Physical Questions

Question 1

Explain how urban growth can result in more people being at risk from flooding (5) June13

Answer 1

Expansion of impermeable surfaces - decreased through flow

Decreased vegetation cover so reduced interception

Drainpipes accelerate water flow towards rivers - increased risk of flash flooding

Developing cities - increased risks due to slums on flood plains

Question 2

Explain why some evidence for past climate change is incomplete and unreliable (5) June13

Answer 2

Data sourced from proxy records such as painting are subjective and the artists impersonation

Tree ring records are regional not global and only date back about 8000 years

Scientific methods may be have been inaccurate e.g. The early telescope for sunspots

There could be bias and alterations of scientific data

Question 3

Using located examples suggest how hazards caused by El Niño events can lead to food shortages (4) June13

Answer 3

Drought in Australia leads to crop failures

Heavy rain in Peru leads to flooding and landslides which could destroy crops and reduce ground availability to grow crops

Question 4

Suggest how global warming could affect food supplies in Africa (3) June13

Answer 4

Increased drought could cause crop failure - particular vulnerability of subsistence farmers

Increased rainfall in some areas - could increase crop yield

Coastal inundation could cause crop failure due to salinisation

Question 5

Suggest how global warming could affect ecosystems in the Arctic (3) June13

Answer 5

Northwards migration of Arctic tundra

Melting ice affecting ice dependant species such as polar bear

Alien insect species invade causing tree death

Food chains modified - phytoplankton at base of food chain destroyed due to increased UV

Question 6

Explain how tropical cyclones contribute to the risk of living in the Philippines disaster hotspot (4) Jan10

Answer 6

Philippines are found in a major cyclone belt

Can trigger other hazards e.g. Mudslides

Also suffer from earthquakes, volcanoes, tsunamis

Vulnerability of population adds to disaster element

Question 7

Describe two recent environmental changes that provide evidence for global warming (4) Jan10

Answer 7

Sea ice melting as a result of both higher surface and ocean temperatures

Sea level rise as a result of on land ice melt

Question 8

Explain why the majority of scientists believe humans are responsible for today’s high level of CO2 (4) Jan10

Answer 8

Human activity know to produce CO2 - burning fossil fuels, deforestation

Current CO2 spike coincides with start of industrial revolution

Acceleration particularly over last century - in line with growth emerging economies such as China

Current levels are unprecedented

Question 9

Suggest how the use of renewable energy sources can help tackle climate change (2) Jan10

Answer 9

Reduces rate of use of fossil fuels

Thus less enhanced greenhouse effect

Question 10

Suggest why progress towards meeting renewable energy targets is so slow (3) Jan10

Answer 10

Costs of building turbines/installing solar panels etc

Some governments may feel less need to act

Lack of large scale alternatives/greater innovation needed

Question 11

Using examples, explain how adaptation strategies can help people cope with the impacts of climate change (5) Jan10

Answer 11

Adaptation is adjusting to climate change but not reducing emissions

Managed retreat of UK coastline

Migration away from low lying places

Flood walls

Changing agriculture as biomes may shift

Question 12

Describe the natural hazards that threaten a named local area you have studied (5) Jan13

Answer 12

California:

Conservative plate boundary made up of North American and guandafuca plate

Friction caused by plate movements cause earthquakes

These can trigger landslides

If earthquakes occurs under the sea they can cause a tsunami which can cause flooding

They also experience El Niño which can cause flooding and La Niña which can cause drought

Question 13

Suggest why data uncertainty decreases over time (3) Jan13

Answer 13

Modern technology increasing accuracy of data

Some data from past based on proxy records

Early data likely to be less comprehensive

Question 14

Explain the processes involved in the natural greenhouse effect (5) Jan13

Answer 14

Greenhouses gases are methane, water vapour, CO2, nitrous oxides, sulphur dioxides, CFCs

Incoming energy from sun absorbed by land

Outgoing energy heads back to space but not all lost because of greenhouse gases

Incoming - shortwave, outgoing - longwave

Earth would otherwise be 33 degrees cooler

Question 15

Explain how afforestation may help tackle global warming (3) Jan13

Answer 15

Tress act as a carbon sink

CO2 locked up in trees - conc. falls if more trees

Lower flood risk due to increased interception

Offsets deforestation

Question 16

Explain why some climate change mitigation strategies are often unpopular (5) Jan13

