Arctic sea ice hit a monthly record low last month while sea surface temperatures reached the second-highest on record, contributing to what climate scientists have now confirmed to the hottest January on record.

It’s a result that has mystified some climate scientists, that, despite the world now officially within a La Niña weather pattern period of supposed global cooling, a run of record-breaking global temperatures has continued.

The Copernicus Climate Change Service said last month was in fact the warmest January on record, with surface air temperatures 1.75°C above pre-industrial levels. It made it the 18th month out of the last 19 to record global-average surface temperatures above that critical 1.5°C pre-industrial marker.

Under the Paris climate agreement, world leaders committed to doing what they could to keep global temperatures from rising by more than 1.5°C above those pre-industrial levels. Only last month, Copernicus – an EU-funded Earth observation programme – told us that global temperatures averaged across 2023 and 2024 had exceeded 1.5°C for the first time.

While startling, this did not – the Copernicus Climate Change Service stressed – represent a permanent breach of the long-term 1.5°C target under the Paris climate accord, but that it was a “clear sign” the limit was being tested. Despite the current track record, scientists at Copernicus say the latest January results have come as a surprise.

Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts, said: “January 2025 is another surprising month, continuing the record temperatures observed throughout the last two years, despite the development of La Niña conditions in the tropical Pacific and their temporary cooling effect on global temperatures.

“Copernicus will continue to closely monitor ocean temperatures and their influence on our evolving climate throughout 2025.”

Last month saw Arctic sea ice reach its lowest monthly extent for January, putting it at 6% below average and almost tied with sea ice cover from January 2018. Across the Arctic region, sea ice concentration anomalies were well below average in the eastern Canadian sector, including Hudson Bay and the Labrador Sea, as well as in the northern Barents Sea.

Copernicus has said that it will closely monitor ocean temperatures for hints about how the climate might behave. The EU monitor uses billions of measurements from satellites, ships, aircraft, and weather stations to aid its calculations. The ocean will continue to be a crucial focal point for such measurements owing to its vital role as a climate regulator and carbon sink.

The ocean stores some 90% of the excess heat trapped by humanity’s release of greenhouse gases, something that scientists unanimously agree has contributed greatly to current record temperatures. Yet, despite the evidence oil and gas drilling continues. 

President Donald Trump made light work of removing the US from the 2015 Paris Accord within the first few hours of his return to office last month with the promise to expand on domestic oil and gas infrastructure under the rhetoric ‘drill baby, drill’. The move, while unsurprising, still came as a major blow to global efforts to reduce greenhouse gas emission levels and mitigate the worst impact of climate change.

Climate activists were forced, therefore, to take their wins from elsewhere and earlier this month, that came in the form of a court decision to temporarily halt developments across the UK’s Rosebank and Jackdaw oil and gas fields. Situated off the coast of Shetland, the Rosebank is the UK’s largest area of currently untapped oil.

Last week, Scottish courts decided that the consent given to the energy companies invested in the sites – Shell, Equinor, and Ithaca – had been done so unlawfully. It was the ruling that the consent had been granted without giving full consideration to the extent of greenhouse gas emissions that would derive from the project.

The ruling has given pause to current developments until a reassessment is made and consent is granted in light of the full-extent of the project’s scope 1, scope 2, and scope 3 greenhouse gas emissions.

While climate campaigners have taken the win for now, Equinor’s CEO Anders Opedal has told the BBC this week that “plans will go ahead” sharing his belief that consent “will come swiftly” from the UK government who has previously stated that the “UK is open to business”. 

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