2025 was planet's third hottest year on record

Planet Earth has just lived through its third-warmest year on record, EU scientists said on Wednesday.

Last year was also the hottest on record for Antarctica, another alarm bell that climate change is even catching up with the remote, ice-covered continent that for decades appeared sheltered from it.

Read more: Why Antarctica could hold key to our future

For the planet as a whole, 2025 came in as the third-hottest on records going back to 1940, according to new data from the European Centre ⁠for Medium-Range Weather Forecasts (ECMWF).

Although the world has experienced other hot periods many thousands of years ago, the danger now is how quickly it is warming, making it hard for people and nature to adapt.

Last year's heat made extreme weather more dangerous, including the intensity of Hurricane Melissa in the Caribbean and monsoon rains in Pakistan that killed more than 1,000 people.

It also drove "nationally significant" water problems in the UK during its record hot summer.

How hot was 2025?

In 2025, average temperatures on Earth's surface clocked in at 1.47C - higher than levels 150 years ago - following 1.6C in 2024, the warmest on record, and 2023 in second place.

The unprecedented heat of those past three years inched the world closer to a point it has been trying to avoid.

Under the landmark Paris Agreement, from 2015, governments agreed to try to limit global warming to ideally 1.5C above levels before humans started burning fossil fuels at scale.

That's because climate impacts beyond that point become more dangerous, costly and disruptive - and some will be irreversible.

But temperatures across the past three-year period averaged 1.5C.

While such heat would have to last for five years before it is classed as a long-term trend, scientists now think that could happen as soon as 2030 - a decade earlier than had been predicted when the Paris treaty was ‍signed.

Samantha Burgess, strategic lead for climate at ECMWF, said: "1.5C is not a cliff edge. However, we know that every fraction of a degree matters, particularly for worsening ‌extreme weather events."

Why was 2025 so hot?

Two main causes have been blamed for the heat of the past three years.

The periodic El Nino weather pattern, which pumps out heat from the Pacific Ocean, added to heat in 2023 and 2024.

But it had subsided by 2025, revealing the persistent, long-term warming trend driven by human-made climate change, scientists said.

Helen Clarkson, chief executive of the Climate Group, said we are now "witnessing human-driven warming in real time".

She added: "Energy and food security, the ability to insure our homes, economic productivity, it's all at risk."

Political pushback

Just as climate impacts worsen, efforts and science to tackle it are being strained.

In the UK, the long-standing political consensus on zeroing out emissions - known as net zero - collapsed last year.

Meanwhile President Donald Trump is pulling the United States out of scores of climate initiatives, including the Paris Agreement and UN science body the IPCC.

This retreat of the world's biggest economy is straining efforts by other countries to reign in climate change, such as last year's COP30 climate summit and proposals to add a green tax to shipping.

But it has not sparked a widespread collapse of climate action that some feared, with most countries maintaining their climate targets - albeit with delivery scientists warn is far too slow.

Bob Ward, of London's Grantham Research Institute on Climate Change and the Environment, said: "Temperatures will continue to rise until the world reaches net zero emissions of greenhouse gases by making the transition away from fossil fuels."

(c) Sky News 2026: 2025 was planet's third hottest year on record