Global change


Globally, CO2 emissions and climate change are accelerating. 2023 saw the highest temperatures in the atmosphere and in the oceans ever recorded, the least sea ice ever observed, and a rapid increase in sea level.

Atmospheric CO2 concentration increased by 2.6 ppm, which is 41% faster than the previous year and 16% faster than the average 2000–2022 growth rate. The rapid increase was due to a combination of ever-increasing fossil fuel emissions and a change to El Niño conditions during 2023.
The average CO2 concentration reached 421 ppm, a 33% increase from 1960. Global average air temperature was the highest on record by a considerable margin. It was 0.32 °C higher than the previous year and 1.18 °C above the 20th-century average. The last ten years (2014–2023) all rank as the ten warmest on record.
Global mean air temperature (difference from 1901-2000 average) (NOAA)
The maximum ozone hole extent was 2% smaller than the previous year. It was 5% larger than the 2000–2022 average but 13% below the maximum extent observed in 2000. The ozone hole has not shrunk over the last two decades but may have stabilised.
Oceans absorb 93% of excess heat from climate change. Global ocean heat content increased by 4.8% compared to the previous year. Globally, sea surface temperatures were the highest on record in 2023. The global mean sea level rose by 11.7 mm in 2023; the most rapid rise since 2015. Sea level has increased by 85 mm since 2000 and 101 mm since 1993.
Sea ice extent was 2% less than the previous year in the Arctic and 8% less around Antarctica, where it broke the record set the previous year. Ice extent on both hemispheres combined was 5.0% less than the previous year, the lowest on record and 9.5% lower than the 2000–2022 average.
Global mean sea level rise from 2000 values (NOAA)