Why do scientists use models to study changes to the earth's surface? Question 7 options: Scientists choose to use models when using real time investigations would be too hard. They want to make sure the process is easy not accurate. Many changes to earth's surface happen to slowly and at a scale that is too large for scientist to observe in real time. Experiments with models, like stream tables, can be used to better understand how changes to earth's surface take place. The rate of changes to earth's surface varies greatly. Some occur over long periods of time and some are rather quick. Therefore, scientists are not sure what the best method is and they choose to use a model such as a stream table to make better predictions.