A robust relationship between multidecadal global warming rate variations and the Atlantic Multidecadal Variability

How much and fast the Earth is warming in response to increasing greenhouse gas concentrations is one of the fundamental questions in climate science. Here we investigate the role that different modes of climate variability play in modulating the temperature response. We show evidence for a robust statistical relationship between global warming rate variations and Atlantic Multidecadal Variability (AMV) across multiple observational datasets since 1850. The correlation between AMV and the global warming rate is maximized—with a correlation coefficient of about − 0.8—at ~ 10 to 20 years lead-time. In contrast, such a relation between global warming rate and the Interdecadal Pacific Oscillation (IPO) is far less coherent, showing negative correlation before the 1920s and positive correlation after that. Similar statistical relationships between global warming rate variations and the AMV/IPO can also be seen in the majority of the models from the Phase 5 of Coupled Models Inter-comparison Project. Further, a targeted model experiment is conducted to demonstrate the dominant control of the AMV on the unforced fraction of the global warming rate (compared to the IPO).