Question: The pre-industrial level of co2 in the atmosphere in ppmv is about?
Answer: 260 -- 280 ppmv
Disambiguated annotations:
qaPairs: question: What is the commonly assumed value of the pre-industrial level of co2 in the atmosphere in ppmv?
answer: 290
question: Based on more recent indirect data, what is the value of the pre-industrial level of co2 in the atmosphere in ppmv?
answer: 260-270