Ozone hole in 2011. Credit: NASA Goddard photo and video/CC BY 2.0

By Marcela Valente
BUENOS AIRES, Nov 23 2012 (IPS)

Argentine scientists agree that there are signs of recovery of the ozone layer that protects life on earth by filtering out the sun’s harmful ultraviolet radiation, but they are cautious about saying that the problem is on its way to a solution.

“This year was benign, but the problem has not been solved. The ozone hole could expand to a record size in 2013,” Gerardo Carbajal, head of the Department of Atmospheric Monitoring and Geophysics (VAyGEO), told IPS.

According to Carbajal, whose department is part of the National Meteorological Service, “this year the ozone hole was one of the smallest ever and it closed up earlier than expected, but we’ll have to wait and see before we can speak of a trend.”

Similarly, Susana Díaz, an engineer with the Southern Centre for Scientific Research (CADIC), told IPS that “in recent years we have observed a slight decrease of the ozone deficit within the so-called ‘hole’.”

Díaz is a member of the state National Scientific and Technical Research Council (CONICET) and heads the CADIC Ozone and Ultraviolet Radiation Laboratory in Ushuaia, the capital of the province of Tierra del Fuego, the most southerly in the country.

Measurements are made there of the ultraviolet rays that filter down over the city, to record the impact of the radiation during the season of ozone hole expansion in the stratosphere, which occurs from September to mid-November.

Ozone is a gas in the stratosphere, between 15 and 35 kilometres above the earth’s surface, which protects the biosphere by absorbing UV rays that are harmful to human health and plant and animal life.

Exposure to high levels of UV radiation can cause a higher incidence of skin cancer and eye problems in the population of affected areas, like southern Argentina and Chile.

“This year the ozone hole season was much shorter than in earlier years, and lasted only two days above Ushuaia. In other seasons it has lasted for 10 days, and it has been felt further north, in Patagonia,” said Guillermo Deferrari, a biologist at CADIC.

The size of the ozone hole varies. Some years it has covered an area of 30 million square kilometres, but in the last few weeks it has extended over 22 million square kilometres – still an area larger than all of South America.

According to the scientific consensus, the thinning of the ozone layer over Antarctica was mainly due to the use of chlorofluorocarbons (CFCs), chemical substances used in the manufacturing of aerosols and refrigerants.

When this evidence was confirmed in the 1970s, countries signed the Vienna Convention for the Protection of the Ozone Layer, and in 1987 they approved the Montreal Protocol. These treaties were ratified by the largest number ever of United Nations members and set a timetable for phasing out and eliminating CFCs.

Twenty-five years after the Montreal Protocol was approved, industry has substituted CFCs by hydrofluorocarbons (HFCs) which, while they do not harm the ozone layer, are greenhouse gases and contribute to global warming.

Meanwhile, there are other substances that destroy ozone and have not been replaced, such as methyl bromide, a pesticide, which in the Protocol is only scheduled for complete elimination in 2015.

Deferrari, who operates equipment at CADIC for measuring UV radiation over Ushuaia, told IPS that “the levels are stable now, with no observed increase in the destruction of the ozone layer.”

He agreed with colleagues that this improvement cannot be said to be a trend, and that the ozone hole could grow again next year, because it depends on meteorological conditions in Antarctica as well. He said, however, that there are clear “signs of recovery.”

The observations confirm the findings of the latest report on the issue by the United Nations Environment Programme (UNEP) and World Meteorological Organisation (WMO), published in 2010.

The study, “Scientific Assessment of Ozone Depletion 2010”, concluded that CFC elimination was having an effect and the ozone hole was not growing – a sign of recovery.

However, Deferrari pointed out that “we have not yet returned to the radiation levels we had in 1980,” since the chemicals that destroy ozone take 10 years to reach the stratosphere, and then the ozone layer takes time to recover.

Complete recovery of stratospheric ozone over Antarctica will take another 40 to 60 years, different studies say. But the fact that this year’s hole is smaller is good news.

The ozone layer if CFCs hadn't been banned. Credit: NASA

By Coralie Tripier
UNITED NATIONS, Aug 2 2012 (IPS)

The Montreal Protocol, a climate treaty that gathers all U.N. member countries behind the goal of protecting the ozone layer, may not be the “most successful international agreement” anymore, as former U.N. secretary general Kofi Annan used to put it.

The treaty has achieved a great deal in the more than two decades it has been in force, with a 97-percent reduction in the consumption of ozone-depleting substances. However, it is now being widely criticised for worsening climate change by replacing those harmful chemicals with climate-threatening substitutes.

