Sostratus
Deity
It depends on difficulty. Often players are ahead of the AI. If the AI is advanced and has some resources they will pollute frequently. If it’s pvp and 4 humans are all polluting, things get go underwater fast.There is a button on the upper left side of the in-game screen for checking the climate change. It has several stages, and it is possible to finish the game before the consequences of climate change really hit.
That said, a common complain about the GS is that the consequences of climate change are really unimpactful.