Volcanoes and other variable natural sources can boost the world CO2 level. I am not sure whether we’re even measuring the world CO2 level in more than one place! I think I remember hearing the complaint that it’s near the active volcanoes of Hawaii.
I teach elementary school, the texts we use absolutely crams climate change down their throats. Of course, there are pictures of industries spewing black smoke into the air which I always point out was probably taken years ago.