Chemistry of the atmosphere Flashcards
What is the first phase of the evolution of the atmosphere and what does it involve?
Volcanoes giving out gas: they released CO2, nitrogen, water vapour, methane and ammonia, with no oxygen
What is the second phase of the evolution of the atmosphere and what does it involve?
Oceans algae and green plants absorb CO2: water vapour condenses to form oceans, green plants and algae evolve and photosynthesise
What is the third phase of the evolution of the atmosphere and what does it involve?
Green plants and algae produce oxygen: start to photosynthesise, building up oxygen levels until complex life could evolve
What is the current composition of the atmosphere?
80% nitrogen, 20% oxygen and small amounts of carbon dioxide, noble gases and water vapour
What is a greenhouse gas?
A gas which acts like an insulating layer in the earth’s atmosphere
What is the greenhouse effect?
Greenhouse gases cannot absorb short wavelength radiation from the sun but can absorb long, which means that from the earth, which they then re-radiate towards the earth, adding thermal radiation
Which forms of human activity affect greenhouse gas composition in the atmosphere?
Deforestation, burning fossil fuels, agriculture and creating waste
What are the consequences of climate change?
Flooding from ice caps melting, changes in rainfall patterns, increase in severity of storms and wildlife distribution due to changes in climate and water availability
Why are carbon footprints hard to measure?
There are too many different factors to consider so only a rough calculation can be made
How can a carbon footprint be reduced?
Renewable or nuclear energy sources used instead of fossil fuels, use of more efficient processes to cut waste, taxes on emissions, caps on emissions and technology that captures CO2
Why is reducing carbon footprints hard?
Governments do not want to impact on economic growth, individuals do not want to sacrifice lifestyle comforts and technology to help has not been perfected
How is air pollution commonly produced produced?
Through complete combustion; when fossil fuels are oxidised(through combustion), CO2 and water vapour are released into the air
What is incomplete combustion?
There is not enough O2, so not all of fuel burns, which means that unburnt fuel, carbon monoxide and particulates of soot are released into the atmosphere
Why are particulates dangerous?
If inhaled, they can become stuck in the lungs and cause damage. They also cause global dimming, where they reflect sunlight back into space
Why is carbon monoxide dangerous?
Binds to haemoglobin in blood which stops blood from carrying oxygen, which can lead to fainting, coma and death. It is especially dangerous as it is hard to detect
