Nonsensical. As a whole, volcanic CO2 emissions are 1/100 of manmade CO2. Yes, an eruption can certaintly output plenty of CO2, e.g. 42 Mt of CO2 with Pinatubo. That's about half a day of manmade. Sometimes people try to conflate Pinatubo's water vapor (which was much larger) with manmade CO2. Volcanic and fossil fuel water vapor are both completely irrelevant compared to evaporation. And evaporated water is much more important than CO2.
One thing controls the planet's temperature: and that is geography. Antarctica is a big freezer and Greenland is a smaller freezer. Both contribute to the cold bottom water that keeps the oceans around 36 or 37F on average.
One thing controls water vapor and that is average weather. Cold and dry La Nina is cooling the entire planet right now. Before that we had a glut of warm and wet El Nino. Those control temperature in the shorter run (years to decades).
One thing controls the planet’s temperature: The Sun.