New Antarctica data reveals ‘tipping point’ for ice melt

Scientists say new research, looking into temperature changes in the Antarctic Ocean over the past 45 million years, paints a worrying picture for the future.

The study’s lead author, Dr Bella Duncan from the Antarctic Research Center, says it’s the first ever catalog of its kind with this range of data.

“My research focuses on looking at times in the past when we had higher CO2 and higher temperatures,” says Duncan.

“The record we’ve produced shows there is a direct response of Antarctic temperature to changing atmospheric CO2 throughout geological time.”

Using molecular fossils from core samples taken during ocean drilling, she and her team have been able to analyze archaea.

Archaea are single-celled organisms similar to bacteria, that adjust composition in response to changing sea temperatures.

By studying these changes, scientists can draw conclusions about the ancient sea temperature at the time a particular sample died.

Analyzing this gives scientists an insight into what might happen going forward, according to Professor Tim Naish, director of the Antarctic Research Center.

“The records Bella has are of a time when CO2 was above 400 parts per million, like it is now,” says Naish.

“If we keep CO2 at that level we will lose a lot of the Antarctic ice sheet and end up with tens of meters of sea level rise, we’re close to that tipping point.”

The research adds to a raft of data pointing towards potentially catastrophic climate change in the Antarctic.

“It’s another nail in that scientific coffin, and we don’t want to end up talking about coffins, but we’re close to a stability threshold for the ice sheet,” says Naish.

Earlier this year the Government released its first emissions reduction plan, in line with global efforts to limit temperature rise to 1.5 degrees Celsius above pre-industrial levels.

According to Naish, the science has been clear for decades.

“If we had acted years ago on this information we would be a lot better off and it would be easier to deal with the climate crisis.”

Duncan says she hopes this research provides more clarity on how global warming is impacting the world’s largest mass of ice.

“Hopefully this work just keeps adding to our pool of knowledge about what is going to be happening in the future with Antarctica.”