They've been doing it for decades, and the news reports on it, but then gaslights anyone who talks about stratospheric aerosol injections. Therr have been ongoing tests of these geo-engineering tools for decades.
Incidental rather than deliberate geoengineering, but totally monitored and openly discussed.
The recent spike in temperatures is obviously related to an el Nino. It will go down again, just like it's done after every other el Nino.
[1] https://ourworldindata.org/grapher/so-emissions-by-world-reg...