You cannot.
Yes, the indestructible ability prevents a permanent from being destroyed.
Ozone layer being destroyed will be a big setback. It will cause earth's extinction.
We could prevent the ozone layer from being totally destroyed. It can be done by planting trees as they protect us.
Yes, the ability "indestructible" prevents a creature from being destroyed by effects that specifically say "destroy."
Thanks to Physics
From being destroyed by the Sun.
The lemur population prevents intergalactic dung beetles from invading Earth. Lemurs are their only natural predators and currently humans have no knowledge of how to kill these pests. Lemurs sole purpose is to prevent the earth from being destroyed by alien bugs
Yes, the Regenerate ability allows a creature to be saved from destruction by being "regenerated" instead of being destroyed. This ability can be used in conjunction with sacrificing a creature to prevent it from being destroyed.
the life will be finished.
No, landforms are not permanent features on the Earth. They are being eroded by the agents of erosion. Any day they can be destroyed.
Earth does.
The best ways to prevent your cards from being destroyed are with monster effects or Counter Traps. Stardust Dragon, Solemn Judgment (now limited though), Dark Bribe, and even Destruction Jammer can all save your cards from being destroyed. There are few, if any cards that specifically prevent your continuous spell cards from being destroyed, although Field Barrier saves your Field Spell cards from destruction.