Edexcel as Geography - Global Challenges

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This revision booklet is for EDEXCEL AS GEOGRAPHY students studying UNIT 1 –

GLOBAL CHALLENGES (6GE01). Please note that this revision booklet only covers TOPIC 1: WORLD AT RISK and NOT TOPIC 2: GOING

GLOBAL.

The following revision booklet is the material I used to prepare for this exam in January 2010. However, please note that this should only be

used to accompany your notes, and not to replace them. This is because this revision booklet does not contain the homework I was set during the course of studying this Unit, and as mentioned

previously, only contains notes on Topic 1 – World at risk, which covers Global Hazards and Climate

Change, as well as The challenge of global hazards for the future.

This unit is worth 60% of your AS result and 30% of your A2 result, and is therefore 1 out of the 2 modules of the whole A level accounting for the

majority of marks.

May I wish you the best of luck with your exams and I hope this has been helpful along the course

of your studies.

CHRISTOPHER CARTWRIGHT ©

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SECTION 1 – GLOBAL HAZARDS

Hazards

Hazards affect and disrupt our lives High hazard – Death Medium Hazard:

o Buildings destroyed

o Disease from dirty water

o Destruction of transport/communication links

LEDC’s have more physical loses, e.g. Deaths MEDC’s have more economic loses, e.g. Collapsed buildings People in LEDC’s are much more vulnerable as they place themselves in high

risk areas

Kiribati

Tebua in Kiribati was inundated due to rising sea levels Rest of Kiribati is suffering from rising sea levels and erosion People are leaving and becoming environmental refugees There are 3 key reasons why Tebua disappeared:

o Global warming has led to rising sea levels due to ice caps melting

o Volume of water has increased due to thermal expansion

o Tebua was very vulnerable because it was very flat and low-lying

Kiribati also faces other risks, such as:o Erosion

o Tsunamis

o Tropical storms

It is an area of multiple hazards The disappearance of Tebua is a clear sign that global warming is happening Since 1920, southwest Pacific sea levels have warmed by 1oC compared to

the world as a whole which has only warmed by 0.6oC. The worst effects of global warming are felt by the poorest countries,

which make the least contribution to the problem are lease equipped to deal with it

Key Definitions

Global warming – When the Earth’s climate warms because of Greenhouse Gases in the atmosphere

Environmental Refugees – People forced to migrate as a result of changes to the environment

Greenhouse Gases – Gases which retain heat within the Earth’s atmosphere and contribute to global warming, e.g. CO2, N2O and CH4


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Multiple Hazards – Where a region suffers from a number of different natural or man-made hazards which make life difficult for people living there

Difference between hazards and disasters

A hazard is a natural event which has the potential to threaten both life and property and disrupt everyday life (e.g. Earthquake)

Some hazards also have human causes (e.g. Wildfires) A disaster is the realisation and actual impacts of a hazard (e.g. the resulting

deaths, injuries, destruction and disruption) Disasters are becoming increasingly frequent as the vulnerability of people

increases and their ability to cope decreases The basic difference is that a hazard is a threat and a disaster is the outcome

of that threat. Not all hazards lead to disasters (e.g. when they occur in unpopulated areas

or are of a small scale nature)

When does a hazard become a disaster?

The EM-DAT international database suggests a hazard becomes a disaster when one of the following criteria are met:

10+ people are killed 100+ people are affected A state of emergency is declared International assistance is called for

The above figures will fluctuate depending on the country due to population densities, corrupt governments, money factors etc.

How a hazard becomes a disaster?

Vulnerability is the main reason why a hazard becomes a disaster

Underlying causes of vulnerability:o Poverty (limited access to power, infrastructure and resources)

o Failing political, social and economic systems

Pressures – local scale:o Lack of education

o Lack of training

o Lack of food security

Macro scale:o Rapid population change

o Rapid urbanisation

o Debt repayment issues

o Over-exploitation of resources/deforestation


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Unsafe conditions of populations – physical:o Dangerous locations

o Unprotected buildings

Unsafe conditions of population – Socioeconomic:o Weak local economy = poverty

o Lack of disaster preparedness

o Hunger and disease

Risks from global hazards (listed in order of decreasing severity)

Hazards to people:o Death and severe injury

o Disease, stress

Hazards to goodso Economic losses

o Infrastructure damage

o Property damage

Hazards to the environmento Pollution

o Loss of flora and fauna

o Loss of amenity

Why people remain exposed to hazard risk

Changing Risks

Difficult to predict when, where and the magnitude of the hazard Rise in sea levels means that low lying coastal plains that were once safe

places to live are now more prone to storm surge and flood Human activity like deforestation increases flooding events

Lack of Alternatives

World’s poorest and vulnerable people are forced to live in unsafe locations such as hillsides, floodplains or regions subject to drought

E.g. slums on hillsides in Rio De Janeiro

Benefits VS Costs

People will weigh up the benefits vs. costs of living in high-risk areas For example, the benefits of fertile farming land on the flanks of a volcano

may outweigh the risk from eruptions

Risk Perception

People tend to be optimistic about the risk of hazards occurring


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Comforted by statistics which show the risk of death from hazards is far lower than car accidents

They believe if a high magnitude event has a occurred, they will be okay for the next few years (this is not true)

Nature of Hazards

Key Definitions

Hazard – A perceived natural event which has the potential to threaten both life and property

Context Hazard – widespread (global) threat due to environmental factors such as climate change, E.g. Global warming, El Nino

Geophysical Hazard – A hazard formed by tectonic/geological processes (Earthquakes, Volcanoes, Tsunamis)

Hydro-Meteorological Hazard – A hazard formed by hydrological (floods) and atmospheric (storms and droughts) processes

Other hazards – Avalanches can be placed in either group. For example, an avalanche is formed from snow and ice (atmospheric conditions), yet the mass movement is a geomorphological process.

Vulnerability – A high risk combined with an inability of individuals and communities to cope

Environmental hazards are specific events like earthquakes or floods, usually classified into:

Natural processes – where the hazard results from an extreme geophysical or hydro-meteorological event, such as a flood or volcanic eruption

Natural technological disasters – where natural hazards trigger environmental disaster (e.g. flooding causing a dam to burst)

Technological accidents – such as Chernobyl, nuclear power plant exploding

Chronic hazards such as global warming and the El Nino – La Nina cycle may increase the threat from environmental hazards. For example, a sea level rise increases the risk of coastal floods and erosion.

Environmental hazards

Key features of environmental hazards:

Short warning time Rapid onset Difficult to predict Most direct loses occur within days or weeks of the event Resulting disaster justifies an emergency response, sometimes international

aid


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Humans are exposed to hazards because people live in hazardous areas through perceived economic advantage or over-confidence about safety, e.g. California.

Social & Economic factors increasing people’s vulnerability to hazards

Overpopulation / High population density makes the problem worse Corruption/inefficiency in government – e.g. Burma not allowing international

aid initially after the 2008 cyclone Poverty The above amplify the risks, particular of death, and increase peoples

vulnerability

Key Terms

Disaster – A hazard becoming reality in an event that causes deaths and damage to foods/property and the environment

Risk – The probability of a hazard event occurring and creating loss of lives and livelihoods.

