New Zealand’s Antarctic Science Platform – a government-funded research organisation – is hosting an emergency summit today to discuss the continued decline of Antarctica’s sea ice due to human-induced climate change and global warming.
Antarctica’s sea ice has recorded a record low this winter. Maximum winter levels in 2023 are at their lowest since satellite monitoring began in the late 1970s.
One of the organisers of the event is Dr Natalie Robinson, a marine physicist with the National Institute of Water and Atmospheric Research (NIWA) in New Zealand.
“Antarctic sea ice and the Southern Ocean are major drivers of global climate,” Robinson writes in an email to Cosmos.
Robinson explains that the topic of Antarctica’s sea ice decline has topped the agenda at recent international conferences that she and her colleagues have attended. But their goal was to better understand the processes and effects.
“We therefore decided to hold the summit in order to gain a better understanding of this extraordinary event, and it’s potential impacts, from a range of expert perspectives,” Robinson tells Cosmos. “The summit seeks to enhance dialogue between scientists across disciplines and provide rapid updates for stakeholders with an emphasis on the public.”
“Australian researchers have identified that this current low likely represents a shift to a new regime for sea ice – driven, at least in part, by warming of the Southern Ocean. Since we anticipate only continued warming of the Southern Ocean (in at least the short-to-medium term), we can similarly expect continued decline in Antarctic sea ice,” Robinson explains.
She notes that the complexity of the climate and its effects on a large system like the Southern Ocean mean an exact prognosis isn’t possible. But it still doesn’t look good for Antarctica’s sea ice.
Robinson highlights 5 ways in which Antarctic sea ice is important for the global climate:
- The “Albedo effect”: Antarctica’s vast ice sheets reflect about 90% of solar radiation back out into space. This prevents it from being absorbed into the Earth’s system which would cause heating. By contrast, the oceans absorb about 90% of this radiation.
- Ocean overturning: As Antarctica’s ice sheets form, they produce huge amounts of cold, salty waters. This controls how heat and nutrients are distributed throughout Earth’s oceans.
- Heat drawdown: The ice sheets help draw heat out of the atmosphere, into the ocean depths.
- CO2 drawdown: Similar to heat drawdown, the ice sheets deliver CO2 into the deepest ocean basins.
- Ecosystem support: Algae call the vast ice sheet surfaces home. This algae is the foundation for entire marine food webs. Emperor penguins rely on the ice sheets for breeding.
The panel event was called at short notice, owing to the desperate situation. Its members are New Zealand-based researchers from fields covering oceanography, remote sea ice sensing, impacts of ice loss on the climate, ocean heat content and heat transport, ocean acidification and deoxygenation, primary productivity and carbon drawdown, seafloor ecology, atmospheric warming, weather extremes, Indigenous perspectives, and polar biodiversity.
Event organisers say the summit will highlight not only the dire situation, but the measures required to stop it.
“It is the emissions from fossil fuels that has brought us to this point,” Robinson says. “The first priority must therefore be to drastically and urgently reduce our reliance on fossil fuels.”
