Café scientifique - how the realm of microscopic oceanic algae influences our climate

The microscopic unicellular algae living in the lighted portion of the  oceans, which are called phytoplankton, have a photosynthetic  activity, like all plants on Earth. Through this process that depends  on sunlight impinging the ocean surface, they take up carbon dioxide  (CO2) and synthesize organic matter. Although they are small, their numbers and, above all, their capacity to double their  biomass roughly every two days, allows generating a staggering amount of ca. 50 billion tons of organic matter.

This is as much as what all terrestrial plants also produce every year.  The overall World oceans phytoplankton biomass is however about 500  times smaller than that of terrestrial plants, which testifies of their  excellent efficiency in turning CO2 into biomass. The  presentation will show how satellite Earth observations have  revolutionised knowledge about these processes, and how phytoplankton  are part  of the global carbon cycle and hence have a role in regulating the  climate of our Planet.

Prof. David Antoine currently leads the Remote Sensing and  Satellite Research Group at Curtin university, Perth (RSSRG; http://rssrg.org).  He is also a senior  scientist with the Centre National de La Recherche Scientifique (CNRS)  in France, with which he still has ties. He holds a PhD in  oceanography from the University Pierre et Marie Curie, Paris. His  research over years has encompassed a number of topics from marine  optics to satellite remote sensing, all together aiming at better  quantifying phytoplankton in the oceans, their productivity, and their  long-term changes in response to environmental changes.