Depressions

Cyclonic storms Form when cool polar maritime (Pm) and warm tropical maritime (Tm) air meet

at the polar front Less dense Tm air rises, forming clouds and precipitation along warm and cold

fronts Depressions rotate around a low pressure centre As they develop, strong winds and heavy rain intensify Gale force winds can cause property damage and floods may occur

Impacts of a depression

Front Associated weather elementsWarm Low cloud

Poor visibility Continuous light to moderate precipitation

Strong windsOccluded Prolonged, possibly heavy precipitation

Cold Heavy showers with hail Strong winds

Lightning

Fronts Description

A 'front' describes the area of transition between two different masses of air. A cold front is formed if cold air is approaching and replacing warmer air. A warm front is formed if warm air is approaching colder air.


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In a weather system, if warm air is totally forced off the ground by cooler air, this is known as an occluded front.

Hurricanes

Intense storms in the subtropics Begin as tropical depressions Need sea surface temperatures of 27°C+ to generate convection, as well a

weak upper level winds to allow the storm to develop its characteristic spiral Hurricanes form 500km North and South of the equator where the coriolis

effect is strong enough to generate spin Hurricane Strength is measured using the Saffir-Simpson scale ranging from

weak category 1, to intense category 5.

Droughts

Lack or shortage of water for an unusually long period of time Takes many months or even years to develop Droughts hit hardest in areas which rely directly on agriculture, e.g.

Developing world Eventually, famine sets in as food supply runs out This often leads to large scale migration Droughts in Somalia often cause both famine and conflict

Floods

Flooding occurs when the capacity of a river channel is exceeded by the water discharge

Persistent rain, over a period of days or weeks, leads to more widespread flooding.

Widespread flooding tends to cause property damage as houses and fields remain underwater for long periods of times (e.g. Tewkesbury in the 2007 floods)

Flooding has complex causes, often partly human, e.g. deforestation and poor river management

Flash floods often occur due to intense precipitation over a small area. 11th July 2007: Flash floods killed 20 people and destroyed more than 15,000

houses across Sudan.

Tornados

Tornados are small-scale, short lived storms They remain in one place for only a few seconds Begin as large thunderstorms (supercells) where warm and cold air meet Rapidly convecting warm air produces towering clouds which are twisted by

strong upper level jet streamed winds


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Winds can reach up to 350km h-1 while the tornado itself moves at an average of about 60km h-1

Tornado wind speed is measured using the fujita scale They can be locally devastating, ripping narrow paths of complete distruction

Fire

Wildfires are a natural phenomenon, often started by lightning Common during heat waves and droughts when vegetation is really dry Strong, dry winds such as the Santa Ana winds of California combined with

drought conditions can create “fire weather” Wildfires become extreme when the canopy of trees catches fire Trying to extinguish forest fires can actually raise risk Unburned leaves, twigs and branches build up over time to create a vast fuel

source making fires more powerful

Volcanoes

Occur when magma is forced to the surface through cracks and fissures in the Earth’s crust

The degree of Volcanic hazard is measured using the VEI (Volcanic explosivity Index) scale ranging from 0-8

Explosivity depends on magma viscosity The more viscous the magma, the more hazardous the volcano Viscosity depends on gas, temperature and silica content Highly explosive volcanoes erupt low temperature, vicious lava with high silica

content

Earthquakes

Most commonly occur when 2 tectonic plates move suddenly against each other

Rocks fracture underground at the Earthquake focus Earth’s crust shakes as energy is released Waves spread from the epicentre (point of Earth’s surface directly above the

focus) Earthquakes are measured using:

o Richter Magniture scale

o Mercalli Intensity scale

Severe earthquake damage can occur when unconsolidated sediment undergoes a process called liquefaction

This is responsible for the worst ground shaking and damage


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Tsunamis

Waves caused by the rapid displacement of water Submarine earthquakes are the most common cause Tsunami waves travel at speeds of up to 700 km h-1 across the open ocean Wavelengths are hundreds of km Height is about 1m Cannot be seen out at sea Once they approach the shore, the waves slow down and increase in height

Landslides

Downslope movements of rock and soil under the influence of gravity Most hazardous landslides involve water Heavy rain is often one of the key causes of landslides Earthquakes can also trigger landslides Rapid liquid flows are the most devastating Humans can also play a part in landslides, e.g. Deforestation

Avalanches

Type of mass movement involving snow, ice and other debris Occur on mountains with slopes of about 30-45° Occur within snowpack’s, which contain both weak and strong layers of snow The following can cause avalanches:

o Changing wind conditions

o Changing temperatures

o Further snow falls

o Skiing

o Earth tremors

Speeds can be of up to 300 km h-1 as the slab breaks up and rushes downslope

Most avalanche fatalities result from burial

Comparing Vulnerability

Location & Date of Earthquake

Bam, Iran – December 2003

Hawaii, USA – October 2006

Magnitude 6.6 6.7Deaths 25,000 0Injuries 30,000 Several hundred minor

Property Damage $10 billion economic Loss

18,000 buildings destroyed

$73 million in damage

1,200 buildings damaged


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Despite the magnitude of the Hawaiian earthquake being stronger, the impact was minute compared to the impact on Bam

90% of the buildings in Bam were constructed of mud with no structural frame In Hawaii, most buildings could resist the ground shaking with only minor

damage In Bam, many emergency service vehicles and buildings were damaged by

the earthquake Average incomes in Hawaii are $30,000 per annum compared to $3,900 in

Iran

Destruction in Bam, one of Iran’s poorest, isolated regions.

Measuring Risk

Risk Equation

The Risk equation measures the level of hazard for an area:

Risk = Frequency or magnitude of hazard x level of vulnerability Capacity of population to cope

Frequency or magnitude of hazard increasing

Use of fossil fuels is warming the planet


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Resulting change in climate is increasing the frequency and severity of weather related hazards (e.g. Floods, droughts, windstorms)

Level of vulnerability increasing

Hazards become disasters only when people get in the way Unsustainable development on poor land (e.g. building on floodplains)

increases the vulnerability Destruction of coastal mangroves decreases coastal protection

Capacity to cope decreasing

Poor and vulnerable communities lack the skills, tools and money to cope with the effects of climate change

Debt repayments and selective foreign investment mean that poorer countries can’t invest money in the skills and tools to cope with the effects of climate change, thus decreasing their capacity to cope

The Future

The most affected areas will be the poorer countries and communities:o Sub-Saharan Africa

o Parts of Southeast Asia

o Many of the small developing islands

This shows how the development gap is widening, with the rich getting richer and the poor getting poorer.

Global warming: Our greatest hazard?

Key terms

Albedo – How much solar radiation a surface reflects Climate change – any long term trend or shift in climate (average weather

over 30 years) detected by a sustained shift in the average value for any climatic element (e.g. Rainfall)

Global warming – A recently measured rise in the average surface temperature of the planet

Greenhouse effect – The warming of the Earth’s atmosphere due to the trapping of heat that would otherwise be radiated back into space. It enables the survival of life on earth.

