Confirmed: 2024 was the hottest year on record in the air and the oceans

Last year was the hottest recorded year in history at 1.55 degrees above the pre-industrial period; the past 10 years are the 10 hottest on record, and greenhouse gas levels in the atmosphere are at their highest in 800,000 years, the World Meteorological Organisation has reported.

The report by the WMO, which serves as the United Nations’ lead agency on climate and weather, finds that the world’s oceans were hotter in 2024 than any other year on record and that each of the past eight years set a new record for ocean heat. The rate of ocean warming is now twice as fast as it was before 2005.

This confirms an analysis published over recent months from other international climate observation organisations.

Sea levels reached a record high in 2024, and the rate of sea level rise has doubled since satellite measurements began, the WMO analysis shows, while the largest glacier loss on record occurred over the years 2022 to 2024.

Last year was the first year during which the world passed the 1.5-degree limit set out by world governments in the Paris Agreement, which only considers the target breached when average temperatures have been above that level for 20 years.

“While a single year above 1.5 degrees Celsius of warming does not indicate that the long-term temperature goals of the Paris Agreement are out of reach, it is a wake-up call that we are increasing the risks to our lives, economies and to the planet,” the organisation’s secretary-general, Andrea Celeste Saulo, said.

UN Secretary-General António Guterres said: “Our planet is issuing more distress signals – but this report shows that limiting long-term global temperature rise to 1.5 degrees Celsius is still possible. Leaders must step up to make it happen – seizing the benefits of cheap, clean renewables for their people and economies – with new national climate plans due this year.”

The current long-term average level of human-induced global warming is estimated at 1.34 to 1.41 degrees above the 1850-1900 baseline.

The extreme temperatures caused massive disruption around the world.

“The frozen parts of Earth’s surface, known as the cryosphere, are melting at an alarming rate: glaciers continue to retreat, and Antarctic sea ice reached its second-lowest extent ever recorded,” Celeste Saulo said.

“Meanwhile, extreme weather continues to have devastating consequences around the world.”

Tropical cyclones, floods, droughts, and other hazards in 2024 led to the highest number of new displacements recorded for the past 16 years, contributed to worsening food crises, and caused massive economic losses.

There were at least 151 “unprecedented” extreme weather events recorded in 2024, and the year saw 824,000 people around the world displaced by such events, the highest number since 2008.

The record global temperatures seen in 2023 and broken in 2024 were mainly due to the ongoing rise in greenhouse gas emissions, coupled with a shift from a cooling La Nina to a warming El Nino event, says the report.

Flooding in Lismore, northern NSW, early last year.Credit: Getty Images

Other factors accelerating the warming may include changes in the solar cycle, a massive volcanic eruption and a decrease in airborne pollution that may have been “masking” warming.

Between December last year and January this year at least one in five people globally felt a strong climate change influence every day, a second report published on Wednesday has found.

The study by Climate Central, a US-based group of independent climate scientists, found
394 million people were exposed to 30 or more days of risky heat added by climate change, defined as days with temperatures hotter than 90 per cent of local temperatures recorded from 1991 to 2020.

Australians experienced an average 35 risky heat days over the studied period, 15 of which were added by climate change.

Of Australian states, Victoria suffered the largest heat anomaly, with average temperatures 1.4 degrees above the 1991-2020 normal.

“Climate change is not a distant threat but a present reality to millions,” said Dr Kristina Dahl, head of Climate Central’s science program. “The increasing frequency and severity of heat events around the world reveal a dangerous pattern of heat exposure that will only worsen if the burning of fossil fuel continues.”

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