Global Temperature in 2021
13 January 2022
James Hansen, Makiko Sato and Reto Ruedy Global surface temperature in 2021 (Fig. 1) was +1.12°C (~2°F) relative to the 1880-1920 average in the GISS (Goddard Institute for Space Studies) analysis.[1],[2],[3] 2021 and 2018 are tied for 6th warmest year in the instrumental record. The eight warmest years in the record occurred in the past eight years. The warming rate over land is about 2.5 times faster than over the ocean (Fig. 2). The irregular El Nino/La Nina cycle dominates interannual temperature variability, which suggests that 2022 will not be much warmer than 2021, but 2023 could set a new record. Moreover, three factors: (1) accelerating greenhouse gas (GHG) emissions, (2) decreasing aerosols, (3) the solar irradiance cycle will add to an already record-high planetary energy imbalance and drive global temperature beyond the 1.5°C limit – likely during the 2020s. Because of inertia and response lags in the climate and energy systems, the 2°C limit also will likely be exceeded by midcentury, barring intervention to reduce anthropogenic interference with the planet’s energy balance.
Transition Studies 