Enhanced greenhouse effect – Greenhouse gases in the atmosphere increase owing to human activity

Fossil fuels – Energy sources that are rich in carbon which release carbon dioxide when burnt

Tipping point – The point at which a system switches from one state to another


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Greenhouse Effect

Natural phenomenon Process by which GHG’s (Water vapour [biggest contributor], Carbon Dioxide,

methane, CFC’s, nitrous oxide and ozone) absorb outgoing long-wave radiation from the Earth and send some of it back to the Earth’s surface, which is warmed

This sustains life on earth by raising temperatures to a global average of 15°C Without the greenhouse effect, the Earth would be up to 30°C cooler In early 19th century, concentrations of CO2 and GHG’s stood at 280ppm

(parts per million) In 2007, the concentrations of CO2 and other GHG’s stands at 430ppm as a

result of human activities Because of these increased levels, an enhanced greenhouse effect is now

occurring A concentration of over 450ppm is expected to lead to a rise of 2°C in the

Earth’s temperature, which will be the global tipping points for dangerous climate change

Why Global warming is important


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Global problem affecting all areas of the world Chronic hazard with an enormous range of direct impact Changes in climate:

o Affects Ecology

o Affects Wildlife

o Could lead to the spread into new areas of disease, e.g. Malaria

Rising ocean temperatures may cause an increasing frequency and magnitude of hurricanes which in turn destruct coral reefs

Thermal expansion leads to sea level rise Earth consists of a number of interlocking systems:

o As glaciers and ice sheets melt, oceans become diluted by fresh water

o This impacts on ocean circulation

o Ice also has a high albedo and as it melts, more heat from the sun will

be absorbedo In turn, this will raise the temperature further and make the remaining

ice melt quicker

Socio-Economic impacts of a 2°C global temperature change

Global Warming: a context hazard

Global warming is a chronic hazard because it is continually present


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Global warming is potentially a global hazard because its impacts could be very widespread

o E.g. Causing whole climate zones to shift

Global warming could cause increases in the frequency and magnitude of hydro-meteorological hazards

It could also increase vulnerability to tectonic hazards by reducing food supply and water availability

As a global problem, it requires a global solution, which is by its very nature, complex

Possible impacts of global warming on hydro-meteorological hazards

Floods Changing rainfall patterns could increase risk in some areas – floods may become more common, e.g. Gloucestershire, Sheffield

Drought Already vulnerable areas such as the Sahel could experience increased drought, e.g. Portugal, Australia

Avalanches Mountain areas could experience more variable weather patterns, reducing predictive ability, e.g. Alps

Hurricanes These may become more intense, and possibly more frequent. New areas could become affected, e.g. S.E America

Depressions These could become more frequent, and more intense over areas such as the UK, e.g. North England

Vulnerability

Developing countries and regions are more vulnerable than developed ones Capacity to cope is generally lower in the developing world, so hazard impact

lasts longer than in the developed world Poverty, poor social conditions, environmental degradation and unfavourable

physical geography all increase vulnerability Impacts on LEDCs last longer because of:

o Corrupt governments delaying aid (e.g. Burma – Cyclone Nargis 2008)

o Poor communication links easily destroyed

o Lack of healthcare

LEDCs are more vulnerable because of:o Lack of evacuation plans

o Dense, poor populations

Increasing Vulnerability Decreasing VulnerabilityPopulation growth

Urbanisation and Urban Sprawl

Environmental Degradation

Warning and emergency-response systems

Economic wealth


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Loss of community memory about hazard

Ageing population

Ageing infrastructure

Greater reliance on power, water, communication systems

Over-reliance on technological fix

Government disaster-assistance programmes

Insurance

Community initiatives

Scientific understanding

Hazard engineering

Risk

Risk, as shown in the disaster risk equation, increases as hazardous events become more common, people become more vulnerable and their capacity to cope decreases

Risk can be reduced by reducing vulnerability, increasing capacity or reducing hazard frequency and/or magnitude

H x V

R = CR = Risk, H = Frequency or magnitude of hazard, V = Vulnerability, C = Capacity to cope

Risk can be reduced by implementing some of the following strategies:

‘Quake proof buildings’ – Shock absorbers, spring-loaded foundations and counterweights on top

Education and public awareness via earthquake drills and through the media Sea walls/Coastal defences can reduce impact from floods Aforestation – Planting of trees near drainage basins to intercept water

SECTION 2 – GLOBAL HAZARD TRENDS


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Hazard Trends (1)


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Hazard trends, 1900 – 2005

Number of reported disasters has risen significantly in recent years Part of this rise is likely to be due to more accurate recording and better

communications with isolated regions. Rapid rise since around 1960, which is when satellite remote sensing and

global communications began. Population growth means more people living in potentially hazardous

locations This means there are a greater number at risk Many people at risk live in the developing world, and are vulnerable due to

low coping capacity

Hazard Trends (2)

Number of natural disasters by type, 1970 – 2005

Earthquakes

The trend for earthquakes is fairly stable. There is no evidence that the number of earthquake events is increasing. There are likely to have been more people in earthquake-prone areas in 2000

than in 1980, and this would explain the slight rise in disasters.

Floods and Windstorms

There is a clearer upward trend for floods and wind storms. This may indicate an increase in the vulnerable population and a rise in the

number of hazardous events. It could be the result of global climate change and/or other environmental

changes.


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Hazard trends (3)

Volcanoes

Country Year

Number of people affected

Philippines

(Mt Pinatubo) 1991 1,036,065

Nicaragua 1992 300,075

Ecuador 2006 300,013

Indonesia 1982 300,000

Indonesia 1969 250,000

Comoros 2005 245,000

Philippines 1993 165,009

Papua New Guinea 1994 152,002

Ecuador 2002 128,150

Dem. Rep. Congo 2002 110,400

Around 50-70 volcanoes erupt every year There is no trend in eruption frequency Very large magnitude eruptions (e.g. Mt Pinatubo in 1991) are rare There is a rising trend in the number of people affected Notice that 8 of the top 10 eruptions have occurred since 1990 This reflects growing population density in the developing world

Hurricane Trends

Some researchers have linked the increase in hurricanes to global warming Others argue the AMO (Atlantic Multidecadal Oscillation) has caused the

increase


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There is a long-term trend in the USA of falling hurricane-related deaths but rising economic costs

Coastal areas of Florida and the Gulf have seen population rises of 400% by 1980

This means an increased number of people are at risk The potential for economic loss continues to grow as populations rise The 5 major hurricanes that struck Florida in 2005 caused $120 billion in

damage and the loss of 2,200 lives

Global Warming

Global temperatures, 1850–2008

Many scientists believe that increased global warming will lead to more unpredictable weather and a rise in extreme weather events.

Global temperatures have risen since 1910, and at a consistently rapid rate since the late 1970s.

The fact that there are only 30–35 years of reliable data about global temperatures makes the scientists’ task of accurately predicting future changes more difficult.

Some data, such as the 20 cm rise in global sea level since 1900 and the decline in Arctic sea ice since the 1970s, are more reliable.

Flood Disaster Trends


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Reported global flood disasters and death tolls, 1977–2007

Trends in global flood disasters show significant rises since the early 1990s. This could be an early signal of climate change. It may also be related to rising populations, rapid urbanisation, deforestation

and other land-use changes. Separating the climate change signal from the human factors that increase

flood risk is a real challenge.

Summer 2007 UK Floods

Rainfall pattern, summer 2007

In summer 2007, many areas in the UK received over 100 mm of rainfall in 24 hours, causing widespread flooding.

50,000 homes and 7,000 businesses flooded, total cost £3 billion+


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The basic cause of the flooding was a southerly jet stream, meaning low pressure and rain over the UK at a time when high pressure was to be expected.

Many meteorologists have linked this situation to La Niña conditions in the Pacific.

Human Trends

Some trends among the human population add to increasing risk. One of these is urbanisation. Over 50% of the world’s population now lives in

urban areas, compared to 29% in 1950. These crowded spaces are especially vulnerable to major earthquakes, floods

and hurricanes. World poverty continues to be a major issue, reducing the capacity to cope

with, and increasing the vulnerability to hazards. In Latin America and Africa, there has been a significant rise of people

earning less than $1 per day. Deforestation results from pressure on land with growing populations,

increasing the risk of flash floods and landslides

Global Trends

Disasters related to human development levels

Overall, global trends show that:o The numbers of reported disasters and people affected are risingo But the number of people killed by disasters is falling.

