Understanding the strengths and limits of predictions is important because our sense of certainty about events in the future influences the actions we take today,”  Pielke Jr. and Sarewitz write. “For example, predictions of global warming have focused international environmental efforts on reducing greenhouse gas emissions. But future economic trends, geopolitical events, and technological advances — three variables that defy predictive accuracy — will have a much greater impact on emissions than any conceivable international agreements.