While it is normally understood that marine biogeochemical processes strongly depend on the physical drivers, but less so in the converse, here the authors demonstrate that nonlinear responses are present in a series of experiments that modify the absorption rate of light based on chlorophyll concentrations. While the leading order mechanism is clear (more absorption, less radiative forcing on the ocean), the more detailed governing mechanisms for the oceanic response are less obvious, and the authors provide some investigations towards that end with a focus on tropical regions. They also suggest that the ongoing observed decrease in tropical Atlantic chlorophyll-a concentration may weaken the interannual variability of sea surface temperature.