Last year was the hottest on record, with a global average temperature at 1.45°C above pre-industrial levels, the World Meteorological Organisation (WMO) confirmed today.
The global average temperature for 2023 "shattered the record of the previous warmest years", which were 2016 and 2020 — at 1.29°C and 1.27°C above the pre-industrial average respectively, the WMO said. The Paris climate agreement seeks to limit global warming to "well below" 2°C above pre-industrial levels, and preferably to 1.5°C.
The average global temperature in the 2014-23 period was 1.2°C above the pre-industrial average, making the past 10 years the warmest on record, the WMO said in its State of the Global Climate 2023 report. Climate science uses the period 1850-1900 as the baseline for a pre-industrial average.
"The long-term increase in global temperature is due to increased concentrations of greenhouse gases (GHGs) in the atmosphere", the WMO said. GHG concentrations hit record high levels in 2022 and real-time data show that levels continued to rise in 2023, it added.
The global mean sea level also reached a record high in 2023, based on satellite records going back to 1993. The rise in the past 10 years is more than twice the rate of increase over 1993-2002, the WMO said.
The organisation's final report outlines a higher temperature increase than in its provisional State of the Global Climate 2023, which it released in November just ahead of the UN Cop 28 climate summit.
The El Nino weather phenomenon, which began in 2023 and typically results in higher temperatures, was partly behind the record heat in 2023. But although this is weakening, it often drives even hotter weather in its second year. There is a "high probability for 2024 to break the record", WMO climate monitoring chief Omar Baddour said today.
Cost of climate inaction
The organisation pointed to finance — which lies at the heart of the energy transition. But the "cost of climate inaction is higher than [the] cost of climate action", it said.
"Extreme weather and climate events had major socio-economic impacts on all inhabited continents" in 2023, it noted.
The cost of inaction is estimated at $1,266 trillion over 2025-2100, although that is "likely to be a dramatic underestimate", the WMO said. That is "the difference in losses under a business-as-usual scenario and those incurred within a 1.5°C pathway", it said. A business-as-usual pathway is equivalent to a temperature rise of around 3°C above the pre-industrial baseline.
Climate finance will be a key topic at Cop 29, to be held in November in Baku, Azerbaijan.