Disaster Management


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Falling death tolls suggest improvements in disaster management. Death tolls are reduced when populations are prepared for a possible hazard. Some hazards can be predicted, e.g. floods, hurricanes, drought and volcanic

eruptions. Prediction allows for warning and evacuation. This can save lives, but is

unlikely to reduce economic losses. After a disaster, immediate rescue and relief is essential. ‘Rapid response’ has improved considerably over the last few decades.

International relief efforts now occur quickly in response to disasters. This saves lives but the numbers affected and the economic losses are still

high. The challenge is to ‘disaster proof’ communities by:

o Using appropriate building techniqueso land-use zoningo educationo developing prevention technology.

These responses are longer term, costly and beyond the reach of many in the developing world.

As part of my October half term homework, I was asked to complete case studies of all the different types of hazards. However, I originally did them on MS Publisher. But, I no longer have MS publisher and therefore cannot access the files to produce my detailed case studies in this revision booklet. Despite this, I still have some of the files to the detailed case studies, so if you would like to have them, then please leave a comment on the section where you download this revision booklet and I will email them to you if possible.


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El Nino/La Nina

This affects the weather around the world – therefore it’s a context hazard These events happen every 2-7 years and last for 1-2 years It is not clear whether global warming is changing the frequency or intensity


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During El Nino:

Rainfall is reduced in Southeast Asia, Oceanic and India, leading to drought, crop failure and wildfires

Heavy rain in California, Mexico and the Coasts of Peru and Ecuador often results in flooding and mudslides

Suppression of the cold current in the east pacific devastates fish catches off the west coast of South America

Tornados in the USA are reduced More cyclones in Hawaii and Polynesia but fewer in North Australia Southern Africa may experience drought East Africa may experience floods

During La Nina:

Higher rainfall in Indonesia and the Philippines Lower rainfall on the west coast of South America Southern Africa and Southern Australia may experience floods Eastern Africa, California and South America may experience drought More hurricanes in the Caribbean and USA

SECTION 3 – GLOBAL HAZARD PATTERNS

Key Definitions

Asthenosphere: A semi-molten zone of rock underlying the Earth’s crust

Lithosphere: The crust of the Earth, around 80-90 km thick

Magma: Molten material that rises towards the Earth’s surface when hotspots within the asthenosphere generate convection currents

Hotspot: A localised area of the Earth’s crust with an unusually high temperature

Plume: An upwelling of abnormally hot rock within the Earth’s mantle

Inter-tropical convergence zone: A zone of low atmospheric pressure near the equator. This migrates seasonally.

Flooding

Flooding is a common hazard Risk is related to physical factors:

o Heavy rain

o Impermeable rock/soil

o Sparse vegetation cover


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o Steep slopes

And human factors:o Urbanisation

o Deforestation

o Poor river management

o Building on floodplains

o Lack of preparedness

Flooding is possible in numerous locations (see map below) and is likely to increase in frequency in many areas due to climate change

Drought

Drought occurs when precipitating falls below ‘normal’ and expected levels Drought has a slow-onset Those who rely directly on food production and natural water sources are

most vulnerable In extreme cases, drought may contribute to the onset of famine


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Tropical Cyclones

Tropical cyclones (hurricanes and typhoons) are intense low pressure weather systems that occur in belts just north and south of the equator

They are generated in source areas and track along the trade wind paths Tropical cyclones occur in distinct seasons, e.g. June-November in the north

Atlantic and October-May in the southern hemisphere

Hurricanes

Hurricane intensity is measured on the Saffir-Simpson scale which ranges from 1 to 5, with 5 the most devastating storm

Storms that make landfall have severe impacts:o Low pressure creates a storm surge, flooding low-lying coastal areas

o Intense rainfall contributes to flooding


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o Winds of up to 280 km h-1 cause structural damage and often deaths

Plate Tectonics

The movement of the Earth’s tectonic plate is responsible for most earthquakes and volcanoes

Oceanic plates are normally thicker and more dense than continental plates Most hazards occur at the boundaries where two plates meet The risk from these hazards is closely related to the type of plate boundary,

with some boundaries more hazardous than others

Volcanoes

Volcanoes occur in well-known, localised areas Monitoring and prediction can often reduce risk The most devastating volcanoes are located on destructive plate boundaries

in densely populated developing countries A single volcano can generate a range of hazards, including lava flows, ash

fall, pyroclastic flows and lahars, often occurring simultaneously

Earthquakes

Earthquakes are not predictable, and their consequences can be catastrophic in terms of both human and economic loss

Large, vulnerable populations live in high-risk locations In the developing world, the capacity to cope is often low

Worst earthquakes in the last decade:

Location Magnitude DeathsSichuan, China, 2008 7.8 70,000

Kashmir, Pakistan, 2005 7.6 80,000+Sumatra, Indonesia, 2004 8.9 200,000

Bam, Iran, 2003 6.6 26,000Gujarat, India, 2001 7.4 17,000

Slides

Landslides and avalanches are 2 types of mass movement Landslides are most common in geologically young mountains and

tectonically active areas Water movement and precipitation, plus land-use change (e.g. deforestation),

are important factors in generating landslides


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Avalanches are most common in alpine environments where winter snowfall is disturbed by periodic thaws, wind, further snowfall and alpine sports

Landslides may be triggered by earthquakes, for example up to a third of deaths in the 2005 Kashmir earthquake were a result of landslides

Disaster hotspots

Disaster hotspots occur when two or more hazards occur in the same location In many cases, one hazard triggers or exacerbates another – earthquakes

trigger landslides, and typhoon rainfall triggers lahars Disaster hotspots are the world’s most unpredictable and dangerous

locations The Philippines and the California coast

California and the Philippines compared

California Coast PhilippinesAverage income (US$) 45,000 1,415

Country type MEDC RICHuman development

index0.95 0.78

Annual population growth

0.7% 2.3%

Under 5 mortality rate 7/1,000 40/1,000Physical geography Plains and mountain

rangesNumerous volcanic islands

Hazards Earthquakes, Tsunamis, Flash floods, Fires

Earthquakes, Volcanoes, Landslides/Lahars, Typhoons, Flooding

The 2 hotspots contrast in terms of physical geography The Philippines sit on a destructive plate margin, where the Eurasian plate

and the Philippines plate collide (Volcanoes and earthquakes) California sits on a conservative plate boundary (earthquakes)

Compulsory Disaster Hotspot Case Study: The Philippines

The Philippines consists of over 7000 islands Many are small and are concentrated at the latitudes between 5 and 20°N of

the equator It lies in a belt of tropical cyclones and an active plate boundary The dense oceanic Philippines plate is being subducted beneath the Eurasian

plate The country experiences a tropical monsoon climate and is subject to

heavy rainfall Flooding can lead to landslides because of the deforestation of hillsides


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The Philippines is a lower middle income country which is developing fast Rapidly increasing young population Average population densities for the country are high at 240 people per km2

Many of these people are very poor and live on the coast, making them vulnerable to tsunamis and typhoon storm surges

On average, about 10 typhoons occur each season, especially in Luzon – the country’s most economically and politically important island of the country

In response, the government has established several organisations to carry out forecasting, warning, hazard risk assessment, disaster training & education:

National Disaster Co-ordinating Council Philippine Atmospheric Geophysical and Astronomical services Land-use planning and building regulation Structural programmes of defence – help people to survive the huge range

of hazards facing them

In 2006, the Southern Leyte landslide killed 1,126 people. The landslide occurred following a 10 day period of heavy rain and a minor earthquake measuring 2.6 on the Richter scale.

