Ozone Layer’s healing process: Is sunscreen necessary anymore?

We are experiencing the coldest month of the year currently. Is it really relevant to talk about sunscreen at the moment? 

Experts say yes – it is even more critical to discuss wearing sunscreen during the winter months. That is because of the relative lack of public awareness surrounding the damage the Sun’s ultraviolet (UV) rays can cause all year round, regardless of seasons. 

This makes people more susceptible to sun damage and skin cancer during winter – as many of us ditch the greasy formulation of sunscreen for convenience during the cloudier, mellower winter daylight.

Since we are talking about UV rays, sun damage and photo-ageing – what about the reports in recent years mentioning the successful projected recovery of the Ozone Layer, the natural sunscreen in the upper layers of the Earth’s atmosphere? Why would we need sunscreen if the Ozone Layer is on track to heal completely, according to various scientific and journalistic reports?

Now, the answer to that is a bit more complicated as it is an ongoing situation replete with various unexpected developmental twists and complications.

However, this article would try its best to track down the different narratives surrounding Ozone Layer depletion and its recovery, in order to bring you the most updated and credible information available at this point.

According to Eamonn Merriman, member of ODS (ozone-depleting substances) & F-Gas (fluorinated gases) Team at the Office of Environmental Enforcement, Environmental Protection Agency (EPA), Ireland, “…there is scientific evidence that the ozone layer is healing itself and is expected to recover by the middle of this century. However, it is advisable to continue to use sunscreen as directed by health authorities.” 

So why are experts drawing this counter-intuitive inference surrounding sunscreen? 

To properly answer this question, a bit of background on Ozone Layer depletion and the complex process of its recovery – is necessary.

This article includes explanations provided by Mr Merriman and other esteemed scientific and journalistic sources.

First off, even though the United Nations has confirmed in a scientific assessment, in late 2018, that the ozone layer is recovering, projecting that it would heal completely in the (non-polar) Northern Hemisphere by the 2030s, followed by the Southern Hemisphere in the 2050s and polar regions by 2060, it is still an ongoing process. That means it could take another 50 years for the Ozone Layer to recover significantly.

According to Allure’s ‘The Science of Beauty’ podcast on sunscreen, we still do not enjoy the same protection from the Sun as our predecessors did 70 years ago.

However, notwithstanding the triumphantly upbeat revelation by the United Nations, there have been some significantly sobering setbacks and discoveries made in recent years that throw the entire narrative around the complete recovery of the Ozone Layer into ambiguity.

What is the Ozone Layer?

Mr Merriman states “The ozone layer is a region of high ozone concentration in the stratosphere, 20 to 30 kilometres above Earth’s surface.”

The Ozone Layer effectively blocks almost all solar radiation of wavelengths less than 290 nanometres from reaching Earth’s surface, including certain types of UV and other forms of radiation that could injure or kill most living beings, breaking organic bonds and working to counteract natural life processes. 

In other words, UV rays are capable of sterilising the surface of the Earth.

And the Ozone Layer is Earth’s natural sunscreen as it absorbs most of the harmful UV radiation from the Sun.

UV rays

The harmful effects of UV rays

Damage to human health

Large-scale ozone depletion would dramatically increase the amount of UV-B exposure, significantly increasing the risk of major health issues worldwide. Too much UV-B can cause sunburns and skin cancers, including malignant melanoma, which can be fatal if not treated. What’s more, exposure to the UV-B in sunlight is linked to the development of cataracts, a clouding of the eye’s lens that is a major cause of blindness globally. Overexposure to the sun can also weaken the immune system.

UV-A rays can travel further than UV-B into the depths of the skin tissue. It can break down the collagen and elastin in our skin and accelerate the skin ageing process. It can also cause mutations in the skin cell’s DNA and give rise to free radicals and oxidative stress. As a result, there is an accumulation of damaged skin cells because the body’s natural healing processes cannot keep up with the destruction caused.

