6.4 Stratospheric Ozone (DP IB Environmental Systems & Societies (ESS): HL): Flashcards
0Still learning
Know0
- FrontUV Radiation
Define ultraviolet (UV) radiation.
Was this flashcard helpful?
Cards in this collection (66)
Define ultraviolet (UV) radiation.
Ultraviolet (UV) radiation is a type of electromagnetic radiation from the Sun that has a shorter wavelength and higher frequency than visible light.
What is the relationship between the wavelength and frequency of electromagnetic radiation?
Shorter wavelengths correspond to higher frequencies in electromagnetic radiation.
Radiation with wavelengths has frequency and more energy.
Radiation with shorter wavelengths has higher frequency and more energy.
Why does ultraviolet radiation pose a greater risk to living organisms than visible light?
Ultraviolet radiation has more energy than visible light, which allows it to cause greater damage to living cells and tissues.
True or False?
Ultraviolet radiation from the Sun can cause mutations in DNA during cell division.
True.
UV radiation can induce mutations in DNA during cell division by damaging genetic material.
Define cataracts.
Cataracts are a clouding of the lens in the eye, often caused by prolonged exposure to UV radiation, leading to blurry vision and possible vision loss.
When the skin is exposed to excessive UV rays, it triggers an response as a defence mechanism.
When the skin is exposed to excessive UV rays, it triggers an inflammatory response as a defence mechanism.
Which type of cancer is most associated with excessive exposure to ultraviolet radiation from the Sun?
Excessive UV exposure increases the risk of developing skin cancer, as UV rays can damage DNA in skin cells.
Define premature skin ageing.
Premature skin ageing is the acceleration of the skin's ageing process due to chronic exposure to ultraviolet radiation, resulting in wrinkles, sagging, and age spots.
How does increased UV radiation affect plant productivity?
Increased UV radiation can reduce photosynthesis rates and decrease crop yields by damaging plant cells and altering metabolism.
True or False?
Reduced phytoplankton productivity caused by UV radiation can impact higher trophic levels in aquatic ecosystems.
True.
When phytoplankton productivity drops, zooplankton and higher consumers like fish and marine mammals have less food, affecting the entire aquatic food web.
Phytoplankton convert sunlight, carbon dioxide and nutrients into organic matter through .
Phytoplankton convert sunlight, carbon dioxide and nutrients into organic matter through photosynthesis.
Define ozone.
Ozone is a molecule composed of three oxygen atoms (O₃).
Where in the Earth's atmosphere is most ozone found?
Ozone is mainly found in the stratosphere, a layer of the atmosphere located approximately 10 to 50 kilometres above the Earth's surface.
What important role does stratospheric ozone play for life on Earth?
Stratospheric ozone protects life on Earth by absorbing a significant portion of the Sun's harmful UV radiation.
The layer of the atmosphere where most ozone is found is the .
The layer of the atmosphere where most ozone is found is the stratosphere.
Ozone absorbs much of the Sun’s harmful radiation, protecting living organisms.
Ozone absorbs much of the Sun’s harmful UV radiation, protecting living organisms.
True or False?
UVB is the most harmful type of UV radiation and is completely absorbed by the stratospheric ozone.
False.
UVB is less harmful than UVC, and only mostly absorbed by stratospheric ozone; some UVB still reaches the Earth's surface.
Which type of UV radiation is completely absorbed by stratospheric ozone?
UVC radiation is the most harmful and is completely absorbed by stratospheric ozone.
Define dynamic equilibrium in the context of ozone in the stratosphere.
Dynamic equilibrium is a state where the rate of ozone formation equals the rate of destruction, so the concentration of ozone remains relatively constant.
When UV radiation breaks apart ozone, it forms an oxygen molecule (O₂) and a .
When UV radiation breaks apart ozone, it forms an oxygen molecule (O₂) and a free oxygen atom (O).
What happens to the free oxygen atom (O) in the stratosphere after ozone is destroyed?
The free oxygen atom (O) can combine with an oxygen molecule (O₂) to reform ozone (O₃).
True or False?
The concentration of ozone in the stratosphere fluctuates wildly over short periods of time.
False.
