Climate Change Flashcards
climate
the average pattern of elements of weather prevailing in an area over a long period of time
30 years +
climate change
an alteration of the climate system over an extended period
main greenhouse gases
- ozone (O3)
- methane (CH4)
- carbon dioxide (CO2)
- water vapour (H2O)
- sulphur dioxide (SO2)
- nitrous oxides
- CFCs and HFCs
these gases damage the ozone layer which protects us from UV radiation
physical causes of climate change
- volcanoes
- sun spot activity
- eccentricity (stretch)
- axial obliquity (tilt)
- melting permafrost
- fumeroles
- melting ice
volcanoes
physical causes of climate change
- volcanoes emit gases (e.g. CO2) which contribute to greenhouse effect
- sulphur dioxide from volcanoes combines with oxygen and water in the stratosphere to form sulphuric acid which condenses to form sulphate aerosole droplets. the droplets form a haze blocking out solar energy causing cooling
- large amounts of ash and dust stops the sun’s energy reaching earth causing cooling
sun spot activity
physical causes of climate change
- sunspots appear on the sun when additional solar energy is being released
- high sunspot activity result in warming
11 year cycles
eccentricity
physical causes of climate change
- earths orbit becomes more elliptical
- this means the amount of energy received varies depending on the earth’s distance from the sun
97,000 year cycle
axial obliquity
physical causes of climate change
- the angle of the earth’s axis changes meaning that the poles are tilted more towards the sun and receive more solar energy
41,000 year cycle
melting permafrost
physical causes of climate change
- during summer in the arctic the top layer of earth defrosts and becomes marshy as permafrost prevents drainage of water
- vegetation therefore decays releasing methane, contibuting to the greenhouse effect, causing warming
every year
fumeroles
physical causes of climate change
- these vents release gases (CO2, hydrogen sulphate, hydrogen chloride) which absorb solar energy, warming our planet
melting ice
physical causes of climate change
- melting ice releases freshwater into the oceans
- this can lead to changes in ocean circulation and reduce the albedo effect so earth absorbs rather than reflects
albedo effect
a measure of how reflective a surface is
ice and snow has high albedo, dark soils and forests have low albedo
carbon dioxide
human causes of climate change
- burning fossil fuels
- icreased car ownership
- deforestation
- peat bog reclaimation
- increased air travel
methane
human causes of climate change
- landfill (decaying waste)
- padi fields (rice production)
- cattle farming (animal feces)
20 times more effective at trapping heat than CO2
nitrous oxides
human causes of climate change
- more cars (exhaust emissions)
- power stations (burning fossil fuels)
- fertilisers
200 - 300 times more effective at trapping heat than CO2