Climate change is affecting Arctic ozone depletion

Climate change will slow the recovery of the ozone layer in the Arctic stratosphere and may even increase ozone depletion, according to a recent study published in the science journal Nature Communications.

In the paper, long-term meteorological data of polar stratospheric cloud (PSC) formation temperatures is analyzed. PSCs contribute to Arctic ozone depletion by both releasing chlorine and in some cases by redistributing HNO3 in the atmosphere. The released chlorine effectively depletes ozone.

Based on the meteorological data, an increase in PSC formation potential is observed in the period 1980-2020. By analyzing long-term stratospheric temperature records, it is found that during years 1965-1979 low temperatures that allowed formation of PSCs occurred very rarely, compared to the latest decades of stratospheric temperature observations.

The study suggests that future greenhouse gas emissions and their mitigation will have a significant impact on the Arctic ozone layer. According to 52 climate models used in the study, it is possible that Arctic ozone depletion will continue at current levels at least until 2100. Alternatively, it cannot be excluded that ozone depletion could even intensify during this century, given the projected increase in stratospheric water vapor.

Climate change mitigation is therefore also important for the ozone layer and ozone depletion. Ozone filters out much of the sun’s harmful UV radiation, so depletion of the ozone layer in the Arctic stratosphere may result in higher levels of UV radiation.

The research was led by Alfred Wegener Institute, Potsdam, Germany (lead author Dr. Peter von der Gathen), and was jointly conducted with the University of Maryland and the Finnish Meteorological Institute’s Space and Earth Observation Centre (FMI-SPACE).

More information:

Senior Research Scientist Dr. Rigel Kivi, Finnish Meteorological Institute, name.surname@fmi.fi

Original publication: Peter von der Gathen, Rigel Kivi, Ingo Wohltmann, Ross Salawitch, and Markus Rex: “Climate change favours large seasonal loss of Arctic ozone”, Nature Communications, 23 June 2021, doi:10.1038/s41467-021-24089-6.