C18 The Earth’s Atmosphere [Paper 2] Flashcards
(21 cards)
What is the atmosphere?
Layer of gas surrounding the Earth
What was the only atmosphere composed of?
Mostly carbon dioxide
How did the oceans form?
Water vapour condensing as the Earth cooled
How did the amount of carbon dioxide in the atmosphere decreased to today’s levels?
Dissolved in the oceans, photosynthesis, converted to fossil fuels, precipitated as insoluble metal carbonates
When did life start to appear, and what was the impact of this on oxygen in the atmosphere?
About two .7 billion years ago; amount of atmospheric oxygen increased as it was released in photosynthesis
How has the amount of nitrogen in the atmosphere changed overtime?
Increased slowly as it is a very stable molecule
Why can scientists not be sure about the composition of the earths early atmosphere?
It was billions of years ago and evidence is limited
What is the current composition of the atmosphere?
Approximately 80% nitrogen, 20% oxygen, and trace amounts of other gases such as carbon dioxide, water vapour, and noble gases
What is a greenhouse gas?
Gas that traps radiation from the Sun
What type of radiation do greenhouse gases absorb?
Longer wavelength infrared radiation
Name three greenhouse gases
Methane, carbon dioxide, water vapour
Give two ways recent human activities have increased the amount of atmospheric carbon dioxide
Burning fossil fuels, deforestation
Give two ways recent human activities have increased the amount of atmospheric methane
Rice farm farming, cattle farming
What is global warming?
An increase in the overall global average temperature
What is global climate change?
The change in the long-term weather patterns across the planet
What are some possible effects of climate change?
Sea levels rising, extreme weather events, changes in the amount and time of rainfall, changes to habitats and ecosystems, polar ice caps melting
What is a carbon footprint?
The amount of carbon a product, process, or person releases into the atmosphere over its lifetime
How is carbon monoxide formed, and what is the danger associated with it?
Incomplete combustion; colourless and odourless toxic gas that binds to haemoglobin
How are particulates formed, and what are the dangers associated with them?
Incomplete combustion; global dimming, respiratory problems, potential to cause cancer
How is sulphur dioxide formed, and what are the dangers associated with it?
Sulphur impurities in fossil fuels react with oxygen during combustion; acid rain, respiratory problems
How are oxides of nitrogen formed, and what are the dangers associated with them?
Atmospheric oxygen and nitrogen react in the heat of a combustion engine in vehicles; acid rain, respiratory problems
