Global warming could increase the amount of carbon dioxide that is released from the ocean.
Researchers looked at 26,000-year-old sediment core from the gulf of California to see how the ocean's ability to absorb atmospheric CO2 has changed over the centuries, a University of Edinburgh news release reported.
They looked at the concentrations of silicon and iron in tiny marine organisms in the sample. Plankton is responsible for the absorption of CO2 from the to atmosphere.
The team found that when silicon and iron were least abundant in the water were the times when the climate was the warmest and the ocean absorbed the most CO2.
The findings suggest iron concentrations at the ocean's surface can limit how other elements absorb carbon.
"This effect is magnified in the southern ocean and equatorial Pacific and coastal areas, which are known to play a crucial role in influencing levels of CO2 in the global atmosphere," the news release reported.
The findings are the first to identify a link between carbon and other key elements that have an affect on how much atmospheric carbon is absorbed by the ocean.
The researchers' findings were backed up by a "global calculation for all oceans," the news release reported.
"Iron is known to be a key nutrient for plankton, but we were surprised by the many ways in which iron affects the CO2 given off by the oceans. If warming climates lower iron levels at the sea surface, as occurred in the past, this is bad news for the environment," Doctor Laetitia Pichevin, of the University of Edinburgh's School of GeoSciences, who led the study, said in the news release.
"The study, published in Nature Geoscience, was supported by Scottish Alliance for Geoscience Environment Society and the Natural Environment Research Council," the news release reported.
