May 9, 2022 - Energy & Environment

World on track to breach key 1.5°C threshold in next 5 years: Report

Man carrying a fan during a heat wave in Kolkata, India, in April 2022.
A man carries a pedestrial fan amid a heatwave in Kolkata, India, on April 26, 2022. (Indranil Aditya/NurPhoto via Getty Images)

There is a 50% chance that, during the next five years, the global average surface temperature will exceed 1.5°C above the preindustrial average for the first time in an individual year, the World Meteorological Organization (WMO) reported Monday.

Why it matters: Under the Paris Agreement, countries are seeking to limit global warming to 1.5°C of warming compared to preindustrial levels, in order to minimize the potential for devastating climate change impacts.

Studies show that if global warming were to exceed 1.5°C above preindustrial levels and remain there, the odds of widespread damage would greatly increase.

Between the lines: The new report, which provides climate projections for the five-year period between 2022 and 2026, does not indicate that the 1.5-degree target will be breached over the long-term, which is the target's meaning under the Paris Agreement.

  • Led by the UK Met Office for the WMO, which is a U.N. agency, with contributions from climate centers in the U.S., Australia, Denmark and other nations, the report shows that the odds of exceeding the 1.5-degree threshold during the short-run are rapidly increasing.
  • For example, the WMO found the odds of a single year seeing temperature anomalies at or above 1.5°C compared to preindustrial levels was just 10% for the 2017-2021 forecast period.
  • Leon Hermanson, who led the report, said in a statement that the increasing odds of exceeding 1.5-degrees in a single year also demonstrates "That we are edging ever closer to a situation where 1.5°C could be exceeded for an extended period."

The big picture: Climate studies have shown that if warming were to exceed 1.5°C as a long-term average, then far more severe consequences would ensure, such as the loss of warm water coral reefs, flooding of small island nations and an increase in deadly heat waves around the world.

  • The 1.5°C figure is not some random statistic," said WMO Secretary-General Petteri Taalas in a statement. "It is rather an indicator of the point at which climate impacts will become increasingly harmful for people and indeed the entire planet."

By the numbers: The climate outlook shows there is a 93% likelihood that at least one year between 2022-2026 will be the warmest on record, knocking 2016 out of the top spot.

  • In addition, it finds that the chance of the five-year average for 2022-2026 being higher than the previous five years is also 93%. There is just a 10% chance that the five-year average will exceed 1.5°C, the report found.
  • As of 2021, the world had already warmed by 1.1°C above preindustrial levels. The period from 2015 to 2021 was the warmest seven-year period on record since records began in 1850, the report found.
  • The high latitudes are warming the fastest, with the Arctic forecast to have a temperature anomaly during the next five years that is more than three times as large as the global mean anomaly.

The intrigue: To produce the five-year outlook, climate scientists ran multiple computer models back in time in order to check how well they simulated real world conditions.

The forecasters noted that they have high confidence in global mean temperature projections due to the high skill estimates from these "hindcasts," among other evidence.

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