Current State of the Art Knowledge in Global Warming

This article addresses in a very synthetic way the physical principles of climate change, starting from the concept of the Earth energy balance, essential mechanism defining the temperature of the Earth and its evolution in connection with human activities. It presents the fundamentals of numerical modeling and simulation protocols developed to understand the climate system and its evolution. It introduces the concept of climate sensitivity, a fundamental property of the climate system and a diagnosis of the magnitude of global warming in response to cumulative greenhouse gas emissions. The magnitude of global climate change is illustrated by geophysical variables whose link to global warming is unmistakable, then the regional responses and impacts of global climate change are discussed.