Methane (CH4) is a fuel with high potential, and enormous quantities are buried underground in the form of natural gas. Also present in the atmosphere, methane is now the second most important greenhouse gas, after carbon dioxide (CO2). Today, 20% of global warming is attributed to methane.
However, the natural processes responsible for CH4 emissions remain ill-defined, especially the role of aquatic environments. Indeed, it is estimated that marine emissions account for 2 to 20% of all natural emissions.
The Groupe Interdisciplinaire d'Etude sur le Climat [Interdisciplinary Group on Climate Research] (GIEC) has observed that most of the CH4 released into marine water bodies could pass into the atmosphere in the form of CO2. The residence time of CH4 is around 50 years for surface waters up to 500 meters deep, and as long as several hundred years for the deepest waters.
The objective of the research team led by Cédric Boulart – CNRS Sorbonne Université / Station Biologique de Roscoff – is to take better account of the role of marine methane in greenhouse gas balances.
The project also aims to evaluate the dynamics of CH4 in varied oceanic systems with a view to providing answers to the following questions:
Cédric Boulart's team is working on the development of new techniques for taking in-situ high-resolution measurements to take into account the great spatial and temporal variability of methane emissions.
The researchers are implementing a new piece of equipment, an In-Situ Mass Spectrometer (ISMS), which allows concentrations of dissolved gases like CH4 and CO2 to be measured in real time during various sea missions.
These offshore missions are carried out in three very contrasting environments:
The Air Liquide Foundation's grant is being used to purchase equipment, including the in-situ mass spectrometer.