The Ozone Layer | UCAR Center for Science Education
Ozone in the troposphere (a pollutant) can lead to deforestation. This is generally caused by pollutants such as CFCs used as propellents and in .. I always tried my best to develop my skills and my future goal was to involve myself in. The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty The stated purpose of the treaty is that the signatory states . HFCs pose no harm to the ozone layer because, unlike CFCs and HCFCs, .. Anarchy and the Environment: The International Relations of Common Pool Resources. Relationship between ozone-depleting substances & climate change substances such as hydrochlorofluorocarbons (HCFCs) and chlorofluorocarbons (CFCs).
In a worrying development, after an extremely cold winter in earlyfor the first time the ozone reduction in the Arctic was comparable to that in the Antarctic.
Stratospheric ozone also has natural processes that remove it from the atmosphere. Tiny sulfate particles aerosols blasted into the stratosphere by the volcanic eruption of Mount Pinatubo in caused measurable decreases in ozone for several years following the eruptions. Does global warming have an impact on the stratospheric ozone layer?
Temperature change in both the lower stratosphere and the lower troposphere go in opposite directions--a telling sign of excess carbon dioxide in the troposphere. Since the s, there has been a trend of increasing warming of the lower atmosphere and a cooling of the upper atmosphere. This warming-cooling dynamic creates conditions that lead to ozone loss.
Observations show that as greenhouse gases increase and result in heating in the lower atmosphere tropospherea cooling is occurring in the upper atmosphere stratosphere. Largely because heat from Earth's surface that normally would convey through the troposphere and stratosphere, and eventually escape to space, is now being trapped or confined to the troposphere. The increasing temperatures at the Earth's surface and decreasing temperatures in higher parts of the atmosphere can be partly explained using the blanket analogy.
Carbon dioxide and other heat-trapping gases rise into the atmosphere and spread around the globe, like a blanket wrapping Earth. This blanket warms the surface of the Earth and protects it from the cold air above it. The increased concentrations of heat-trapping gases make the blanket uncomfortably thicker.
The blanket also prevents heat from moving from the lower atmosphere to the stratosphere, cooling down the stratosphere as a result. In other words, heat-trapping gases contribute to creating the cooling conditions in the atmosphere that lead to ozone depletion. Greenhouse gases absorb heat at relatively low altitudes and warm the surface--but they have the opposite effect in higher altitudes because they prevent heat from rising.
In a cooler stratosphere, ozone loss creates a cooling effect that results in further ozone depletion. UV radiation releases heat into the stratosphere when it reacts with ozone. Why would ozone levels have dropped? Could it just be natural variation?
Since ozone concentrations over this region often vary from season to season, the researchers weren't concerned, but record low ozone levels kept occurring nearly every spring.
Montreal Protocol - Wikipedia
No one knew why. They were the first to find an ozone hole and it would later be identified as the world's largest ozone hole. An ozone hole is really not a hole but rather a thinning of the ozone layer in the stratosphere that changes seasonally.
It wasn't until that scientists were certain that this was a major problem and it was human-caused. The culprit were chemical compounds called chlorofluorocarbons CFCswhich started to be used in the s in air conditioners, aerosol spray cans, and industrial cleaning products. They were also used to make Styrofoam. And they were capable of breaking apart ozone molecules, causing the breakdown of ozone in the stratosphere to happen faster than it could be built back up.
This animation shows the destruction of an ozone molecule by a chlorine atom. UV radiation breaks a chlorine atom off a CFC molecule.
The chlorine atom breaks an ozone molecule apart into an oxygen molecule O2 and a chlorine monoxide molecule ClO. Crutzen, Molina and Rowland were awarded the Nobel Prize for Chemistry for their work on this problem. The environmental consequence of this discovery was that, since stratospheric ozone absorbs most of the ultraviolet-B UV-B radiation reaching the surface of the planet, depletion of the ozone layer by CFCs would lead to an increase in UV-B radiation at the surface, resulting in an increase in skin cancer and other impacts such as damage to crops and to marine phytoplankton.
But the Rowland-Molina hypothesis was strongly disputed by representatives of the aerosol and halocarbon industries. The chair of the board of DuPont was quoted as saying that ozone depletion theory is "a science fiction tale Robert Abplanalpthe president of Precision Valve Corporation and inventor of the first practical aerosol spray can valvewrote to the Chancellor of UC Irvine to complain about Rowland's public statements Roan, p.Stratospheric Ozone
After publishing their pivotal paper in JuneRowland and Molina testified at a hearing before the U. House of Representatives in December As a result, significant funding was made available to study various aspects of the problem and to confirm the initial findings.
Is There a Connection Between the Ozone Hole and Global Warming? | Union of Concerned Scientists
Inthe U. National Academy of Sciences NAS released a report that confirmed the scientific credibility of the ozone depletion hypothesis.
They speculated that this was connected to increased levels of CFCs in the atmosphere. It took several other attempts to establish the Antarctic losses as real and significant, especially after NASA had retrieved matching data from its satellite recordings.
The impact of these studies, the metaphor 'ozone hole', and the colourful visual representation in a time lapse animation proved shocking enough for negotiators in Montreal, Canada to take the issue seriously. After the discovery of the ozone hole by SAGE 2 it only took 18 months to reach a binding agreement in Montreal, Canada.