Under a broader, functional definition centered on planetary maintenance, what constitutes the most significant proof of Earth's 'aliveness'?

Answer

The emergent property created when the geochemistry and the biosphere interact across eons

The broader view suggests the most significant proof of Earth's functional 'aliveness' is the emergent property arising from the long-term interaction between the planet's geochemistry and its biosphere.

Under a broader, functional definition centered on planetary maintenance, what constitutes the most significant proof of Earth's 'aliveness'?
EarthsystemplanetlifeProof