• Jim East@slrpnk.net
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    3 days ago

    archived (Wayback Machine)

    record annual jump cited (Wayback Machine)

    Please note that this article contains questionable arithmetic:

    That brings the annual mean global concentration close to 430 ppm, about 40 percent more than the pre-industrial level, and enough to heat the planet by about 2.7 degrees Fahrenheit (1.5 degrees Celsius).

    The actual figure from NOAA is 428.15 ppm (last updated 2025-04-14). If we use the more precise pre-industrial estimate of 278 ppm, then we get an increase of 54%, which is indeed “about 40%” if we round to the nearest multiple of 40%.

    Climate models tend to underestimate the cooling effect of aerosol pollution, and the climate sensitivity is actually about 50% greater than previously thought, so a more realistic estimate of the warming caused by a doubling of carbon dioxide concentration over the pre-industrial level is 4.5°C. If we assume that the relationship is linear, this means that the current level of 428.15 ppm is “enough to heat the planet” by 4.5°C * 54% = 2.43°C, which is… more than 1.5°C.

    the 2023-2024 spike of the global average surface temperature, which has also not been fully explained

    Yes it has.