![Ozone Layer Depletion](https://cdn.slatesource.com/a/9/7/a97b8f18-082a-4251-a437-1a8577c52d0c.webp) # Ozone Layer Depletion - [Made in Slatesource](https://slatesource.com/@steph/ozone-layer-depletion) - By [Steph](https://slatesource.com/@steph) - Created on Aug 8, 2026 ## OzoneOzone LayerLayer DepletionDepletion This is the oneone globalglobal airair pollutionpollution problemproblem the worldworld has clearlyclearly turnedturned aroundaround. ScientistsScientists predictedpredicted it in 19741974. GroundGround stationsstations provedproved it in 19851985. CountriesCountries agreedagreed to fixfix it in 19871987. It is nownow healinghealing. This slateslate coverscovers how that happenedhappened, and the newnew problemsproblems the fixfix createdcreated on the wayway. [ozone.unep.org](https://ozone.unep.org/?utm_source=slatesource) ## StatusStatus mostlymostly solvedsolved. RecoveryRecovery is nownow measuredmeasured, not just predictedpredicted. But the finishfinish lineline is stillstill about 40 yearsyears awayaway, and severalseveral harmfulharmful gasesgases are stillstill not controlledcontrolled. NOW About 99% of the controlled ozone-damaging chemicals have been phased out. \[8\] Updated Aug 2026 **2066** Antarctic Return to 1980 Levels [8] [ozone.unep.org](https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022-Executive-Summary.pdf?utm_source=slatesource) ## The ProblemProblem CFCsCFCs were cheapcheap, safesafe to handlehandle, and usedused everywhereeverywhere in fridgesfridges, foamfoam and sprayspray canscans. That was the troubletrouble. They do not breakbreak downdown at groundground levellevel, so they lastlast 40 to 150150 yearsyears and floatfloat up to the stratospherestratosphere, where sunlightsunlight splitssplits them and releasesreleases chlorinechlorine that destroysdestroys ozoneozone. \[1\] OneOne chlorinechlorine atomatom destroysdestroys manymany ozoneozone moleculesmolecules beforebefore it is removedremoved, so smallsmall leaksleaks causedcaused bigbig losseslosses. The ozoneozone layerlayer blocksblocks the ultravioletultraviolet lightlight that causescauses skinskin cancercancer, cataractscataracts and weakenedweakened immuneimmune systemssystems, and that harmsharms cropscrops and oceanocean planktonplankton. At its worstworst the holehole over AntarcticaAntarctica coveredcovered 29.9 millionmillion squaresquare kilometreskilometres, whichwhich is biggerbigger than NorthNorth AmericaAmerica. \[21\] If nothingnothing had been donedone, modelsmodels saysay about twotwo thirdsthirds of the world'sworld's ozoneozone wouldwould have been gonegone by 20652065, and you couldcould have burnedburned your skinskin in fivefive minutesminutes. \[20\] [nature.com](https://www.nature.com/articles/249810a0?utm_source=slatesource) ## KeyKey NumbersNumbers The figuresfigures this slateslate restsrests on. EachEach has a valuevalue, a unitunit, a yearyear and a sourcesource. CorrectingCorrecting oneone of these is the smallestsmallest and mostmost welcomewelcome contributioncontribution you can makemake. How long CFCs last, 1974 \[1\] 40-150 yr Largest hole on record, 2000 \[21\] 29.9 M km2 Countries signed at the start, 1987 \[4\] 46 Controlled chemicals phased out, 2022 \[8\] 99% World return to 1980 levels, 2022 \[8\] 2040 Antarctic return to 1980 levels, 2022 \[8\] 2066 CFC-11 emissions drop, 2018 to 2019 \[13\] 26% Warming avoided by Kigali \[9\] 0.5 C Delay caused by feedstock leaks \[17\] 7 yr UV rise in a world with no treaty, by 2065 \[20\] 650% Recovery dates differ by region and by scenario, and the reports give them as estimates. The 2066 date in \[8\] and the 2073 date in \[17\] do not contradict each other. They are different scenarios, so both belong here. Where two good sources disagree, both stay on the slate with their citations.