Changes in the flow of energy through the Earth's climate system

A review is given of the trends, variability, mean and annual cycle of energy flowing through the climate system, and its storage, release, and transport in the atmosphere, ocean, and land surface as estimated with recent observations, with some new updates using the latest datasets. The current imbalance in radiation at the top-of-atmosphere owing to human-induced increases in greenhouse gases means that the atmosphere, land and ocean are warming up, and ice is melting, leading to a rise in sea level. A discussion is given of our ability to track these changes with current observations and analyses. Current global analyses of the atmosphere and the ocean contain spurious variability on decadal time scales that arises from inadequacies and changes in the observing system. A holistic integrated approach that brings all information to bear can provide constraints on what is happening and where the main weaknesses are in the observing system. Results for ocean heat content are discussed in the light of recent corrections to ocean soundings and new ocean observations, and in the context of the thermosteric contributions to sea level rise.