Improved quantification of the rate of ocean warming

Using the recommended methods, ocean warming for the upper 2000 m increases from about 0 to 0.06 +/- 0.08 W m(-2) for 1958-73 to 0.58 +/- 0.08 W m(-2) for 2003-18, indicating an acceleration of ocean warming that happens in all four ocean basins and from near the sea surface to 2000 m. There is consistency between multimodel-mean historically forced climate models and observations, which implies that the contribution of internal variability is small for global 0-2000 m OHC.

Notable increases of OHC in the upper ocean (i.e., 0-300 m) after about 1980 and the deeper ocean (300-2000 m) after the late 1980s are also evident. This study suggests alternative methods to those currently used to estimate ocean warming rates to provide a more accurate quantification of long-term Earth's energy changes.