U. study challenges iron levels theorized in Antarctica, skews climate change predictions

On Thursday, a study conducted by marine scientists from the Rutgers School of Environmental and Biological Sciences found that iron fertilization in Antarctica was far less common than theorized, skewing our understanding of climate change effects.

Comprehensive measurements of iron levels in Antarctic glaciers have revealed that their ice shelves produced far lower levels of iron through their melted water than previously believed, disproving a long-standing theory that “iron fertilization” from glaciers in particular would help mitigate the effects of climate change.

According to a press release on the study from Rutgers Today, iron fertilization sharply reduces carbon dioxide in the atmosphere by feeding it to algae. In showing that melted glacier water significantly lacks the iron to use in this process, the study recognizes that current climate change predictions may require significant adjustments.  

“Our claim in this paper is that the meltwater itself carries very little iron, and that most of the iron that it does carry comes from the grinding up and dissolving of bedrock into the liquid layer between the bedrock and the ice sheet, not from the ice that is driving sea level rise,” Rob Sherell, a professor in the Department of Marine and Coastal Sciences and chief investigator behind the study, said. 

In 2022, Sherell worked with a mixture of marine researchers from Rutgers, the greater U.S.and even the United Kingdom, to collect and closely analyze melted water directly from glaciers in the Amundsen Sea’s Dotson Ice Shelf. 

His findings were later published in the Communications Earth and Environment journal with the assistance of the study’s lead author Venkatesh Chinni, postdoctoral research associate in the Department of Marine and Coastal Research, working alongside Texas A&M University Oceanography Professors Jessica Fitzsimmons and Janelle Steffen. 

“Roughly 90 percent of the dissolved iron coming out of the ice shelf cavity comes from deep waters and sediments outside the cavity, not from meltwater,” Chinni said.