General Circulation Models (GCMs) are complex computer simulations used to understand and predict the Earth's climate system. They represent the atmosphere, oceans, and land surface, allowing scientists to analyze how different factors, such as greenhouse gas emissions, affect global temperatures and weather patterns over time. GCMs divide the Earth into a three-dimensional grid, calculating interactions between various components like air, water, and land. By simulating these interactions, GCMs help researchers forecast climate changes, assess potential impacts on ecosystems, and inform policy decisions related to climate change and environmental management.