An increase in effective radiative forcing from human activity is now said to be mostly driven by a decline in aerosol pollution, superseding the effects of CO2 emissions.
The majority of an alleged acceleration in anthropogenic global warming in the 21st century “is driven by changes in the the aerosol [effective radiative forcing] trend, due to aerosol emissions reductions” (Jenkins et al., 2022).
Image Source: Jenkins et al., 2022
This is supported by other studies reporting a direct radiative forcing increase of +1.59 W/m² over the US from 1996-2019 and +2.0 W/m² impact over Europe from 1980-2018 (Augustine and Hodges, 2021, Kejna et al., 2021) due to these countries reducing their sulphate aerosol emissions through policy initiatives.
Image Source: Augustine and Hodges and Kejna et al., 2021
Considering it reportedly takes 10 years and 22 ppm for CO2 to exert a total surface forcing impact of just 0.2 W/m², reducing our aerosol emissions has a much larger impact on Earth’s radiation budget than reducing our CO2 emissions.
So, if we want to more efficiently (and with far less cost) reduce global warming, apparently what we need to do is increase our aerosol pollution rates.
The science is now settled. Right?
By Kenneth Richard on 10. November 2022