Global Warming

Increase in the average global surface temperature (oceans, land, cryosphere), measured over a fairly long period and relative to an initial reference period. The main cause of current global warming is the increase in greenhouse gas emissions due to human activity. These have been rising steadily since the pre-industrial period 1850-1900, which serves as a baseline (the earliest period of reliable observations with sufficient geographic coverage). Source: IPCC glossary, 2021