C9 - Chemistry Of The Atmosphere Flashcards
What happens in phase 1 - Evolution of the Atmosphere
- The surface was covered in volcanoes that erupted and released lots of gases
- Early atmosphere was peobably mostly carbon dioxide, with virtually no oxygen. This is quite like the atmosphere of Mars and Venus today
- Volcanic activity also released nitrogen, which built up in the atmosphere over time, as well as water vapour and small smalunts of methane and ammonia
Phase 2 (Oceans, algae and green plants photosynthesising)
- When water vapour is condensed, it forms the ocean
- Lots of carbon dioxide in the atmosphere dissolved into the ocean (formed carbon precipitates)
- Green plants and algae evolved and absorbed some carbon dioxide to carry out photosynthesis
- Carbon organisms took in the form atmosphere and oceans became locked up in rocks and fossil fuels
Phase 3 - Photosynthesis
- Plants used carbon dioxide, water and light to produce oxygen and sugars
- 2.7 billion years ago, algae evolved into plants
- 200 million years ago, the atmosphere was similar to today’s formation
What is our atmosphere consistent of?
- 80% nitrogen
- 20% oxygen
- 1% other gases (water vapour, carbon dioxide, noble gases)
What are greenhouse gases?
Gases that act like an insulating layer in the Earth’s atmosphere which allows Earth to be warm (and support life)
Give examples of greenhouse gases
Carbon dioxide, methane, water vapour
Why do incoming short wavelength radiation pass through the atmosphere from the sun?
Greenhouse gases do not absorb the incoming short wavelength radiation
What happens to the reflected radiation (Greenhouse effect)?
- They re-radiate it in all directions including back towards the Earth (thermal radiation)
- However long wavelength radiation gets reflected back down to Earth
What are some examples of human activity that affect the amount of greenhouse gases in the atmosphere?
- Deforestation
- Burning fossil fuels
- Agriculture
- Creating waste
What are some predicted consequences of climate change?
- Increased flooding in costal areas and coastal erosion
- Changes in rainfall patterns
- Change in temperatures
- Differences in distributions of wild species
What are carbon footprints?
A measure of the amount of carbon dioxide and other greenhouse gases released over the full life cycle of something (that can be almost anything)
Why are carbon footprints difficult to measure?
There are so many different factors to consider
Give some ways that we can reduce carbon footprints
- Renewable energy resources
- Using more efficient processes
- Taxing cars based on consumption
- Cap on emissions
Complete combustion
All the fuel burns when there is plenty of oxygen
Incomplete combustion
Only some of the fuel burns when there is not enough oxygen
