Understanding the role of Arctic sea ice on climate change

ACCESS models and expertise of researchers have helped significantly to understand the role of Artic sea-ice as an important modulator of global climate.

The Arctic sea-ice is an important modulator of global climate and its long-term changes can significantly affect the climate change in both hemispheres through teleconnections. Therefore, a realistic simulation of sea-ice in the Arctic (and the Antarctic) is an important performance indicator for climate models, including ACCESS.

A recent study analysed and compared the evolution of Arctic sea-ice area and volume in forty CMIP6 models, including ACCESS-ESM1.5 and ACCESS-CM2 with CMIP3 and CMIP5 model results. While the newer and older models agreed on some aspects, a larger fraction of CMIP6 models captured the observed sensitivity of Arctic sea ice to human-caused emissions and global warming.

The CMIP6 models simulate a large spread for when Arctic sea-ice area is predicted to become practically sea-ice free (below one million square kilometer sea-ice area). However, the clear majority of all models, including ACCESS, project that the Arctic will become almost sea-ice free in September by the end of the century under both a medium (SSP2-RCP4.5) and high (SSP5-RCP8.5) emissions scenario.