HFC-125 is a potent greenhouse gas that contributes significantly to global warming. Used mainly in cooling systems and fire extinguishers, its concentration in the atmosphere has increased exponentially over the past two decades. A recent Canadian study measured its levels in the upper troposphere and lower stratosphere for the first time using satellite data. These results reveal the scale of the problem and underline the urgency of taking measures to limit its impact.
What is HFC-125 and why is it of concern?
The HFC-125 belongs to the family of hydrofluorocarbons (HFCs), synthetic gases created to replace chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). These were once used in aerosols and refrigerators before being phased out because they depleted the ozone layer.
Although HFCs, including HFC-125, have no effect on ozone, they pose another major problem. Commonly used as a refrigerant in air conditioners and refrigerators, as well as in fire extinguishing systems, they have a global warming potential (GWP) of approximately 3,500 times higher than carbon dioxide (CO₂) over a period of 100 years. This means that a small amount of HFC-125 in the atmosphere has a much greater effect on the climate than an equivalent amount of CO₂.
Measuring HFC-125 from space: a world first
Until recently, HFC-125 concentrations were measured only at ground level or in the lower layers of the atmosphere. These data, although valuable, did not provide sufficient overview to fully understand the distribution of this gas in the Earth's atmosphere.
To overcome this gap, a team of researchers from the University of Waterloo, under contract with the Canadian Space Agency, used the satellite ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer). In orbit since 2004, its mission is to collect data on the composition of the Earth's atmosphere. Using this technology, scientists were able to measure HFC-125 concentrations in the high troposphere and lower stratospherebetween 11 and 25 kilometers above sea level.
These satellite measurements offer a global perspective and unrivaled precision. They provide a better understanding not only of the geographic distribution of HFC-125, but also of its evolution over time.
An alarming increase
The results of this study are concerning. Since 2004, the concentration of HFC-125 in the atmosphere has been multiplied by tenan exponential growth which reflects the increase in its use in the industry. This rapid increase is directly linked to the growing demand for cooling systems and fire-fighting equipment, particularly in emerging countries where these technologies are developing rapidly.
This trend is all the more worrying since HFC-125 stays in the atmosphere for a long timehelping to trap heat and worsen global warming. If no action is taken to limit its use, its concentrations will continue to increase, thus accentuating the negative impacts on the climate.
Towards international regulation
Faced with this situation, the international community has already begun to act. HFCs, including HFC-125, are regulated by the Kigali Amendment to the Montreal Protocol. This treaty, initially designed to protect the ozone layer, was expanded to include powerful greenhouse gases like HFCs. The objective is to gradually reduce their production and use, while encouraging the development of alternatives that are less harmful to the environment.
The study carried out by the Canadian team reinforces the importance of these regulations. Researchers hope that, as was the case with CFCs and HCFCs, international efforts will soon see a reduction in HFC-125 concentrations in the atmosphere. However, they also emphasize that these measures must be applied quickly and effectively to avoid irreversible climate consequences.
Related News :