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Wëssenschaftlech Publikatioun vum Dr. Charel Wohl ( am Journal Science - Advances

Mir gratuléieren dem Charel (vill vun Iech kennen hien vun onsem PSP-Classic Projet Dustbuster) fir des prestigiéis Publikatioun !

Emissions of unexpected gases from marine life affect the air and climate over the poles !

Such is the main conclusion of a new study by the Institut de Ciències del Mar (ICM-CSIC), the Instituto de Química Física Rocasolano (IQFR-CSIC) and the Plymouth Marine Laboratory (PML).

The work reveals that trace atmospheric gases thought to be pollutants are also produced by marine plankton and emitted by the ocean, with potential climatic effects.

The air we breathe is much more than oxygen and nitrogen, even more than greenhouse gases like carbon dioxide. It also contains small amounts of many of organic gases, like benzene and toluene. These atmospheric compounds are important because they oxidize into little particles, called aerosols, that seed water condensation into droplets to form the clouds that filter solar radiation. Mathematical models of climate underestimate the amount of clouds, particularly in the Southern Ocean, and thus carry large uncertainties in climate projections.

"If we don't get the clouds right, we won't get the climate right," says Charel Wohl, ICM-CSIC researcher and lead author of the study, who adds that "we just begin to unveil the multiple ingredients that form cloud seeds”.

The study published now in the journal Science Advances reports the first measurements of benzene and toluene in the polar oceans and indicates that these compounds have a biological origin. Until now, the occurrence of these compounds in polar marine air was thought to be a sign of the far-reaching spread of human pollution from coal and oil burning and the use of solvents.

The breath of the sea in the pre-industrial times

The only way to investigate how the composition of the atmosphere was regulated before the profound impacts of human activities in the industrial era is to study the regions of today’s cleanest air. The authors took measurements of benzene and toluene in the surface seawater and the overlying air during two oceanographic campaigns: one in the Arctic and one in the Southern Ocean. The distribution of these gases, their relationship to the amount of phytoplankton, and the fact that the ocean was constantly emitting them into the air, instead of capturing them from the air, led the researchers to the conclusion that they had a biological origin.

Later on, by incorporating the data into a global model of atmospheric chemistry and climate, researchers noticed that ocean-borne benzene and toluene were significant contributors to aerosol production, particularly in the extremely clean, non-polluted atmosphere over the Southern Ocean, where these two gases increased the mass of organic aerosols by 8%, and up to 80% in transient events.

According to the authors, most likely, the natural effect of marine benzene and toluene on atmospheric chemistry was a globally widespread phenomenon before the Industrial Revolution and is now masked by the widespread impact of pollution. In any case, “climate models will have to consider the emissions of benzene and toluene from the oceans if they want to get clouds right in climate projections towards both the past and future”, affirms Alfonso Saiz-López of the IQFR-CSIC, who was responsible for the atmospheric modeling part.

Another co-author of the study, ICM-CSIC researcher Rafel Simó, adds that “this is another example of how millions of years of evolution have shaped the interactions between the ocean and the atmosphere in such a way that ocean life has not only adapted to climate but has contributed to regulate it”.

For future research, the team will further study the impact of marine microscopic life on the atmosphere. In fact, in two weeks the authors of the study published now will travel to Antarctic waters again to confirm the current finding and make further measurements.

Reference article

Wohl, C., Q. Li, C. A. Cuevas, R. P. Fernandez, M. Yang, A. Saiz-López, R. Simó. 2023. Marine biogenic emissions of benzene and toluene and their contribution to secondary organic aerosols over the polar oceans. Science Advances 9: eadd90319, doi: 10.1126/sciadv.add9031.

Researchers contact

Charel Wohl |

Rafel Simó |

Alfonso Saiz-López |

About the ICM The Institut de Ciències del Mar (ICM) is the fourth largest research institute of the Spanish National Research Council (CSIC) and the largest dedicated to marine research. Under the motto “Ocean Science for a Healthy Planet,” the ICM conducts frontier research and foster both knowledge and technology transfer on topics related to ocean and climate interactions, conservation and sustainable use of marine life and ecosystems, and impact mitigation of natural and anthropogenic hazards. In-depth knowledge, determined action, and coordinated management are essential to confronting these global challenges, thereby driving sustainable development of humankind. In 2020, the ICM was awarded with the Severo Ochoa Centre of Excellence accreditation, further promoting ICM’s leadership role in marine research in Spain with a relevant commitment to generating societal impact.

(c) Pressrelease January 2023, by R. Simó