An annual assessment
This report covers many aspects of the climate system, including atmospheric and ocean conditions, El Niño, the cryosphere, greenhouse gas concentrations, regional extremes, tropical cyclones and ozone depletion.
The Statement draws on in situ and space-based observations collected through various WMO and co-sponsored programmes. It also draws on numerical objective analyses. These observations are the Essential Climate Variables that have been defined by the Global Climate Observing System.
The international datasets underpinning this assessment are maintained by advanced climate data, monitoring and research centres that collaborate with WMO. In addition, data and climate information has been collected directly from WMO Members through a special WMO survey.