Flashcards in Chapter 7 - The Atmosphere Deck (46):
An organism that gains it's metabolic energy using energy from chemical reactions, e.g. nitrifying bacteria in the nitrogen cycle.
The layer of the atmosphere that absorbs UV and contains the ozone layer. It is above the troposphere at an altitude of approximately six to 30 miles.
Define: Dynamic Equilibrium
A combination of active processes that cancel out each other's effect so that there is no overall charge.
The layer of the atmosphere below the stratosphere, from ground level to about six miles.
Define: Infrared (IR) Radiation
Long wavelength electromagnetic radiation emitted from warm objects.
Define: Nuclear Fusion
The release of energy during the joining of he nuclei of small atoms.
Define: Electromagnetic Radiation
Energy in the form of energy waves with a range of frequencies.
Define: Global Climate Change
The various changes to the climate caused by increased energy retained in the atmosphere as a result of human activities.
Define: Greenhouse Effect
The natural processes by which atmospheric gases allow visible light to pass through but absorb infrared energy, causing heating.
Define: Enhanced Greenhouse Effect
An alternative name for global climate change.
Define: Tropospheric Ozone
Ozone in the troposphere, largely produced by human activities.
Define: El Niño
The name given to the reversal of the equatorial Pacific Ocean current that normally flows westwards.
Define: La Niña
The name given to the strengthening of the westward flowing equatorial Pacific Ocean current.
Define: Positive Feedback Mechanism
A situation where an initial change causes a reaction that increases the original change.
Define: Negative Feedback Mechanism
A situation where an initial change causes a reaction that reduces the original change.
Define: Kyoto Protocol
The international agreement intended to control emissions of greenhouse gases.
Hydrofluorocarbons are a group of chemicals used to replace CFCs.
Hydrochlorofluorocarbons are a group of chemicals used to replace CFCs.
More Economically Developed Countries.
Something made or caused by human activities.
Chlorofluorocarbons are pollutants that cause ozone depletion and contribute to global climate change.
The process by which surface water enters the ground between the particles of soil or rock.
Define: Montreal Protocol
International agreement that has controlled the release of ozone-depleting substances.
What are the gases of the atmosphere, including proportion and importance for life?
- Nitrogen (78%) [Used in proteins]
- Oxygen (21%) [Used in aerobic respiration]
- Carbon Dioxide (0.038%) [Used in photosynthesis]
- Rare Gases (1%)
- Methane (0.00017%) [Chemoautotrophs use methane as carbon]
- Ozone (0.000007%) [Absorbs UV light in stratosphere]
- Water Vapour (Variable) [water in the water cycle]
What are the major anthropogenic sources of greenhouse gases?
- Carbon Dioxide (Combustion of fossil fuels, deforestation)
- Methane (Landfill sites, livestock intestines, pipeline leaks)
- Nitrogen Oxides (Power stations, vehicle engines)
- CFCs (Aerosol propellants, fire extinguishers, refrigerants)
- Tropospheric Ozone (Photochemical breakdown of NO2)
What are the likely consequences of global climate change?
- Sea level rise
> Thermal Expansion (sea warms up and expands)
> Melting land ice (flows into sea, increases volume)
- Changes in climate
> Wind patterns (change in velocity, direction, frequency)
> Precipitation (increased evaporation rates)
- Ocean current changes
> El Niño (reversal of Equatorial Pacific Ocean current)
> La Niña (normal Equatorial Pacific Ocean current strengthened)
> North Atlantic Conveyor (Greenland land ice melting)
- Ecological changes
> Faster plant growth
> Shallow rooted plants cope less well
> Hibernating species disturbed frequently
> Wetland habitats enlarged/shrunk
> Ecological events changed (migration, flowering)
What are the changes in currents in an El Niño year?
- Wind direction reversed (eastwards, Australia to South America)
- Ocean current reversed (water warms up and is carried east)
- Colder Australian water (dry season, little rainfall, droughts)
- Warmer South American water (increased evaporation, heavy rains and floods)
How does global climate change affect the North Atlantic Conveyor?
- Melting Greenland icecap (increased melt water)
- Reduced return current
- Cooled seawater diluted by freshwater (melting ice)
- Smaller density increase (less sinking of water)
- Europe becomes colder
Why is it difficult to predict global climate change accurately?
- Natural changes (difficult to tell if humans caused it)
- Limited historical data (rainfall patterns, wind velocity)
- Natural processes interconnected (unexpected effects)
- Very slow changes (sea level rise)
- Changes in different locations/times
- Do not fully understand Earth's climate systems
What would raised temperatures cause?
- Increased decomposition rates (more carbon dioxide released)
- Reduced albedo (smaller area of ice/snow)
- Methane released from methane hydrate in methane sediments
- Melting permafrost release methane gas bubbles
- Drier forests (fires more frequent, extra carbon dioxide)
What are the methods of reducing Carbon Dioxide levels?
- Energy conservation to reduce use of fossil fuels.
- Use of alternative energy resources.
- Carbon sequestration by planting more trees.
- Storage of CO2 from power stations underground.
- Kyoto Protocol emission reductions.
What are the methods of reducing Methane levels?
- Reduced dumping of waste in landfill sites.
- Reduced livestock production.
- Better collection of gas from coal mines and gas and oil facilities.
What are the methods of reducing Nitrogen Oxides levels?
- Reduced use of internal combustion e.g. more use of public transport.
- Catalytic converters in vehicle exhausts.
- Addition of urea to power station effluents.
What are the methods of reducing Chlorofluorocarbons levels?
- Use of alternative methods:
> Butane or propane in aerosol cans.
> HFCs and HCFCs in refrigerators.
> Alcohols as solvents for cleaning equipment.
- Use of alternative processes:
> Trigger and pump action spray cleaners.
> Stick deodorants.
What are the methods of reducing Tropospheric Ozone levels?
- Same as Nitrogen Oxides methods.
How can agricultural strategies been out into place to cope with climate change?
- Cultivate warmer climate crops
- Cultivate drought-resistant crops
- Abandon unsustainable irrigation areas.
- Increase soil organic matter to increase water retention
- Water storage in times of water surplus for irrigation use
How can building design strategies be put into to place to cope with global climate change?
- Better ventilation/cooling systems (reduce air conditioning)
- Paler materials (reduce heat absorption)
Why is there concern about ozone depletion?
- UV B reach Earth's surface (absorbed by living cells)
- DNA damage
- Skin cancer
- Plant tissue damage
How can flooding strategies be put into place to cope with climate change?
- Riverbank defences
- River barrages (protect against high tides)
- Less building on flood plains
- Reduce runoff rates (reduced paved areas increase infiltration)
- River regulation dams
How can coastal erosion strategies be put into place to cope with climate change?
- Improved coastal defences
- Managed retreat (abandon lower value areas)
How can storm damage strategies be put into place to cope with climate change?
- Stronger building design
What are the categories of UV light and their characteristics?
- UV A (Not absorbed by ozone)
- UV B (Almost fully absorbed by ozone)
- UV C (Completely absorbed by ozone)
What are the reactions involved in ozone depletion by chlorine?
1) Cl + O3 ---> ClO + O2
2) ClO + O ---> ClO2
3) ClO2 ---> Cl + O2
Summary Reaction) Cl + O3 + O ---> 2O2 + Cl
Why is ozone depletion greatest in Polar Regions?
- Reaction occurs in low temperatures
- Ice crystals provide catalytic surfaces
- Spring time, sunlight causes reaction