Global warming reached 1.48 degrees Celsius in 2023, data published on Tuesday showed, as the world’s warmest year on record left the world just hundredths of a degree shy of a critical climate threshold.
Analyzes from last year had already confirmed that 2023 would be the warmest year on record, but Tuesday’s data shows an alarming jump in warming compared to 2016, previously the warmest year. In 2023, the average global temperature was 14.98 degrees Celsius – 0.17 degrees above the previous record – while ocean warming also reached a new high.
Scientists have repeatedly expressed shock as back-to-back heat records fell in 2023, warning that the world is moving dangerously close to the 1.5 degree limit that nearly 200 countries sought to avoid in the 2015 Paris Agreement.
The data and an analysis published by Copernicus – the EU’s climate and weather monitoring agency – say global warming could worsen early this year, predicting that a twelve-month period ending in January or February is likely to be the 1, will exceed 5 degrees.
But scientists are much more concerned about long-term warming of 1.5 degrees or more – than about individual years. Above that threshold, many of Earth’s ecosystems will struggle to adapt, and summer heat will approach the limits of human survival in some places.
The unprecedented heat in 2023 was mainly caused by climate change, Copernicus said, but was exacerbated by El Niño, a natural climate variability that increases the heat of the Pacific Ocean and typically raises global temperatures.
While some scientists have said the 1.48 degree warming is in line with last year’s heat records, others are still surprised at how much hotter 2023 was compared to previous years.
“It is a shock that this year has undeniably broken the global temperature record,” said Bill Collins, a professor of climate processes at the University of Reading in Britain. “There is no room for arguing about hundredths of a degree here; exceeding the previous record by 0.17 degrees should be a wake-up call for everyone.”
In 2023, the average temperature on Earth every day was at least 1 degree warmer than the corresponding day in the pre-industrial period 1850-1900, according to Copernicus. That’s the first time this has happened.
Global temperatures have risen steadily since the 1970s, until 2015 marked the first time a degree of global warming was exceeded, according to historical temperature data from Copernicus. It took just eight years to reach another half degree above pre-industrial levels.
Even compared to the past thirty years, when temperatures were warmer, 2023 stands out. The year was 0.6 degrees Celsius warmer than the 1991-2020 average.
Temperatures are rising ‘exponentially’
Several months ago, there was a prediction among the scientific community that warming would be about 1.3 degrees by 2023, said Liz Bentley, CEO of Britain’s Royal Meteorological Society. That forecast has been “destroyed,” she said, as temperature records have fallen at regional, national and international levels around the world, including daily and monthly records.
Other thresholds are also being exceeded: two days in November were more than 2 degrees warmer for the first time. Every month in 2023 between June and December was the warmest month on record. Overall, July and August were the first and second warmest on record, Copernicus said.
Given the declining records, Bentley said, it wasn’t so much the 1.48 degree temperature increase that was surprising, but the pace of climate change in recent years.
“If you look at climate projections, when we expect temperature changes of almost 1.5 degrees Celsius, it has indeed come sooner than many expected,” Bentley told CNN. “We’ve definitely seen an acceleration in that direction, rather than it being kind of a linear progression. It feels like it’s increasing exponentially a lot.”
Annual average air temperatures were either the hottest or nearly the hottest ever recorded over all ocean basins and all continents except Australia, the Copernicus data show. This temperature increase covers almost the entire world map.
The year of record heat, with deadly extreme weather events including wildfires in Canada, Hawaii and southern Europe, “has given us a taste of the climate extremes happening near the Paris targets,” said Brian Hoskins, president of the Grantham Institute. , Imperial College London.
“It should shake the complacency evident in the actions of most governments around the world,” he said.
The world’s oceans also experienced unprecedented heat, remaining unusually warm in 2023. Sea surface temperatures were 0.44 degrees above the 1991–2020 average, the highest on record and a jump from the 0.26 degree increase in 2016, the second warmest year.
The main long-term factor behind the alarming heat of the oceans is fossil fuel pollution, but El Niño – which started in July – has also contributed. Higher sea surface temperatures can lead to more powerful hurricanes, typhoons and tropical cyclones.
At the end of the hottest year on record, almost 200 countries represented at the COP28 climate talks in Dubai last month agreed for the first time to contribute to a global transition away from fossil fuels, the main cause of the climate crisis. The deal was widely welcomed, but critics say it has holes that leave major fossil fuel producing countries with little action to take.
“The extremes we have observed in recent months are dramatic evidence of how far we are now from the climate in which our civilization developed,” said Carlo Buontempo, director of Copernicus’ Climate Change Service. “This has profound implications for the Paris Agreement and all human endeavors. If we are to successfully manage our climate risk portfolio, we must urgently decarbonize our economy while using climate data and knowledge to prepare for the future.”
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