The ozone layer may recover more slowly than expected

The prediction of full recovery of the ozone layer by the middle of this century seems questionable now that researchers have discovered that ultraviolet radiation has recently become more successful at reaching the surface in some places on Earth.

In the 1980s, scientists sounded the alarm: The concentration of ozone in the stratosphere was declining, especially over Antarctica. And that was our fault. We pumped substances into the air that destroy the ozone layer. And this was a bad thing, because the ozone layer blocks ultraviolet radiation from the sun that is harmful to humans, animals and plants, and is therefore essential to life on Earth. Enough reason to save the ozone layer from destruction. A few years later I did Montreal Protocol on Substances that Deplete the Ozone Layer called to life. Governments around the world have signed this protocol, pledging to phase out production of substances that deplete the ozone layer. Governments put their money where their mouths are and since 2000 it has become clear that they have already led to the restoration of the ozone layer. Researchers recently predicted that the ozone layer – if we continue on this path – will return to normal within four decades.

New search
But new research published in the journal Advances in Atmospheric Sciences, now suggests that we may have cheered up too soon. In the study, scientists came to the conclusion that the amount of ultraviolet radiation that managed to reach the Earth’s surface has increased again in recent years, particularly in the northern hemisphere. It indicates that the ozone layer is recovering more slowly than previously thought. “Our study indicates that stratospheric ozone recovers particularly in the stratosphere and in the Southern Hemisphere,” said researcher Yan Xia. “But we also found that the concentration of ozone in the middle and lower parts of the stratosphere has been decreasing since 2010 between latitudes 30 and 60 north.”

the reasons
“The slow recovery of stratospheric ozone is highly unexpected,” Xia concludes. The research reveals that slower recovery has at least two causes. First of all, it seems that it can be traced back to a weak air current in the middle part of the stratosphere. As a result, less ozone is transported from the tropics to higher northern latitudes, Xia says. But it seems we humans also have a big toe in the pie. “Our analysis shows that the decrease in stratospheric ozone after 2010 may be related to an increase in stratospheric NOx,” said Xia. “This, in turn, is due to increased emissions of nitrous oxide (N2O or nitrous oxide, ed.).” that increase According to KNMI Mainly as a result of “production and use of synthetic fertilizers and increased production of animal manure from animal husbandry”.

worrying
The fact that the ozone layer appears to be recovering more slowly than previously thought is worrying, says Shea. Because the ozone layer – because it blocks harmful ultraviolet rays – is crucial to (healthy) life on Earth. “Ultraviolet radiation from the sun is known to play an important role in the development of skin cancer and is harmful to the immune system and human DNA. It also has a significant impact on the productivity of agriculture and ecosystems on land and in water.” Simply because UV rays can also cause damage to plants and other organisms.

future
Shea stresses that more research is needed to determine what the future of the ozone layer looks like. “Continuous monitoring of ozone concentration and UV levels is important if we are to better understand why ozone layer recovery has been delayed and whether this trend will continue.”

In any case, and further research pending, recovery of the ozone layer is certainly not a sprint yet. “Our results remind us that ozone recovery is a complex process that is affected by many factors,” said Xia. Whether a full recovery is possible remains uncertain. More research and implementation of policies, such as the Montreal Protocol, is critical to turning the tide, reducing UV exposure and protecting life on Earth.”