C9 Ai Flashcards
(59 cards)
What was the main composition of the early atmosphere?
Mostly carbon dioxide with little or no oxygen
The early atmosphere was similar to that of Mars and Venus today.
What gases were released by volcanoes during the first phase of atmospheric evolution?
Carbon dioxide, nitrogen, water vapour, methane, ammonia
These gases contributed to the formation of the early atmosphere.
What formed the oceans in the early Earth?
Water vapour condensed into liquid
This occurred as the atmosphere cooled over time.
How did carbon dioxide levels change over time?
Much of the carbon dioxide was removed from the atmosphere
This was due to dissolution in oceans and photosynthesis by plants and algae.
What is the process of photosynthesis represented by?
carbon dioxide + water → glucose + oxygen
The equation shows how green plants and algae produce oxygen.
What are fossil fuels and how are they formed?
Coal, crude oil, and natural gas formed from remains of ancient organisms
Coal from plant layers, oil and gas from plankton.
What is limestone primarily made of?
Calcium carbonate from shells and skeletons of marine organisms
Limestone is a significant sedimentary rock formed over millions of years.
When did algae evolve, and what was their significance?
About 2.7 billion years ago; they produced oxygen
Their evolution was crucial for the development of an oxygen-rich atmosphere.
What are the current proportions of gases in the atmosphere?
About 80% nitrogen, 20% oxygen, less than 1% other gases
Other gases include carbon dioxide, noble gases, and water vapour.
True or False: The proportions of gases in the atmosphere have remained stable for the last 200 million years.
True
This stability allowed for the evolution of various life forms.
Fill in the blank: Sedimentary rocks are formed when sea organisms die and get _______.
buried
What is the role of photosynthesis in the evolution of the atmosphere?
It produces oxygen, allowing for animal evolution
Photosynthesis is essential for maintaining oxygen levels.
What are the main greenhouse gases?
Carbon dioxide, methane, and water vapour.
How do greenhouse gases keep the Earth warm?
They absorb thermal radiation and re-radiate it, warming the atmosphere.
What type of radiation does the sun emit?
Short wavelength radiation.
What is the greenhouse effect?
The process where radiation from the sun warms the Earth’s surface and greenhouse gases trap that heat.
How does deforestation contribute to climate change?
Fewer trees mean less carbon dioxide is absorbed for photosynthesis.
What is the impact of burning fossil fuels on carbon dioxide levels?
It releases carbon dioxide into the atmosphere.
How does agriculture contribute to greenhouse gas emissions?
More farm animals produce more methane during digestion.
What is the role of landfill sites in greenhouse gas emissions?
They release carbon dioxide and methane as waste breaks down.
What is a carbon footprint?
The total amount of carbon dioxide emissions released over the lifecycle of a product or service.
What recent trend has been observed regarding Earth’s average temperature?
It has been rising over recent years.
What human activities are believed to contribute to increased carbon dioxide levels?
Burning fossil fuels, deforestation, and agriculture.
What do scientists believe the increase in carbon dioxide will lead to?
Climate change.