Chemistry Of The Atmosphere Flashcards
What was the early chemistry of the atmosphere like?
Mainly carbon dioxide
Some other gases
What factors and events caused the earth’s early chemistry of the atmosphere?
High volcanic activity released carbon dioxide, water vapour which condensed to form the oceans, small proportions of methane and ammonia
What was the chemistry of the atmosphere like 2 billion years ago?
Still mainly carbon dioxide, but a higher proportion of nitrogen and oxygen, with a smaller amount being other gases.
What factors and events caused the chemistry of the atmosphere 2 billion years ago?
Green plants and algae evolve and carbon dioxide reduces and plants take it in and give out oxygen, microorganisms that can’t tolerate oxygen die, carbon from carbon dioxide becomes locked in rocks formed from shells and skeletons of marine animals, other gases interact with oxygen to release nitrogen, nitrogen is produced by bacteria removing nitrates from decay plant material
What is the current chemistry of the atmosphere?
Mainly nitrogen (about 80%), with some oxygen (almost 20%) and very small amount of carbon dioxide which has decreased significantly and other gases, about 0-3% water vapour
What caused the increase of oxygen in the atmosphere?
Algae first started producing oxygen about 2.7 billion years ago in photosynthesis, so levels of oxygen rose. This allowed plants to develop and even more oxygen to be produced over time
What caused the decrease in carbon dioxide in the atmosphere?
Plants evolved so more was used in photosynthesis, carbon becomes locked in sedimentary rocks and fossil fuels, limestone contains calcium carbonate and is formed from shells and skeletons of sea creatures, sea water has absorbed some carbon, producing insoluble carbonates that are deposited as sediments, soluble hydrogen carbonates (this can cause the ocean to become acidic which harms marine life)
How does the greenhouse effect work?
High energy, short wavelength infrared radiation from the sun passes through the earth’s atmosphere to the earth’s surface. Some of this is absorbed by the earth. Lower energy, longer wavelength infrared radiation is reflected by the earth’s surface. Greenhouse gases in the atmosphere absorb this outgoing radiation
Why do we need greenhouse gases?
The earth would be too cold for water to be a liquid and it wouldn’t be able to harbour life
Human activities that increase the amount of greenhouse gases
Carbon dioxide- Burning fossil fuels, deforestation
Methane- decomposition of rubbish in landfill sites, animal farming
Effects of climate change
Rising sea levels, more frequent and severe storms, changes in amount and timing of rainfall, increased number of heatwaves, more drought, change in distribution of plants and animals, food shortage in some areas
What is a carbon footprint?
The full amount of greenhouse gases emitted by a product, service or event over its full life cycle
Ways of reducing carbon footprints
Renewable energy resources or nuclear energy used instead of fossil fuels
Using more efficient processes to conserve energy and cut waste
Tax companies or individuals based on amount of CO2 they emit
Use technology to capture CO2 produced by burning fossil fuels before they’re released into the atmosphere and store it deep underground
What’re the problems with reducing the carbon footprint?
disagreement over the cause of climate change, lack of info in the public, reluctance to make lifestyle changes, economic considerations, disagreement between countries
Proportions of gases in the atmosphere
- 80% nitrogen
- 20% oxygen
- Small proportions ions of various other gases including carbon dioxide, water vapour and noble gases
