NOAA scientists are at the forefront of studying climate change and modeling what the effects will be on the Earth. Researchers at NOAA’s Great Lakes Environmental Research Laboratory (GLERL) have developed the Coupled Hydrosphere-Atmosphere Research Model (CHARM) to enable a valid assessment of the impact of how climate change might affect the climate and ecology of the Great Lakes. The CHARM model provides a realistic surface-atmosphere feedback portrayal, and accounts for runoff from land surfaces. It allows researchers to predict that global warming likely will bring higher temperatures and increased precipitation to the Great Lakes. Development of a second generation of CHARM is underway to help answer questions about greenhouse warming effects on Great Lakes water quantity.