Reducing Ozone Depletion - AP Environmental Science

What is the primary role of the ozone layer in Earth's atmosphere?

Absorbing UV radiation. Ozone filters harmful UV-B and UV-C radiation from reaching Earth's surface.
Which compound replaces CFCs to reduce ozone depletion?

Hydrochlorofluorocarbons (HCFCs). HCFCs have lower ozone depletion potential than CFCs but still cause damage.
What percentage reduction in CFC levels does the Montreal Protocol aim for?

100%. The protocol aims for complete elimination of CFC production and consumption.
Name a natural source of ozone-depleting substances.

Volcanic eruptions. Volcanoes release sulfur compounds that can deplete ozone temporarily.
List a key provision of the Montreal Protocol.

Phasing out CFC production. The protocol mandates complete phase-out of CFC production by developed nations.
Which gas, used in refrigeration, has replaced CFCs but still poses an environmental risk?

Hydrofluorocarbons (HFCs). HFCs don't deplete ozone but have high global warming potential.
Which substance, used in fire extinguishers, depletes the ozone layer?

Halons. Halons contain bromine atoms that are particularly destructive to ozone.
How does increased UV-B radiation affect agriculture?

Decreased crop yields. Excess UV-B radiation damages plant cells and reduces photosynthesis efficiency.
Which factor enhances the breakdown of ozone-depleting substances in the atmosphere?

Polar stratospheric clouds. These clouds provide surfaces where chlorine compounds become ozone-destroying.
Name an industrial process that releases CFCs.

Aerosol propellants. CFCs were commonly used to propel contents from spray cans and bottles.
What is the main anthropogenic cause of ozone depletion?

Chlorofluorocarbons (CFCs). CFCs release chlorine atoms that destroy ozone molecules in the stratosphere.
Which international agreement aims to reduce ozone-depleting substances?

The Montreal Protocol. Signed in 1987, this protocol phases out ozone-depleting substances globally.
Which strategy can individuals take to reduce ozone depletion?

Using energy-efficient appliances. Efficient appliances reduce demand for refrigerants containing ozone-depleting chemicals.
What measures the effectiveness of ozone-depleting substances?

Ozone Depleting Potential (ODP). ODP compares substances to CFC-11's ozone destruction capability (ODP = 1.0).
What human activity is a major source of CFCs?

Refrigeration and air conditioning. CFCs were widely used as coolants before their ozone-depleting effects were known.
Which UV type does the ozone layer primarily absorb?

UV-B. Ozone molecules absorb UV-B wavelengths (280-315 nm) most effectively.
Which element in CFCs primarily causes ozone destruction?

Chlorine. Chlorine atoms act as catalysts, destroying many ozone molecules per atom.
Which compound is used as a foam-blowing agent and depletes ozone?

Methyl bromide. Used in fumigation and foam production, methyl bromide releases bromine atoms.
What is the relationship between ozone depletion and global warming?

HFCs contribute to global warming. HFC replacements for CFCs are potent greenhouse gases warming the climate.
What is the main objective of the Vienna Convention?

Protecting the ozone layer. Signed in 1985, this convention established framework for ozone protection.
Which technology reduces the need for ozone-depleting substances in insulation?

Cellulose insulation. Natural insulation materials eliminate need for foam-blowing chemicals.
What environmental effect does ozone depletion have on marine ecosystems?

Reduced phytoplankton growth. Increased UV-B damages marine phytoplankton, disrupting ocean food webs.
Which sector is a significant source of halons?

Firefighting. Fire suppression systems historically used halons before safer alternatives.
Which UV radiation type is most harmful to living organisms?

UV-B. UV-B causes skin cancer, cataracts, and immune system suppression in humans.
Identify a health effect of increased UV exposure due to ozone depletion.

Increased skin cancer risk. More UV-B radiation penetrates when ozone layer is depleted, causing DNA damage.
What is one outcome of the Montreal Protocol's success?

Decrease in atmospheric chlorine. Reduced chlorine levels indicate the protocol's effectiveness in ozone protection.
Which alternative technologies help reduce reliance on ozone-depleting substances?

Ammonia-based refrigeration. Natural refrigerants like ammonia don't contain ozone-depleting halogens.
Identify a substance that contributes to ozone layer depletion.

Halons. Halons contain bromine which is highly effective at destroying ozone.
Which amendment addresses HFCs under the Montreal Protocol?

The Kigali Amendment. This 2016 amendment targets HFCs to prevent climate change acceleration.
Name a method for monitoring ozone layer recovery.

Satellite observations. Satellites measure total ozone column thickness to track layer recovery.
Which international body oversees the implementation of the Montreal Protocol?

United Nations Environment Programme (UNEP). UNEP coordinates global efforts and monitors compliance with ozone treaties.
Which part of the atmosphere contains the ozone layer?

The stratosphere. The ozone layer is located 15-35 km above Earth's surface in the stratosphere.
Which industry is responsible for substantial methyl bromide emissions?

Agriculture. Soil fumigation with methyl bromide releases bromine into the atmosphere.
Which chemical reaction is involved in the natural formation of ozone?

Oxygen molecules and UV light. UV light splits $O_2$ molecules; oxygen atoms combine with $O_2$ forming $O_3$ .
Which chemical reaction involves ozone depletion?

CFCs releasing chlorine atoms. Chlorine atoms from CFCs catalytically destroy thousands of ozone molecules.
Identify a technological innovation that reduces ozone depletion.

Non-halogenated solvents. These solvents lack halogen atoms that cause ozone destruction.
What is the typical lifespan of CFCs in the atmosphere?

50 to 100 years. CFCs persist for decades, continuing to destroy ozone long after release.

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