Record temperatures in 2024 on land and at sea have prompted scientists to question whether these anomalies are in line with predicted global heating patterns or if they represent a concerning acceleration of climate breakdown.
Heat above the oceans remains persistently, freakishly high, despite a weakening of El Niño, which has been one of the major drivers of record global temperatures over the past year.
Scientists are divided about the extraordinary temperatures of marine air. Some stress that current trends are within climate model projections of how the world will warm as a result of human burning of fossil fuels and forests. Others are perplexed and worried by the speed of change because the seas are the Earth’s great heat moderator and absorb more than 90% of anthropogenic warming.
Earlier this month, the World Meteorological Organization announced that El Niño, a naturally occurring climate pattern associated with the warming of the Pacific Ocean, had peaked and there was an 80% chance of it fading completely between April and June, although its knock-on effects would continue.
The WMO secretary general, Celeste Saulo, said El Niño contributed to making 2023 easily the warmest year on record, although the main culprit was emissions from fossil fuels.
When it came to oceans, she said, the picture was murkier and more disturbing: “The January 2024 sea surface temperature was by far the highest on record for January. This is worrying and can not be explained by El Niño alone.”
Sea surface temperatures in February were also hotter than any month in history, breaking the record set last August, according to Europe’s Copernicus satellite monitoring programme.
Worldwide, the heat above the land and sea was remarkable. Between 8 and 11 February, global temperatures were more than 2C above the 1850-1900 average. Over the month as a whole, Europe experienced heat that was 3.3C above that benchmark.
Carlo Buontempo, the director of the Copernicus Climate Change Service, said it was a taste of what was to come because of the increase of greenhouse gases in the atmosphere: “Unless we manage to stabilise those, we will inevitably face new global temperature records and their consequences.”
Heat records are becoming the norm, but the extent of the anomaly above the seas has prompted concern.
Carlos Nobre, one of Brazil’s most influential climatologists, said no climate model accurately predicted how high sea surface temperatures would reach during the past 12 months. Given the continued heat over the sea, he said 2024 was likely to be another unusually hot year for the world as a whole.
The anomaly is strongest in the North Atlantic, where Brian McNoldy, a climatologist at the University of Miami, calculated the deviation from statistical averages as a one-in-284,000-year event. “It has been record-breaking warm for an entire year, often by seemingly impossible margins,” he tweeted. He has described the trends as “deeply troubling”.
Zeke Hausfather, a scientist at Berkeley Earth in the US, said global sea and surface temperatures were “quite high” but he said they were still well within the projections of climate models: “We don’t have any strong evidence yet from observations that suggests the world is warming faster than anticipated given human emissions.”
The impacts on corals and other forms of marine life are incalculable. Australia’s Great Barrier Reef is suffering its fifth mass bleaching event in eight years. Meteorologists warn that high surface temperatures may also presage a longer and more active hurricane season.
Raúl Cordero, a climate professor at the University of Groningen and the University of Santiago, said the growing possibility of a cooling La Niña between June and August could bring respite from the global heat, but this would only be temporary: “All recent temperature records will likely be broken sooner rather than later. The situation will continue to deteriorate until we halt the burning of fossil fuels.”
