Ozone Hole — Revision Notes

⚡ 30-Second Revision

1987: Montreal Protocol.
2016: Kigali HFC phasedown for climate.
Below 220 DU: Antarctic ozone-hole area threshold.
2022 assessment: conditional 1980-baseline recovery around 2040 near-global, 2045 Arctic, 2066 Antarctic.

2-Minute Revision

Ozone's role depends on altitude. Stable source gases can release reactive chlorine/bromine in the stratosphere. Polar clouds and isolation prepare conditions; spring sunlight drives rapid loss. Area and minimum column are different metrics. HFC warming controls do not make HFCs chlorine-bearing ozone depleters. Recovery dates are conditional assessment projections with specific domains.

5-Minute Revision

Write the depletion sequence in five steps and name the role of cold and sunlight separately. Explain how a smaller area can coexist with a similar minimum column. Compare Montreal, Kigali and Paris without merging their mechanisms. End with one correctly qualified sentence using the 2022 Antarctic recovery projection.

Vyyuha Quick Recall

Source gas → polar preparation → sunlight → catalytic loss → monitored recovery.