How does the ozone layer affect life on Earth?.

It protects the earth from ultraviolet radiation

Migration people get up and go cause they feel it is best for them 

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.