Chemistry of the Atmosphere (Paper 2) Flashcards
What were the first few billions of Earth’s history like?
explosive - the surface was covered in volcanoes that erupted and released lots of gases. This is how the early atmosphere was formed
What was the early atmosphere made up of?
mostly carbon dioxide, virtually no oxygen
What did volcanic activity release?
nitrogen, water vapour, methane and ammonia. these built up in the atmosphere over time
How were the oceans formed?
When the water vapour in the atmosphere condensed
What happened to the carbon dioxide that caused it to be removed from the early atmosphere?
It dissolved into the oceans and went through a series of reactions to form carbonate precipitates that formed sediments on the seabed
What were the earliest life forms to evolve?
marine animals - their shells and skeletons came from the seabed
green plants and algae
What is coal made from?
a sedimentary rock made from thick plant deposits
What is limestone made from?
a sedimentary rock made from calcium carbonate deposits from the shells and skeletons of marine organisms
Which organism evolved first?
algae - about 2.7 billion years ago
Why couldn’t animals evolve at the same time as algae?
Because the algae and other plants produced oxygen via photosynthesis, allowing other organisms to evolve later on when there was enough oxygen for them to survive
What is the composition of the atmosphere today?
80% Nitrogen
20% Oxygen
other gases making up 1% - mainly CO2, noble gases and water vapour
What are the main greenhouse gases?
Methane, CO2 and water vapour
What is the purpose of greenhouse gases?
To act as an insulating layer in the Earth’s atmosphere - allowing it to stay warm enough to support life
What type of wavelength of radiation do greenhouse gases absorb?
Not the incoming short wavelength radiation from the sun but the long wavelength radiation (thermal) that is reflected back off the Earth
What happens to the radiation once it is absorbed by a greenhouse gas?
It is re-radiated in all directions
What are the 4 human activities that affect the amount of greenhouse gases in the atmosphere?
- deforestation
- burning fossil fuels
- agriculture
- creating waste
How does creating waste affect the greenhouse effect?
More landfill sites and more waste from agriculture means for CO2 and methane released by decomposition of waste
Name 4 possible effects of climate change
- ice caps melting, rise in sea levels, increased flooding
- change in rainfall patterns, some places may get too little or too much
- frequency or severity of storms
- changes in temperature / amount of water which can affect wild species and differences in distribution
Define carbon footprints
A measure of the amount of carbon dioxide and other greenhouse gases released over the full life cycle of something
What are 5 ways of reducing carbon footprints?
- renewable energy sources or nuclear energy
- using more efficient processes
- Government taxes on companies based on their greenhouse gas emissions
- Government caps on emissions allowed
- technology that captures CO2 produced before it is released into the atmosphere
What are two examples showing that reducing CO2 emissions is easier said than done?
- carbon capture and storage technology is a new idea and it is still in the developmental stage
- many renewable energy sources eg solar panels are expensive. more development can make them cheaper
Why are governments worried about reducing emissions?
it could have an impact on economic growth of their countries - especially for countries that are still developing
Why is it hard to make international agreements about emission reductions?
not everyone wants to reduce emissions if it means sacrificing economic growth
What are 3 ways an individual can make changes to their lifestyle to reduce greenhouse gas emissions?
- cycling or walking instead of taking a car
- reducing how much they use air travel
- anything that saves energy at home (eg turning down heating)
