Updated Jan 15, 2022 - Energy & Environment

Earth's climate went off the rails in 2021, reports show

Climate map showing temperature departures from average during 2021.

Temperature departures from average in degrees Celsius during 2021. (Berkeley Earth).

Global warming became local to a new and devastating extent in 2021, with the year ranking as the sixth-warmest on record, according to new, independent data from NASA, NOAA and Berkeley Earth.

Why it matters: Each year's data adds to the relentless long-term trend, which shows rapid warming due overwhelmingly to human-caused greenhouse gas emissions during the past several decades in particular.

  • The global shifts in ocean heat, atmospheric moisture, and surface temperatures on shorter timescales are increasingly being felt in the form of unprecedented and deadly extreme weather and climate events.

The big picture: The three temperature tracking groups matched data released earlier this week by the European Union's Copernicus Climate Change Service, and show how the presence of a La Niña event in the tropical Pacific Ocean, which features cooler than average sea surface temperatures near the equator, failed to dislodge 2021 from the list of top 10 years.

Between the lines: The next year that features an El Niño in the tropical Pacific, which is La Niña's warmer sibling, is almost assured to set a record for the warmest year, since it can further accelerate human-caused warming.

  • Last year featured a relentless series of extreme weather and climate disasters that saw temperatures and water levels reach unprecedented levels.
  • A June heat wave in the Pacific Northwest, for example, set a temperature record for the hottest reading (121°F) ever seen in Canada, along with all-time highs in Oregon and Washington. The town that set the Canadian record, Lytton, British Columbia, burned in a wildfire the next day.
  • A study found the heat wave could not have occurred without human-caused global warming.
  • "Changes in extreme events are global warming writ local," NASA's Gavin Schmidt, who directs the agency's Goddard Institute for Space Studies in New York City, told Axios in an email.

To illustrate how much the world has warmed in many peoples' lifetimes, consider these two facts, one from NOAA and one from NASA:

  • The world has not experienced a cooler than average year, compared to the 20th century average, since 1976.
  • In NASA's data set, 1988 — the year that climate scientist James Hansen famously testified before Congress, warning that human-caused global warming was underway — long reigned as the warmest year on record.
  • Due to the warming since then, 1988 now stands as the 28th warmest year in NASA's data set, according to Schmidt.

By the numbers: The statistics contained in these reports are astounding, and drive home just how different the climate is today from just a few decades ago.

  • Nearly 2 billion people lived through their hottest year on record, since 25 countries earned this distinction, including China and Nigeria. No place on Earth had its coldest year on record, according to Berkeley Earth.
  • Four of the top 20 largest wildfires in California history occurred in 2021, as heat waves and drought primed the environment for massive blazes. This included the second-largest blaze on record, the Dixie Fire, which scorched more than 963,000 acres.
  • The nine years from 2013 through 2021 rank among the top 10 warmest years on record, according to NOAA.
  • The world is now 1.2°C (2.2°F) warmer than preindustrial levels, Berkeley Earth found, closing in on the Paris Climate Agreement's temperature target of limiting warming to 1.5°C above preindustrial levels.
  • Beyond that point, scientists say, more perilous and potentially irreversible climate consequences may occur, including melting polar ice caps and loss of iconic ecosystems, such as coral reefs.

The bottom line: Even the world's relatively "cool" years are now ranking among the top eight warmest on the list, with no prospect of slowing global warming, scientists say, unless the world bends the greenhouse gas emissions curve sharply downward, all the way to zero and eventually below zero in coming decades.

Go deeper: In photos: 2021's devastating climate disasters

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