Causes Of Climate Change Flashcards
What are some of the theories that have been put forwards to explain climate change
- variations in solar activity (sunspot activity)
- changes in orbit and axis tilt
- meteorite impact
- volcanic activity
- plate movement
- oceanic circulation changes
- atmospheric composition changes
What is the greenhouse effect
Greenhouse gases in the troposphere, such as CO2, absorb some long wave radiation that is reflected back from the Earth (originally from the sun). This is radiated back to Earth and traps the heat.
Without the greenhouse effect…
The planet would be about 30 degrees C colder
What are the greenhouse gases that are responsible for trapping heat
Include: CO2, chlorofluorocarbons, methane, nitrous oxide and ozone
When does the temperature of the Earth remain in balance
The amount of CO2, solar radiation and water vapour in the atmosphere stay the same
Why is the temperature of the earth unbalanced
Human activity
CO2 has increased by 15% (last 100 yrs)
+
Other greenhouse gases such as methane and nitrous oxide
If carbon dioxide levels double, by how much will temperatures increase by?
2-3 degrees C, with greater rises at higher latitudes, perhaps of the order of 7-8 degrees C.
What is one of the main reasons for the increase in CO2
The burning of fossil fuels in the industrialised nations of the world
Deforestation link to global warming
Rainforests of the world act as a ‘carbon sink’ as trees are a major store of non-atmospheric carbon
Why are tropical rainforests diminishing
Because of the demand for space and resources in countries such as Brazil
How does agriculture add to global warming
Large-scale cattle-rearing for beef in areas of cleared forest contributes as the cattle emit methane.
Problem with deforestation for reservoirs
Vegetables decay and release CO2 (goes against the positive effects of hydroelectric power)
