It helps decompose dead waste such as animals and mice and birds and plants, it makes the earth cleaner.
I just had this answer but it hasn't been graded. I put 1. Meteor impacts, 2. volcanic gases and 5. Milankovitch cycles. I didn't put earthquakes because I wouldn't think it would affect the climate changing since they just affect ground movement.
Sensory" Neuron
"Associative Neuron"
"Motor" Neuron