The concentration of ozone in the stratosphere remains relatively constant over long periods due to dynamic equilibrium.
The rate of the forward reaction the rate of the backward reaction in the dynamic equilibrium of ozone in the stratosphere.
The rate of the forward reaction equals the rate of the backward reaction in the dynamic equilibrium of ozone in the stratosphere.
Define Montreal Protocol.
The Montreal Protocol is an international agreement that regulates the production, trade and use of ozone-depleting substances (ODSs).
What role has the United Nations Environment Programme (UNEP) played in protecting the stratospheric ozone layer?
UNEP has been vital in raising awareness, providing information, and creating international agreements to protect the stratospheric ozone layer, such as the Montreal Protocol.
The Montreal Protocol was initiated in and originally signed by countries.
The Montreal Protocol was initiated in 1987 and originally signed by 24 countries.
What substances does the Montreal Protocol aim to regulate?
The Montreal Protocol aims to regulate the production, trade and use of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODSs).
UNEP has been involved in creating agreements that aim to the use of ozone-depleting substances (ODSs).
UNEP has been involved in creating agreements that aim to reduce the use of ozone-depleting substances (ODSs).
True or False?
The number of countries that have signed the Montreal Protocol has remained at 24 since 1987.
False.
The number of signatories has increased to 197 countries.
Define ozone-depleting substances (ODSs).
Ozone-depleting substances (ODSs) are chemicals that destroy stratospheric ozone, for example chlorofluorocarbons (CFCs).
How has the Montreal Protocol affected the emissions of ozone-depleting substances since 1987?
The Montreal Protocol has led to a rapid fall in emissions of ozone-depleting substances from about 1.5 million tonnes in 1987 to around 400,000 tonnes in 2010.
The Montreal Protocol provided time for the development and adoption of to ODSs through gradual reduction schedules.
The Montreal Protocol provided time for the development and adoption of alternatives to ODSs through gradual reduction schedules.
What major challenge does the illegal market for ozone-depleting substances present?
The illegal market for ozone-depleting substances undermines international efforts and requires consistent monitoring and enforcement to tackle effectively.
What are planetary boundaries?
Planetary boundaries are thresholds in Earth systems beyond which significant environmental changes may occur if crossed.
How has the Montreal Protocol contributed to the planetary boundary for stratospheric ozone depletion?
Actions taken under the Montreal Protocol have prevented the planetary boundary for stratospheric ozone depletion from being crossed and have helped the ozone layer recover.
Define ozone depletion.
Ozone depletion is the gradual thinning of the ozone layer in the Earth's stratosphere, often caused by human-made chemicals called ozone-depleting substances (ODSs).
Ozone depletion refers to the gradual of the in the Earth's stratosphere.
Ozone depletion refers to the gradual thinning of the ozone layer in the Earth's stratosphere.
What are ozone-depleting substances (ODSs) and how do they contribute to ozone depletion?
Ozone-depleting substances (ODSs) are human-made chemicals such as refrigerants, aerosols, and solvents, which are released into the atmosphere and cause the thinning of the ozone layer.
Define chlorofluorocarbons (CFCs).
Chlorofluorocarbons (CFCs) are human-made chemicals used in products like refrigerants, aerosols, and solvents, and are a major group of ozone-depleting substances.
CFCs are stable compounds that do not readily degrade in the . They eventually drift upward into the .
CFCs are stable compounds that do not readily degrade in the troposphere. They eventually drift upward into the stratosphere.
Describe the role of chlorine radicals in the breakdown of the ozone layer.
Chlorine radicals act as catalysts in the stratosphere, breaking down ozone (O₃) molecules into oxygen (O₂) and continuously repeating this process without being used up.
One chlorine radical can thousands of molecules before being removed from the stratosphere.
One chlorine radical can destroy thousands of ozone molecules before being removed from the stratosphere.
True or False?
Chlorine radicals are used up during the reactions that break down ozone in the stratosphere.
False.
Chlorine radicals are not used up in these reactions; they act as catalysts and can destroy many ozone molecules before removal from the stratosphere.
When does polar stratospheric ozone depletion mainly occur over the poles?
Polar stratospheric ozone depletion mainly occurs during spring over the poles.
