The ozone hole is both an environmental success story and an enduring global threat

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Researchers release a balloon carrying instruments to measure ozone levels above Antarctica.
Kelli-Ann Bliss/NOAA, CC BY

Shane Keating, UNSW and Darryn Waugh, Johns Hopkins University

The headlines in recent months read like an international eco-thriller.

At Mauna Loa Observatory, perched high on a Hawaiian volcano, researchers measure unusual levels of CFC-11 in the atmosphere. The measurements baffle the scientific community: CFC-11, a potent ozone-depleting gas, has been carefully monitored since it was banned under the 1987 Montreal Protocol. But the measurements are soon confirmed by observing stations in Greenland, American Samoa and Antarctica. The evidence points to illegal production of the banned chemical, threatening the fragile recovery of Earth’s UV-shielding ozone layer. But the identity of the environmental super-villain remains a mystery.

Then, a breakthrough. By running global climate models backwards, a team of scientists in Boulder, Colorado, trace the source of CFC-11 to East Asia. The trail is picked up by the Environmental Investigation Agency, a tiny activist organisation based above a coffee shop in Islington, London. EIA dispatches investigators to China and uncovers rampant illegal production of CFC-11 for insulation foam used in the Chinese construction industry. “This is an environmental crime on a massive scale,” says Clare Perry, EIA’s climate campaign leader.

Meanwhile, scientists and diplomats from around the world converge on Vienna for a meeting of the United Nations working group on the Montreal Protocol. EIA’s blockbuster report is high on the agenda. But can the international community band together once more to protect the ozone layer and save “the world’s most successful environmental treaty”?

Read more:
After 30 years of the Montreal Protocol, the ozone layer is gradually healing

A model of cooperation

The last time the ozone hole was front-page news, President Ronald Reagan was still eating jelly beans in the Oval Office. In 1985 British scientists announced the discovery of a shocking decline in atmospheric ozone concentrations high above Antarctica. The “ozone hole”, as it became known, was caused by ozone-eating chemicals called chlorofluorocarbons (CFCs) used as refrigerants in air conditioners and propellants in aerosol spray cans.

The discovery galvanised public opinion, particularly over concerns about the risk of skin cancer, cataracts and sunburn associated with increased exposure to ultraviolet radiation. In Australia and New Zealand, popular ad campaigns featuring a dancing seagull encouraged the beach-goers to “Slip on a shirt, slop on sunscreen, and slap on a hat!”.

The 1981 “Slip! Slop! Slap!” ad campaign by Cancer Council Victoria (Australia).

Although many uncertainties over the science remained – which were eagerly exploited by the chemical industry – President Reagan recognised the danger posed by the ozone hole and vigorously backed international negotiations to ban CFCs, including CFC-11. On January 1 1989, the Montreal Protocol on Substances that Deplete the Ozone Layer became law.

In his signing statement, Reagan heralded the Montreal Protocol as “a model of cooperation” and “a product of the recognition and international consensus that ozone depletion is a global problem”. It remains his signature environmental achievement.

An enduring impact on Earth’s climate

Three decades after Montreal, the ozone layer is showing signs of recovery. In January 2018, a NASA study found that the ozone hole was the smallest it had been since 1988, the year before the Montreal protocol went into effect. But a full recovery will take decades. “CFCs have lifetimes from 50 to 100 years, so they linger in the atmosphere for a very long time,” said NASA scientist Anne Douglass, one of the authors of the study. “As far as the ozone hole being gone, we’re looking at 2060 or 2080.”

In the meantime, CFCs continue to impact Earth’s climate in some unexpected ways. CFCs are powerful greenhouse gases, with more than 5,000 times the warming potential of an equivalent weight of carbon dioxide. It is estimated that banning CFCs and other ozone-depleting chemicals has delayed global warming by as much as a decade.

However, those gains are threatened by the ozone-friendly, but heat-trapping, chemicals that have replaced CFCs in our air conditioners and insulation. The latest amendment to the Montreal Protocol will phase out the use of this new class of chemicals by 2028.

Read more:
Explainer: hydrofluorocarbons saved the ozone layer, so why are we banning them?

Even more surprising is the complex influence of the ozone hole on Earth’s atmosphere and oceans. The loss of UV-absorbing ozone over the South Pole has changed the pattern of winds around Antarctica. Strengthened winds blowing over the Southern Ocean draw more deep water towards the surface, where it is “ventilated” by contact with the atmosphere.

Deep Antarctic water is rich in carbon, making it a poor absorber of atmospheric CO₂. That means that the ocean has become less efficient at removing excess carbon dioxide from the atmosphere, reducing its ability to offset global warming.

Darryn Waugh on the ozone threat.

Lessons from a world avoided

The success of the Montreal Protocol holds lessons for today’s efforts to confront human-induced climate change. Vigorous leadership by Reagan and the then British prime minister, Margaret Thatcher, a trained chemist, was crucial during the negotiations of the treaty. The protocol began modestly and was designed to be flexible so that more ozone-depleting substances could be phased out by later amendments. Developing countries were also provided with incentives and institutional support to meet their compliance targets.

Lessons from the World Avoided: Dr Sean Davis at TEDx Boulder 2017.

But perhaps the most important lesson is the need for action, even when the science is not yet conclusive. “We don’t need absolute certainty to act,” says Sean Davis, a climate scientist at the US National Oceanic and Atmospheric Administration. “When Montreal was signed, we were less certain then of the risks of CFCs than we are now of the risks of greenhouse gas emissions.”

