Carbon dioxide released by the ocean thousands of years ago may have ended the ice age

UK (Next Media) – Recent research conducted by the University of Southampton and published in Nature magazine suggests that carbon dioxide released from the ocean played a large role in ending the most recent ice age.

The studies were based on analyzing the calcium carbonate shells in plankton that lived in the ocean thousands of years ago. By examining the shells of microbes called foraminifera, which preserves the ratio of chemicals in seawater as they grow, researchers were able to determine the concentration of dissolved inorganic carbon in ocean water thousands of years ago.

Research points to a huge, sudden rise in dissolved carbon concentrations in the surface water of the Atlantic Ocean and in the eastern equatorial Pacific Ocean at the end of the last ice age. This sudden rise in concentration corresponds to the simultaneously increasing levels of atmospheric carbon dioxide.

Based on these findings, scientists suggest that at that point in time, upwellings in the Southern Atlantic Ocean and the eastern Pacific Ocean occurred. This caused isolated reservoirs of cold, carbon-rich waters to churn up to the surface. There’s a high concentration of dissolved carbon at greater depths in the ocean because waste and decay fall to the bottom of the ocean and some of the carbon is further retained in calcium carbonate shells like those examined in this recent study.

The upwelling reconnected large concentrations of carbon with the water surface where it readily transformed into carbon dioxide and was absorbed into the atmosphere. As a greenhouse gas, carbon dioxide in the atmosphere absorbed solar energy and thereby warmed the atmosphere. As the oceans began to warm as a consequence, the oceans are also unable to absorb as much atmospheric carbon dioxide and this continues to lead to an increasingly warm atmosphere.

SOURCES: BBC, Nature, Science Daily, Nature World News