The Atmosphere Flashcards
What percentages do Nitrogen, Oxygen and Carbon Dioxide make up of our atmosphere?
Nitrogen: 78%
Oxygen: 21%
Carbon Dioxide 0.04%
What is dynamic equilibrium?
Where processes are in a state of balance so composition can only change over long periods of time
Name 3 ways the atmosphere supports life
- Contains gases necessary for natural processes like photosynthesis
- The ozone layer absorbs UV light
- Greenhouse effect
- Winds create ocean currents that distribute heat and nutrients
- Wind transports water vapour to otherwise dry areas
Why is atmospheric pressure important?
It controls how easy it is for water molecules to evaporate, therefore maintaining liquid water
What are the 4 layers of the atmosphere? What happens to the temperature in each layer?
Troposphere: temp falls as you reach the top
Stratosphere: temp rises as you reach the top
Mesosphere: temp falls as you reach the top
Thermosphere: temp rises as you reach the top
What 3 wavelengths of electromagnetic radiation arrive in the atmosphere?
UV, visible and near infrared
What wavelength of electromagnetic radiation leaves the atmosphere?
Long wavelength infrared
What is the natural greenhouse effect?
The process that warms the troposphere by having gases absorb infrared emitted by the earth’s surface
What is the enhanced Greenhouse effect?
Where human activities have increased the concentration of greenhouse gases increasing the amount of IR absorbed and therefore increasing temperatures
What human activities release Carbon Dioxide?
Combustion of fossil fields, ploughing of soils and draining marshes
What human activities release Methane?
Anaerobic respiration in padi fields, landfill, livestock, ventilation of coal mines
What human activities release Oxides of Nitrogen?
Vehicle engines, power stations, fertilisers
What human activities release CFCs?
Aerosol propellants, refrigerator solvents
How can animals be affected by climate change?
- Cannot live in certain temps
- Hibernation disturbed
- Change in distribution as conditions change
- Stormier weather can affect flight
How can plants be affected by climate change?
- Higher temps may make plants grow faster
- Shallow root plants may lose access to water
- Seasonal events may be disrupted
- Change in distribution as species change
How can abiotic features be affected by climate change?
- Precipitation may increase or decreases
- Temperature increase
- Change in wind patterns due to weaker jetstreams
- Snow and ice may melt
- Decrease in sea salinity
- Sea level rise
- Changes in ocean current
How can human society be affected by climate change?
- Health issues for individuals in already warm climates
- Worsening of heart or respiratory conditions
- Faster pathogen growth
- Decreased or Increased water supply
- Loss of certain crops species
- Landslides
- Building structure buckling
- Road heat stress
What are jet streams?
Strong winds blowing East to West due to density differences between hot and cold air
What is the North Atlantic Conveyor?
The movement of water from warmer areas in the tropical Atlantic to North West Europe thanks to friction with winds
When does El Nino happen and what is it?
El Nino ocurrs every 2 to 7 years as the westward blowing trade winds from south america to australia that usually cause cold water to be pulled up on the coast of south america which pulls nutrients to the surface change directions and causes the ecosystem fuelled by the usual upwelling to collapse.
What is La Nina?
The westward blowing trade winds from south america to australia that usually cause cold water to be pulled up on the coast of south america which pulls nutrients to the surface increases, causing a boom in the south american coast ecosystem
Why is it difficult to monitor climate change?
- Changes can occur over different timescales
- Changes can occur over varying spatial scales
- We do not fully understand the processes and systems that cause it
- Time delay between cause and effect
- Natural climate change VS Human-caused climate change
Why can historic data be unreliable?
- Lack of sophisticated equipment
- Lack of global data
What ways do we have of collecting proxy data?
- Dendrochronology, studying tree rings to indicate growth rate and therefore conditions
- Pollen analysis from grains preserved in lake sediment
- Ice core sampling, checking oxygen isotopes and carbon dioxide levels
- Computer models to simulate past and future conditions
What are Negative Feedback Mechanisms? Give an example
When an environmental change causes other changes which decrease the rate of the initial change, re-establishing the equilibrium.
Examples:
- Increased temp, increased cloud cover, increased albedo, decreased temp
- Increased temp, increased photosynthesis, decreased carbon dioxide, decreased temp
What are Positive Feedback Mechanisms? Give an example
When an environmental change causes other changes which increase the rate of the initial change, pushing the conditions away from equilibrium.
Examples:
- Increased temp, melted permafrost, methane release, further increased temp
- Increased temp, ocean acidification, coral death, less carbon sequestration, decreased temp
- Increased temp, increased forest fires, carbon dioxide release, increased temp
What is a tipping point?
The concept that a human activity may cause changes in natural processes to the extent that the original activity isn’t needed for climate change to continue increasing due to positive feedback mechanisms
What is CSS?
Carbon Capture and Storage, the process of capturing or removing CO2 from the fuel, transporting and storing it in depleted oil fields, gas fields or aquifers
How can we adapt to climate change?
- Flood control using raised riverbanks and flood barriers
- Coastal erosion prevention using sea walls and wave screens
- Increasing permeable urban surfaces
- Managing river flow
What is the importance of stratospheric ozone?
It makes up the ozone layer, which absorbs harmful UV rays which can cause skin damage, DNA damage, skin cancer, cataracts and leaf tissue damage.
What are CFCs and why were they developed?
Chlorofluorocarbons, developed for use in AC units, refrigerators, as propellants and as cleaning solvents
What is the Rowland-Molina hypothesis? When was it?
In 1974 two scientists suggested that CFCs were causing ozone depletion because they were stable enough to reach the stratosphere, broke apart in the UV radiation, the chlorine reacted with oxygen stopping the formation of ozone
When was the Vienna Convention for the Protection of the Ozone Layer? What was in it?
1985, an agreement to protect the ozone layer, but it had no legally binding goals
What was in the Montreal protocol?
- Manufacture and use of CFCs was phased out by 2030 and then banned
- Some essential uses are still permitted
- A fund is available to help countries implement the protocol
What alternatives are there to CFCs?
- pump action sprays instead of propellants
- roll-ons instead of propellants
- HCFCs (Hydrochlorofluorocarbons) which are less stable so do not reach the stratosphere
