Question: The pre-industrial level of co2 in the atmosphere in ppmv is about?
Disambiguated questions and answers: question: What is the commonly assumed value of the pre-industrial level of co2 in the atmosphere in ppmv?
Based on more recent indirect data, what is the value of the pre-industrial level of co2 in the atmosphere in ppmv?
answer: 290
260-270
Natural Questions answer: 260 -- 280 ppmv (from the Wikipedia article "Carbon dioxide in Earth's atmosphere")