Chlorofluorocarbons (CFCs): an imminent threat

CFCs, or chlorofluorocarbons, are gases with a huge environmental impact. They represent the greatest threat to the precious layer of oxygen that protects the earth from ultraviolet radiation. This is why the Montreal protocol has forbidden their use and production in industry.

Researchers at MIT (Massachusetts Institute of Technology) however, have discovered the existence of natural sources which continue to release CFCs into the atmosphere. This phenomenon relates to CFC-11, a substance which previously used in the production of refrigerants and insulation materials and subsequently banned in 2010.

The oceans and CFC absorption

One of the most important methods previously relied upon to contain and combat CFC-related pollution is the oceans. This precious ally has always played a crucial role in the absorption of chlorofluorocarbons, especially in the case of CFC-11.

It is estimated that, on average, the seas and oceans are able to process 5-10% of total global CFC-11 emissions, by storing it at depth in a completely natural process. It is no coincidence that marine CFCs were long used as trackers in the study of ocean currents.

This has made a significant contribution to highlighting the drastic decrease in the concentration of gas in the ozone layer but while this was previously considered beneficial for man, the latest discoveries have become cause for concern among researchers.

For years, the absorption of CFCs by the oceans went un-noticed, as people believed that their capacity to store these dangerous gases was virtually limitless. MIT academics have however realised that this is not the case and that the seas will soon reach saturation point.

Consequences of saturation and its repercussions on the atmosphere

Although peak saturation is expected to be reached in about 2075, the most worrying event will take place during the 55 years after that. The oceans will stop absorbing CFCs and will start to release them into the atmosphere in quantities similar to those produced by a nation who does fails to observe the Montreal protocol.

Further estimates suggest that if man does not start to reduce the level of pollutant emissions, the process described above could take place ten years earlier than originally calculated.

This is due to the fact that global warming, determined by the lack of a shield against ultraviolet radiation, will lead to increases in ocean temperatures and a consequent reduction in their capacity for absorption.

Simulations via comparison of complex models

In order to understand the impact of climate change on the oceans’ capacity to absorb CFCs, researchers at MIT used a hierarchy of models in their simulations.

They began with a simple model of the atmosphere and the upper and lower layers of the ocean, repeating the experiment for the northern and southern hemispheres. They then added the anthropogenic CFC-11 emissions recorded in previous years.

The simulation took into account the years from 1930 until the present day and the results obtained were coherent with what is actually taking place now. This allowed scientists to verify the calculations mentioned above as reliable, including figures which indicate that by 2145, the oceans will have started to release CFCs.

This extremely important discovery will help future researchers to avoid potential errors in the formulation of hypotheses and perhaps help them to prepare a plan of action in order to intervene effectively.

Translated by Joanne Beckwith