Compulsory Disaster Hotspot Case Study: California Coast

40 million people High-income economy Suffers from a vast range of hazards, including huge risks from geophysical

hazards (especially earthquakes) as well as a range of atmospheric hazards such as fog, drought, and associated wildfires, and major impacts from the El Nino Southern Oscillation.

The hazardous zone is concentrated along the San Andreas Fault Much of the coastline is crowded as various land users compete for prime

space This human-physical interface increases the danger from hazards Sophisticated management prevents California from becoming a disaster

zone For example, a recent earthquake which struck off the Northern shore of

California in January 2010 measuring 6.5 resulted in no deaths.


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A large proportion of the 3.5 million underclass live in hazardous locations

Investigating the hazard risk of your local area: Shropshire

Research the history of hazard events in your local area using:o Historic newspapers (history archive in local library)

o Searching online

o Interviewing older residents

4 main hazard types in Shropshire

1) Flooding

Flooding from major rivers such as the Severn Between 1970 and 2000 flooding was eliminated by catchment management

in the upper Severn (the building of Clyweddog dam and Melverley Washlands basin)


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2007flash food: Tenbury wells resulted from torrential rainfall of up to 20mm in 3 hours

2) Earthquakes

Range from 4 to 5 on the Richter scale Result from movement along historic fault lines, e.g. Church Stretton fault These minor earthquakes cause damage to a few buildings and occasional

minor injury but no deaths

3) Snowstorms and droughts

Shropshire’s continental position within the UK leads to harsh winters and severe snowfalls

In March 2007 there were heavy snowfalls for 2 days Shropshire also experiences heat waves and droughts in summer, when the

whole of the country falls under the influence of an anticyclone

4) Storms and Tornadoes

Violent storms and flash flooding in Tenbury wells (2007) and the Telford Tornado in 2007

The Distribution of Geophysical Hazards – Volcanoes

World’s active volcanoes are found on:o Constructive plate boundaries

o Destructive plate boundaries

o Hotspots

Volcanoes often occur in localised areas Plate movement is about 15cm every year New technology means we can monitor and predict when they will erupt and

this can often reduce risk

Destructive plate boundary

The worst volcanoes occur on destructive plate boundaries in densely populated regions

80% of the worlds active volcanoes are located on destructive plate boundaries, E.g. Soufriere Hills in Montserrat

Constructive plate boundary

Most of the constructive plate volcanoes don’t pose a threat to humans, as only in Iceland do they go above sea level

Hotspots


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A hotspot is a localised area of the Earth’s crust with an unusually high temperature

Plume is the fixed point under the plate As a plate moves over the hotspot a chain of volcanoes are created, E.g.

Hawaii

Volcanic Hazards

Lava Ash falls Tsunamis Mudflows Pyroclastic flows – move about 100 km/h and are 300°C

Earthquakes

The Lithosphere is divided into 7 major plates These plates float on the asthenosphere

Destructive Plate Boundary

One plate is forced underneath of the other Associated with ocean-ocean subduction and ocean-continent subduction The further into the subduction, the bigger the earthquake The most destructive plate boundaries are also associated with volcanoes Example of D.B.P: Nazca underneath South American plate

Constructive plate boundary


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2 plates separate/move away from each other Magma rises up through the Earth’s crust forming volcanoes Example of Constructive P.B: Mid-Atlantic Ridge

Conservative plate boundary

Slide passed each other in opposite directions Friction causes vibrations which is the earthquake Example of Conservative P.B: The San Andreas Fault

Other Earthquakes

A small minority earthquakes occur on ancient fault lines, e.g. Church Stretton fault in Shropshire

Earthquakes can also occur from human actions:o Dam & reservoir construction – Increases weight & stress on land

E.g. Killari, North Indian (1993) killed 10,000 peopleo Deep seam mining – Decreases support & stability of land

Earthquake hazards

Primary Hazards

Result from ground movement and shaking Surface seismic waves can cause:

o Buildings to collapse

o Water & gas pipes to burst

Secondary Hazards

Soil Liquefaction Landslides


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Avalanches Tsunamis All of the above significantly add to the death toll

Distribution of Geophysical Hazards – Landslides

Landslides are the 7th biggest killer with over 1400 deaths per year (higher than volcanoes and droughts)

Most mountainous areas experience landslides after abnormally heavy rain, or seismic activity

Humans can increase landslide risks by hillside deforestation, E.g. Laos Buildings on hill slopes can lead to widespread landslides, E.g. Norway

Hillside Deforestation in Laos

Landslide in Alesund, Norway, on a slope under an apartment block

The Distribution of Hydro-Meteorological Hazards – Drought

Drought has a dispersed pattern – Over 1/3 of the world’s land surface has some level of drought exposure

This includes 70% of the world’s people and agricultural value – which means that drought has an effect on global food security

Countries suffering from drought


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Drought causes famine, particularly in LEDC’s such as Kenya, Ethiopia and Sahel

Additional areas suffering drought:o South East & South West Australia

o Sahelian Africa

o Great plains of the USA

o Mediterranean Europe, E.g. Spain & Portugal

o Interior Asia, E.g. Northern Kazakhstan

o Northeast Brazil

Causes of Drought

Drought has a slow onset and is a creeping hazard Variations in the movement of the intertropical convergence zone (ITCZ) -

band around the equator of the tropics where warm moist air gathers As the ITCZ moves North and South through Africa, it brings a band of

seasonal rain In some years, High-pressure zones expand and block the rain-bearing winds In Ethiopia and Somalia, families may suffer from famine if the summer rains

never arrive

Drought and El Nino

El Nino can bring major changes to rainfall patterns In 2006, it brought drought to Indonesia and Australia whilst South America

got loads of heavy rain

Changes in mid-latitude depression tracks

In temperate regions, depressions bring large amounts of rainfall, like the UK However, if blocking anticyclones form and persist, depressions are forced to

track further north, leading to very dry conditions Droughts from blocking anticyclones were felt in France and UK in 2003 and

2006

Drought Hazards

Crop failure Loss of livestock Wildfires Dust storms Famine


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Drought also has economic impacts on agriculture and water-related businesses in developed countries

Distribution of Hydro-meteorological hazards – Flooding

Flooding is a frequent hazard and is evident in some 33% of the world’s area, which is inhabited by over 80% of its population

Regional scale, high-magnitude floods are frequent events in India, Bangladesh and China

The main cause of flooding is excessive rainfall from monsoons, cyclones and depressions

Flash floods can have devastating affects Intense rainfall sometimes associated with thunderstorms can lead to

localised flash flooding El Nino can bring devastating floods, as in Mozambique in 1997 and 2006 Rapid snowmelt can add water to an already swollen river

Flooding Hazards

Deaths by drowning and disease


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Destruction of food crops Destruction of infrastructure Loss of home Disruption of transport and communication networks Damages livelihoods Creates high insurance costs

Distribution of Hydro-meteorological hazards – Storms

Storms include tropical cyclones, mid-latitude storms and tornadoes Tropical cyclones occur North and South of the Equator, ranging from 5 to 20° Bangladesh suffers from tropical cyclones Tropical cyclones will only occur over warm oceans that are 26°C+ Tropical cyclones are most common in the East Pacific between June and

October – occur 3 or more times a year on average Caribbean creates 11% of tropical cyclones between August and October Tropical cyclones created over East Asia from May to December and happen

over 5 times a year on average

Tropical storm hazards

Heavy rain (leading to mudslides and floods) High wind velocity and low central pressure (leading to storm surges and

coastal flooding)


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They can be devastating, E.g. Hurricane Katrina

SECTION 4 – CLIMATE CHANGE & ITS CAUSES

Introductory points

Current research estimates that average global temperatures will increase by between 1.8 and 4°C in the next 100 years

The climate of the Earth exists due to a naturally occurring phenomenon known as the Greenhouse Effect

Without it, the surface of the planet would be 33°C cooler and life on earth would have not been able to exist or evolve


http://upload.wikimedia.org/wikipedia/commons/0/04/Hurricane_Isabel_from_ISS.jpg

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Natural Greenhouse Effect

Solar radiation from the sun beats down on the Earth. Some radiation bounces straight back into space, whilst the rest is absorbed by the Earth. However, some of the radiation bouncing back into space is intercepted and absorbed by greenhouse

gases present in the atmosphere. Consequently, the heat is re-radiated which warms the Earth up even more.

