Hacker News Reader

Comment by eloff | Hacker News Reader

Yes, but the point is the danger from the warming contribution is less than the danger from an ozone hole, so why focus on the warming? Unless the ozone depletion is below the recovery rate.

View on HN

The combined emissions of CFC-13, CFC-112a, CFC-113a, CFC-114a and CFC-115 increased from 1.6 ± 0.2 to 4.2 ± 0.4 ODP-Gg yr-1 (CFC-11-equivalent ozone-depleting potential) between 2010 and 2020. The anticipated impact of these emissions on stratospheric ozone recovery is small. However, ongoing emissions of the five CFCs of focus may negate some of the benefits gained under the Montreal Protocol if they continue to rise. In addition, the climate impact of the emissions of these CFCs needs to be considered, as their 2020 emissions are equivalent to 47 ± 5 TgCO2.

https://www.nature.com/articles/s41561-023-01147-w

Thanks, that makes sense now.

Gg, Tg? Is that Giga-gram and Tera-gram? Why not kg, the SI standard unit for mass?

I think it is an SI unit: https://en.wikipedia.org/wiki/Orders_of_magnitude_(mass)

"Teragram" appeared in the original IPCC reports circa 1990, so this has been a thing for at least a gigasecond.

Adding an SI prefix to an SI unit is standard practice rather than adding a bunch of trailing zeros.

> Is that Giga-gram and Tera-gram?

Should be "gigagram" and "teragram," with no capitalization and no hyphen. See section 5.3 ("Unit Names") of the official SI Brochure.[0]

[0] https://www.bipm.org/documents/20126/41483022/SI-Brochure-9-...

The article suggests that it is currently below the recovery rate (but only just).

Reply on news.ycombinator.com