The study of the earth's air and weather is called

the study of the earth's air and weather is called Meteorology.

Explanation:

Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting.

Meteorological phenomena is observable weather and then explained by the science of meteorology.

Those events are bound by the variables that exist in Earth's atmosphere. These variables are  temperature, pressure, water, and the gradients and interactions of each variable.

The majority of the observed weather is located in the troposphere of Earth.

Although meteorologists now use computer models it is still  common to use techniques and conceptual models that were developed before computers.

the answer u all are looking for is 4000000000000000000000 million years.