I saw this and got annoyed too. But I’m not 100% sure about the LESS vs FEWER thing now.
When people talk about “reducing CO2 emissions” aren’t they talking about reducing the total amount, rather than the number of individual emissions? In which case shouldn’t it, rather awkwardly, be less emissions? Would anyone actually say “We need fewer CO2 emissions”?
“CO2 emissions” as a thing to be improved seems to have become a single thing, something you can have less of, rather than, as one would think purely grammatically, many things you can have fewer of.