Summary Unit 6 IB ESS Notes

Unit 6: Atmospheric systems and Society
6.1. Introduction to the atmosphere
Atmosphere: dynamic system with inputs, outputs, storages and flows
 Essential to life on Earth
 Mixture of nitrogen and oxygen and small amounts of CO2 and water vapour
 Human activities alter inputs and outputs of the system -> affects ecosystems
Climate is influenced by:
 Abiotic factors – temperature
 Biotic factors – plants and animals
The greenhouse effect: natural phenomenon which maintains suitable temperatures for
living systems. This is caused by water vapour, CO2 and methane.




Albedo: the amount of radiation that a surface is able to reflect


6.2. Stratospheric ozone
Ozone (O3): radioactive gas that blocks incoming ultraviolet radiation from the sun and
protects life from damaging ultraviolet radiation
 Found in the stratosphere (good) and in the troposphere (bad)
 Mostly found in the ozone layer
 Human activities have disturbed the dynamic equilibrium (state of balance
between continuing processes) of stratospheric ozone formation
Ultraviolet radiation
 Damaging effects:
o Genetic mutation
o Skin cancer
o Damage to photosynthetic organisms