Fight against the clock to close the hole in the ozone layer

The days are getting longer, the trees are in leaf and the parks are filling up - spring is arriving in South America. But as pleasant as it is to say goodbye to winter for another year, the changing season causes an environmental reaction, which threatens the health of Latin Americans.

25 kilometers above our heads, the invisible ozone layer brings life to our planet. This barrier of gas protects us from the sun's harmful rays and allows life as we know it to flourish.

However, decades of unchecked emissions of ozone depleting substances (ODSs) have taken a heavy toll and each year, the arrival of spring not only brings the sun back to the world’s most southerly continent but also causes an environmental phenomenon which has ramifications far beyond the Pole.

Today there are few who have not heard about the hole in the ozone layer. Discovered nearly 30 years ago, depleted levels of ozone in the atmosphere above the Antarctic reach their lowest levels at this time. Changing weather systems then cause this 'hole' to extend, to varying degrees, across the southern mid-latitudes - an area which, in Latin America, extends from the border of Uruguay and Brazil downwards.

In fact, the hole reached the Argentine and Chilean Patagonia region 3 times in 2013, according to the Izaña Center for Atmospheric Research. The result: an increased risk from one of the most harmful of the sun rays - UV-B.

Normally filtered by the sun, UV-B rays burn and are linked to skin cancer and cataracts. Punta Arenas in Chile, the world’s most southerly city, is on the frontline of related battle. Over the past 20 years, the city has regularly experienced high levels of UV-B radiation. The sun beats down with more and more strength in the south.

Increased solar radiation does not only impact health. UNEP has linked the hole in the ozone layer over the Antarctic with changes in the southern hemisphere summer climate as well, affecting temperatures, rain and even the ocean.

Closing the hole

The discovery of the hole in the ozone layer over Antarctica nearly 30 years ago provoked an unprecedented international response and was the catalyst for one of the most successful environmental conventions, the Montreal Protocol (MP).

"It drastically changed the attitude towards ozone depleting substances," says Robert Dixon, Chemicals and Climate Specialist at the Global Environment Facility (GEF). "Today the phaseout is already nearly complete in developed countries but there is still some work to do in developing countries and those with economies in transition."

As United Nations members, Latin American countries are signatories to the MP and have banned/strictly regulated the use of chlorofluorocarbons (CFCs), halons, and methyl bromide, and are currently working towards phasing-out consumption of hydrochlorofluorocarbons (HCFCs) . These chemicals have been/still are commonly found in refrigerants, commercial refrigerators and air conditioners, among others. Once released into the atmosphere, they not only deplete the ozone layer but are also up to 10,000 times more potent greenhouse gases than CO₂.

The effects of efficient phase-out efforts are already being seen in the health of our world’s protective layer and experts are cautiously optimistic that by 2050 this delicate barrier would recover to its benchmark level of 1980.

"As per a fresh Assessment Report by the World Meteorological Organization and United Nations Environment Programme, experts confirm that we are progressing closer to the 1980 ozone level and the recovery can be expected by mid-century if countries continue with full compliance with the MP," explains Tuuli Bernardini, Environmental Specialist for the World Bank. "However, at the Antarctic level, recovery is slower, which is of special concern to Argentina where the Bank has been supporting the Government on ODS phase-out since mid-90s. Given their vulnerability, the country has been at the forefront of promoting ozone protection at the international level. In January 2010, Argentina completed the CFC phase-out and now focuses on reducing HCFC consumption and production."

The key is to continue the phase-out efforts until the end and not to declare the battle won until the use of these destructive chemicals has been eliminated completely. It is also of high importance that any alternative substances are as environmentally friendly as possible, for example in terms of their global warming potential and related contribution to climate change or its mitigation.