by Global warming in 2023 hit 1.48 degrees Celsius, data published on Tuesday show, as the hottest year on record left the world just one hundredth of a degree away from a critical climate threshold.
Last year’s analysis already confirmed that 2023 would be the hottest on record, but Tuesday’s data shows an alarming jump in warming since 2016, the previous hottest year. In 2023, the global average temperature was 14.98 degrees Celsius – 0.17 degrees above the previous record – and warming in the world’s oceans also hit a new high.
Scientists have repeatedly expressed shock in 2023 when consecutive heat records fell, and warned that the world is moving dangerously close to the 1.5 degree limit that almost 200 countries sought to avoid in the Paris Agreement in 2015.
The data and analysis, published by Copernicus – the EU’s climate and weather monitoring agency – says global warming could worsen at the start of this year, predicting that a 12-month period ending in January or February is likely to exceed 1.5 degrees .
But scientists are far more concerned about a long-term scenario of warming of 1.5 degrees and above – rather than individual years. Above that threshold, many of the Earth’s ecosystems will struggle to adapt and the 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 mainly exacerbated by El Niño, a natural climate variability that heats the Pacific Ocean and raises global temperatures.
Although some scientists have said that the 1.48 degree warming is in line with last year’s heat records, others are still surprised by how hot 2023 has been in recent years.
“It’s a big surprise that this year just broke the global temperature record,” said Bill Collins, professor of climate processes at the University of Reading in the UK. “There is no chance here to make up a few hundredths of a degree, going over the previous record by 0.17 degrees should be a wake-up call to everyone.”
Every day in 2023, the average global temperature was at least 1 degree warmer than the corresponding day in the pre-industrial period 1850-1900, Copernicus said. That’s the first time on record that’s happened.
Global temperatures have been steadily increasing since the 1970s, until 1 degree of global warming was exceeded for the first time in 2015, according to historical temperature data from Copernicus. It took only eight years to jump another half step above pre-industrial levels.
Even compared to the last thirty years, when the temperature was warmer, 2023 stands out. The year was 0.6 degrees Celsius warmer than the 1991-2020 average.
Temperatures rising ‘more exponentially’
Several months ago, there was a prediction among the scientific community that warming would hit about 1.3 degrees in 2023, said Liz Bentley, chief executive of the United Kingdom’s Royal Meteorological Society. That prediction is “unbroken,” she said, as temperature records have fallen at the regional, national and international levels around the world, including daily and monthly records.
Other thresholds are also being crossed – two days in November were, for the first time, more than 2 degrees warmer. Every month in 2023 between June and December was the hottest month on record. July and August were the first and second warmest on record, overall, Copernicus said.
Given the tumbling records, Bentley said, it wasn’t the 1.48-degree temperature rise that was surprising but the pace of climate change in recent years.
“If you look at climate projections, when we expect to see temperature changes close to 1.5 degrees Celsius, it actually came earlier than many would have expected,” Bentley told CNN. “We’ve definitely seen an acceleration in that, rather than it being kind of a linear progression. It feels like it’s rising much more exponentially.”
Average annual air temperatures were the warmest, or near the warmest, on record across all ocean basins and continents, except Australia, the Copernicus data show. That temperature rise covers almost the entire world map.
The hottest year on record, which saw deadly extreme weather events, including wildfires in Canada, Hawaii and southern Europe, “gave us a taste of the climate extremes that happen close to the Paris targets,” Brian said. Hoskins, chairman of the Grantham Institute. , Imperial College London.
“It should shake the complacency shown in the actions taken by most governments around the world,” he said.
The world’s oceans also experienced unprecedented warmth and remained extremely warm in 2023. Sea surface temperatures were 0.44 degrees above the 1991-2020 average, the highest level on record and a jump from the 0.26 degree increase seen in 2016, the second warmest year.
The main long-term factor behind the alarming warming of the oceans is fossil fuel pollution, but El Niño – which began in July – also contributed. Higher sea surface temperatures can lead to more powerful hurricanes, typhoons and tropical cyclones.
At the tail end of the hottest year on record, nearly 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 there were loopholes that would have allowed major fossil fuel-producing nations to take small action.
“The extremes we have seen in the last few months provide great evidence of how far we are now from the climate in which our civilization developed,” said Carlo Buontempo, director of the Copernicus Climate Change Service. “This has major consequences for the Paris Agreement and all human endeavours. If we want to successfully manage our climate risk portfolio, we must urgently decarbonise our economy and use climate data and knowledge to prepare for the future.”
For more CNN news and newsletters create an account at CNN.com
