Chenistry of the Atmosphere Flashcards
What is a theory about the composition of the early atmosphere? - The Atmosphere
A theory suggests that the early atmosphere was comprised of gases from intense volcanic activity which released a large amount of CO2, with small amounts of ammonia and methane, as well as nitrogen
What is the composition of the modern atmosphere like? - The Atmosphere
Nitrogen makes up approximately 80% of the atmosphere. Oxygen makes up approximately 20% with other gases like CO2, water vapour and noble gases 1%
How did oxygen begin to grow in volume in the atmosphere? - The Atmosphere
Plants make their own food through photosynthesis, as the combine CO2 and water to produce oxygen and glucose
What organism is believed to have grown the volume of oxygen in the atmosphere? - The Atmosphere
Algae, which supposedly photosynthesised to produce oxygen which gradually built up in the atmosphere
How did carbon dioxide levels decrease in the atmosphere? (Sea) - The Atmosphere
Carbon dioxide is a soluble gas, and therefore dissolved into the ocean as it formed to create carbonate compounds. Carbonate compounds were then precipitated as sedimentary rocks
How did carbon dioxide levels decrease in the atmosphere? (Organisms) - The Atmosphere
Carbon dioxide absorbed from the oceans into algae and plants. These were turned into crude oil, coal and natural gas over million of years under heat and pressure.
What are greenhouse gases present in the atmosphere? - The Atmosphere
Water vapour
Carbon dioxide
Methane
What do greenhouse gases do? - The Atmosphere
Greenhouse gases absorb energy radiated from the earth and release energy in all directions which warms the Earth
Describe the greenhouse effect - The Atmosphere
EM radiation at most wavelengths passes through the atmosphere. The Earth absorbs this and warms up. The Earth radiates energy as infrared radiation, some of which is absorbed by greenhouse gases. As a result, the lower atmosphere warms up.
Name 3 human activities involved in increasing the volume of greenhouse gases in the atmosphere - The Atmosphere
Farming cattle which releases methane
Paddy rice farming releases methane
Burning fossil fuels releases CO2
Deforestation releases CO2 and reduces the absorption of CO2
Do scientists believe that humans are responsible for increased greenhouse gases? How do you know? - The Atmosphere
The vast majority of scientists believe that humans are responsible for increases in greenhouse gases. This is because evidence in peer reviewed journals indicate this theory.
What is important to do when evaluating the quality of evidence on climate change? - The Atmosphere
See who did the research and whether they are trustworthy and skilled
See who funded the research
See which organisation is reporting the evidence
How is climate different from weather? - The Atmosphere
Climate is average weather conditions over longer periods and over large areas. Weather is the day to day conditions in a specific region
How has the Earth’s climate changed ever since the Earth was formed? - The Atmosphere
The earth has undergone several ice ages and interglacial periods, which were all caused by volcanic activity and changes in energy from the sun. This was until 200 years ago.
What is global warming usually describing? - The Atmosphere
Global warming describes the warming of the earth over the past 200 years, believed to be caused by human activities