This leads to skin sagging, sun spots, fine lines and wrinkles. In fact, it’s estimated that 90% of skin ageing is due to the effects of the sun. The sun causes proteins in our skin to deteriorate, leading to the loss of our youthful appearance over time. On the bright side, this type of ageing can be prevented with proper sun protection.

Ozone Layer
“Wishing there was an ozone layer” by gregoryperez is licensed under CC BY-NC-SA 2.0

Severe damage to marine life

The sun’s UV rays penetrate deep into our oceans. Increased exposure to UV radiation damages algae, crustaceans and fish eggs, the base of the ocean’s food chain. A growing hole in the ozone layer can cause a reduction in marine life, thus threatening the ocean’s food chain and our own food supply.

Reduced plant growth and crop yields

Ozone depletion can reduce plant growth. Uncontrolled ozone depletion can reduce the amount of crop production globally, leaving us all with less food. The health of the wild plants that are the foundation of all ecosystems on land can also be threatened.

Disruption of the cycling of carbon, nutrients and other elements in the atmosphere

Large-scale increases in UV-B can alter the way carbon dioxide is exchanged between the atmosphere and the biosphere. Increased UV radiation stimulates the breakdown of decaying leaves and other organic matter, hence reducing the ability of ecosystems to trap carbon dioxide. With large-scale ozone depletion, this can further contribute to climate change. Changing UV-B also alters the cycling of nitrogen and other nutrients in the environment, which may worsen air pollution.

Damage to outdoor materials

Exposure to UV-B also affects natural and synthetic materials, including wood, plastic and rubber. Large-scale depletion of the ozone layer causing greater exposure to the sun’s UV rays would increase this damage and weaken these materials. This would lead to more rapid deterioration and the need for additional UV protection, increasing the cost and reducing the reliability of many products.

Ozone depletion and the ‘ozone hole’

In the mid-1970s, scientists became aware that the ozone layer was threatened by the accumulation of gases containing halogens (chlorine and bromine) in the atmosphere. Then, in the mid-1980s, scientists discovered a ‘hole’ in the ozone layer above Antarctica – the region of Earth’s atmosphere with severe depletion.

The ‘hole’ is actually an area of the stratosphere with extremely low concentrations of ozone that reoccurs every year at the beginning of the Southern Hemisphere spring (August to October). Spring brings sunlight, which releases chlorine into the stratospheric clouds.

So, what causes the thinning of the ozone layer around the globe and the “ozone hole” above Antarctica? Man-made chemicals containing halogens were determined to be the main cause of ozone loss. These chemicals are collectively known as ozone-depleting substances (ODSs). The most important are chlorofluorocarbons (CFCs), which at one time were widely used in air conditioners, refrigerators and aerosol cans. Other chemicals, such as hydrochlorofluorocarbons (HCFCs), halons and methyl bromide- used in car dashboards, insulation foams, military bases, fire extinguishers and more- also deplete the ozone layer.

ODS’s were used in a plethora of products, indeed.

aerosol particles

The Montreal Protocol

In the 1980s, the global community decided to do something about ozone depletion. With growing evidence that CFCs were damaging the ozone layer and with the understanding of the many consequences of uncontrolled depletion, scientists and policymakers urged nations to control their use of CFCs. In response, the Vienna Convention for the Protection of the Ozone Layer was adopted in 1985, followed by the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987.

The substances regulated by the Montreal Protocol are also significant greenhouse gases.

Thus the Montreal Protocol is also reducing climate warming considerably.

Without the Montreal Protocol, large-scale depletion of the ozone layer would have occurred with major consequences. Without the pact, we would have seen an additional 280 million cases of skin cancer, 1.5 million skin cancer deaths, and 45 million cataracts across the globe—and the world would be at least 25 per cent hotter.

Rising Complications

Every season, the appearance of the ozone hole and its evolution is monitored by means of satellites and a number of ground-based observing stations. Research in early 2018 in atmospheric sciences has indicated that the path to Ozone Layer recovery is not as straightforward as climate models have predicted so far.

