Simplify the following text for a Grade 12 native English-speaking person.
Original: The Thornthwaite system , in use since 1948 , incorporates evapotranspiration in addition to temperature and precipitation information and is used in studying animal species diversity and potential impacts of climate changes .
Simplified: The Thornthwaite system , which was used from 1948 , not only uses temperature and precipitation information , evapotranspiration too .