Greenhouse Gases
What is a greenhouse gas?
It is a gas that absorbs heat energy and stops heat from escaping into space.
The Earth would be extremely cold as nothing would absorb the heat.
What can an increase in temperature of the air do?
- Melts polar ice caps
- Increases sea levels
- Flooding of low- lying areas
Carbon dioxide and _____ are ____ gases that increase ____ warming.
- methane
-greenhouse
-global
What are the main greenhouse gases?
- Carbon Dioxide
- Methane
- Nitrous oxide
- CFCs
Why do we have global warming?
As there is an increase in greenhouse gases like CO2, increasing the amount of heat absorbed and thus more heat is re- radiated back to Earth and less is lost into space, heating up the atmosphere more.
What are the problems of less rainfall?
- Formation of more deserts
- Less food production
The greenhouse gases _____ heat energy _____ from the Earth's surface. The more carbon dioxide there is in the ____, the greater the ______ in global warming.
- absorb
-radiated
-atmosphere
- increase
Where are these gases present?
In the atmosphere
What type of rays get through the earth's atmosphere easily and aren't absorbed by CO2?
Ultraviolet rays
What might the weather be like if there was an increase of temperature?
- More violent weather
- More storms and strong winds, causing destruction of crops and property
State the percentage of CO2 in the air now.
0.038%
If there was a small change in the concentration of greenhouse gases how would it affect us?
It would cause a change in the climate.
In which form is heat energy lost from the Earth's surface and can it be absorbed? If yes by which greenhouse gas?
Infrared rays. Can be absorbed by CO2
Methane is a greenhouse gas, state 2 sources of methane other than natural gas.
decomposition of vegetation, the bacterial action in the digestive system of cows, pigs and sheep.
What are the sources of greenhouse gases?
Carbon dioxide- naturally present in the atmosphere, burning of fossil fuels, industrial processes.
Methane- naturally present in the atmosphere, growing numbers of cows sheep and pigs (digestive system), decomposition of vegetation, rice paddy fields and termites.
Nitrous oxide- bacteria in the soil
Explain the entire process of the greenhouse effect
i.) ULTRAVIOLET RAYS from the sun (short wavelengths) get through the Earth’s atmosphere and do not get absorbed by carbon dioxide.
ii.) The ultraviolet rays hit the Earth’s surface and are absorbed thus heating the Earth.
iii.) Heat energy is lost from the earth’s surface as infrared rays. This is long wavelength radiation
iv.) Infrared rays can be absorbed by carbon dioxide
v.) Some of the heat is re-radiated back to earth and some escapes into space
Methane is an atmospheric pollutant.
i) Explain how methane may contribute to climate change
ii) State 1 effect of climate change
i) It absorbs much more heat than CO2 despite having a lower concentration that it in the air. Thus and increase in it's concentration would cause a drastic increase in global warming.
ii) increase in sea levels, less food production, etc.