Lower stratospheric ozone decline 

Even though the Montreal Protocol continues to predictably demonstrate its effectiveness for increasing ozone density in the upper stratosphere, mysteriously enough, the lower stratosphere has shown a larger-magnitude ozone decline over the same time period.

This discovery was not predicted by any of the state-of-the-art climate models so far. In fact, researchers are puzzled about this surprising discovery themselves. 

Since the effect of the lower stratospheric ozone depletion has actually been more powerful than the recovery in ozone concentrations in the upper layer of the Stratosphere, the overall global mid-latitude ozone density has ended up decreasing instead.

Scientists are not certain about the causes behind such an unexpected phenomenon. They are attributing this development to two possible factors. 

The first one would be very short-lived substances (VSLS), including unregulated short-lived chlorine species that have the potential to degrade portions of the Ozone Layer. Research investigations into this claim are still in the process.

The second plausible reason could be global warming itself.

There are suggestions that global warming has impacted the rise of the tropopause and that it is going to continue to rise in the future because of it, along with general warming up of the Troposphere. This could result in depleting the lower stratospheric ozone content. Moreover, the increase in greenhouse gases is rising water levels in the tropics and this, in turn, could affect lower stratospheric ozone content in the region.

Although the exact mechanisms behind such occurrences have not yet been scientifically confirmed, it is pretty certain that the ‘100% recovery by 2100’ prediction did not take such developments into account. 

Under the current timescale, that recovery could be delayed significantly, if it happens at all. The worst part is that global warming might actually be contributing to ozone loss, or may be even causing it.

Indeed, the ozone hole over Antarctica is shrinking. However, there are parts of the stratosphere other than what is above one particular pole, that are not showing the same trend in recovery. In fact, according to Forbes, “the overall concentrations of ozone in the atmosphere, worldwide, have not increased since 1997, but are the same today as they were back then.”

global warming

Ongoing violations of the Montreal Protocol

Atmospheric monitoring for Ozone Depleting Substances is also undertaken at various air monitoring stations globally. One of these detected an atmospheric increase of CFC11 from around 2014 in each Asia. CFC11 is a banned ozone-depleting gas which had been commonly used as a refrigerant and insulation propellant. Much of the rise in CFC11 concentration was linked to illegal production and the use of CFC-11 for polyurethane foam insulation in some provinces of China. Subsequently, the Chinese authorities announced in 2018 a crackdown on the illegal use and production of ozone-depleting substances, including CFC11.

Harmful chemical agents still in use

Research continues on other substances of concern not regulated by the Montreal Protocol, such as chloroform, which continues to be assessed in relation to its potential role in ozone depletion.

According to National Geographic, transitional substitutes to CFC like hydrochlorofluorocarbons (HCFCs) that are less damaging but still harmful to the Ozone Layer continue to be used. Developing countries need more resources from the Montreal Protocol’s Multilateral Fund to completely phase out the use of HCFC’s, the most prominent one among them being known as the refrigerant, R-22.  

The next generation of coolants, hydrofluorocarbons (HFCs) does not deplete the Ozone Layer directly. They are powerful greenhouse gases that trap heat and as a result, can contribute to global warming in a major way. In fact, some HFCs are more than a thousand times more potent than carbon dioxide in contributing to climate change.

Although this is a gravely worrisome outcome in itself, following previous discussions in this article, global warming itself is being considered as one of the plausible causes behind the mysterious disappearance of lower stratospheric ozone content, depleting the overall ozone reserve in the atmosphere.

In conclusion

While uncertainties and inexplicable phenomena abound the Ozone Layer situation, one thing is for certain. UV rays are powerful enough to penetrate clouds, glass or even certain types of clothes. Therefore, the next time you are in doubt about wearing sunscreen, just slather on that wonder formulation without a second thought, even if you are indoors, regardless of the time of day or the time of the year. Your skin will thank you.

Yishi Chakrabarty
Yishi Chakrabarty

As a journalist in Ireland, Yishi primarily writes about women's issues and mental health. Her work includes political analyses and social commentary. Originally from India, she has an academic background in History and Journalism.

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