4.4 Climate Change Flashcards
The most significant greenhouse gases
carbon dioxide and water vapour
How heat is trapped in the atmosphere
Greenhouse gases absorb and emit long-wave (infrared) radiation –> heat is trapped and held in atmosphere
Amount of greenhouse gases in earth’s atmosphere
less than 1%
Greenhouse gases with the largest warming effect
water vapour (clouds)
carbon dioxide
How water vapor is created
evaporation of water bodies and transpiration
How water vapor is removed
precipitation (rain)
Less significant greenhouse gases
methane and nitrogen oxides
How methane is emitted
from water logged habitats and landfills
how nitrogen oxides are released
naturally by certain bacteria
exhaust by certain vehciles
most abundant greenhouse gases
water vapour
The impact of greenhouse gases is determined
ability to absorb long-wave radiation
concentration within atmosphere
effect of greater ability to absorb long-wave radiation
have a greater warming impact per molecule
effect of greater concentration within atmosphere
greater warming impact within the atmosphere
how the concentration of gas within atmosphere is determined
rate of release & persistence within the atmosphere
Impact of methane
larger capacity to absorb long-wave radiation than CO2
HOWEVER< significantly less abundant
Persistance of water vapour
enters atmosphere rapidly, but only remains for short periods
persistence of carbon dioxide
persists for years (5-200)
The greenhouse effect
Natural process –> causes atmosphere to behave like a greenhouse (trapping heat)
The warmed Earth emits longer wavelength radiation (heat)
Purpose of greenhouse effect
maintains moderate temperatures needed for organisms an life processes (homeostasis)
Consequence of no greenhouse effect
temperatures would drop at night due to absence of direct sunlight
Process of Greenhouse effect
- Functions to trap heat within the atmosphere - prevents temp fluctuations
- Incoming radiation is shorter wave (ultraviolet) (pass or absorbed by GH gases)
- earth surface absorbs or reflects short waves
- reflected re-emits as longer waves (infra-red / heat)
- greenhouse gases absorb and re-radiate longer waves –> retain the heat within atmosphere
Process of Greenhouse effect
- Functions to trap heat within the atmosphere - prevents temp fluctuations
- Incoming radiation is shorter wave (ultraviolet) (pass or absorbed by GH gases)
- earth surface absorbs or reflects short waves
- reflected re-emits as longer waves (infra-red / heat)
- greenhouse gases absorb and re-radiate longer waves –> retain the heat within atmosphere
