3.1 Global temperature rise

Figure 8 illustrates the unprecedented extent and speed of recent changes to our atmosphere. Climate models have long predicted that this will lead to the Earth warming further and faster than has occurred for millions of years. The Earth’s climate system is now responding in line with these predictions. Since the 1970s, each decade has been approximately 0.2 °C warmer than the last one, meaning that we no longer have stable climate ‘normals’.

More recently, the World Meteorological Organization (WMO) has called 2011–2020 ‘a decade of acceleration’ (WMO, 2023a). It was the warmest on record for both land and ocean, with a rise in the global mean surface temperature (GMST) of the Earth of 1.1 °C above the 1850–1900 baseline (WMO, 2023b).