A UN report says the ozone layer is getting thicker, thanks to cooperation by the world’s nations. What lessons can we learn from that?
A report released this week by the UN Environmental Program shows that efforts to repair the vital atmospheric shield known as the ozone layer are working, largely as a result in a decline in global emissions of chemicals that attack it. According to the Washington Post, the report says the ozone layer — which blocks ultraviolet sunlight from reaching Earth’s surface — is slowly getting thicker. Meg Seki, executive secretary of the UN Environment Program’s Ozone Secretariat, called the findings “fantastic news.”
In 2018, observed levels of the chemical known as CFC-11 reached a higher level than expected. The source of the increase was traced to China. As a result of international cooperation, the release of CFC-11 from China was largely eliminated and recent observations show the concentration of CFC-11 is declining. That’s proof that societies can collaborate to address a confounding environmental problem, said Martyn Chipperfield, a professor at the University of Leeds who serves on the scientific panel. “That turned out to be another success story. Communities came together and it was addressed.”
What Is Ozone?
Ozone is a molecule composed of three oxygen atoms. In nature, it tends to collect in the upper stratosphere, where it acts as a shield against certain portions of the sun’s radiation, especially the UV-B part of the electromagnetic spectrum. UV-B can cause skin cancer and lead to cataracts. It can also damage plants, inhibiting their growth and curbing their ability to store carbon dioxide. Not to put too fine a point on it, life as we know it on Earth would be impossible without the ozone layer to protect us.
Ozone levels tend to fluctuate over time, but beginning in the 1970s, scientists noticed the ozone layer was not repairing itself as quickly as expected. The cause was traced to an increase in chlorine in the upper atmosphere. One chlorine atom can destroy 100,000 ozone molecules, according to EPA. The principal sources of the chlorine in the atmosphere were chloroflourocarbons (CFCs) and hydrochloroflourocarbons (HCFCs) used as refrigerants in air conditioners and refrigerators. They were also commonly used in fire suppressant materials, foam insulation, and as a propellant in aerosol cans.
In particular, the thinning of the ozone layer was greatest over Antarctica, a phenomenon that became known in the media as an “ozone hole.” That discovery led the world community to create the Montreal Protocol, a 1987 agreement in which all the nations of the world agreed to halt the production and use of CFCs. Later in 2016, the Kigali Amendment also banned the manufacture and use of HCFCs. It was finally ratified by the US Senate last September.
Some natural processes, such as large volcanic eruptions, can have an indirect effect on ozone levels, the EPA says. For example, Mt. Pinatubo’s 1991 eruption did not increase stratospheric chlorine concentrations but it did produce large amounts of tiny particles called aerosols like sulfur dioxide. Those aerosols in the stratosphere create a surface on which CFC-based chlorine can destroy ozone. Fortunately, the aerosols disperse fairly quickly, which allows ozone levels to increase once again. Hold that thought. We will get back to that topic shortly.
According to the UN report, which was presented Monday morning at the annual meeting of the American Meteorological Society in Denver, scientists have now confirmed that the ozone layer is repairing itself at a rate faster than expected and could recover to 1980s levels across most of the globe by the 2040s and by 2066 in Antarctica. That may seem like a long time to some, but it is a blink of the eye in geological terms. “We can already see HFCs are not increasing as fast as we thought they would because countries are starting to implement their own controls,” said Paul Newman, one of four co-chairs of the Scientific Assessment Panel of the Montreal Protocol.
Today, Ozone. Tomorrow, Carbon Dioxide
Petteri Taalas, secretary general of the World Meteorological Organization said at the meeting in Denver this week, “Ozone action sets a precedent for climate action. Our success in phasing out ozone-eating chemicals shows us what can and must be done — as a matter of urgency — to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase.”
Still, Paul Newman says it is possible that forthcoming data on ozone levels may show the ozone layer is not recovering as quickly as the report concludes because the Hunga Tonga volcanic eruption that started in December, 2021, and continued for four weeks blasted so much material into the atmosphere. Volcanic eruptions are known to accelerate ozone depletion.
Which raises another point. Progress toward restoring the ozone layer could very likely be slowed if humans pursue geoengineering to reverse global warming by injecting sunlight-reflecting particles into the upper atmosphere, Newman says. The panel, which considered the potential impact of that practice for the first time for this new report, found that, depending on the timing, frequency, and amount of such injections, the particles could alter aspects of atmospheric chemistry that are important in ozone development. “The Antarctic ozone hole is the poster child of ozone depletion,” Newman said. “Stratospheric aerosol injections will probably make it a little bit worse.”
There are plenty of people who believe geoengineering will correct the damage done to the environment by human activity. The sun heats the Earth, so if things get too hot simply blot out some sunlight just the way you might pull down a shade to keep your living room cool on a summer day. Easy peasy!
The problem is one of human arrogance. Throughout history, we the people have behaved as if we know all the answers and the Earth was placed here to serve us. No need to worry about tomorrow. Nothing we do could possibly disrupt the course of nature. Well, that fiction has been pretty much ripped to shreds by melting ice caps, warming seas, rising ocean levels, raging forest fires, prolonged droughts, and punishing floods, all of which are attributable to human activity.
What we fail to see is that our environment is far more complex than we can imagine or understand. Our puny brains just can’t comprehend it all. The world is like a giant billiard table with billions of balls on it. Strike one over here by the corner pocket and it sets a chain of events in motion with trillions of permutations. We simply cannot predict with any degree of certainty what will happen if we start to muck about with the atmosphere.
The latest UN report shows it is possible for nations to work together to reduce threats to the environment. That means they could do the same with carbon and methane emissions, right? Maybe, but here’s the thing. The companies that manufactured CFCs and HCFCs didn’t own world governments the way the fossil fuel companies do. The difference is greed. We could reduce carbon and methane emissions much as we reduced CFC and HCFC emissions, but will we? The jury is still out on that question.
Courtesy CleanTechnica. By Steve Harley. Article available here.