The earths atmosphere Y9 Flashcards
(23 cards)
What two thing played pivotal roles in the evolution of the Earth’s early atmosphere?
Volcanoes and the ocean
Highly active ……………… were littered across the Earth’s surface for the first billion years of its existence.
Volcanoes
In photosynthesis, what is used to produce glucose and oxygen from carbon dioxide and water?
Light energy
What caused the oxygen levels in the atmosphere to increase?
Photosynthesis
What is photosynthesis?
Photosynthesis is the process in which light energy is used to convert carbon dioxide and water into glucose and oxygen.
When did the first photosynthetic organisms evolve
first photosynthetic organisms to evolve approximately 2.7 billion years ago.
Photosynthesis is the process in which light energy is used to convert ………….and ………..into ……….. and…………… . The evolution of photosynthesising organisms underpinned the accumulation of oxygen in the Earth’s atmosphere.
Photosynthesis is the process in which light energy is used to convert carbon dioxide and water into glucose and oxygen . The evolution of photosynthesising organisms underpinned the accumulation of oxygen in the Earth’s atmosphere.
Name the three factors that contributed to the decrease in atmospheric carbon dioxide
Oceans
Photosynthesis
Marine animals
What was produced when the carbon dioxide that was dissolved in the oceans reacted with seawater?
Carbonate precipitate
How to test for oxygen?
Insert a glowing splint into a test tube containing a gas.
If the gas is oxygen, the splint will relight.
What is the greenhouse effect
Greenhouse gases cause the greenhouse effect. This helps keep the Earth warm enough for life. But, the greenhouse effect can cause global warming if it is too intense.
How does the green house effect work?
The Sun emits short wavelength infrared radiation that enters the atmosphere and travels towards the Earth.
The Earth absorbs a portion of this radiation, but longer wavelength radiation is reflected back into the atmosphere.
Greenhouse gases can’t absorb the short wavelength radiation emitted by the Sun, but they can absorb the reflected radiation.
The gases re-radiate this as heat energy, some of which heads back to Earth.
This increases the temperature at the Earth’s surface.
What happens to longer infrared radiation emitted by the sun in the greenhouse effect?
Longer wavelength radiation
Reflects off Earth and back into space
Absorbed by greenhouse gases
Re-radiated in all directions
What happens to shorter infrared radiation emitted by the sun in the greenhouse effect?
Shorter wavelength radiation
Absorbed by the Earth
Name 3 green house gasses
Methane
Carbon dioxide
Water vapour
Which region on Earth do you think reflects the greatest proportion of radiation arriving from the Sun?
The white surface of Antarctica makes it the most reflective region in the world.
This is one of the reasons why it’s so ridiculously cold!
Human activities that increase the atmospheric concentration of greenhouse gases
Deforestation
Burning fossil fuels
Agriculture
Landfill sites
Deforestation increases the atmospheric concentration of greenhouse gases because fewer ………….. means less carbon dioxide is being used up in the process of …………………….
Trees
Photosynthesis
The current scientific consensus is that increased ………………….. gas emissions caused by changes to ……………………………activity will lead to global climate change.
Greenhouse
Human
Melting of polar icecaps
Polar ice caps could melt. This would cause:
Sea levels to rise. This would cause flooding and erosion of coastal regions.
Some species to be less successful hunters. For example, the polar bear.
Meteorological events related to climate change
Meteorological events
Extreme meteorological events, such as storms, heatwaves and droughts, could increase in frequency and intensity.
Possible consequences of global warming
Melting of polar ice caps
2
Increased extreme meteorological events
3
Changing water availability
4
Changes in precipitation
5
Food shortages
