Question: What does Buddhism say about the end of the world?
Answer: As Buddhism speaks of the whole universe, with many planets and such, its teachings are not merely earth-centric. Since nothing physical in Saṃsāra (i.e. cycle of rebirth) is permanent, the earth will indeed by destroyed eventually. However, this will not occur for at least billions of years, as the Buddha spoke of Maitreya Bodhisattva arriving here 5.6 billion years later.
Of course, we should take care of the environment. However, even humans’ destructive efforts that contribute to the climate crisis cannot destroy earth itself, while the crisis can destroy many humans and animals. There are already many fatal victims of extreme weather conditions. This reminds us that the end of life is nearer than the end of this world. Thus, the immediate matter of concern is to ensure there will be a fruitful rebirth.
Even when a planet ends, those not liberated will karmically be reborn elsewhere. In this sense, Buddhists do not have to worry about physical end of this world being the end of life. Even if physical life ends, spiritual (or wisdom) life should be supported to continue. What matters is to be reborn where liberation is guaranteed — to exit the cycle of rebirth. The easiest place to reach for this is Amitābha Buddha’s (Āmítuófó) Pure Land.
Sūtra in which the Buddha Speaks of the Dharma’s Complete End