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What was measured. A laboratory photolysis spectrum of dichlorine peroxide, the molecule the ozone-hole mechanism uses to return chlorine radicals in dim spring light. Not a measurement inside the hole.

What it does to the budget. The new cross section was almost an order of magnitude below the rate in the model, at the wavelengths the stratosphere actually has. Markus Rex: if the measurements are correct, at least 60 percent of polar ozone destruction is an unknown mechanism, and “we can basically no longer say we understand how ozone holes come into being.” Later laboratory spectra did not confirm that low value, and the assessment put a higher rate back. The correction was another lab spectrum. The reaction has still not been watched in the air. The model’s central step was, for a time, wrong by enough to break the explanation, and the repair was not a stratospheric observation.

The spectrum is a laboratory curve of cross section against wavelength. Nature’s news piece did not print the wavelength table, and a redrawn curve would be an invention. The claim that was printed is the size of the miss: almost an order of magnitude too slow, at the wavelengths present in the polar spring.