We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

Why is the Hole in the Ozone over Antarctica?

By R. Kayne
Updated Jun 04, 2024
Our promise to you
All Things Nature is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All Things Nature, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Ozone is a natural trace gas in Earth’s atmosphere. In the lower atmosphere, ozone helps trap heat to keep the earth warm. In the upper atmosphere, it plays an even more important role by filtering harmful ultra-violet (UV) rays from the sun. Overexposure to UV rays destroys skin cells, causes cancer and cataracts, and can lead to macular degeneration. Without a protective ozone layer, there would not be life on earth as we know it. For this reason, scientists and environmentalists the world over were extremely concerned to discover a large hole in the ozone over Antarctica.

Man-made chlorofluorocarbon (CFC) compounds, chlorine, and bromine are attributed with creating the hole in the ozone. CFCs, used in aerosol products, air conditioners, and refrigeration units, were banned in 108 countries in the 1980s; however, they continue to be released into the atmosphere from older products still in use. Additionally, experts estimate that about half of the bromine in the atmosphere is from human use, along with nearly all of the chlorine.

CFCs rise into the atmosphere and, through exposure to other compounds, extreme cold, and sunlight, convert to chlorine atoms. Chlorine atoms change ozone molecules into oxygen. The problem here is that oxygen, while good to breathe in the lower atmosphere, doesn’t filter UV rays. CFCs effectively “open a window” in our protective atmosphere. This window in the ozone builds over Antarctica.

This remote region might seem like an odd place for a hole in the ozone. Antarctica is unpopulated by any permanent human beings and remains pristine. Why isn’t the hole over highly populated areas where CFCs and other greenhouse emissions are known to be high? It turns out the answer has to do with the earth’s rotation and other climatological factors.

First, the earth’s spinning motion ensures that all gasses or emissions released into the air, whether natural or manmade, spread more or less evenly throughout the troposphere, or lower atmosphere, over the period of about a year. According to the Environmental Protection Agency (EPA), it then takes anywhere from two to five years for these gasses to spread into and throughout the stratosphere, or upper atmosphere. From here, climate comes into play in the changing chemistry of the CFCs and their role in creating the hole in the ozone.

In winter, the earth’s tilted axis prevents sunlight from shining on the South Pole. This causes temperatures in the atmosphere over Antarctica to plummet as low as -108° Fahrenheit (-78° Celsius). Cool air descending from the South Pole creates a “winter vortex” of circulating winds in the middle latitudes over Antarctica, acting like a huge whirlpool. This effectively cuts off the ozone over Antarctica from mixing with the planet’s larger atmospheric pool.

As temperatures continue to drop in the sunless winter, Polar Stratospheric Clouds (PSCs), or clouds of nitric acid ice-crystals, begin to form over Antarctica. CFC compounds collect on these ice-crystals, combining with the nitric acid compounds that convert the CFCs to more active forms of chlorine. These compounds build over the long winter season.

When spring comes and sunlight strikes the clouds, UV radiation splits the motherlode of chlorine molecules into highly active chlorine atoms. Each single chlorine atom can destroy a massive amount of ozone molecules, converting them to oxygen. The result is a runaway process that eats up the protective gasses, creating a huge hole in the ozone.

Each year, scientists monitor the hole as it seasonally expands and contracts. In 2005, the hole in the ozone measured a startling 10-million square miles (25,899,881 sq. km), or roughly three times the size of the United States. Only the year 2003 beat this dubious record, with a hole that measured 11-million miles.

As seasons change and the vortex subsides, the upper area ceases to be isolated, temperatures rise, and the opening in the ozone shrinks. However, scientists now believe that the hole may not fully repair itself until the year 2065. The lesser-damaged ozone over the North Pole is expected to heal by about 2040.

While it may be encouraging that we have a predictive scale for recovery of the hole in the ozone, there is another concern. Ozone depletion is taking place at a rate of a few percent per year, most noticeably at the mid-latitudes of the planet. While scientists struggle to understand this phenomenon, humans are at risk of increased cases of cancer due to greater UV exposure, both through a thinner protective atmospheric blanket and because of the ozone hole. These complex conditions are also closely associated with global warming.

All Things Nature is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By BioNerd — On Jan 23, 2011

Global warming is a big worry as the ozone hole continues to expand due to pollutants. If more of the ice cap melts, the world will spike in temperature and there will be massive flooding. There is so much snow in the world, if it all melted, continent sizes would decrease and cities would be completely inundated with a deluge.

By GigaGold — On Jan 21, 2011

The seasons at the north and south poles are unique in that the winters are almost completely dark and the summers can sometimes be completely sunny. The changing seasons cause drastic changes in temperature and light. The auroras can be a helpful mood lifter in the dark winters. Nevertheless, people living near the North Pole tend to have a higher rate of depression.

By TrogJoe19 — On Jan 20, 2011

The beautiful aurora effects near the north and south poles are caused by charged particles in the earths magnetic field colliding. Since these areas are the pinpoints of the magnetic field, charged particles are driven here and create a spectacular color collision in the sky. These can sometimes be seen as far south as New England, but are actually invisible all the way up at the pole.

By anon103191 — On Aug 11, 2010

Since ozone is a polar molecule and magnetic lines originate from north pole and terminate at south pole. Then can we quote this reason for the ozone hole to be on Antarctica.

All Things Nature, in your inbox

Our latest articles, guides, and more, delivered daily.

All Things Nature, in your inbox

Our latest articles, guides, and more, delivered daily.