text: The importance of ocean acidification is reflected in its inclusion as one of seven Global Climate Indicators. These Indicators are a set of parameters that describe the changing climate without reducing climate change to only rising temperature. The Indicators include key information for the most relevant domains of climate change: temperature and energy, atmospheric composition, ocean and water as well as the cryosphere. The Global Climate Indicators have been identified by scientists and communication specialists in a process led by Global Climate Observing System (GCOS). The Indicators have been endorsed by the World Meteorological Organization (WMO). They form the basis of the annual WMO Statement of the State of the Global Climate, which is submitted to the Conference of Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC). Additionally, the Copernicus Climate Change Service (C3S) of the European Commission uses the Indicators for their annual "European State of the Climate".