Warming world neared critical 1.5°C limit in 2023
The year of 2023 was the hottest on record, with the increase in Earth’s surface temperature nearly crossing the critical threshold of 1.5 degrees Celsius, European Union climate monitors said this week.
Climate change intensified heatwaves, droughts and wildfires across the planet, and pushed the global thermometer 1.48°C above the pre-industrial benchmark, the Copernicus Climate Change Service (C3S) reported.
“It is also the first year with all days over one degree warmer than the pre-industrial period,” said Samantha Burgess, deputy head of the C3S.
“Temperatures during 2023 likely exceed those of any period in at least the last 100 000 years.”
Nearly half the year exceeded the 1.5°C limit, beyond which climate impacts are more likely to become self-reinforcing and catastrophic, according to scientists.
But even if Earth’s average surface temperature breaches 1.5°C in 2024, as some scientists predict, it does not mean the world has failed to meet the Paris Agreement target of capping global warming under that threshold.
That would occur only after several successive years above the 1.5°C benchmark, and even then the 2015 treaty allows for the possibility of reducing Earth’s temperature after a period of “overshoot”.
The Copernicus findings come one month after a climate agreement was reached at COP28 in Dubai calling for the gradual transition away from fossil fuels, the main cause of climate warming.
The year saw another ominous record: two days in November exceeded the preindustrial benchmark by more than 2°C.
Copernicus predicted that the 12-month period ending in January or February 2024 would “exceed 1.5 degrees Celsius above the pre-industrial level”.
Reliable weather records date back to 1850, but older proxy data for climate change — from tree rings, ice cores and sediment — show that 2023 temperatures “exceed those of any period in at least the last 100 000 years”, Burgess said.
Records were broken on every continent. In Europe, 2023 was the second-warmest year on record, at 0.17°C cooler than 2020.
Last year saw the beginning of a naturally occurring El Niño weather phenomenon, which warms waters in the southern Pacific and stokes hotter weather beyond.
The phenomenon is expected to reach its peak in 2024, and is linked to the eight consecutive months of record heat from June to December.
Ocean temperatures globally were also “persistently and unusually high”, with many seasonal records broken since April. These unprecedented ocean temperatures caused marine heatwaves devastating to aquatic life and boosted the intensity of storms.