Long-term Climate Scenarios

Long-term climate scenarios are projections of how the climate could change over many decades, depending on the choices societies make. Scientists build them using models of the atmosphere, oceans, and energy use. Government agencies and international scientific panels publish them, and they show a range of outcomes rather than one prediction.

People usually ask what a scenario is, how reliable the models are, and what a range of outcomes means for planning. They also ask how projections for the next decade differ from those for the end of the century, and how policy makers use them.