About a month ago, the results of an international study were presented at the annual meeting of the American Meteorological Society, which can report good things: the ozone layer in the upper stratosphere has recovered significantly and is on the way to full recovery.
What the international community has achieved with the ozone hole does not seem to work with global warming: the goal set in the 2015 Paris Agreement to limit man-made temperature rise to 1.5°C by the year 2100 is now considered almost impossible. reaches. Why are we making little progress on global warming when measures to protect the ozone layer appear to have been successfully implemented?
Both environmental crises were identified as problems by scientists before the general public became aware of them. The phenomenon of anthropogenic global warming had been known since the late 19th century, but was not considered problematic at the time. It was not until the 1940s that there were isolated warnings of the effects of global warming. With the increasing availability of measurement data from the 1950s, concern among scientists also steadily increased; In 1979, the first global climate summit was held in Geneva, but politics was largely ignored.
In the 1980s, the warnings became clearer and reached a wider audience. In 1986, the newspaper “Spiegel” put the “climate catastrophe” on the front page for the first time, and in 1988 the Intergovernmental Panel on Climate Change (IPCC) was established, which published its reports regularly from then on. However, the increasing focus on global warming did not translate into appropriate action – for decades almost nothing happened except cheap expense claims.
Almost a quarter of a century has passed from the environmental summit in Rio de Janeiro in 1992 to the climate conference in Paris in 2015, where all ratifying states committed for the first time to reduce greenhouse gas emissions. These must be reduced to zero globally in the second half of the 21st century. But humanity is still blowing more and more greenhouse gases into the atmosphere.
It also took a while for science to recognize the danger of the ozone hole. Chlorofluorocarbons (CFCs), which caused the ozone hole, were first manufactured for industrial production in 1929. They are a group of carbon compounds in which hydrogen atoms have been replaced by chlorine or fluorine. The odorless and non-toxic gases are non-flammable and easy to handle – real panacea in fact. But as early as 1957, almost 30 years after industrial use began, there was the first evidence of a weakening of the ozone layer over Antarctica; they came from the British research station Halley Bay. However, these measurements were hardly noticed at first.
It was not until the early 1970s that Frank Sherwood Rowland and Mario J. Molina discovered the mechanism leading to damage to the ozone layer during laboratory measurements: CFC molecules are split at high altitudes and in very cold weather by the effects of sunlight, producing a highly reactive chlorine radical (chlorine atom) is formed, which then reacts with an ozone molecule and splits it. This creates a chlorine monoxide radical, which in turn binds a free oxygen atom that would otherwise combine with an oxygen molecule to form ozone.
The two chemists published their groundbreaking hypothesis in 1974, but it didn’t change anything at first – also because there was resistance from the industry. This did not change until the middle of the next decade, when a series of measurements from Halley Bay showed dramatic ozone depletion over the South Pole. After the data was published in the scientific journal “Nature” in 1985, satellite data from NASA confirmed the finding – the ozone hole had been discovered. Rowland and Molina shared the 1995 Nobel Prize in Chemistry with atmospheric chemist Paul Crutzen.
Unlike the other environmental crisis, global warming, it moved quickly. Dramatic progress in ozone depletion forced politicians to act: the same year, an agreement was reached in Vienna to protect the ozone layer under the guidance of the UN Environment Programme. But even more important was the 1987 Montreal Conference, which itself was supported by US President Ronald Reagan and British Prime Minister Margaret Thatcher – two politicians who otherwise held very few ecological positions.
The Montreal Protocol, which was adopted the same year and came into effect in early 1989, committed signatory states to reduce and ultimately eliminate CFC emissions. Their production was completely banned from 1990. This was done, of course, against the fierce resistance of the industry that made and sold these substances.
The measures were effective. According to the US National Oceanic and Atmospheric Administration, the amount of substances that cause ozone depletion in our stratosphere will decrease by about 50 percent by early 2022. This reached values measured before the ozone hole became a problem. However, it will take a long time before the ozone layer is fully recovered: if current measures remain in place, the ozone layer over Antarctica will expand around 2066, over the North Pole around 2045 and in the Arctic rest of the world will recover to levels in 2040 from 1980.
A reason not to be underestimated that the ozone hole could not develop into such a looming environmental crisis as global warming is simply “incredible luck”, as it says in an article in “Die Zeit” about the road to the Protocol from Montréal. It was a stroke of luck that the element chlorine was chosen for the industrial production of CFCs and not bromine – which serves the same purpose but would have depleted the ozone layer much more. So much so that it could not have been saved in the 1970s. It was also fortunate that scientists recognized the danger of CFCs in time, even though they initially thought the amounts were far too small to cause global problems.
The fact that the Montreal Protocol not only contained declarations of intent, like the Paris Agreement, but also provided for sanctions if a signatory state violated the resolutions was instrumental in successfully combating the ozone hole. Some of the sanctions include restricting trade in products that contain or are manufactured with controlled substances; such as refrigerators or air conditioners. As a rule, the threat of sanctions was enough to convince Member States to comply with the protocol.
However, the main reason for the rapid response to the threat of the ozone hole is probably that CFCs were used in what was ultimately a limited sector – mainly as a refrigerant in refrigerators, as a propellant in aerosol cans, in the manufacture of foam materials or as cleaning and solvents . Alternatives were quickly found for these applications, such as hydrofluorocarbons such as HFCs, which did not have the excellent properties of CFCs but did not deplete the ozone layer. Some of the alternative substances naturally promote global warming themselves, but in general their input is relatively low.
In stark contrast to these expendable CFC gases, the main anthropogenic greenhouse gas, CO2, still an indispensable part of the economy. The odorless and colorless gas, which accounts for most of the man-made additional greenhouse effect, is created when fossil fuels such as coal, oil or natural gas are burned. Clean alternatives are generally expensive and therefore unaffordable for developing countries. This complicates the transition to CO2– free energy production.
Another factor may have contributed to the rapid and efficient response to the ozone hole: fear. As atmospheric chemist Thomas Peter of ETH Zurich explained to German broadcaster NTV, almost everyone had to fear the consequences for personal health if the ozone layer was damaged – such as skin cancer or serious eye disease from aggressive UV radiation.
The prospect of soon having to wear goggles and clothing to protect oneself from dangerous UV rays everywhere outside has probably increased the acceptance of measures to combat the ozone hole. This danger, of course, seemed much more concrete than, say, an increase in the average temperature on earth by two or even three degrees. The consequences of such warming, while devastating, may occur later and not to the same degree across the globe. The dangers of global warming therefore remain rather abstract to many people – especially in wealthy countries, which can more easily bear the resulting costs of extreme weather events.
Nevertheless, the risks of global warming are great. This also includes the risk that the warming of the atmosphere will promote ozone depletion. Signs of this are, in particular, a record loss of ozone in the Arctic stratosphere in the spring of 2020. As a result, the recovery of the ozone layer above the North Pole, which was actually expected, could not take place. In addition, a research team from ETH Zurich already established in 2018 that the ozone layer developed in the opposite direction at mid-latitudes. Thomas Peter, co-author of the study, finds these new findings worrying, but not alarming. But you have to keep an eye on the development and investigate further.
Source: Blick
I am Ross William, a passionate and experienced news writer with more than four years of experience in the writing industry. I have been working as an author for 24 Instant News Reporters covering the Trending section. With a keen eye for detail, I am able to find stories that capture people’s interest and help them stay informed.