Answer 16

Mitigation means acting to reduce greenhouse gas emissions

Some governments unwilling to invest if it won’t benefit them

Lack of trust in climate change science

Lack of faith in viability of proposals e.g. Knows costs of proposals such as nuclear power

Question 17

Why are earthquakes common in some parts of the world (4) Jan09

Answer 17

Associated with plate boundaries where movement is occurring

Constructive, destructive, conservative

Conservative - where tension builds up - e.g. San Andreas fault

Destructive - friction at subduction zone - e.g. Philippines trench

Minor EQs possible wherever deep fault lines occur

Question 18

With reference to a named example, explain what is meant by a disaster hotspot (4) Jan09

Answer 18

Hotspot is a place where two or more hazards occur

E.g. Philippines suffer from volcanoes, earthquakes, typhoons and more

Philippines is on a destructive boundary made up of Philippine and Eurasian plate

The disaster occurs when vulnerable people encounter the hazard and experience losses

Question 19

Suggest reasons for the loss of ice taking place in most Arctic areas (4) Jan09

Answer 19

Climate change is causing ice melt

Global warming more pronounced in arctic areas because higher altitude

As ice melts albedo falls - positive feedback

Melting of permafrost

Question 20

Describe two ecological impacts of climate change in the Arctic (4) Jan09

Answer 20

As the permafrost thaws lakes drain which moves fish habitats such as Arctic char

More uv destroys marine phytoplankton at base of food chain - food webs modified

Northward shift of biomes

Question 21

State three economic consequences of widespread flooding for a city such as London (3) Jan09

Answer 21

Businesses damaged

Transports services/infrastructure damaged - tourism may be reduced

Costs for insurance companies

Question 22

Suggest reasons why flood defences, such as those in London, have been raised and improved over time (5) Jan09

Answer 22

More storms and extreme weather events

Rise in sea level due to ice melt and thermal expansion

Knowledge was imperfect when walls first built

More property at risk so value of possible damage increased

In some places risk has risen due to population growth/urbanisation

Question 23

Describe some possible impacts of climate change on farming in Africa (3) June10

Answer 23

Low lying farming areas may be lost to the sea, e.g. Parts of Nile delta

Desertification so harsh growing conditions e.g. In Sahel

Rain fed farming will suffer, subsistence farmers like to be hit worst

Question 24

Suggest reasons why increasing numbers of the world’s people are affected by floods (4) June09

Answer 24

Global warming - sea level rise because of ice melt - particularly affected in vulnerable areas such as Maldives

Global warming - sea level rise because of thermal expansion

Increased storms due to warmer temperatures

El Niño causes periodic flood increases e.g. In Peru

Deforestation - reduced interception

Urbanisation - more impermeable surfaces

Question 25

Identify some natural causes that have led to past climate change (4) June09

Answer 25

Milankovitch cycles - orbit, tilt, wobble Solar output variation - 11 year sunspot cycle Major volcanic eruptions - ash and dust in atmosphere so cooling effect El Niño/La Niña - short term changes

Question 26

Distinguish between a natural hazard and a natural disaster (2) June10

Answer 26

A hazard is an event that is potential threat to people/property A disaster is an event where losses are actually experienced

Question 27

Explain how physical and human factors have made the Philippines a disaster hotspot (5) June10

Answer 27

In a tropical cyclone belt Destructive plate boundary - Philippine plate sub-ducted beneath Eurasian plate - volcanoes and earthquakes Landslides and tsunamis secondary impacts of earthquakes Poverty increases vulnerability High population density (240 per sq. Km)

Question 28

Suggest how the physical geography of some coastal areas makes them more at risk from sea level rise than others (3) June10

Answer 28

Low lying land so higher flood risk from even small sea level rise High erosion risk Some are physically isolated, e.g. Pacific Islands, no where to flee to as sea levels rise

Question 29

Suggest how the human geography of areas such as the Maldives or Bangladesh makes them especially vulnerable to sea level rise (3) June10

Answer 29

Dense/high population Poor so more vulnerable Limited coping capacity - can't afford defences Political issues, e.g. Government inertia

