Spiralling weather impacts were experienced across the planet in 2024 leading to “massive economic and social upheavals from extreme weather”, the World Meteorological Organisation (WMO) has said.
In its annual review of the global climate published on Wednesday, the UN agency said “clear signs of human-induced climate change reached new heights in 2024″, with some consequences “irreversible over hundreds, if not thousands of years”.
Last year was likely to be the first with average temperatures of more than 1.5 degrees above the pre-industrial era, with a global “mean near-surface temperature” of 1.55 degrees above the 1850-1900 average – the warmest year in 175 years of observations.
It is still possible to keep global average temperatures to within 1.5 degrees, the WMO says, while that critical target under the Paris Agreement to limit the worst climate impacts – measured over several decades – has not been exceeded.
The report, however, shows atmospheric concentrations of carbon dioxide, which fuels warming, are at the highest levels in the past 800,000 years.
Globally, each of the past 10 years were individually the 10 warmest years on record while each of the past eight years has set a new record for ocean heat content. Ireland had its fourth warmest year on record.
The 18 lowest “Arctic sea-ice extents” on record were all in the past 18 years, while the three lowest Antarctic ice extents were in the past three years. The largest three-year loss of glacier mass on record occurred in the past three years, the report said, coinciding with the rate of sea-level rise doubling since satellite measurements began.
Of key global climate indicators, ocean warming and sea-level rise are accelerating.
[ Hottest year on record as 2024 breaks 1.5 degrees global warming limitOpens in new window ]
“Our planet is issuing more distress signals – but this report shows limiting long-term global temperature rise to 1.5 degrees 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,” said UN secretary general António Guterres.
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
— Prof Celeste Saulo
“While a single year above 1.5 degrees of warming does not indicate 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,” said WMO secretary general Celeste Saulo.
Record temperatures of 2023, which were in turn broken in 2024, were mainly due to an ongoing rise in greenhouse gas emissions, coupled with a shift from a natural cooling La Niña to a warming El Niño event in the Pacific.
Other factors may have contributed to unexpectedly unusual temperature jumps, “including changes in the solar cycle, a massive volcanic eruption and a decrease in cooling aerosols”. Temperatures, however, are just a small part of a bigger picture, the report adds.
“Our oceans continued to warm, and sea levels continued to rise. 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. Meanwhile, extreme weather continues to have devastating consequences around the world,” Prof Saulo said.
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 huge economic losses.
“In response, [the] WMO and the global community are intensifying efforts to strengthen early warning systems and climate services to help decision-makers and society at large be more resilient to extreme weather and climate.
“We are making progress but need to go further and need to go faster. Only half of all countries worldwide have adequate early warning systems,” Prof Saulo said.
Investment in weather, water and climate services is more important than ever to meet challenges and build more resilient communities, she added.
WMO experts are examining longer-term warming trends to ensure reliable tracking of temperature changes. “Regardless of methodology used, every fraction of a degree of warming matters and increases risks and costs to society,” Prof Saulo said.
