A new study has linked the role between sea ice across the Southern Ocean and Co2 levels during times of climate change.
Science Daily reported that the study could provide a much needed resource for developing future climate change models.
The international team of researchers, led by Keele University and including experts from the University of Exeter, “demonstrated that seasonal growth and destruction of sea ice in a warming world enhances the amount of marine life present in the sea around Antarctica, which draws down carbon from the atmosphere and stores it in the deep ocean.”
According to the study, the Southern Ocean has captured “half of all human-related carbon,” which has entered the ocean.
Based on that fact, the Southern Ocean around Antarctica is a very important area to examine. Essentially, these researchers attempted to pinpoint why this area is so effective as a “carbon sink,” and then use those conclusions to reduce the uncertainty of future climate change models.
To understand this process further, the researchers studied data relating to one period where atmospheric CO2 levels changed rapidly.This occurred after the Last Ice Age, around 18,000 years ago, when the world transitioned naturally into the warm interglacial world we live in today.During this period, CO2 rose rapidly from around 190 parts per million (ppm) to 280 ppm over around 7,000 years, but one period in particular stands out; a 1,900 year period where CO2 levels plateaued at a nearly constant level of 240 ppm.The cause of this plateau, which occurred around 14,600 years ago, is unknown, but understanding what happened during this period could be crucial for improving climate change projections.Professor John Love, from Exeter’s Biosciences department and co-author of the study said: “My research group and I are very excited about being part of this important investigation. We developed new techniques in cell biology to find, collect and analyse the rare and very tiny particles and cells that had been frozen in the ice for millennia.“Like flies in amber, these minute fragments give us a unique window into past events, enabling our colleagues in the Earth, Atmosphere and Ocean sciences to develop a better understanding of climate change then, and now.”Lead author Professor Chris Fogwill, Director of Keele University’s Institute for Sustainable Futures said: “The cause of this long plateau in global atmospheric CO2 levels may be fundamental to understanding the potential of the Southern Ocean to moderate atmospheric CO2.”
Professor Chris Turney, a visiting Fellow at Keele’s Institute for Liberal Arts and Sciences from UNSW Sydney said: “Instead of drilling kilometres into the ice, we can simply walk across a blue ice area and travel back through time.“This provides the opportunity to sample large amounts of ice for studying past environmental changes in detail. Organic biomarkers and DNA from the Southern Ocean are blown onto Antarctica and preserved in the ice, providing a unique record in a region where we have few scientific observations.”
This modelling revealed that the plateau period coincided with the greatest seasonal changes in sea ice during a pronounced cold phase across the Southern Ocean known as the Antarctic Cold Reversal. During this period, sea ice grew extensively across the Southern Ocean, but as the world was warming rapidly, each year the sea ice would be rapidly destroyed during the summer.The researchers will now use these findings to underpin the development of future climate change models. The inclusion of sea ice processes that control climate-carbon feedbacks in a new generation of models will be crucial for reducing uncertainties surrounding climate projections and will help society adapt to future warming.