Define ozone hole.
An ozone hole is an area where the concentration of ozone is much lower than normal, not a literal hole, allowing more harmful UV radiation to reach Earth's surface.
True or False?
The ozone hole is most commonly observed over Antarctica during the Southern Hemisphere's spring.
True.
The ozone hole is usually seen over Antarctica from September to November, the Southern Hemisphere's spring.
The Protocol reduced CFC emissions, but the Antarctic ozone hole is still yearly.
The Montreal Protocol reduced CFC emissions, but the Antarctic ozone hole is still monitored yearly.
Define polar stratospheric clouds (PSCs).
Polar stratospheric clouds (PSCs) are clouds that form in the polar stratosphere at extremely low temperatures, providing surfaces for chlorine chemistry that destroys ozone.
What role do polar stratospheric clouds (PSCs) play in ozone depletion?
PSCs provide active surfaces where chlorine compounds are converted into forms that can destroy ozone, especially when sunlight returns in spring.
The vortex isolates air over the poles, trapping substances and increasing ozone depletion.
The polar vortex isolates air over the poles, trapping ozone-depleting substances and increasing ozone depletion.
Why is ozone depletion more severe in Antarctica than in the Arctic?
Ozone depletion is more severe in Antarctica because the Antarctic polar vortex is stronger and more stable than the Arctic vortex, leading to greater isolation and more PSC formation.
How do volcanic aerosols influence ozone depletion in the polar stratosphere?
Volcanic aerosols released by eruptions provide additional surfaces for ozone-destroying reactions, amplifying ozone depletion especially in the presence of PSCs and within the polar vortex.
Define chlorofluorocarbons (CFCs).
Chlorofluorocarbons (CFCs) are chemical compounds containing chlorine, fluorine, and carbon. They were widely used in products like aerosols and refrigerators but are harmful to the ozone layer.
Define hydrofluorocarbons (HFCs).
Hydrofluorocarbons (HFCs) are chemical compounds containing hydrogen, fluorine, and carbon. They are used as replacements for CFCs and do not deplete the ozone layer significantly but are potent greenhouse gases.
What was the main environmental concern that led to the ban on CFCs under the Montreal Protocol?
CFCs deplete the ozone layer by releasing chlorine radicals in the stratosphere, increasing harmful UV radiation reaching the Earth's surface.
True or False?
HFCs have no impact on the environment because they do not deplete the ozone layer.
False.
Although HFCs do not significantly deplete the ozone layer, they are potent greenhouse gases with high global warming potential.
What international agreement set targets to reduce the production and consumption of HFCs?
The Kigali Amendment (2016) to the Montreal Protocol set targets to reduce HFC production and consumption globally.
CFCs were replaced by because they do not deplete the .
CFCs were replaced by HFCs because they do not deplete the ozone layer.
Define air conditioning.
Air conditioning is the process of regulating indoor temperature and humidity to improve comfort in buildings, vehicles, and public spaces.
How can traditional air conditioning contribute to greenhouse gas emissions?
Traditional air conditioning can increase greenhouse gas emissions through energy consumption (from fossil fuels) and leakage of refrigerants such as CFCs and HFCs, which are potent greenhouse gases.
The use of in air conditioning is being phased down because of their high potential.
The use of HFCs in air conditioning is being phased down because of their high global warming potential.
What are hydrofluoroolefins (HFOs) and why are they important in air conditioning?
Hydrofluoroolefins (HFOs) are new refrigerants with a low global warming potential being adopted in air conditioning systems as alternatives to HFCs.
How does urban greening help reduce the need for air conditioning in cities?
Urban greening lowers urban temperatures through shade and evapotranspiration, reducing the demand for energy-intensive air conditioning.
Passive cooling techniques, such as , , and , reduce the need for artificial cooling systems.
Passive cooling techniques, such as shading, ventilation, and thermal mass, reduce the need for artificial cooling systems.
True or False?
Cool roofs can help reduce the urban heat island effect and lower energy consumption.
True.
Cool roofs reflect sunlight, reducing indoor heat absorption and lowering urban temperatures and energy use for cooling.
Sign up to unlock flashcards
or