Awareness of Both Type 1 and 2 Errors in Climate Science and Assessment

Abstract

Treatment of error and uncertainty is an essential component of science and is crucial in policy-relevant disciplines, such as climate science. We posit here that awareness of both “false positive” and “false negative” errors is particularly critical in climate science and assessments, such as those of the Intergovernmental Panel on Climate Change. Scientific and assessment practices likely focus more attention to avoiding false positives, which could lead to higher prevalence of false-negative errors. We explore here the treatment of error avoidance in two prominent case studies regarding sea level rise and Himalayan glacier melt as presented in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. While different decision rules are necessarily appropriate for different circumstances, we highlight that false-negative errors also have consequences, including impaired communication of the risks of climate change. We present recommendations for better accounting for both types of errors in the scientific process and scientific assessments.