Reasons for Climate Change

Climate change is part of a naturally occurring cycle influenced by many different factors

Recent evidence suggests that human activities are largely responsible for the warming trend

This is largely due to the influence of human activities on GHG concentrations, resulting in an Enhanced Greenhouse Effect

The enhanced greenhouse effect is the increase in the natural greenhouse effect, said to be caused by human activities which increase the quantity of greenhouse Gases in the atmosphere

Main Greenhouse Gases (GHG’s)

Water Vapour Carbon Dioxide Nitrous Oxide Chlorofluorocarbons (CFC’s) Methane Ozone

Increasing Concentrations


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The quantities of some of these gases have increased by 25% since 1750, when industrialisation began in the UK

Due to the increase in global temperatures, this encourages the evaporation of water vapour, the main GHG

More water vapour, more condensation and therefore more cloud cover to trap heat in the atmosphere

Key GHG’s & their contribution to Global Warming

Greenhouse Gas Source Contribution to Global Warming

Carbon Dioxide Burning of Carbon-based fuels (e.g. Coal and Oil)

Increased atmospheric CO2 by 25%

Chlorofluorocarbons (CFCs)

Propellants in spray cans, foam plastics and refrigerant

fluids

CFCs absorb solar radiation. The thinning in the Ozone layer between 10 and 25km above

Antarctica was probably caused by CFCs

Methane Rice production, burning vegetation, coal mining,

livestock flatulence

Very effective in retaining heat. Since 1950, annual emissions have increased 4x faster than

CO2

Nitrous Oxide Agricultural fertilisers, burning fossil fuels,

production of synthetic chemicals (e.g. Nylon)

Traps infrared radiation in the atmosphere, changing to nitric

oxide which destroys ozone

Ozone N/A Acts like a greenhouse gas but plays a vital role in dispersing

harmful UV rays

Evidence of a changing world

Tropics – increased evaporation due to warmer temperatures has led to an increase in rainfall

Sahel – increased evaporation has made water even scarcer Catchment areas of Niger, Lake Chad and Senegal have seen a 40-60%

reduction in the total amount of water available Mediterranean and Southern Asia – Reduced amounts of rainfall has lowered

soil moisture, thus making existing problems of drought and desertification worse

Northern Europe – Frequency of heavy rainfall events has increased North Atlantic – Warmer oceans expected to give rise to an increased

intensity of tropical cyclones, evident since 1970s


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The Wane of Winter

Arctic: Summer of 2008, both the NE and NW passages around the Arctic were clear of sea ice due to a net fall of the pack ice accumulation during the winter months

Collectively, the Northern hemisphere has seen a 10% reduction in the amount of snow cover in its mid to high latitudes since the 1960s

Switzerland has lost 2/3 of the volume of its glaciers during the 20th century Melt water from Greenland and Antarctica has been one of the main

contributors of rapid sea level rise that has occurred in recent decades Between 1961 and 1993 the average rise in sea level was 1.8mm per year Between 1993 and 2003, the annual rate of increase was 3.1mm per year Alps – changes have resulted in the loss of traditional species from mountain

slopes and the migration of species to higher altitudes due to increased temperatures

Arguments for and against Climate Change

For AgainstThere is a lot of Bleached coral present on the ocean/sea floors, a vivid sign that the coral is responding to stress induced by

increased or decreased water temperatures (often attributed to global warming).

Sceptics also argue that while environmentalists are very keen to show photographs of polar bears struggling on

supposedly melting icebergs, it is estimated that there are now 22,000 polar bears

compared with 5,000 in 1940 and there are several reputable scientific studies that have

shown that the mass of the Greenland ice sheet is actually expanding.

Global surface temperatures have increased by between 0.4 and 0.8ºC since the late 19th

century and by about 0.2 to 0.3°C over the last 40 years

Some scientists have argued that the current climate changes we are experiencing might

actually be part of our "normal" climate. They argue that although the global surface

temperature has risen in the last 200 years, it is still very low compared to the time of the

dinosaurs, 65 million years ago.Snow, mountain glaciers and Arctic sea ice in the northern hemisphere are all melting.

Alaska’s permafrost temperature has increased 0.5ºC to 1.5ºC since 1980 with

resulting forest damage, sinking roads and buildings, eroding tundra riverbanks,

changes in tundra vegetation and increased carbon dioxide and methane emissions from

thawed peat.

While global warming might cause the sea level to rise, this situation will also create more water to absorb carbon dioxide from

the atmosphere with and so global warming is further reduced.

Over the last 100 years, the global sea level has risen by about 10 to 25 cm

Satellite readings of temperatures in the lower troposphere (an area scientists predict

would immediately reflect any global warming) show no warming since readings began 23 years ago. These readings are

accurate to within 0.01ºC, and are consistent with data from weather balloons.


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Rainfall around the world has risen by about 1%. Many Indian states, such as Bangladesh and Orissa, have suffered severe flooding in

recent years. If global warming continues, the situation is likely to get worse

The science of global warming is not proved. It is argued that we don’t have long term

historical records of weather.

Over the past few years, floods, storms and droughts have shown how vulnerable the UK is to extreme weather events and scientists predict increasing episodes of such events

because of climate change

The Earth's temperature may stay roughly the same for a decade, as natural climate

cycles enter a cooling phase, scientists have predicted.

The increase of three-quarters of a degree centigrade (0.75°C) in average global

temperatures that we have seen over the last century is larger than can be accounted for

by natural factors alone.

Rising levels of carbon dioxide (CO2) and other greenhouse gases (GHGs) do not

correlate with global warming.

The Earth is absorbing more energy from the Sun than it is giving back into space, according to a new study by climate

scientists in the US

Some experts think we’ve got it all completely wrong because the climate

system is very complex, so predicting climate change is like rolling dozens of dice: you can’t be sure what your final result will be

because there are so many possible results.Tebua Tarawa and Abanuea, 2 South Pacific Islands, disappeared under the waves of the

sea in 1999. This occurred as a result of rising sea levels, and scientists believe this

was an affect of global warming.

There is an argument that CO2 levels lag behind temperatures by 800 years or so.

First, this possibility depends on proxy data, since records don't go back that far. But it

could well be true because it's so consistent. If so, the current climate change would have

nothing to do with humans today/recently.Tuvalu is seeing increased intensity of tidal waves, which are now starting to submerge

the tiny islands. One of the Island’s main road has started to get submerged and

homes are at threat. A resident said they have never come in so inland before, and

scientists claim that global warming is what is making them do so, as a result of sea level

rise and increased water in the sea.

