Climate Change

Question 1

1. a)Physical causes of climate change

Answer 1

• amount of energy emitted changes- as sun reaches end of life, expands and becomes hotter
• sun spots- numbers vary from year to year- 11-22 year cycles- dark spots on sun- increase in number- more energy to earth
• Volcanoes- ash blocks out suns energy- sulfur dioxide + water = sulfuric acid droplets- absorbs insolation
• comets/ meteors- dust thrown into atmosphere blocking sun insolation- dinosaurs wiped out due to meteor striking 65 million years ago radically altering climate

milankovich cycle changes climate in following ways:

• over period of 100,000 years earths orbit changes- circular to oval- at times during oval cycle earth is further away from sun
• tilt changes every 41,000 years- greater tilt = more sun in polar regions- wobbling on axis(19-23,000)- believed to cause ice ages
• over millions of years- continents move by convection currents in mantel- continental drift- disrupts circulation of warm and cold ocean currents

Question 2

1. b)Human causes of climate change

Answer 2

(•extraction and burning of fossil fuels- carbon dioxide)

• less trees taking in CO2- clearing areas means burning trees- releases more CO2
• cleared land- millions of cattle- grassy diet and 4 stomachs- biggest methane emitters- exhale with every breath
• methane = 20x more effective at trapping heat that CO2- accounts for 20% of enhanced greenhouse effect- stays in atmosphere for about 12 years
• cleared land- crop farms- billions of tonnes of fertilisers and pesticides- nitrous oxide- powerful greenhouse gas
• lorries and ships- oil powered- more CO2 into atmosphere
• aerosols and fridges- CFC’s- massive rubbish dumps outside every world city- millions of tonnes of methane
• continuing urbanisation of developing world- more power needed for growing number of bigger cities- more fossil fuels used and burned

Question 3

1. b)i)Human ACTIVITIES that cause climate change

Answer 3

The increasing demand for energy has resulted in increased … 1 (from human causes)

The desire from countries like Brazil to develop from exploiting natural resources like the amazon rainforest result in … 2

Increasing world population means more demand for meat … 3

Also with rising population more demand for crops is created thus … 4

Demand from worldwide food markets requires quick delivery of large amounts of food to feed increasing population … 5

Increasing world population means more fridges … 6

Question 4

2. Global impacts of climate change

Answer 4

•Rising temperatures- sea levels rise as glaciers and polar ice caps melt- Greenland, Antarctica- thermal expansion- sea expands as gets warmer

• low lying countries(Bangladesh) become part of sea again- millions of refugees- lose valuable farmland and destruction of property
• changes to ocean current circulation- Atlantic Ocean- North Atlantic drift starts to lose impact on NW Europe- considerably colder winters(Scotland)
• Tropical diseases- yellow fever- spread to new places- warmer areas spread further from the equator- 40 million more exposed to contracting malaria in Africa
• coral reefs under threat- warmer, more acidic oceans- up to 80% bleaching- thousands of different species of fish affected in different ways- harder for juvenile clownfish to tell difference between predator and non-predator
• increase in forest fires- increased surface temperatures + decreased rainfall- Australia + California

Question 5

3. Strategies for managing climate change

Answer 5

(Local)
•to reduce CO2 generated by burning fossil fuels~ energy saving light bulbs- less energy- last 10-50x longer- turn light off when leaving room
- energy efficient with water- only run dishwasher when completely full and fix leaking taps immediately

• to reduce amount of refuse sent to rubbish dumps therefore reducing methane emitted~ reduce, reuse, recycle- save energy, lowers emissions of greenhouse gases- less products required to be manufactured- recycling programmes
• to reduce demand on fossil fuel burning power stations~ generate own renewable energy- solar panels- small wind turbines- reduces need for fossil fuel burning power stations

(National)
•to lower demand for energy from households and therefore overall CO2 emissions of a country~ Scottish government- grants to insulate lofts and cavity walls- keeps warm air in house- 20% more energy efficient

•to lower CO2 emissions from vehicles~ governments encourage: public transport, walking, cycling, hybrid/electric cars- city centres (Glasgow) offer free all day parking for certain types of hybrid/ electric cars- mass automated cycle hire (MACH)- cheap way to hire bikes

(International)
•to lower impacts of increasing greenhouse gasses on climate change~ 2005 Kyoto protocol- treaty governments could sign up to- reduce emissions of CO2 by 2012- if country releases CO2 it must find way to absorb it- planting appropriate number of trees

Question 6

4. a)Effectiveness of strategies to reduce emissions of greenhouse gases

Answer 6

•Although most countries ratified Kyoto agreement- two biggest polluters (America and China) haven’t which reduces effectiveness
-even though most countries publicly stated wishes to reduce greenhouse gas emissions- getting effective agreement that everyone agreed on- proved difficult- fear impact on economy

• amount of CO2 in atmosphere continues to increase past 400ppm- shows no sign of slowing down- countries like China and India are developing and becoming major global polluters
• Scotland has achievable plan- significantly reduce carbon intensity by 2030 from generating even more electricity from renewables- leading the way in successful dealing with climate change- wind turbines alone already produce more than 100% of the country’s domestic electricity needs
• government insulation grants- very effective at getting people to insulate houses- studies show amount of energy used by households has dropped over recent years
• recycling in Scotland has increased dramatically in past 10 years- less waste sent to landfill sites which emit methane- means local council policies and education campaigns are working

Question 7

4. b)Effectiveness of strategies to manage local effects of climate change

Answer 7

•Flood defences built to manage local effects of extreme weather events- Thames barrier very successfully protected London from flooding on numerous occasions- predicted to provide protection from ‘1 in a thousand year’ flood events

-conversely, second barrier may be needed to cope with flooding beyond 2070- advanced warning system- need further development to warn households of potential risks of flooding

• London has built a desalination plant- only to be used in periods of extreme drought due to high operational costs
• to manage effects of drought- hose-pipe ban put in place even during periods of extended rainfall- unpopular and difficult to enforce