040 halogen conditions. This reduc-tion brings TCO values close to the observed minimum inthe 1990s. Less ozone loss would be expected for a laterSAI start date, when halogen concentrations are project-ed to be lower.º Beyond the first 20 years, the continued application ofstrong SAI, to offset almost 5 °C of warming by 2100, re-duces Antarctic ozone in October * *by similar amounts (55± 20 DU) throughout the 21st century despite decliningabundances of ozone-depleting substances (ODS). Inthis case, ozone hole recovery from ODSs is delayed bybetween 25 and 50 years. A peakshaving scenario po-tentially leads to less ozone depletion.º Under stronger SAI scenarios, ozone is significantlyenhanced in NH mid-latitudes in winter owing to strato-* *spheric heating from injected sulfur, which leads to in* *-creased equator to poleward transport of ozone.º Ozone loss within the Arctic polar vortex has not yetbeen robustly quantified for SAI.* Best, Ron On Wed, Mar 15, 2023 at 3:42 PM Rebecca personal em <[email protected]> wrote: > Good afternoon to you in Chicago Ron, > > Thank you for sending, it’s hard to keep up with all the reports and > actions people are taking. > > Herb did send a link for this report, but it’s worth drawing it to > everyone’s attention again. > > Unfortunately, it buys right into the net zero story, at least from the > executive summary, excerpt below. Perhaps it is part of a strategic > picture/plan that we’re not seeing, and also any news is good news? > > https://wedocs.unep.org/handle/20.500.11822/41903 > Quote from Ms Inger Andersen, ED UNEP > [image: image.png] > > Best regards to all , > Rebecca > > On 16 Mar 2023, at 7:25 am, Ron Baiman <[email protected]> wrote: > > > Dear Colleagues, > > Apologies if this has already been posted: > > > https://www.unep.org/news-and-stories/story/new-report-explores-issues-around-solar-radiation-modification > > I did a quick search and didn't find anything in my inbox. In any case, > it seems important enough to resend just in case! > > Best, > Ron > > -- > You received this message because you are subscribed to the Google Groups > "NOAC Meetings" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/noac-meetings/CAPhUB9CVY7Y_%2BdYAbH5SEqSqoRWbJsTUvcJ3fTHivvkp6%2BZxkQ%40mail.gmail.com > <https://groups.google.com/d/msgid/noac-meetings/CAPhUB9CVY7Y_%2BdYAbH5SEqSqoRWbJsTUvcJ3fTHivvkp6%2BZxkQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAPhUB9DbvoMUpq4vXXYawayVO7VPN441MbwMZ02813Ja5stmqw%40mail.gmail.com.
