"Parforce" an EU-funded research project has discovered a new link between marine algae and climate change. Researchers working on the project found out that iodine vapours, released from algae or plankton, condense over oceans to form aerosols. These aerosols, which tend to counter "global warming", can have a significant impact on climate change as well as on precipitation patterns. "This new discovery represents a major breakthrough in the prediction of climate change, as no current prediction model takes this fact into account" says Commissioner for research Philippe Busquin.Aerosols have an important influence on climate regulation since they contribute to the Earth's "heat shield" through the formation of haze and cloud layers. Aerosols work in a way opposite to greenhouse gases: greenhouse gases trap heat escaping from the Earth's surface and lead to "global warming", while aerosols block heat from reaching the surface where it is absorbed, and may have a "global cooling" effect.
All aerosol types contribute to the "heat shield", but marine aerosols formed over oceans are its most important source, as oceans cover 70% of the Earth's surface.
What nobody knew until now was that algae and plankton are an important natural source of iodine-oxide aerosols. It was thought that the main source of oceanic aerosols were their emissions of sulphur compounds.
Increasing oceanic biological activity (of algae or plankton) resulting from changes in ocean temperatures, can lead to increased iodine vapour emissions, which in turn, can lead to an increased abundance of aerosol particles. The iodine vapour released from algae is in the form of methyl-iodine molecules, which react with sunlight and ozone to produce iodine-oxide aerosol particles.
Thus, increasing the availability of aerosols will increase the solar blocking efficiency of the haze and cloud layers. Such a trend comprises a global cooling effect that could partially offset global warming from greenhouse gases.
Also, an increased abundance of aerosols will lead to a reduction in precipitation, and therefore longer-lived clouds further adding to the effect.
Experimental field studies into the phenomenon were made on the Irish Atlantic coast, and now the researchers are investigating whether this transformation occurs on a large oceanic-scale. In this regard, the research team (EU project PARFORCE), led by Professor Colin O'Dowd (National University of Ireland, Galway) and comprising a total of 15 research groups and dozens of scientists from Ireland, Finland, Sweden, Germany, UK and The Netherlands (see Annex), have also collaborated with US scientists from the California Institute of Technology to unravel the new process producing marine aerosols.
This research discovery has been recently reported in the scientific journal Nature (June 6).
Research at the European Commission
Nature magazine
