The Council for Scientific and Industrial Research (CSIR) on Thursday highlighted the role one of its chief researchers played in the compiling of the US National Oceanic and Atmospheric Administration’s (NOAA’s) 2023 State of the Climate Report, which was published last month as a special supplement to the Bulletin of the American Meteorological Society. This was the thirty-fourth edition of the NOAA report, which is published annually.

CSIR chief researcher Dr Sandy Thomalla headed the team of 15 researchers (including herself) which produced the “Antarctica and the Southern Ocean” chapter of the report. The chapter was divided into seven sections, and while Thomalla’s team wrote it, the total number of experts involved in its compilation was 52. (In all, the complete 2023 NOAA report involved 592 experts from 59 countries, with 25 editors.)

For the report, Thomalla and her team assessed the climatological anomalies in critical biological and physical metrics in the Southern Ocean, during 2023. As has been widely reported, Southern Ocean sea ice coverage last year was at record low levels. This could indicate changes in the deeper processes that determine the condition of the sea ice.

“This analysis revealed substantial ocean warming, with mostly positive anomalies evident in sea-surface temperatures, ocean heat content and air-sea heat flux,” reported the CSIR. “These changes may be exacerbated by the warm conditions of the 2023 El Niño, with evidence of impacts on the ocean’s biochemistry. These significant findings highlight the impact of changing atmospheric-ocean dynamics.”

The findings were particularly concerning, given that the Southern Ocean had a central role in regulating the climate system. It accounted for 50% of all human-generated CO₂, and 75% of all human-generated heat, absorbed by the world’s oceans and seas.

“It has been a privilege to collaborate with international peers and experts working together to produce this important body of work that highlights the susceptibility of this critical ecosystem to change,” said Thomalla.