It seems that CFC's may have have been falsely convicted of ozone depletion. I hope everyone will follow the science. Hasty conclusions seem to be the origin of the mistake; let's try to do better this time. CFC Bans Did Nothing To Interrupt The Ongoing Trend Of Antarctic Ozone Losses By Kenneth Richard on 25. March 2024 There has been a “continued, significant ozone reduction since 2004, amounting to 26% loss in the core of the ozone hole” (Kessenich et al., 2023). It is not at all evident that the 1987 Montreal Protocol bans on presumed ozone-depleting substances (ODS) like chlorofluorocarbons (CFCs) materially affected the flat to negative trajectory of stratospheric ozone over Antarctica. Massive Antarctic ozone holes – the largest on record in 45+ years of tracking – have been ongoing in the 21st century. In fact, “five of the past eight years overall have exhibited record ozone holes,” with a negative trend resulting in a “26% loss in the core of the ozone hole” from 2004-2022 (Kessenich et al., 2023). Because the presumed effect of the ODS bans have not been realized in the last 35 years, the scientists who still believe humans are responsible for ozone losses (i.e., 2022 Scientific Assessment of Ozone Depletion) are now saying the ozone recovery from ODS damages “should be on track” to being realized by 2065 – over 40 years from now. This estimate is quite convenient, as most of the scientists formulating these predictions will be dead. Image Source: Kessenich et al., 2023 Another new study (Jonas, 2024) points out that ozone holes were observed in the 1960s too. This is well before 1979, the conveniently-chosen “start” year for ozone hole formation. Also, the data appear to show “the annual ozone minimum at the South Pole is related to lower stratospheric temperature independently of chlorofluorocarbons and nitrous oxide.” Image Source: Jonas, 2024
But... but.... but... you're missing the point. Demand planning by government prodded by lobbying for specific future economic outcomes is the key principle here..... LOL Good post Btw>
Meh I don't know. The use of CFCs didn't officially hit "zero" until about 2010. Quite a bit still in 2005, officially. The hole in the ozone layer is slowly shrinking | World Economic Forum (weforum.org) But actually, CFC production never went to zero, or even especially low. Ozone-depleting chemicals may spend less time in the atmosphere than previously thought | MIT News | Massachusetts Institute of Technology And even the revised estimates of their lifetimes is pretty long: "After including these chemistry-climate modeled lifetimes into a Bayesian simulation model of production and emissions, the team was able to reduce the uncertainty in their lifetime estimates. They calculated the lifetimes for CFC-11, 12, and 113 to be 49 years, 85 years, and 80 years, respectively, compared with current best values of 52, 100, and 85 years." Bottom line is that yes, this science is difficult to pin down, but recent ozone values do not actually poke holes in the idea of CFCs as the culprit... because CFCs are still being produced in large quantities despite the ban. Further, looking at your graph, there is clearly a major shift down in the 1980s of the ozone layer. This corresponds to increased CFC use at the time. There was a prior peak in the 1970s in use, but given these things hang out in the atmosphere for at least decades, it's unsurprising that it had accumulated by the 1980s.
That is what I remember. After we all switched CFCs out of our refers, etc., and after waiting, the ozone hole did start mending. Regardless of exact amounts and dates, this has to be looked at as a significant positive. It showed the world CAN come together to improve our environment on something requiring broad cooperation and that was not totally free.
Usual blog hocum... From the actual article: The link we identify between the mid-spring ozone hole evolution and the timing/depth of mesospheric air arrival into the polar vortex sheds light on the potential drivers behind the recent large ozone holes. This mechanism is of dynamical origin and could be operating independently from the volcanic and wildfire effects implicated in the heightened ODS-induced ozone loss during the early springs of recent years1,16,19,25. More study is warranted to determine the precursors for the changes we identify in mesospheric descent and better understand the extent to which these effects will impact polar ozone in our changing climate.
The data are the data, and the relevant papers are linked. Don't you think the language "the potential drivers behind the recent large ozone holes" implicitly undermines the CFC hypothesis?
I misread your post. I think it suggests a number of potential drivers. I don't truly understand the science, but there appear to be multiple drivers.
