If we can track weather conditions in Antarctica, we can determine if and when planes should depart from Christchurch, New Zealand to land safely at McMurdo Station. We also can determine the best places for field camps and research stations. Photograph courtesy of Eric R. Venteris, The Ohio State University. For an even bigger picture, we reconstruct past climate changes and predict future climate changes. We create computer simulations of global climate changes, using GCM's, or General Circulation Models.
Models are very powerful.
They are simple representations of a real system, say the global atmospheric circulation. The human mind cannot keep track of all the details and infer all the possible results. The GCM's help us see how changes in Antarctic climate can cause changes in climate elsewhere, such as in North America. The models predict cloud cover, for example. Models allow you to simplify a system so that you can change one variable and see the potential impact.