Earth And Atmospheric Science Flashcards
Describe how the Earth’s early atmosphere was formed
The Earth was formed about 4.5 billion years ago. It is believed that there was intense volcanic activity for the first billion years of the Earth’s existence. Its early atmosphere was probably formed from the gases given out by volcanoes.
State the names and relative amounts of gases found in the Earth’s early atmosphere
95.3% carbon dioxide, 2.7% nitrogen, 1.6% argon and 0.13% oxygen (large amount of carbon dioxide, little to no oxygen)
Explain how oceans were formed
Oceans were formed because 4 billion years ago when the earth cooled down, which caused water vapour in the atmosphere to condense to liquid water
Describe how the formation of the oceans influenced the composition of the atmosphere
The formation of the ocean dissolved carbon dioxide into the oceans, reducing the amount of carbon dioxide there is in the atmosphere, helping create todays atmosphere
Explain how photosynthetic organisms changed the composition of the atmosphere
Photosynthesis uses up carbon dioxide and releases oxygen
State the chemical test for oxygen
A glowing splint is held at the open end of a test tube. If the test tube contains oxygen, the glowing splint will relight
Recall the names of significant greenhouse gases
Carbon dioxide, methane, water vapour, nitrous oxide
How does human activity increase the concentration of greenhouse gases?
Burning fossil fuels, cutting down forests and farming livestock add enormous amounts of greenhouse gases to those naturally occurring in the atmosphere, increasing the greenhouse effect and global warming.
Evaluate the correlation between atmospheric carbon dioxide concentrations and fossil fuel use
When fossil fuels are burnt, they release large amounts of carbon dioxide into the air
Describe the process involved in the greenhouse effect
When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back to space and some is absorbed and re-radiated by greenhouse gases
Suggest possible effects on the climate of increased levels of carbon dioxide and methane
Glaciers and polar ice would melt, sea levels would rise, some animals may move away from their natural habitat to find cooler areas, some animals and plants may become extinct, some areas will become drier and wetter, more extreme weather events, more acidic sea
State examples of human activity which leads to increased carbon dioxide levels
Burning fossil fuels, cutting down forests, farming, development, and industrial activities
Describe how human activity leads to increased methane levels
Examples: Landfills, oil and natural gas systems, agricultural activities, coal mining.
Describe the projected effects of climate change
Warmer atmosphere, a warmer and more acidic ocean, higher sea levels, and larger changes in precipitation patterns
Describe how the potential harmful effects of climate change can be addressed and limited
Saving energy at home, walking cycling and taking public public transport, eating more vegetables, recycling
