'A measure of optimism': University of Newcastle researchers reveal Southern Ocean's climate power

It is the chance discovery that University of Newcastle researchers say provides renewed optimism in the fight against climate change, with an analysis of a calcite crust deposit found in a dry Antarctic valley revealing that lessons from Earth’s past could help shape the future.

It began after New Zealand researcher Paul Augustinus took samples from the deposit while stranded in Antarctica’s Boggs Valley during a snowstorm. The samples found their way to UON crystal expert Silvia Frisia, who saw their value in providing a snapshot of another time.

What followed was an interdisciplinary study that showed the Southern Ocean’s ability, through large algal blooms, to act as a “biological pump” for carbon.

Associate Professor Frisia said the team discovered that a sub-glacial volcanic eruption 24,000 years ago had created a large lake underneath the ice sheet.

As that lake drained, she said, water was enriched with iron – a key ingredient in the creation of large algal blooms.

“The iron is a very important micro-nutrient. It fertilises the ocean and forms those algal blooms,” she said. “The algae captures the carbon and puts it deep down into the ocean.”

Associate Professor Frisia said the research provided a “measure of optimism” in that iron fertilisation could be used as a means to slow down climate change.

“Maybe this could be a trick we could use to help the biological pump speed up a little bit,” she said.

“It’s not an excuse for people to behave badly, but it provides a measure of optimism. Without advancing scientific knowledge, we wouldn’t know the many possibilities we could use.”

Fellow UON researcher Dr Andrew Borsato also hoped the study would help advance knowledge of climate change.

“Currently scientists are exploring the idea of imitating the process that fertilises the Southern Ocean with iron to replicate past natural sequestration events,” he said.

“We hope by understanding the past we can better help present research to counteract the effects of climate warming and, hopefully, better plan for the future.”

The results of the study were published in the journal Nature Communications.