ESS TOPIC 6: Atmospheric Systems and Societies

Define ‘albedo’

A measure of the reflectivity of a surface. The albedo effect when applied to the Earth is a measure of how much of the Sun's energy is reflected back into space.

Identify conditions necessary for formation of tropospheric ozone.

Warm, sunny days when the air is stagnant - because the reactions are photochemical

Why do ozone depleting substances affect the production of ozone in the stratosphere?

When chlorine and bromine atoms come into contact with ozone in the stratosphere, they destroy ozone molecules.

Outline the consequences of ozone depletion on ecosystems and societies.

Ozone depletion can cause increased amounts of UV radiation to reach the Earth which can lead to more cases of skin cancer, cataracts, and impaired immune systems. Excessive UV inhibits the growth processes of almost all green plants. Ozone depletion may lead to a loss of plant species and reduce global food supply.

Suggest 3 management strategies to reduce ozone depleting substances.

Altering human activity e.g. replace gas-blown plastics.

Controlling release of pollutant e.g. recover and recycle CFCs.

Clean-up and restoration e.g. add ozone to or remove chlorine from stratosphere.

Describe what is meant by a temperature inversion.

A reversal of the normal behaviour of temperature in the troposphere in which a layer of cool air at the surface is overlain by a layer of warmer air. (Under normal conditions air temperature usually decreases with height.)

How do temperature inversions affect smog?

They trap the smog in valleys and basins (e.g. in LA/Mexico City).

The air is unable to disperse as the cold air from the surrounding mountains and hills prevents the warm air from rising.

What role does deforestation and burning have in smog?

Burning forests increase greenhouse gases in the atmosphere by releasing the CO2 stored in the biomass and removing the forest so that it cannot store CO2 in the future.

Describe some of the possible economic losses that can occur due to urban air pollution.

* Higher rates of asthma and other chronic respiratory diseases leads to lower workforce.
* Loss of tourism
* World Bank - China air pollution worth 4% annual GDP.

Distinguish between direct and indirect effects of acid precipitation.

Direct effect - acid falling on aquatic organisms and coniferous forests. Indirect toxic effect - increased solubility of metal such as aluminium ions on fish. Indirect nutrient effect - leaching of plant nutrients.

Outline 3 pollution management strategies for acid precipitation.

Altering human activity: alternatives to fossil fuels; international agreements. Regulating pollutants: scrubbers or catalytic converters.

How successful has the Montreal Protocol been in reducing ODS in the atmosphere?

The Parties to the Protocol have phased out 98% of ODS globally compared to 1990 levels. The ozone layer is recovering and is projected to be fully recovered by 2066.

What are the main human activities that contribute to the increase of greenhouse gases in the atmosphere?

Burning of fossil fuels is the largest single source of greenhouse gas emissions; deforestation is second largest source of carbon dioxide; domesticated animals emit methane.

What are the differences between tropospheric and stratospheric ozone?

Stratospheric ozone forms naturally in the upper atmosphere and protects from the sun’s harmful ultraviolet rays.

Tropospheric ozone is created through the interactions of man-made and natural emissions of volatile organic compounds and nitrogen oxides in the presence of heat and sunlight and has many harmful impacts.

Outline how ozone is formed.

1. ‘High-energy’ ultraviolet radiation strikes an oxygen molecule
2. Causes it to splint into two free oxygen atoms
3. These free oxygen atoms collide with molecules of oxygen
4. To form ozone molecules.

What are halogenated organic gases and what effect can they have on the ozone layer?

Gases which are very stable under normal conditions but can liberate halogen atoms when exposed to ultraviolet radiation in the stratosphere.

These atoms react with monatomic oxygen and slow the rate of ozone reformation.

Where is most ozone created and why?

Over the equator and between the tropics - because this is where solar radiation is strongest

Evaluate the role of the 1987 Montreal Protocol in reducing emissions of ozone-depleting substances.

* The most successful and significant international agreement relating to an environmental issue.


* Raised public awareness of the use of CFCs and provided an incentive for countries to use alternatives.
* HOWEVER: harder for LEDCs to implement changes
* Second-hand appliance market means that old fridges are still in circulation
* Depends on governments being willing to comply

Why is tropospheric ozone a secondary pollutant?

