3.5 percent of global methane deposits could be melted by 2100 due to climate change

Spanish version: sl.ugr.es/metanoES 

French version: sl.ugr.es/metanoFR 

Researchers from the Andalusian Earth Sciences Institute (CSIC-University of Granada) and the University of Cambridge warn of the possibility that tons of this potent greenhouse gas reach the atmosphere

Their work, published in the renowned Nature Communications journal, has proven, through simulations, that in addition to the already known mechanisms, osmosis, another mechanism that has been ignored until now, may play a key role in this event

A team of researchers from the Andalusian Earth Sciences Institute (IACT, from its abbreviation in Spanish) (CSIC-University of Granada) and the University of Cambridge has proven that 3.5 percent of the world’s deposits of methane hydrate (equivalent to about 60,000 million tons of carbon) could begin to melt by 2100 due to climate change and the warming of ocean waters, a fact that would cause tons of this potent greenhouse gas to be discharged into the atmosphere.

This research, published in the renowned Nature Communications journal, has proven, through simulations, that in addition to known mechanisms, another previously unknown mechanism, osmosis (diffusion that takes place between two liquids or gases capable of mixing through a septum or semipermeable membrane), may play a key role in this event.

In addition to analyzing the theoretical understanding of this mechanism (osmotic pump), this work has for the first time highlighted the risk of under-studied climate change on methane hydrate deposits.

As explained by one of the authors of this paper, Julyan Cartwright, from the IACT (CSIC-UGR) and the Carlos I Institute of Theoretical and Computational Physics (UGR), «there are places under the seas and oceans where methane from lower rock layers emerges. We often find huge deposits of methane hydrates -solid material containing methane, a potent greenhouse gas- within the seabed. However, we must better understand and analyze if there is a risk that these deposits could be melted with climate change, thus discharging their methane to the environment».

Mud volcanoes and submarine seeps are phenomena in which a certain fluid (water, mud, sometimes gas bubbles) emerges from the seabed. «Using fluid dynamics we have calculated the forces associated with fluid flow of an emanation or a mud volcano», Silvana Cardoso from the department of Chemical Engineering and Biotechnology, University of Cambridge (UK), author of the paper, concludes.

1. Submarine mud volcano emitting water mixed with methane (NOAA, USA, public domain) [Credit: Sea Research Foundation (SRF) and Ocean Exploration Trust (OET)]

Bibliographic references:

Cardoso, S. S. S. & Cartwright, J. H. E. Increased methane emissions from deep osmotic and buoyant convection beneath submarine seeps as climate warms. Nat. Commun. 7, 13266

DOI: 10.1038/ncomms13266

Link to complete article: http://www.nature.com/articles/ncomms13266

Contact:

Julyan Cartwright

Instituto Andaluz de Ciencias de la Tierra (IACT) (CSIC-UGR)

E-mail: julyan.cartwright@csic.es

Silvana Cardoso

Reader in Fluid Mechanics and the Environment, Department of Chemical Engineering and Biotechnology, Cambridge, CB2 3RA, UK.

E-mail: sssc1@cam.ac.uk