State of the Global Climate 2020

Global climate indicators reveal the ways in which the climate is changing and provide a broad view of the climate at the global scale. They are used to monitor the key components of the climate system and describe the most relevant changes in the composition of the atmosphere, the heat that arises from the accumulation of greenhouse gases (and other factors), and the responses of the land, ocean and ice to the changing climate. These indicators include global mean surface temperature, global ocean heat content, state of ocean acidification, glacier mass balance, Arctic and Antarctic sea-ice extent, global CO2 mole fraction and global mean sea level and are discussed in detail in the sections in this report. Further information on the data sets used for each indicator can be found at the end of this report.