Jan 6, 2022 - Energy & Environment

Early data ranks 2021 as Earth's fifth warmest year

Data: ERA5/ECMWF; Chart: Thomas Oide/Axios

The early numbers are in, and 2021 ranks as the fifth warmest year on record, according to the European Union's Copernicus Climate Change Service.

Why it matters: The ranking signals that the temporary cooling influence of a moderate La Niña event in the tropical Pacific Ocean cannot do much to dampen the influence of human-caused global warming.

Details: The preliminary data from Copernicus is in line with projections by U.S. climate agencies such as NOAA, which has forecast that the year was almost certain to rank as the sixth warmest year in its database, which dates back to the late 19th century.

  • Copernicus' data, based on sophisticated splicing of observations with computer model, goes back to 1979.
  • As the chart shows, natural variability, such as La Niña episodes and their warmer relatives, known as El Niños, can cause global temperature anomalies to bounce up or down from year to year.
  • However, the overall trend consists of a relentless, human-driven upward march.
  • Copernicus has found that 21 of the 22 hottest years have come since the year 2000, while NOAA's records show the world's 10 warmest years have all happened since 2005.
  • The approximately 1.1°C (1.98°F) of global warming that's taken place since the preindustrial era is already leading to unprecedented extreme weather events, from heat waves to wildfires and more powerful hurricanes.

What's next: The Copernicus data will soon be finalized and joined by information from other global temperature tracking groups.

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