Marine nitrogen fixers mediate a low latitude pathway for atmospheric CO2 drawdown
"Roughly a third (~30 ppm) of the carbon dioxide (CO2) that entered the ocean during ice ages is attributed to biological mechanisms. A leading hypothesis for the biological drawdown of CO2 is iron (Fe) fertilisation of the high latitudes, but modelling efforts attribute at most 10 ppm to this mechanism, leaving ~20 ppm unexplained [...]"
Source: Nature Communications
Authors: Pearse J. Buchanan et al.