Chapter 5 - EM Waves - Global Warming Flashcards
What does the sun emit the Earth’s day side, and what does this do?
It emits infra-red radiation, which is absorbed by the day-side, heating it up
What would happen to the Earth if there was no atmosphere?
The Earth’s night side would become very cold
Why is the atmosphere vital to life on Earth?
Because it can store the infra-red radiation that is emitted by the sun - regulates temperature (range of 140˚C)
What are the gasses that contribute to the greenhouse effect?
Carbon dioxide (CO2), methane (CH4), water vapour (H2O) - clouds
What is global warming?
The rise to the mean average temperature globally
What does the sun emit to the Earth, and what does it do?
Infra-red radiation, which heats it up
What does the Earth do to the infra-red radiation and why?
Absorbs it, then re-emits it back into the atmosphere as an attempt to cool down - because Earth is hotter than space
Why doesn’t the re-emitted radiation from the Earth leave the atmosphere?
Because the gases in the atmosphere, such as carbon dioxide and water vapour (clouds), absorb the heat energy, and then re-emit it back down to Earth
What is the link between the amount of radiation absorbed and emitted?
There needs to be the same amount of radiation absorbed as emitted for the transfer to be stable
What does the greenhouse effect do to the amount of radiation absorbed and emitted?
More radiation is absorbed by the Earth than emitted
How will increased CO2 emissions in the atmosphere lead to global warming?
There will be more carbon dioxide in the atmosphere to absorb the heat, and emit it back down to Earth. This means the heat is trapped and there is a rise to the main average temperature globally.
What happens if the rate of infra-red energy absorbed is greater than the infra-red emitted?
The Earth’s average surface temperature will rise until it is sufficiently hot for the rates to be equal again and stabilise at that new higher temperature
