Earth's Atmosphere Flashcards
How old is the Earth?
4.6 billion years
Where did the original atmosphere come from?
Volcanic activity
What gases were released by volcanoes?
Water vapour, carbon dioxide, methane, ammonia, nitrogen
How were the oceans formed?
Water vapour cooled and condensed
How did carbon dioxide levels decrease in the early atmosphere?
Dissolved in oceans, formed sedimentary rock, photosynthesis by algae/plants
What gas made up most of the early atmosphere?
Carbon dioxide
How did oxygen increase in the early atmosphere?
Released by photosynthesis by algae/plants
What gas makes up most of the current atmosphere?
Nitrogen
How much of the current atmosphere is nitrogen?
78%
How much of the current atmosphere is oxygen?
21%
How much of the current atmosphere is carbon dioxide?
0.04%
How is carbon removed from the atmosphere?
Photosynthesis by plants
How is carbon added to the atmosphere?
Respiration by animals and plants, combustion of fossil fuels, decomposition of waste
What is a carbon sink?
A store of carbon, not in the atmosphere
Name a carbon sink
Oceans, sedimentary rocks, fossil fuels, marine organism’s shells
What is the greenhouse effect?
The trapping of infrared radiation by gases in the atmosphere
Name three greenhouse gases
Carbon dioxide, water vapour, methane, oxides of nitrogen
What type of waves are absorbed by greenhouse gases?
Long wavelength
Why is the greenhouse effect vital for Earth?
Maintains a temperature suitable for life
What human activities contribute to the greenhouse effect?
Combustion of fossil fuels, cattle farming, rice farming, decomposition of waste in landfill, deforestation
Describe one consequence of ice caps melting
Sea levels rising causing flooding of low lying land, loss of habitat
Describe one consequence of changing rainfall patterns
Drought and flooding more likely leading to changes in food production
How can humans mitigate the effect of global warming?
Using renewable resources, reducing waste, stopping deforestation, carbon capture and storage
Name four pollutants
Carbon monoxide, particulates, sulphur dioxide, oxides of nitrogen
What is the effect of carbon monoxide on the body?
Binds to haemoglobin, reduces the amount of oxygen carried in the blood, causes breathlessness, loss of consciousness and death
What is the effect of sulphur dioxide on the environment?
Causes acid rain - damages buildings and statues, damages plants and aquatic animals
What is the effect of oxides of nitrogen on the body?
Causes respiratory diseases like emphysema, bronchitis, asthma
What is the effect of particulates on the body?
Breathed in, pass into the lungs, cause DNA mutations and cancer
What are the four types of precipitation?
Rain, snow, sleet, hail
How do clouds form?
Water vapour cools and condenses
Name three sources of freshwater
Rain, lakes, rivers
What is potable water?
Water that is safe to drink
What are the three properties of potable water?
pH 6.5-8.5, low levels of dissolved minerals, no pathogens
Name three ways to sterilise water
Ozone, UV light, chlorine (boiling)
Why does water need to be sterilised?
To remove pathogens
What are three stages in freshwater treatment?
Sedimentation, filtration, sterilisation
What extra stages are involved in waste water treatment?
Aerobic and anaerobic digestion of waste by bacteria
What is desalination?
Removal of salt from saltwater
What are the two methods of desalination?
Distillation and reverse osmosis
Describe distillation
Saltwater is heated until the water evaporates, the water vapour cools and condenses to produce pure water
Describe reverse osmosis
Saltwater is forced under pressure through a partially permeable membrane to remove the water
Why aren’t desalination techniques a sustainable way of producing potable water?
They have high energy requirements so are costly, reverse osmosis produces a very salty solution (brine) which is damaging to the environment
Describe the effects that the evolution of plants had on the Earth’s atmosphere
carbon dioxide decreased, oxygen increased
Name two gases that contribute to global warming
Carbon dioxide and methane
What is the carbon footprint?
amount of carbon a product, service or event emits over its full life cycle
