This sound very similar to David Hume theory of "problem of induction", as any assumption that the past predicts the future can be wrong.

Personally I think there is value in looking at past decision and seeing what the outcomes were. We can compare two nations like France and Germany and objectively say who has contributed more to global warming. We can also calculate how much they paid for it. The cost side is less relevant as I don't live in either country, but the global warming does impact me so I have some stake in the outcome.

Ban globally the act of burning fossil fuels in power plants. That fixes the outcome I want. The cost questions can be address politically within each country.