Climate Scenarios are Off Track

(2020) perform the most rigorous evaluation to date of how key variables in climate scenarios compare with data from the real world (specifically, it focuses on the four factors of the Kaya Identity: population, economic growth, energy intensity of economic growth and carbon intensity of energy consumption). [...] 2 below shows the difference between observations of the Kaya factors and the values found in the baseline scenarios of the IPCC Fifth Assessment Report Scenario Database (AR5).1 The figure shows that most references scenarios of the IPCC AR5 overestimated both carbon dioxide growth and per capita GDP growth, and in most of the subregions of the IPCC (for details, see Burgess et al. [...] (2020) builds upon a growing literature indicating that commonly used climate scenarios are already well off track and will become increasingly off track e.g., A growing literature has begun to recognize the divergence of commonly used scenarios and the evolution of the real world (e.g., see Ritchie and Dowlatabadi 2018 as one of the first and most significant contributions to this literature). [...] As a result of such high prevalence of such studies in the literature, they are also the most commonly cited within scientific assessments of the Intergovernmental Panel on Climate Change (Pielke and Ritchie 2020). [...] That particular scenario is also by far the most commonly cited in recent climate assessments of the IPCC and the U.