The total phaseout of chlorofluorocarbons (CFCs), which were widely used as refrigerants and had a high ozone depletion potential, has led to a climate protection bonus equivalent to 11 billion tonnes of CO2 reductions each year, according to the U.N. Environment Programme.

To put it in simpler terms, the Protocol had the annual environmental impact of one billion homes being completely off the electrical grid.

But this remarkable achievement is now being undermined by the chemicals that were used to replace CFCs: hydrofluorocarbons, known as HFCs, a group of “super” greenhouse gases. HFCs, which can be found in many products such as refrigerators and aerosols, are the fastest growing class of greenhouse gas and have an extremely high global warming potential, scientists say.

The situation is critical: without fast action to limit their growth, HFCs could annually contribute up to 20 percent as much to global warming as carbon dioxide by 2050, according to a recent press release by the Institute for Governance and Sustainable Development

The U.S., Mexico, Canada and Micronesia have taken a firm stance, proposing an amendment to the Montreal Protocol during the last meeting of state parties in Bangkok last month, which addresses HFCs.

“Phasing down HFCs is essential to… limit the adverse environmental effects, including effects on the climate system, of actions taken to protect the ozone layer,” according to the text submitted at the end of July in Bangkok.

But the discussion was cut short as the proposed amendment, which would have helped attain an equivalent reduction of 100 billion tonnes of CO2 by 2050, was blocked by India, China and Brazil for the fourth year.

The three powers delayed any potential action by arguing that the phase-down of the harmful chemical should be addressed under the Kyoto Protocol, since it is a matter of global warming and not ozone depletion.

But most parties think that since the growth in HFCs is a direct consequence of the Montreal Protocol, it is also the treaty’s duty to find climate-safe alternatives.

“The legal mandate of Montreal is not limited only to phasing out ozone depleters. It includes making sure the replacement compounds are safe, including for the climate,” David Doniger, policy director for the U.S.-based National Resources Defence Council’s climate and clean air programme, told IPS.

“HFCs would not exist without the Montreal Protocol,” Clare Perry, senior campaigner at the Environmental Investigation Agency, told IPS.

“(The Montreal Protocol) is also the body most experienced in phasing out these types of chemicals and has all the necessary institutions and procedures to do it effectively,” Perry added.

But political manoeuvring appears to be overshadowing the initial purpose of the treaty. The dissenters might just be trying to narrow the scope of the Montreal Protocol in order to act in their own financial interests, according to Perry.

“There’s clearly a reluctance to take on binding commitments to deal with HFCs,” she told IPS.

India and China are “the precursors of HFCs, and their industries are determined to continue making massive and increasing profits from these super greenhouse gases,” she added.

The decision to block the progressive phase-down of HFCs is not in line with the recent promises made by 192 state parties, including the three blockers, during the U.N. Conference on Sustainable Development that took place in Rio de Janeiro in June.

“We recognize that the phase-out of ozone-depleting substances is resulting in a rapid increase in the use and release of high global-warming potential hydrofluorocarbons (HFCs) to the environment. We support a gradual phase-down in the consumption and production of hydrofluorocarbons,” the final document, which was also signed by India, China and Brazil, stated.

“Apparently their commitment to safeguard the climate from HFCs had less than a one-month half-life,” said NRDC’s Doniger.

The matter must be addressed urgently, since global warming and ozone damage are “intimately connected”, according to James G. Anderson, a scientist and lead author of a recent study published by Harvard University.

More global warming leads to more storms, and those storms will increase the risk of ozone loss from convectively injected water vapour, the study found.

But phasing down HFCs is far from impossible, as was made clear at the technical conference that took place on the weekend prior to the meeting of the Montreal Protocol state parties, and which presented the wide range of options available.

“There are many climate-friendly alternatives to HFCS in pretty much every sector… and this would be some of the most cost-effective climate mitigation available,” Perry told IPS.

Reducing consumption in HFCs would also allow world leaders to achieve the seventh Millennium Development Goal, set in 2000, which strives to “ensure environmental sustainability” by 2015 through the Montreal Protocol.
If the 25-year-old international climate treaty – the most widely ratified in U.N. history – wants to restore its reputation, action needs to be taken, Perry warned.

“(The Montreal Protocol) is widely considered to be the most successful multilateral environmental agreement, however we believe that the best is yet to come and it needs to ensure it deserves this accolade by swiftly adopting measures to phase-out out HFCs,” she told IPS.