Flashcards in Chemistry of the atmosphere Deck (17)
How was the early atmosphere probably formed?
by volcanic activity
(volcanoes released a lot of carbon dioxide as well as some nitrogen, water vapour and a little methane and ammonia)
Why did the amount of carbon dioxide in the atmosphere decrease?
-dissolved in oceans
-was stored as carbonates in marine animal's shells/skeletons
-was absorbed by photosynthesis
-became locked up in sedimentary rock (by being compressed over millions of years)
How was oxygen become present in the atmosphere?
plants and algae produced oxygen via photosynthesis
What is the Earth's atmosphere roughly contain today?
traces of other gases (carbon dioxide, noble gases, water vapour)
What is the greenhouse effect?
greenhouse gases act as an insulating layer in the atmosphere
they don't absorb the incoming short wavelength radiation from the sun but do absorb the the long wavelength radiation which gets reflected back off Earth and re-radiated in all directions (including back towards Earth)
the long wavelength radiation is thermal radiation so results in the Earth's surface being warmed
What are some examples of human activities that affect the amount of greenhouse gases in the atmosphere?
Deforestation (less trees means less carbon dioxide taken in by photosynthesis)
Burning fossil fuels (carbon dioxide released into atmosphere)
Agriculture (animals eg. cows produce methane)
Waste (carbon dioxide and methane are released by the decomposition of waste at landfill sites)
What are the main greenhouse gases?
What are some consequences of climate change?
ice caps melting (loss of habitat, sea levels rising, flooding, coastal erosion)
an increase in frequency and severity of storms
change in rainfall patterns (disrupts food production)
What is a carbon footprint?
a measure of the amount of greenhouse gases are released in something's life cycle
Why is it hard to measure a carbon footprint?
there are lots of factors to consider
How can a carbon footprint be reduced?
replacing fossil fuels with renewable energy sources
using efficient processes (reduces energy and cuts waste)
tax companies/people based on how much greenhouse gas they emit
using technology that captures carbon dioxide
Why is it difficult to make reductions to a carbon footprint?
still a lot of work needs to be done on alternative technologies
governments are worried to change things because of the impact it could have on a country's economic growth or development
individuals struggle to make changes to their lifestyle (eg. by walking instead of driving)
lack of education on why we need to change and how we can change
What is complete combustion?
When there is plenty of oxygen, all of the fuel burns
What is incomplete combustion?
When there isn't enough oxygen, not all of the fuel burns
What is the problem with incomplete combustion?
Particulates (solid particles of soot and unburned hydrocarbons) are released and carbon monoxide can be produced.
Particulates can be inhaled and cause respiratory problems and can cause global dimming by reflecting sunlight back into space.
Carbon monoxide is dangerous as it binds to haemoglobin in someone's blood, meaning they can no longer carry oxygen, which results in comas, fainting and death.
What can be produced by burning fossil fuels?