Because it is formed by reactions involving oxides of nitrogen.

Where does ozone tend to concentrate and why?

Over the polar regions - because winds within the stratosphere transport the ozone there.

What is the ozone hole?

An area of reduced concentration of ozone in the stratosphere, which varies from place to place and over the course of a year.

Why is there an illegal trade in ODSs?

* ODS substitutes often costlier than CFCs
* Updating equipment for use of alternatives is expensive
* Lifetime of CFC-containing equipment is often long
* Penalties in many countries for ODS smuggling are small.

Why is the management of urban air pollution difficult?

* Catalytic converters reduce fuel efficiency and increase CO2 emissions
* Public transport can be expensive and inconvenient
* Sustainable urban design is expensive

Should acid precipitation be considered a global, regional, or local issue? Explain your reasoning.

Until c.1960s, acid rain was a local phenomenon - however, construction of tall smokestacks forced the pollutants higher in the atmosphere and resulted in acid rain falling at greater distances from the original source.

What is the difference between the greenhouse effect and the enhanced greenhouse effect?

The greenhouse effect traps some of the energy from the Sun, which keeps the planet at a suitable temperature for living. However, increased release of greenhouse gases leads to an increase in the greenhouse effect called the enhanced greenhouse effect. This is leading to global warming.

Suggest 4 reasons as to why the annual average temperature of the Earth has been rising.

* Onset of global industrialisation and the subsequent production of pollution derived from fossil fuels (CO2 emissions)
* Deforestation, particularly of rainforest (CO2 emissions)
* Volcanic activity (natural phenomena)
* Sunspot activity (natural phenomena)

State, from lowest to highest, the layers of the atmosphere.

Troposphere - stratosphere - mesosphere - thermosphere

How does deforestation affect carbon dioxide levels?

CO2 released through breakdown of forest biomass and increased rate of breakdown in organic content in soils (due to exposure to heat and water).

Reduction in forest cover reduces the amount of CO2 taken out of atmosphere by photosynthesis.

Deforestation largely to free up land for housing and agriculture.

Which areas tend to have poor air quality and why?

Places such as Mexico City and Athens which are surrounded by high ground - cold air sinks from the higher ground, preventing the dispersion of pollutants

What is the difference between wet and dry acid deposition?

* Dry: oxides e.g. sulfur dioxide and nitrogen oxides are emitted from industrial areas, vehicles etc. and fall directly to the ground close to the source


* Wet: oxides remain in the air longer and become oxidised into sulfuric and nitric acid. These dissolve in cloud droplets and reach the ground as wet deposition. Can be carries thousands of km downwind from source.

What are acidified lakes characterised by?

* an impoverished species structure
* visibility several times greater than normal
* white moss spreading across the bottom of the lake
* increased levels of dissolved metals such as cadmium, copper, aluminium, zinc, and lead (so these metals become more easily available to plants and animals)

Discuss the role of the albedo effect from clouds in regulating global average temperature.

Because a cloud usually has a higher albedo than the surface beneath it, the cloud reflects more shortwave radiation back to space than the surface would in the absence of the cloud, thus leaving less solar energy available to heat the surface and atmosphere.

Outline the role of the greenhouse effect in regulating temperature on Earth.

When the thermal radiation (or heat) arrives from the sun, some of it is bounced from the surface of the Earth by the ozone layer, leaving only some heat to make it through to heat the Earth.

This heat then rises back through the atmosphere, but most of it gets trapped by the greenhouse gases, which causes it to remain in the Earth's atmosphere.

Without the effect, the heat would be lost.

Define and give an example of buffering capacity.

The ability of some environments to neutralise acid rain. For example, chalk and limestone areas are very alkaline and can neutralise acids very effectively.

Suggest 5 strategies to manage acid deposition.

* Reducing the demand for electricity
* Reducing the amount of fossil fuel combustion
* Removing the pollutants before they reach the atmosphere
* Use of limestone scrubbers in chimneys of power stations (to neutralise the acid)
* Spraying powdered limestone onto acidified soils or waters.