by K. Richard, Nov 6, 2023 in NoTricksZone
Significant 21st century cooling in the Central Pacific, Eastern Pacific, and nearly all of Antarctica “implies substantial uncertainties in future temperature projections of CMIP6 models.” – Zhang et al., 2023
New research indicates West Antarctica’s mean annual surface temperatures cooled by more than -1.8°C (-0.93°C per decade) from 1999-2018. In spring, the West Antarctic Ice Sheet (WAIS) cooling rate reached -1.84°C per decade.
Not only has the WAIS undergone significant cooling in the last two decades, most of the continent also cooled by more than 1°C. See, for example, the ~1°C per decade cooling trend for East Antarctica (2000 to 2018) shown in Fig. ES1.
Of 28 CMIP6 models, none captured a cooling trend – especially of this amplitude – for this region. This modeling failure “implies substantial uncertainties in future temperature projections of CMIP6 models.
The post-1999 cooling trend has not just been confined to Antarctica. Sea surface temperatures (SSTs) in the Eastern and Central Pacific (south of 25°N) also cooled from 1999-2018 relative to 1979-1997. This cooling encompasses nearly half of the Southern Hemisphere’s SSTs.