Iron penetrating in the Pacific Ocean may cause a ripple effect that is leading to global climate change.
A new study by researchers from Texas A&M University shows at least eight occurrences of iron seeding in the Pacific coinciding with abrupt global climate change.
The researchers examined ocean sediment cores over the past 100,000 years and found that the iron likely came in the form of dust blown into the ocean during the last glacial period between 14,000 and 71,000 years ago.
Each pulse of iron resulted in a climate change event that affected temperatures, according to the study.
“Some of the dust dissolved and released iron to the surface waters of the ocean,” Franco Marcantonio, Ph.D., a professor in the Department of Geology and Geophysics said in a statement. “Each time the dust and iron were added to the surface ocean, we found that there was a corresponding pulse of algae growth.
“The timing of the pulses is associated with cooler temperatures in the northern hemisphere,” he added. “The connection to carbon dioxide levels is not clear but we do raise the provocative idea that the last time global carbon dioxide levels were rising in the past, adding iron to the equatorial Pacific Ocean may have acted to lower these levels to some extent.”
According to Marcantonio, some researchers believe that seeding the ocean with iron enables the capture of large amounts of carbon dioxide gas from the atmosphere.
“Plants need trace amounts of iron to photosynthesize,” he said. “So adding iron to the oceans would fertilize the growth of algae.”
Marcantonio explained that the algae would absorb more atmospheric carbon dioxide from the atmosphere and then sink to the seafloor when they die.
If a significant amount of atmospheric carbon dioxide is absorbed and removed from the atmosphere by algae and transported to the ocean, then the atmosphere may stop warming and get cooler.
