Nuclear waste has a lifecycle of 1000s of years. The heat surplus kills river life. If things go southwards, whole regions are no longer livable for us humans.

Nuclear energy is climate change wise, surely a good deal but environment wise and human population wise, the thing is not that easy.

And nuclear waste is only easy contained if you are the US, Russia, Canada or Australia. Because otherwise you do not have a significant sized land area where you can burry that waste without creating massive problems.