The ozone hole over the Antarctic in 2025 was the fifth smallest since 1992 — "the year a landmark international agreement to phase out ozone-depleting chemicals began to take effect," per a new NOAA-NASA report.

Why it matters: While the ozone hole varies in size from year to year, the report says this year's monitoring shows "controls on ozone-depleting chemical compounds established by the landmark Montreal Protocol and subsequent amendments are driving the gradual recovery of the ozone layer." • The ozone layer shields Earth's inhabitants from the sun's harmful ultraviolet radiation as it sits in the stratosphere 9-22 miles above Earth. Its depletion "increases the amount of UVB that reaches the Earth's surface" — and this can impact plants, marine ecosystems UVB causes non-melanoma

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