It is true that the fluctuations in temperatures that caused the ice ages were initiated by

changes in the Earth's orbit around the Sun which, in turn, drove changes in levels of carbon dioxide in the atmosphere. This is backed up by data from ice cores which

show that rises in temperature came first, and were then followed by rises in levels of carbon dioxide up to several hundred years

later.

Paeleoclimatology

The study of past climates is important as it allows us to make judgements as to whether present-day global warming is part of a natural cycle or fluctuation, or whether it is occurring because of anthropogenic influences (human-induced).

Climate Timescales

Long term Climate Data Long term climate change has occurred


http://en.wikipedia.org/wiki/Greenhouse_gas

http://en.wikipedia.org/wiki/Carbon_dioxide

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on geological timescales, over several hundreds of thousands to millions of years. Evidence for this most often

comes from ice cores.

Medium term Climate data Medium term timescale covers changes over the last few thousand years. Since around 1850, direct measurements of

climate variables have been made using thermometers and rain gauges, so climate data prior to this cannot be accurately verified. It may only be inferred from written accounts and descriptions that only indicate the prevailing climate and not actually

measure it.

Short term Climate data Short term climate change has been measured over the last few decades

using sensitive, accurate equipment such as satellites and ocean temperature

buoys.

Evidence for Short Term Climate Change


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Changes in global ice cover in response to recent climate change


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Evidence of Medium-term Climate Change


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Proxy records are used to reconstruct climate before the start of instrumental records

Proxy records include:o Paintings

o Poems

o Record books

o Diaries & Journals

o All of which recorded weather at the time

The Thames froze over regularly between 1500 and 1850 – this period was known as the Little Ice Age

Mid 14th century – dates of the grape harvest in France had been carefully recorded and used to indicate past climate

HOWEVER, the grape harvest could have been affected by non-climate factors such as conflict or decreased vines

Reliability of such data would have been reduced due to the fact that the harvest dates would have been recorded by different individuals and the recording methods would have changed

Old paintings involving weather events, such as that of the Frost Fair on the Thames during the Little Ice Age, are highly subjective

They are one person’s view of an event, and the artists interpretation is open to artist flair and freedom

Because the freezing of the Thames was an extreme and unusual event, it may have been exaggerated

The actual temperature and the duration of the event cannot be easily estimated

Using Historical records to indicate past climate change

Historical records can be used to indicate past climate change by analysing paintings, photographs and sequences such as the Grape Harvest data.

Written accounts such as the Greenland sagas are also useful records

Problems in using the above as sources of evidence

The sources did not set out to record climate, and must be used with care They are usually local, and it is difficult to use them to generalise

Tree ring analysis indicating change in climatic conditions

Wide tree rings reflect good growing conditions Narrow tree rings reflect periods of climate stress Long term sequences of tree rings can be obtained from living trees, such as

the Bristlecone pines of the Western USA

Relative merits of tree ring climatic record


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Accuracy of tree ring record is good, but it is localised It is difficult to determine the relative importance of temperature, precipitation,

sunlight and wind

Glacier position indicating climate conditions

Glacier position can indicate climate conditions because some glaciers, such as valley glaciers, grow and shrink in response to climate

Thames Frost Fair, 1683-84, by Thomas Wyke

Evidence of Long Term Climate Change


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Palaeoclimatology Evaluation


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Milankovitch Cycles

Surface temperature of the Earth changes over time because the Earth’s orbit and axis tilt vary over time

These variations lead to changes in the amount and distribution of solar radiation received by the Earth from the sun

Cycle Explanation Effect on ClimateOrbital Shape (Eccentricity)

100,000 years

Eccentricity is the shape of the Earth’s orbit around the sun.

The Eccentricity is a measure of the departure of the ellipse from

circularity. The shape of the Earth’s orbit varies from being

nearly circular (low eccentricity) to being mildly elliptical (high

eccentricity)

Today the Earth experiences a 6% difference in the amount of

solar radiation received in January compared to July. When the Earth’s orbit is more elliptical,

the amount of energy received would vary much more between seasons, in the range of 20-30%

Axial Tilt (Obliquity)

41,000 years

Axial tilt refers to the inclination of the Earth’s axis in relation to its orbit around the sun. The tilt in the Earth’s axis usually varies

by 2.4°C periodically, taking approximately 41,000 years to shift between a tilt of 22.1° and 24.5° and back again. Currently the Earth is tilted as 23.44° and is in its decreasing phase of its

cycle.

When the tilt of the Earth increases, the seasons would be

more extreme – warmer summers and colder winters – as one hemisphere receives more solar radiation than the other. When the tilt decreases, the

seasons are less severe – cooler summers and milder winters – as

solar radiation is distributed more evenly between the

hemispheres.Axial

Precession (Wobble)

21,000 years

Earth does not have a perfect spin about its axis. It wobbles, and this wobble is precession.

Precession refers to the direction the Earth tilts in

relation to its orbit around the sun and this cycle occurs

approx every 21,000 years

The hemisphere which is in summer at perihelion will receive

much of the increase in solar radiation, but that same

hemisphere will be in winter at aphelion and have a colder

winter. The other hemisphere will have a relatively warmer winter

and cooler summer.


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Milankovitch Cycle questions

Evidence to support the theory of Milankovitch Cycles

Ice ages have occurred at regular 100,000 year intervals However, the actual impact of orbital changes on solar radiation amount and

distribution is small – probably no more than enough to change global temperature by 0.5°C

Why do scientists believe that the cycles have a significant influence on our climate?

Milankovitch cycles may just be enough to trigger a major global climate change, but climate mechanisms are needed to sustain it

From evidence of past climate change, ice ages were about 5°C cooler than interglacials

Positive Feedback

Amplify a small change and make it larger E.g. Snow and Ice cover

o Small ↑ in snow and ice dramatically raise surface albedo (reflectivity)

o Consequently, more solar energy is reflected back into space


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o This contributes to further cooling, which might encouraged further

snowfallo This may be how the 0.5°C cooling identified by the Milankovitch is

amplified into a 5°C global cooling

Negative Feedback

Diminish the change and make it smaller E.g. Cloud cover

o As global warming occurs, more evaporation will occur and this may

increase global cloud covero Increasingly cloudy skies could reflect more solar energy back into

space, and diminish the effect of the warming

Solar Output Questions

What are sunspots and is there a pattern to their occurrence?

