All informed decision making is made on the basis of probabilities. You're setting an impossibly and arbitrarily high threshold for action on climate change.
The burden of proof is on you to explain how CO2 levels not seen for 3 million years won't have a major impact on the biosphere.
The burden of proof is on you to explain how CO2 levels not seen for 3 million years won't have a major impact on the biosphere.