40 years since the Vienna Convention for the Protection of the Ozone Layer

When the world acted for the environment- And it worked?!

Back in the 80s, the ozone hole made headline news. Scientists were sounding the alarm, people were worried, and governments listened. What followed was one of history’s most successful examples of global environmental cooperation. So, what happened and what can it teach us about climate action today?

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What is the Ozone layer?

The ozone layer is the part of the Earth’s atmosphere located in the Stratosphere (10-50km above the Earth’s surface). It is an area with a high concentration of the molecule ozone (O₃). It acts as a layer of sunscreen protecting us from harmful ultraviolet (UVB) radiation. Without it, life on Earth would be highly unpleasant.

Where did the hole come from?

Chlorofluorocarbons (CFCs), discovered in the 1920s, were quickly hailed as wonder chemicals used in fridges, fire extinguishers and hairsprays. Though harmless at ground level, up in the Stratosphere, these chemicals were broken down by UV light, releasing chlorine that reacted with and broke down the ozone.

Scientists only learned of this reaction in the 1970s, and it wasn’t till 1985 that we realised the scale of the resultant Ozone depletion. An enormous “hole” was discovered in the Ozone layer above Antarctica. Unsurprisingly, scientists were worried, and soon so was the public.

Why were we worried?

The depletion of the Ozone layer led to heightened UVB exposure on the Earth’s surface which research clearly linked to the increasing risk of both melanoma and non-melanoma skin cancers. Furthermore, UVB exposure is also associated with cataract formation, causing clouding of the eye’s lens. Similarly, this radiation harms the early developmental stages of various marine animals, including fish, shrimp, crabs, and amphibians. Reducing the reproductive capacity and impairing larval development.

UVB radiation also harms plants and phytoplankton, slowing their growth and reducing their potential to lock up carbon dioxide from the atmosphere. The potential long-term impacts and knock-on effects on global ecosystems and human health left scientists worried, and they were unafraid to voice their alarm.

A Call for Action.

Scientists took on a role as advocates and campaigners, communicating the dangers of CFCs. Crucially, they made this message accessible enough for the average person on the street to understand the threat and what they needed to do about it. The public’s support for change drove industry shifts away from CFCs. It showcased the positive effect of behavioural change, even if it begins with something small like abstaining from hairspray or switching to brands which didn’t use CFCs.

Crisis averted Ish

The worldwide recognition of CFCs’ detrimental effects prompted the Vienna Convention for the Protection of the Ozone Layer and two years later enactment of the Montreal Protocol in 1987; a treaty aimed at phasing out the production of ozone-depleting substances (ODS). The Protocol was a landmark multilateral environmental agreement which regulated nearly 100 ODS. It is one of the globe’s most triumphant environmental pacts and a rare treaty to achieve universal ratification.

The Protocol entailed a phased reduction in ODS consumption and production, implemented stepwise with distinct timetables for developed and developing countries. Nations were assigned specific responsibilities for phasing out use, production, trade, licensing, and annually submitting data.

The Kigali Amendment

Though positive in many ways, the Montreal Protocol left wiggle room for creating and using a new wonder chemical for air conditioning and refrigeration: hydrofluorocarbons (HFCs). Deemed initially a safer substitute, they were later found to be a greenhouse gas, 150-12,500 times more potent than carbon dioxide. Thus, in 2016, the Kigali Amendment expanded the Protocol’s scope to include the cessation of HFCs.

These agreements have led to a significant reduction in ODS emissions over the past four decades. Studies show 95% confidence that the Ozone layer is recovering via its self-healing capacity. This incredible positive response highlights how environmental problems can be solved when everyone listens to the science and acts together.

“Thanks to this global accord, humanity has successfully sidestepped a significant health crisis caused by ultraviolet radiation penetrating a substantial gap in the ozone layer,” – UN Secretary-General Antonio Guterres.