The World Meteorological Organization (WMO) has released its annual assessment of the state of the global climate. The report shows that 2023 broke records for greenhouse gas (GHG) levels, surface temperatures, ocean heat and acidification, sea level rise, Antarctic sea ice cover, and glacier retreat. It highlights the potential of renewable energy to help achieve decarbonization targets, warning that the cost of inaction is higher than the cost of action.

The ‘State of the Global Climate 2023’ report confirms that 2023 was the warmest year on record, with the global average near-surface temperature at 1.45°C (with a margin of uncertainty of ± 0.12°C) above pre-industrial levels. It was also the warmest ten-year period on record.

“Never have we been so close – albeit on a temporary basis at the moment – to the 1.5°C lower limit of the Paris Agreement on climate change,” said WMO Secretary-General Celeste Saulo. 

The report shows that on an average day in 2023, almost one-third of the global ocean was affected by a “marine heatwave,” damaging vital ecosystems. Towards the end of 2023, more than 90% of the ocean had undergone heatwave conditions at some point during the year.

According to the report, the global set of reference glaciers experienced the largest loss of ice on record since 1950, and Antarctic sea ice extent was the lowest on record “by far,” having shrunk by an equivalent of the size of France and Germany combined compared to the previous record year.

In addition, the report identifies weather and climate extremes as aggravating factors driving global food insecurity. They also undermine resilience and create new protection risks among the most vulnerable populations, it warns.

“The impact on sustainable development is devastating,” lamented UN Secretary-General António Guterres in video message on the occasion of the report’s launch. He urged climate leaders to “match[] the speed of climate change with radical climate action that aligns with sustainable development.”

Highlighting the role of renewable energy in achieving decarbonization targets, the report shows that renewable capacity additions increased in 2023 by almost 50% from 2022, to a total of 510 gigawatts (GW). This is the highest rate of growth observed in the past two decades.

However, there is a large financing gap, the report warns. For a 1.5°C pathway, annual climate finance investments need to grow more than six-fold, to nearly USD 9 trillion by 2030 and a further USD 10 trillion through to 2050, according to the report. At the same time, the cost of inaction is even higher, estimated at USD 1,266 trillion. This figure reflects “the difference in losses under a business-as-usual scenario and those incurred within a 1.5°C pathway,” and is likely to be “a dramatic underestimate.”

The State of the Global Climate report was released on 19 March 2024, ahead of World Meteorological Day on 23 March. It sets the scene for a new climate action campaign by the UN Development Programme (UNDP) and WMO that launched on 21 March. It also informed deliberations at a climate ministerial meeting in Copenhagen, Denmark, from 21-22 March, where leaders discussed enhancing countries’ nationally determined contributions (NDCs) ahead of the February 2025 deadline. [Publication: State of the Global Climate 2023] [Publication Landing Page] [WMO Press Release] [UN News Story]