ATMOSPHERE × TECHNOLOGY

The Hole We Closed

1985 to 2016 CE

Phanerozoic · Cenozoic · Quaternary · Holocene · Meghalayan

Refrigerant gases were destroying the ozone that keeps ultraviolet off the surface, and every southern spring a hole opened over Antarctica. It was found from the ground, by people whose readings fell so far outside expectation that satellites had been discarding the same numbers as errors. Within two years the world had signed a treaty to phase the gases out, and in 2016 the first signs of healing were measured.

Why it matters

This is the one time our species noticed it was breaking a planetary system, agreed to stop, and could afterwards watch the repair begin. Three decades separate the treaty from that first detection, which is the honest measure of how slowly a planet answers, and it is the precedent every argument about carbon has to reckon with.

Dating & uncertainty

The dates are firm: the hole was reported in 1985, the treaty signed in 1987, and the first statistically significant healing published in 2016. That last date marks a beginning of recovery, not its completion.

Sources

1. Farman, Gardiner & Shanklin (1985), Nature · Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction
2. Solomon et al. (2016), Science · Emergence of healing in the Antarctic ozone layer
3. Cooke et al. (2022), Royal Society Open Science · A revised lower estimate of ozone columns during Earth's oxygenated history

Earth history as one day

23:59:59.9992780 µs before midnight

if Earth’s 4.54 billion years were compressed into a single day