Climate & Environment Introduction
The Great Lakes-St. Lawrence River Basin is a dynamic, ever evolving environment. Climate variability is the norm for the region and not the exception. This vast region is continuously affected by hydrologic and climatic forces. It has been, and will continue to be, a major indicator of global climate change.
Ever since the last glaciers retreated more than 10,000 years ago, Great Lakes water levels have varied dramatically, as have the flows of water between these five massive lakes and their combined outflow to the Atlantic Ocean. The Great Lakes affect human activities and all aspects of the natural environment, from weather and climate to wildlife and habitat. Our knowledge of the geophysical, ecological, and socioeconomic characteristics of the system is improving over time but we will continue to be challenged by uncertainty and the randomness of nature.