(top) Global average surface temperature each year since 1900 compared to the 20th-century average (the zero line). A slowdown in surface warming in the first decade of the 21st century was associated with frequent La Niña conditions. (bottom) Satellite and ocean observations of energy increasing in the oceans, atmosphere, and land (planetary heat uptake) show that more heat is entering than leaving the planet (an energy imbalance) due to increasing greenhouse gas levels. NOAA Climate.gov image, based on data from NOAA National Centers for Environmental Information (top) and NASA/CERES data from Norman Loeb (bottom). **