Even with Obama mandating NASA to prove man causes climate change, it’s hard to refute 4 billion years of climate change on Earth. 99.9% of Earth’s climate change was before man was on Earth so proving man causes it is a uphill battle.
Actually it is statistically impossible to separate human effects from historical non human effects. At least to any significance. And NASA has no clue what drove non human effects. So you are absolutely correct. That is why we cannot play god. We do not have the knowledge or experience and we certainly lack the integrity required.