1
Q
How does the greenhouse effect work?
A
- Earth absorbs short wavelengths of EM radiation from Sun
- the earth emits long wavelength infrared radiation
- a lot is absorbed by atmospheric gases, CO2, methane and water vapour
- gases re-radiated heat in all directions, including back to earth
- the atmosphere acts as an insulating layer to stop the earth getting cold at night
2
Q
How have humans caused an increase in the amount of greenhouses gases?
A
- carbon dioxide: burning fossil fuels, chopping down and burning trees for space
- methane:decaying waste in landfill sites, cattle farming has increases and cattle digestion produces methane
3
Q
How does the greenhouse effect affect the climate?
A
- global temperature has risen (global warming)
- global warming leads to other climate changes, e.g. weather changes: warmer water means more hurricanes
4
Q
What are the humans causes of weather changes?
A
- rising levels of CO2 from burning fossil fuels causes the green house effect and global warming
- soot and gases produced by factories can reflect heat back down to Earth, increasing local temperature
5
Q
What are the natural causes of weather changes?
A
- ash and gases from volcanoes can reflect radiation from the Sun back into space, cooling down the earth
- changes in our orbit can cause ice ages
6
Q
How do changes in the weather affect food production?
A
- regions become too dry to grow food, others too wet
- this will get worse as temperatures increase and weather patterns change more
