My bad, I was only talking about the readings in my city, not the whole planet. I assumed it would scale to the whole planet in that period.

Ah. I’d consider _city-level_ readings an absolutely useless metric here, because, particularly if it’s a city with a large commuter hinterland, a lot of people were simply not present in the city, but still existed out there somewhere, running their heating/cooling/etc. Daytime populations of large cities generally dropped during the covid wfh period, so yeah, no shit CO2 emissions dropped; people were off emitting CO2 elsewhere.