Constraints on Climate Change Stabilization Based on Observations of Earth's Energy Imbalance

Abstract

The Earth's energy imbalance (EEI) at the top of the atmosphere is a key indicator of climate change that determines the Earth's heating rate. Here, we use a global reconstruction of surface temperature and EEI measurements to constrain global projections of the Earth heating rate until the end of the century. Our robust statistical method is shown to withstand changes in the prior distribution or the length of the EEI record, and to perform well when evaluated against independent pseudo-observations. Results show that the reversal of the Earth heating rate is very unlikely to occur before the early 2040s, even under a low emission scenario. This is more than 10 years later than expected from the raw projections, with significant implications for both mitigation and adaptation policies. Future research is however needed to better attribute the observed EEI changes and to explore the patterns of recent versus future EEI changes.