According to new research, ozone in the lower atmosphere contributed more than previously thought to warming in the Southern Ocean, which absorbs much of the planet’s surplus heat. The findings reveal that ozone is more than simply a pollutant; it may also be contributing to climate change.
According to new study, ozone may be weakening one of the planet’s most critical cooling systems, making it a more significant greenhouse gas than previously thought.
Changes in ozone levels in the upper and lower atmosphere were shown to be responsible for over a third of the warming recorded in ocean waters surrounding Antarctica in the second half of the twentieth century, according to a recent research.
The Southern Ocean’s deep and rapid warming has an impact on its position as one of the primary locations for absorbing surplus heat as the earth heats.
The majority of this warming was caused by higher levels of ozone in the lower atmosphere. Ozone, one of the primary components of smog, is already a dangerous pollutant, but new study suggests it may also play a key role in climate change in the coming years.
One of the study’s authors, Dr Michaela Hegglin, an Associate Professor of atmospheric chemistry, said: “People and the environment are both harmed by ozone near the Earth’s surface, but this study shows that it also has a significant impact on the ocean’s ability to absorb excess heat from the atmosphere.
“These findings are eye-opening and underscore the necessity of regulating air pollution to avoid higher ozone levels and additional rises in global temperatures.”
The new study, conducted by the University of California Riverside, was published in Nature Climate Change by an international team of experts.
The researchers utilised models to mimic variations in ozone levels in the upper and lower atmosphere between 1955 and 2000 in order to isolate them from other impacts and improve our knowledge of their impact on Southern Ocean heat absorption, which is presently lacking.
These simulations indicated that a drop in upper-atmosphere ozone and an increase in the lower-atmosphere ozone both contributed to the warming found in the upper 2km of ocean waters at high latitudes due to overall greenhouse gas concentrations.
They discovered that increasing ozone in the lower atmosphere was responsible for 60% of the overall ozone-induced warming in the Southern Ocean during the study period, significantly more than previously anticipated. This was unexpected because increases in tropospheric ozone are typically thought of as a climatic forcing in the Northern Hemisphere, where the majority of pollution occurs.
When a hole in the ozone layer was detected high in the sky above the South Pole in the 1980s, it was attributed to damage caused by chlorofluorocarbons (CFCs), a chemical used in industrial and consumer items.
The ozone layer is essential because it prevents harmful UV radiation from reaching the surface of the Earth. The Montreal Protocol, an international agreement to phase down the use of CFCs, was born as a result of this discovery.
Dr. Hegglin explained: “We’ve known for a long time that ozone depletion high in the stratosphere has influenced the Southern Hemisphere’s surface temperature. Ozone rises in the lower atmosphere owing to air pollution, which mostly happens in the Northern Hemisphere and ‘leaks’ into the Southern Hemisphere, is a severe concern, according to our research.
“There is hope for finding answers, and the Montreal Protocol’s achievement in reducing CFC use demonstrates that international action can be taken to minimise environmental damage.”
The interaction of oxygen molecules with UV light from the sun produces ozone in the upper atmosphere. Chemical interactions between pollutants such as automobile exhaust fumes and other pollution cause it to develop in the lower atmosphere.
Changes in ozone concentrations in the atmosphere impact westerly winds in the Southern Hemisphere, as well as salt and temperature levels near the surface of the Southern Ocean. Both have different effects on ocean currents, which affects ocean heat uptake.
