
The success story of tackling the hole in the Ozone Layer together
In 1985, a group of scientists sounded the alarm that the ozone layer was rapidly thinning. They warned that if nothing was done, it could result in massive environmental damage. Thankfully, their warning was heard, and a concerted effort was made to repair the damage.
How it began
The hole in the ozone layer was first discovered in 1985 by a group of British scientists. They found that the amount of ozone in the atmosphere was decreasing at an alarming rate and that if nothing was done to stop it, the hole would continue to grow, rendering disruptive consequences to humankind and our environment at large.
Understanding the problem
Ozone is a gas in the Earth’s stratosphere. This layer is 10-50 km above the Earth’s surface. Ozone protects us from the sun’s harmful ultraviolet (UV) rays. Without it, we face many dangers to our health and environment. These dangers include skin cancer, certain eye diseases, and permanent damage to plant life. Such damage can disrupt entire ecosystems.
When exposed to intense UV light, some compounds release chlorine or bromine into the stratosphere. These compounds contribute to ozone depletion. They are called ozone-depleting substances (ODS). For example, one chlorine atom can destroy over 100,000 ozone molecules before it is removed from the stratosphere. This means ozone can be destroyed faster than it is naturally created.
ODS that release chlorine include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), carbon tetrachloride, and methyl chloroform. ODS that release bromine include halons and methyl bromide. Although ODS are emitted at the Earth’s surface, they eventually reach the stratosphere. This process can take two to five years.
Not all chlorine and bromine sources contribute to ozone depletion. Researchers have found that chlorine from swimming pools, industrial plants, sea salt, and volcanoes does not reach the stratosphere.
The Montreal Protocol
In 1987, the Montreal Protocol was initially signed by 46 countries but now has almost 200 signatories. This treaty banned the use of chlorofluorocarbons (CFCs), a human-made compound which was found to be responsible for the depletion of the ozone layer. This resulted in a significant reduction in the consumption of ODS.
The extent of the ozone hole is strongly driven by stratospheric temperature, with warmer temperatures leading to a smaller ozone hole, such as in 2019 when the hole was recorded the smallest in size since the 80’s. The hole however continues to fluctuate in size annually, usually reaching its largest area during the coldest months in the southern hemisphere, from late September to early October.
Altogether, the ozone hole has shown signs of healing since 2000, which is predominantly a result of phasing out ODS. From 30.31 million sq km in 2000, to 24,8 million sq km in 2021, we are set on a good trajectory for the 21st century.
APPROXIAMATELY
Montreal Protocol signatories
Decrease in size since 2000
2019 has presented the best year yet, with the size of the hole equating to 10 mil sq km.
A positive perspective for the better
As the ozone layer began to heal, the Montreal Protocol emerged as a success story. It is often cited as one of the most effective environmental treaties ever signed. This treaty is a perfect example of what the international community can achieve when it comes together to solve a problem. The Montreal Protocol shows that we can repair the damage we’ve done to the environment. However, we must act quickly, decisively, and collectively.
The mitigation of ozone depletion remains a delicate subject. Scientific evidence suggests that more action is needed to relieve the pressure on the ozone layer caused by ozone-depleting substances (ODS).
Overall, the story of the ozone layer’s depletion is hopeful. It demonstrates that by choosing to do better together, we can achieve positive outcomes if we remain committed to the cause.
We hope this story inspires you to take action in your community. Together, we can make a difference for our people, our planet, and its resources.
We can always #dobetter.