If you are aware that solid prediction is not possible, and you find predestination distasteful, you can put biases into whichever direction you want to push the balance.
Do you want dystopia? Unleash the methane.
Want Earth all cleaned back? Let humans invent/design efficient bacteria which converts CO$_2$ from atmosphere back to oil, and pump it back to underground.
Both outcomes are plausible. BTW such bacteria was already found, it is just hard to grow on industrial scale (and Yale bio-magicians are working on it).
