Here, go and have a read of this article: http://skepticalscience.com/how-do-climate-models-work.html http://skepticalscience.com/how-do-climate-models-work.htm

Here, go and have a read of this article: http://skepticalscience.com/how-do-climate-models-work.html http://skepticalscience.com/how-do-climate-models-work.html - they talk in great detail about how the models work, starting with one equation. Also look at this image further down the page: http://www.skepticalscience.com/pics/sea_ice_prediction.jpg http://www.skepticalscience.com/pics/sea_ice_prediction.jpg The glacier model is wrong, but wrong in the wrong direction (Actually I think that's combined results from multiple models, but anyway...). How do they know? Because there are climatologists out on the ice, or in satellites taking measurements-1. Testing the model - you know, all that stuff that is supposedly impossible to do. 1- there are even high resolution GPS modules in Greenland which can estimate ice loss by how far up the crust lifts (as well as detecting plate tectonics).