There’s an ominous new significance to the phrase ‘off the charts’, according to the World Meteorological Organization (WMO), with 2023 breaking every single climate indicator.

2023 was the warmest year on record and broke every other climate indicator, according to the World Meteorological Organization.  (Supplied: World Meteorological Organization)

The UN agency’s annual State of the Global Climate report confirmed it wasn’t just the hottest year on record, ocean heat reached its highest level since records began, global mean sea level also reached a record high and Antarctic sea ice reached a record low.

The impacts of extreme weather and climate events up-ended life for millions of people across the world and inflicted billions of dollars in economic losses, according to the WMO. 

“Extreme climate conditions exacerbated humanitarian crises, with millions experiencing acute food insecurity and hundreds of thousands displaced from their homes,” WMO Secretary General Professor Celeste Saulo said. 

“Heatwaves, floods, droughts, wildfires and intense tropical cyclones wreaked havoc on every continent and caused huge socio-economic losses.” 

In the arid landscape of Shyamnagar Union, Satkhira in Bangladesh, a young man braves the drought, trekking to a reservoir to collect water.(Supplied: Muhammad Amdad Hossain, World Meteorological Organization)

Hot waters

Ocean heat reached its highest level in the 65 years it’s been recorded, with the WMO’s analysis showing a strong increase in the past two decades.

The report found on an average day in 2023, nearly one third of the global ocean was gripped by a marine heatwave, harming vital ecosystems and food systems.

Towards the end of 2023, over 90 per cent of the ocean had experienced heatwave conditions at some point during the year.

Ocean heat content reached its highest level in 2023, the global ocean experienced an average daily marine heatwave coverage of 32 per cent, well above the previous record of 23 per cent in 2016.(Supplied: World Meteorological Organization)

That heating is expected to continue, with the report stating it could be ‘irreversible on scales of hundreds to thousands of years’. 

Oceans rising

Increased temperatures are not just impacting the warmth of the ocean, there are other flow on effects, including sea level rise.

“The ocean, which covers around 70 per cent of the Earth’s surface, absorbs heat and CO2, which can act to slow the rate of warming in the atmosphere,” the report explained. 

“However, the heat absorbed by the ocean leads to ocean warming which, together with the melting of ice on land, raises sea levels.

“The ocean also absorbs CO2 leading to ocean acidification.”

The report found, global mean sea level reached a record high, with the rate of sea level rise in the past 10 years more than doubling since the first decade of the satellite record (1993–2002).

Global mean sea level rise reached its highest level since records began, according to the World Meteorological Organization’s State of the Climate 2023. (Supplied: World Meteorological Organization)

Ice retreats

Glaciers in North America and the European Alps suffered massive losses after experiencing an extreme melt season, according to the WMO.

In Switzerland, glaciers lost around 10 per cent of their remaining volume in the last two years. 

It also found the global set of reference glaciers for the hydrological year 2022-2023 experienced the largest loss of ice on record from 1950-2023.

Glacier retreat is clearly visible in Alaska.(Supplied: Marcel Haefliger, World Meterological Organization)

Sea ice saw similar retreats, with Arctic sea ice extent well below normal and Antarctic sea ice at an absolute record low. 

“(Antarctic) Ice extent was at a record low for the time of year from June till early November, and the annual maximum in September was around 1 million km2 below the previous record low maximum,” the report said.

Greenhouse gases

Concentrations of the three main greenhouse gases, carbon dioxide, methane and nitrous oxide all reached record high observed levels.

“The long-term increase in global temperature is due to increased concentrations of greenhouse gases in the atmosphere,” the report stated. 

Global mean temperature graph showing 2023 was the hottest year on record. (Supplied: World Meteorological Organization)

The shift from La Niña to El Niño explains some of the rise of temperatures in 2023, but other factors, which are still being investigated, may also have contributed to the exceptional warming. 

Glimmers of hope

Despite the dire state of the climate, the WMO said there was a glimmer of hope, with the rapid expansion of renewable energy generation leading efforts to decarbonise.

It found added renewable capacity increased by 50 per cent compared to 2022, the highest rate observed in the past two decades.

WMO Secretary General Professor Celeste Saulo said she hoped the report will help to scale up the urgency and ambition of climate action and called for more resources for climate data and monitoring.

Secretary General of the World Meteorological Organization Professor Celeste Saulo says she hopes the state of the climate report will spur more urgent action.(Supplied: World Meterological Organization)

“Climate action is currently being hampered by a lack of capacity to deliver and use climate services to inform national mitigation and adaptation plans, especially in developing countries,” she said.

“We need to increase support for National Meteorological and Hydrological Services to be able to provide information services to ensure the next generation of Nationally Determined Contributions are based on science.”

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