The Barcelona Supercomputing Center is one of the four Global Producing Centres among the 15 institutions that contributed to the Lead Centre for Annual-to-Decadal Climate Predictions, providing the basis for the report
The forecasts indicate that it is very likely (more than 80% probability) that at least one year in the period 2024-2028 will exceed the warmest year on record, 2023, with the possibility of one exceeding 1.5°C above pre-industrial values.
The World Meteorological Organization (WMO) has just released the Global Annual to Decadal Climate Update (GADCU) for 2024 and the range 2024-2028. Issued annually by the WMO, it is a report that synthesises the global multi-model initialised predictions from an annual to a decadal range produced by the WMO-designated Global Producing Centres and other contributing centres for the coming 5-years.
The Barcelona Supercomputing Center-Centro Nacional de Supercomputación (BSC-CNS) is one of the four Global Producing Centres included in the WMO Lead Centre for Annual-to-Decadal Climate Prediction, together with the Canadian Centre for Climate Modelling and Analysis, Deutscher Wetterdienst, and the Met Office. The Lead Center collects and disseminates hindcasts, forecasts and verification data from several contributing centres worldwide.
Roberto Bilbao, a researcher at the Climate Variability and Change (CVC) group at the Earth Sciences Department of BSC, stated: “Since it was appointed a Global Producing Center by WMO in 2018, the BSC has issued every new year a decadal prediction outlook, working in parallel on different developments to improve the accuracy of these predictions.”
This year, 15 different decadal prediction centres have contributed to the report, forming a large ensemble of 190 forecasts. These predictions suggest that for the next five years (2024-2028), global temperatures will continue to hit record levels, and the mean near-surface temperature for each year between 2024 and 2028 is predicted to be between 1.1°C and 1.9°C higher than the average over the years 1850-1900. There is an 80% chance that global mean near-surface temperature will exceed 1.5°C above the preindustrial levels (1850-1900 average) for at least one year between 2024 and 2028.
Moreover, the report also states that there is a 47% probability that the five-year mean will exceed the threshold of 1.5°C. It must be noted that the 1.5°C-level specified in the Paris Agreement refers to long-term warming over 20 years. Still, temporary exceedances are expected to occur with increasing frequency as global temperatures approach the long-term threshold.
The results also indicate a high probability (86%) that at least one year between 2024 and 2028 will exceed the warmest year on record so far, which was last year, 2023. Also, the five-year average for 2024-2028 will very likely be higher than the previous five years, i.e. 2019-2023 (with a 90% probability).
Markus Donat, ICREA Professor and co-leader of the BSC’s Climate Variability and Change group, commented: “These predictions confirm that despite the possible year-to-year variations, where individual years can be slightly warmer or cooler than previous years, the global climate is still on a concerning warming trajectory, which is bringing us very close to breaching the goals that global leaders agreed upon in Paris in 2015.”
Near-surface temperatures in 2023 showed conditions in most regions were warmer than the long-term average, with a warmer tropical East Pacific, consistent with El Niño conditions, which prevailed for most of the year. In this direction, the report also notes that the 2023-24 El Niño has peaked, and a transition to La Niña will likely occur in 2024. This change in the outlook is expected to be accompanied by warming over the Arctic in the next five extended winters (November to March), relative to the 1991-2020 average, which will be more than three times the global average temperature warming.
Pablo Ortega, the other co-leader of the same group at BSC, explained: “These substantially warmer conditions in the Arctic are due to the presence of critical mechanisms between the sea ice and the ocean that amplify the local warming and could lead shortly to the first ice-free summer.”
Projected precipitation patterns for 2024, relative to the 1991-2020 average, suggest a higher probability of low precipitation in northeastern Brazil and a higher probability of wet conditions in the African Sahel, consistent with warmer-than-usual temperatures in the North Atlantic. In addition, forecast conditions in the North Atlantic for May-September 2024-2028 indicate above-average tropical cyclone activity. In fact, already for 2024, the BSC's Seasonal Hurricane Prediction platform foresees a highly active Atlantic hurricane season.