The ConversationProfessor Darryn Waugh will present a public lecture about the enduring impact of the ozone hole on climate at UNSW Sydney on July 30, 2018. Details and registration information are available here.

Shane Keating, Senior Lecturer in Mathematics and Oceanography, UNSW and Darryn Waugh, Professor, Earth and Planetary Sciences, Johns Hopkins University

This article was originally published on The Conversation. Read the original article.


How a saviour of the ozone hole became a climate change villain – and how we’re going to fix it

Ian Rae, University of Melbourne

Over the weekend, international leaders meeting in Kigali, Rwanda, agreed to a remarkable deal to phase-out hydrofluorocarbons (HFCs), used as refrigerants and propellants. HFCs are potent greenhouse gases.

The agreement ended a decade of negotiations under the Montreal Protocol, established in 1987 to protect the ozone layer. Under the new agreement, developed nations will reduce HFCs 85% below current levels by 2036.

So how will the deal work?

Fixing the ozone hole

The Montreal Protocol was established under the Vienna Convention for the protection of the ozone layer. It followed evidence that chlorine atoms were damaging the stratospheric ozone, which protects the Earth from the most energetic ultraviolet radiation coming from the sun.

These chlorine atoms came from refrigerant and propellant gases, the chlorofluorocarbons (CFCs), that we were releasing into the atmosphere.

By 1990, nations had agreed to restrict production and consumption of CFCs and a timetable for their eventual phase-out over the next two decades. More time was allowed for developing countries and a multilateral fund was established to help them meet their targets.

With just a few exceptions, complete phase-out has been achieved. As well as ozone protection, there was a climate benefit from phasing-out the CFCs because they are much stronger greenhouse gases than carbon dioxide.

Related gases that were less damaging to the ozone layer, the hydrochlorofluorocarbons (HCFCs), were next targeted and they will have been phased out by about 2020.

In developed countries such as Australia they have largely disappeared already, although there is still a lot of one HCFC, R-22, in older air-conditioners. Other ozone-depleting substances such as the fumigant methyl bromide and a number of solvents were also targeted for elimination under the Montreal Protocol.

New villain

Major replacements for the CFCs were the hydrofluorocarbons (HFCs). Their molecules contain no chlorine so they are “ozone friendly” but like the CFCs these substances are serious global warmers.

HFCs are not manufactured in Australia but we import several thousand tonnes each year, which is a small proportion of world production. Our imports will be capped from 2018 following a recent government decision.

Nations under the Montreal Protocol realised that by using HFCs to replace ozone-depleting substances they had contributed to another environmental problem – global warming and climate change.

Despairing of any action under the climate change-centred Kyoto Protocol, the representatives of developed countries began to push for addition of HFCs to the Montreal Protocol where production and consumption data could be monitored and there was potential for an agreement to phase them out.

The process was fractious. Some parties argued that the Montreal Protocol could not be extended to cover substances that were not ozone-depleting. Others pointed to a clause in the preamble to the protocol that would allow HFCs to be covered.

This was a practical view, but perhaps it also contained an element of guilt: “we created the problem so it’s up to us to fix it”.

Resistance came from developing countries that were struggling financially to achieve the phase-out of HCFCs and did not want the expense of retooling for whatever would replace the HFCs.

In the corridors one could hear cynical voices saying that the phase-outs of CFCs and HCFCs would leave delegates and officers with nothing to do, so an extension to HFCs was needed to keep the “Montreal Club” alive.

Send in the replacements

Sensing that change was likely, the chemical industry in the US had already produced HFC replacements that are neither ozone-depleting nor global warming – the hydrofluoroolefins (HFOs).

These substances are designed to rapidly degrade in the lower atmosphere so that releases would not contribute to environmental problems. Other industrial players, strongly backed by environment groups, opted for natural refrigerants such as ammonia (already coming into widespread use in Australia), carbon dioxide (yes, the villain in new clothes!), and low-boiling hydrocarbons such as isobutane that can be “dropped in” to air-conditioners to replace the HFC R-134a.

Last week in Kigali, countries agreed to a phase-out schedule they could live with. Reductions will occur in steps: developed countries have until 2036 to reduce HFC consumption to 85% of current levels, while developing countries have until the mid-2040s. This is too slow for some observers but the experience of the last decade’s negotiations showed that measured pace would be important in securing the agreement.

Australian delegates had been involved all along in the group pushing for the extension of the Montreal Protocol to cover the HFCs. More than that, our lead delegate, Patrick McInerney (Department of the Environment) was co-chair of the working group that fashioned the Kigali consensus and enabled the 197 parties to bring the matter to conclusion.

Even the most pedantic observer, while questioning the validity of extending the Montreal Protocol, would have to agree that it was the right thing to do.

The Conversation

Ian Rae, Honorary Professorial Fellow, School of Chemistry, University of Melbourne

This article was originally published on The Conversation. Read the original article.

Antarctica: Ozone Hole Healing

The link below is to an article that brings some good news regarding our environment – the ozone hole over Antarctica is healing and should continue to do so. This is a story that shows we can manage the environment in a much better way when nations actively work together to solve the problems we face.

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Climate Change: Hole in the Ozone Layer

The link below is to an article that looks at the problem of climate change and the ozone layer.

For more visit:–And-Worse-Than-Ever-180011891.html

Climate Change: Further Evidence

Further evidence has emerged for climate change with the seeming appearance of a hole in the ozone layer over the Artic.

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