Physical factors causing climate change (4)
- Changes in the earths stretch, wobble and tilt
- Plate tectonic movement
- Ice cap/ ice sheet melting
- Permafrost melting
Changes in earths stretch wobble and tilt
Stretch:
The shape of earths orbit amount sun becomes slightly more then less oval every 100,000 years. Affects amount of energy received
Wobble:
Earth wobbles on its axis as it spins, completing full wobble every 23,000 years
Tilt:
Angle of earths axis relative to plane of orbit changes about 3 degrees every 41,000 years. Greater tilt = more sunlight in polar regions and colder temps
Plate tectonic movement
As continental plate moves to higher latitudes it will receive less incoming solar radiation and climate will cool
If it moves to lower latitudes temperatures will rise
Position of land masses and oceans can affect amount of energy reflected back out to space and is lost to climate system
Ice cap/ ice sheet melting
Snow and ice affects climate
Because the snow and ice of the cryosphere are light in colour and have a large albedo
Permafrost melting
Carbon is frozen deep in Arctic permafrost
As earth warms, scientists worry that some of carbon in permafrost could escape to atmosphere as CO2 or methane
Human factors causing climate change
- Deforestation, peat bog reclamation - increased CO2
- Land fill sites, padi fields - increased methane
- Car exhaust fumes, fertilisers - increased nitrous oxides
- Aerosols - increased chlorofluorocarbons
Deforestation
Carbon stored can store up to 100x more carbon than agricultural land
Peat big reclamation
Peat burned - CO2 released
Decomposed if mixed with soil
Important carbon sink
Improves soil for growing crops
Land fill sites
Rotting food waste
Third largest resource of methane
Padi fields
Farmland for rice has doubled in last 45 years
Anaerobic conditions
Padi fields produce methane because they’re grown in waterlogged conditions
Car exhaust fumes
Cars also give off CO2 and power plants do too
Fertilisers
Fertilisersused cof meeting demands of food
Aerosols
Ozone layer hole in Antarctica could disappear by 2060
Responsible for depleting ozone layer
CFC’s found in aerosols
CFC’s banned in many countries in mid 1990’s when found out it was braking ozone layer
Iceland
70% of energy is hydroelectric power
Connect electricity to Scotland - sell electricity
Maldives
Rise is sea level and land is 1m above sea level
Evacuate by 2100
Fishing - biggest industry
Levels rising 9mm per year
Bangladesh
Increased rate of river erosion
Eroded 500 yards in a fortnight
Cyclone Isla
Bangladesh Rising sea levels Climate change - flooding, drought Salty water left behind - can't grow crops Locals change food production - crabs
Explain the greenhouse effect
- Sunlight passes through atmosphere and warms the earth
- Infrared radiation is given off by earth
- Most escapes to outer space, allowing the earth to cool
- But some IR is trapped by gases in air (including CO2), keeping earth warm enough to sustain life
- ENHANCED GREENHOUSE EFFECT
Increasing levels of CO2 increase the amount of heat retained, causing atmosphere and earths surface to heat up
Positive effects of climate change in the U.K.
+ Mediterranean summers
+ Higher yields of potatoes and outdoor tomatoes
+ higher fruit and veg growth in England
+ higher plant and shrub grown up north
Negative effects of climate change in the U.K.
- Arctic plants will face extinction
- Greater risk of forest fires
- Coastal ports flooded
- More pests and diseases will exist due to mild winters
Individually and locally management strategies for climate change
- Reduce, reuse, recycle
Local recycling centres for paints, household electrics, batteries, textiles and some landfill
Door stop collections
National management strategies to reduce greenhouse gases
Insulating homes, flooring lofts or switching lights off in homes
Amount of energy used by household is decreasing
Target to reduce greenhouse gas emissions by 42%
2014 gas emissions 45.8% lower than 1990
Hydrogen buses
International management strategies to reduce greenhouse gases
1992 - Rio Earth Summit, 162 countries resolved to stabilise greenhouse gas concentrations
2015 - Paris Summit, deal to attempt to limit the rise in global temps to less than 2 degrees, first to commit all countries to cut carbon emissions, review every 5 years, £65bn a year to help poorer countries
How can governments try and reduce their emissions
- Wind power
- Wave power
- Tidal power
- Nuclear power
