A newly identified greenhouse gas shatters all other records for the chemical’s potential to contribute to climate change.
Perfluorotributylamine (PFTBA) is the most radiatively efficient chemical found to date. Radiative efficiency describes how effectively a molecule can affect climate. This value is then multiplied by its atmospheric concentration to determine the total climate impact.
PFTBA has been in use since the mid-20th century for various applications in electrical equipment and is currently used in thermally and chemically stable liquids marketed for use in electronic testing and as heat transfer agents.
It is produced by humans and does not occur naturally. There are no known processes that would destroy or remove PFTBA in the lower atmosphere so it has a very long lifetime, possibly hundreds of years, and is destroyed in the upper atmosphere.
“Global warming potential is a metric used to compare the cumulative effects of different greenhouse gases on climate over a specified time period,” says Cora Young, who was part of the University of Toronto team that discovered the gas.
Time is incorporated in the global warming potential metric as different compounds stay in the atmosphere for different lengths of time, which determines how long-lasting the climate impacts are.
Carbon dioxide (CO2) is used as the baseline for comparison since it is the most important greenhouse gas responsible for human-induced climate change.
“PFTBA is extremely long-lived in the atmosphere and it has a very high radiative efficiency; the result of this is a very high global warming potential. Calculated over a 100-year timeframe, a single molecule of PFTBA has the equivalent climate impact as 7,100 molecules of CO2,” says team member Angela Hong.
The Natural Sciences and Engineering Research Council of Canada funded the study, which was published in the journal Geophysical Research Letters.
Source: University of Toronto