Precipitation differences are the factor that does not contribute to "water stress" on the Earth.
<u>Explanation:</u>
- Less ocean water sources, population differences, Scarcity of economic water resources are the factor which leads to water stress on the Earth.
- Precipitation differences do not cause much difference in water stress. So it will not contribute to the water stress.
- An increase in population will cause major water stress because availability drinking water is less in the earth. Population increase can cause a major problem.
Atmosphere of the early earth + lighting = paleolightning
An invertebrate, because an animal with a vertebrate is an animal with a backbone.