Question 30

Explain why it is difficult to predict future sea level rise (4) June10

Answer 30

Different climate change estimates due to so many variables e.g. can't predict the rate at which places will develop and produce emissions Can't predict future international agreements Uncertainty about impact of feedback and thermal expansion

Question 31

What is meant by the term total greenhouse gas emissions (2) June10

Answer 31

The annual GHG output of a country The greenhouses gases are methane, CO2, water vapour, CFCs, sulphur dioxides, nitrous oxides

Question 32

Explain why some countries lack enthusiasm for implementing global agreements to manage climate change (5) June10

Answer 32

Some countries will be less affected e.g. Landlocked not affected by seal level rise so unwilling to invest in strategies that won't benefit them Developing countries say developed countries have greater responsibility Scientific communities in some countries may be more sceptical A countries business interests are threatened Public opinion - NIMBY

Question 33

Describe the processes at a conservative boundary that cause earthquakes (3) June11

Answer 33

Plates move past each other sliding in different directions/different speeds E.g. San Andreas fault - North American and guandafuca plate Build up of fictions - release of energy causes earthquake

Question 34

Explain how global warming leads to rising sea levels (4) June11

Answer 34

Warmer temperature heat top layer of ocean - it expands causing sea levels to rise (thermal expansion) - this increases as sea ice melts and more ocean is exposed Melting of land ice which runs into the sea so adds more volume to them e.g. Greenland ice sheet

Question 35

Explain why some nations will suffer more than others from the impact of predicted sea level rises (5) June11

Answer 35

Low lying nations, e.g. Bangladesh - 60% is flood plains Less affluent nations suffer more because don't have money to defend themselves High coastal population/population density Physically isolated places e.g. Pacific Islands because very low to sea level but have nowhere to flee to

Question 36

Suggests two reasons why cities in California sometimes suffer from flooding (4) Jan12

Answer 36

Coastal location - increased flooding from storms and already low to the sea El Niño - bring heavy rain that can lead to flooding Big urban areas - impermeability of surfaces so increased overland flow and decreased through flow

Question 37

Explain how changes in the albedo in the Arctic may contribute to accelerated global warming (3) Jan12

Answer 37

As ice melts albedo decreases because dark ocean surface reflect less light More light absorbed so increased water and surface temperatures So more melting - positive feedback

Question 38

Explain why some people could benefit from climatic change in the Arctic region (5) Jan12

Answer 38

Greenlanders - opportunities for agriculture and tourism Energy companies - access to Arctic oil resources as ice melts TNCs - easier-quicker transport routes (North-West passage) Scientists - study opportunities

Question 39

Explain why the costs of climate change adaptation strategies keep rising (5) Jan12

Answer 39

Examples of adaptation costs include flood walls, flood barriers etc Costs are rising as GHG emissions rise - linked to industrialisation of NICs etc Increasing events require more spending on strategies e.g. as sea levels rise more flood walls need to be put in place Failure to introduce more mitigation measures means that impacts and costs will be worse

Question 40

Explain how El Niño can lead to drought (5) June12

Answer 40

Cycles occur roughly every 3-7 years in the Pacific Associated with trade winds reversing Warm water sloshes eastwards Colder water off Australia - less evaporation - drought conditions on land Pressure becomes unusually high in Australia La Niña is the reverse of this, a stronger version of the walker circulation, and can cause drought on the coast of South America

Question 41

Explain how natural changes in the earth's climate can be caused by changes in solar output (2) June12

Answer 41

Increased solar output leads to warming Magnetic flares lead to warming More sunspots lead to warming Sunspots occur in an 11 year cycle

Question 42

Explain how natural changes in the earth's climate can be caused by volcanic eruptions (2) June12

Answer 42

Eruptions have a cooling effect Fire dust/ash into atmosphere - reflects radiation E.g. 1991 pinatubo eruption

Question 43

Explain how human activity has led to enhanced greenhouse gas emissions (5) June12

Answer 43

GHG concentrations have all increased since 1750 Fossil fuels for industry release CO2 Deforestation causes CO2 rise by loss of carbon sink Methane increase driven by agriculture, e.g. Cattle ranching Nitrous oxide increase as a result of use in agriculture

Question 44

Explain how increasing climate risk contributes to rising food insecurity at a global scale (5) June12

