Marine life, and particularly microscopic plankton, influence climate over long and short time scales. In the long term they do this by shaping the biogeochemical cycles of elements (such as C, O, N, P, Si, S, Fe) essential for Earth-system functioning. In the short term they do it by exchanging climate-active gases with the atmosphere. Here we focuse on the short term effects. Oceans influence heat retention in the atmosphere by the exchange of green-house gases, regulate atmospheric photochemistry through the emission of oxidant scavengers and radical precursors, and influence the energy budget of the atmosphere (and, by extension, of the planet) through the emissios of primary aerosols and secondary aerosol and cloud precursors. For example, the oceans represent the largest natural source of tropospheric sulfur, with associated significant consequences for planetary albedo, and they compete with continents as emittors of primary aerosols in the form of sea-salt crystals, organic polymers and microorganisms. Ongoing international initiatives for global data integration, together with the invaluable information registered by remote sensing from satellites, are revealing that marine micorbiota do not only influence the properties and behavior of their host oceans but also leave their footprint in the ocean's sky. A further evidence of the complex and fascinating architecture of our living planet

Peer Reviewed