Although it is important to control emissions of CO2 to mitigate global warming, atmospheric levels of the gas are also related to how quickly it is removed from the air by the means of land and ocean storage. The micronutrient iron is crucial for oceanic carbon storage because it can support the production of chemical energy in marine ecosystems by photosynthesis (known as iron fertilization), a process that converts CO2 into O2 and organic compounds.
It is generally thought that iron inputs from the atmosphere to the ocean primarily come from natural sources. However, a study reported in npj Climate and Atmospheric Science led by Associate Professor Hitoshi Matsui and Mingxu Liu of the Graduate School of Environmental Studies, Nagoya University, in collaboration with Cornell and Colorado Universities, found that the contribution of human-made iron in the Southern Ocean is probably much larger than previously thought. It may, in fact, be up to ten times higher. This may have implications for future environmental management.
The human-made contribution to iron is mostly produced by fossil fuel combustion, in which iron is released into the atmosphere and then transported to remote oceans. To better understand how human activities affect iron concentration levels, the scientists combined data obtained by aircraft measurement with an advanced global atmospheric model.
Read more at Nagoya University
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