Answer 44

Less food produced if water availability lessened Increased hurricane frequency could impact on crops e.g. Bananas in the Caribbean Land lost due to sea level rise from ice melt Less food grown in one place could impact on availability in another place that trades with them Loss of income for farmers so can't buy food Changing climate could limit growing locations

Question 45

Identify two reasons for deforestation in some developing countries (2) June13

Answer 45

Clear space for farming Logging/timber - resources for export

Question 46

How might global warming increase hurricane disaster risk? (3) Jan11

Answer 46

Warmer ocean = more energy/higher wind speed Ocean temperatures of 26-27 degrees needed More evaporation = heavier rain Sea level rise leads to more people at risk

Question 47

Explain how human factors have contributed to the increased reporting of earthquake disasters (5) Jan11

Answer 47

Better technology to detect earthquake events that have happened Greater variety and coverage of media = wider reporting Population natural increase in risky areas Migration into risky areas

Question 48

Describe the strengths and weaknesses of adaptation as a way of managing climate change (4) Jan11

Answer 48

Strengths: Property etc saved May be only option for poor societies - can't afford to mitigate Weaknesses: Does not tackle underlying cause of climate change Limited scale - have to keep being improved etc Other losses still occur e.g. Biodiversity

Question 49

Suggest why the economic impacts of climate change in Africa are complex (5) Jan11

Answer 49

Animals may die - costs for farmers Crop change may required - costs farmers Increase in malaria - strain/costs to healthcare systems Environmental refugees - pressure on services Loss of hydroelectric power Water stress could lead to poverty

Question 50

Explain two ways in which climate change may lead to an increase in river flooding (4) Jan11

Answer 50

Torrential rain causes river levels to rise - effects areas such as deltas - e.g. Nile Storm surges may be driven inland more often e.g. Thames estuary

Question 51

Explain why future changes in global sea level are hard to predict (5) Jan11

Answer 51

Can't predict positive/negative feedback e.g. Albedo changes at Arctic GHG emissions hard to forecast - can't predict how much warming so don't know how much ice will melt Can't predict thermal expansion Difficult to predict speed of post Kyoto political developments so can't predict what will be done to mitigate

Question 52

Describe how plate tectonics cause volcanic activity in the Philippines (3) June14

Answer 52

Destructive plate boundary - Philippine plate subducted beneath Eurasian because more dense Melting of plate generates rising magma This can rise up through cracks in rocks to form volcanoes E.g. 1991 pinatubo eruption

Question 53

Explain why tropical cyclones and flooding both occur frequently in the Philippines (5) June14

Answer 53

Located in a tropical cyclone belt Sea temperatures around 26 degrees allowing warm moist body of air perfect for cyclone formation Has many low lying areas e.g. Manila so more prone to flooding Floods can be a secondary hazard following on from cyclones Destructive boundary - tsunamis - flooding Low income so limited flood defences

Question 54

Explain two ways in which a warming climate can lead to a rise in global sea level (4) June14

Answer 54

Leads to melting of sea ice which exposes more ocean so more thermal expansion Melting land ice adds volume and changes to albedo can lead to positive feedback

Question 55

Suggest possible economic impacts of rising sea levels on developing countries such as those on the African continent (4) June14

Answer 55

Many countries reliant on agriculture so Coastal flooding causes loss of land so reduce crop yield and thus income e.g. In Nile delta Increased costs of drinking water Loss of tourist amenities Losses for the poor who cannot afford sea defences - infrastructure losses e.g. Coastal roads Reduction in hydroelectric power so money has to be spent dele eloping new energy sources

Question 56

State what is meant by carbon footprint per person (1) June14

Answer 56

A measure of carbon dioxide emissions that a person is responsible for

Question 57

Explain how the planting of new forests could assist with climate change mitigation (2) June14

Answer 57

New forests increase uptake of CO2 and act as a carbon sink

Question 58

Explain how the planting of new forests could assist with adapting to climate change (2) June14

Answer 58

Could help reduce the effects of flooding due to increased interception

Question 59

Suggest one physical reason why the risk of increased coastal flooding is very high for some low lying coastlines (2) June14

Answer 59

A lot of land is below sea level, e.g. Island like Tuvalu, so if flooded the water has no way of then being removed