Sunspots are dark spots that appear on the sun’s surface, caused by intense magnetic storms

There is a well known 11 year sunspot cycle, as well as longer cycles

Relationship between sunspots and global temperatures

The total variation in solar radiation caused by sunspots is about 0.1% A long period with almost no sunspots occurred between 1645 and 1715 –

linked to the little ice age The medieval warm period has been linked to more intense sunspot activity,

although it is unclear whether the medieval warm period was a global event

Evidence that sunspots have influenced the Earth’s climate

Some scientists have suggested that around 20% of 20th century warming may be attributed to solar output variation

Volcanic and cosmic causes

How volcanic activity can alter global climates

Major eruptions eject material into the stratosphere, where high-level winds distribute it around the globe

Volcanoes eject huge volumes of:o Ash

o Sulphur dioxide

o Water vapour

o Carbon dioxide


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High in the atmosphere, sulphur dioxide forms a haze of sulphate aerosols, which reduces the amount of sunlight received at the Earth’s surface

Evidence/events to support this theory

Tambora eruption (1815) ejected 200 million tonnes of sulphur dioxide, resulting in a ‘year without a summer’ in 1816 as global temperatures dipped by 0.4 – 0.7°C

Mt Pinatubo eruption in 1991 ejected 17 million tonnes of sulphur dioxide resulting in temperature falls

Global Dimming

What global dimming is and its influence on the climate

Atmospheric pollutants like soot and sulphur dioxide reflect solar energy back into space and so have a net cooling effect

Evidence to support Global Dimming

Between 1950s and‘ 1990s, the level of solar energy reaching the earth’s surface dropped:

o 9% in Antarcticao 10% in USAo Almost 30% in Russiao 16% in parts of the British Isles

In 1990s, the rate of pan evaporation was falling, but global temperatures were going up

Temperature not the most factor in pan evaporation Sunlight (dominant), humidity and wind Decline in pan evaporation in Russia, US and Eastern Europe – pan on

average evaporated 100mm less of water in the last 30 years Drop of 250 megajules in the decline of sunlight in Russia The drop in evaporation rate, matched exactly the drop in sunlight reported by

Scientists

Causes of global dimming

Energy production causes pollution Burning fuel not only produces GHGs, but it also produces tiny airborne

particles such as sut which causes the haze/smog In North Maldives, Pollution particles were blocking sunlight However, they also turned clouds into giant mirrors reflecting sun back into

space They do this as the polluted air contains particles of sut, ash and sulphur

dioxide, which provided 10x more sites for water droplets to form


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Instead of the water droplets being large and few like they are naturally, they were small and many of them which reflect more light, so consequently, they prevented the heat of the sun getting through.

It was the same over India, China, Pacific, Western Europe, Africa & British Isles

Effects of global dimming

The more reflective clouds could alter the pattern of the worlds rainfall with tragic consequences

Could have been responsible for famine and death on a biblical scale 1984 Ethiopian famine was partly caused by a decade’s long drought across

the Sahel Year after year, the summer rains failed – Scientists blamed overgrazing and

poor land management However, evidence suggests that the cause was global dimming Polluted clouds stopped the heat of the sun getting through, which was

needed to draw the tropical rains northward to the Sahel Pollution from North America and Europe meant that the Africa monsoons

failed which directly killed 1 million people and affected 50 million more

How have humans lessened the sources of particular matter into the atmosphere to reduce global dimming?

Scrubbers in power stations Cayalytic convetors Low sulphur fuels Banned 4* petrol Renewable, sustainable resources (e.g. Wind/Solar) Recycle Improve public transport so there are less cars on the road EU Ban on the manufacturing of filament 100w light bulbs

How reducing global dimming has grave consequences for the future

As we reduce global dimming, we induce global warming In 2003, over 11,000 people died in France due to temperatures rising over

40°C in the first 2 weeks of August Temperatures could rise as double as Climatologists originally thought,

triggering irretrievable changes such as the melting of ice caps which would rise sea levels by 8m

TRF’s would burn down and turn into desert 10,000 billion tonnes of methane would be released into the atmosphere

SECTION 5 – IMPACTS OF CLIMATE CHANGE

Impacts of Climate Change on the world’s oceans


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Role of Oceans and winds in making the Earth habitable

Oceans and winds help to distribute heat from the equator towards the poles Winds blowing across the sea transport heat through the atmosphere and

drive ocean currents towards the poles

Northern flow of the Gulf Stream influence on the UK

AKA North Atlantic Drift It flows north past the west coast of the UK, making the UK’s climate warmer It also influences the growth of sub-tropical plants in the Scilly isles

Thermohaline Circulation

The flow of warm and cold water that circulates around the world’s oceans In the far North Atlantic, the water is cold and very saline, which makes it

denser, heavier and causes it to sink When the water sinks, it draws warmer water in from the ocean surface above This then draws water across the ocean surface from the Tropics Eventually, the movement from the Tropics draw cold water up from the

ocean bottom, ready to be warmed again.

How the global conveyor belt is being disturbed

More freshwater is entering the Arctic Ocean as a result of global warming, which melts the ice and increases rainfall

Melt water lowers the salinity, which decreases the density of the ocean, and slows down the rate at which the ocean sinks

This means that the water further down cannot draw warm water in from the ocean surface above

What could be the result for Europe?

If the Thermohaline circulation stops, January Western Europe temperature would drop by at least 5°C, creating bitter winters

Increasing River Flows

Where does the freshwater come from in the Arctic Ocean?

Mostly comes from the 6 largest Eurasian Arctic Rivers

What effect will increased freshwater flow have in the Arctic?

Could slow down or even shut off the North Atlantic Drift, affecting the thermohaline circulation and cooling the whole of Northern Europe.

Changes in the Polar Oceans


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Carbon Sink

Southern Ocean around Antarctica absorbs CO2 from the atmosphere Cold dense seawater absorbs CO2

These sinks are vital as they absorb excess CO2 slowing down G.W

What researchers have found regarding the CO2 Sink

Researchers have found that CO2 sinks have stayed the same since 1981, even though CO2 emissions have risen by 40%

This may increase CO2 levels in the atmosphere The cause of the sink staying the same is increasing windiness As wind increases, the ocean is stirred up, and CO2 that would normally stay

there is released into the atmosphere

Britain without the Gulf Stream

Impact on the weather

UK would be 5°C cooler in the winter time This would bring the average London December temperature to 2°C

Impact on the environment

UK could eventually experience another ice age if the Gulf Stream shut down This is because the UK should have really cold winters due to its latitude, but

the Gulf Stream warms our winters by 5°C

Consequences on Energy supply

Currently, the gulf stream transports 27,000 times more heat to British shores than all the nations power supplies could provide

This means that the UK would have to open more power stations in order to produce much more energy, resulting in:

o Increased emissions in the atmosphere enhancing global warming

o Our natural resources being used up at a much faster pace

o Extortionate prices of energy (Gas & Electricity)

Consequences on Agriculture

Crops will have reduced growing seasons, as the 5°C temperature boost from the gulf stream allows arable farming to continue passed summer (such as East Anglia).

Indirect Impacts: The Global Impact of Sea Level Rise

Change the basic shape of nations and continents


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Significant tracts of highly productive land will be lost to the oceans Coastal and low-lying communities:

o Threat to the population

o Threat to the infrastructure

Loss of biodiversity as habitats such as:o Coral reefs

o Coastal mangroves

o River Deltas ...

... Disappear under the waves Coral reefs cover 0.2% of the Earth’s surface but hold 25% of the worlds

biodiversity which could hold cures for cancer

Modelling the Rise in Sea Level

Worst case scenario is a 15m rise in sea level by 2100 would put many of the world’s great cities in peril, including New York, London and Tokyo (Financial districts)

Predicting eustatic (changes in the sea level due to changes in the amount of water in the oceans) sea level rise is complex

Most models predict a rise of up to 1m by 2100

Reasons for the huge differences in prediction models

Difficult of estimating future GHG emissions Whether the prediction model adopts a ‘business as usual’ or a sustainable

scenario Difficult to predict the impact of thermal expansion of the oceans and the

contributions of melting of ice sheets and glaciers

Rising sea level notes continued ..

Even if greenhouse gas emissions stabilised, the sea level would continue to rise due to the continued warming of the deep ocean

This is because there is a lag time of about 50 years in the atmosphere Although sea level rise is a worldwide process, the rise will vary depending on

the region This is due to the fact that there will be localised land movements caused by

tectonic movements and isostatic change (movement of land in response to loss or gain of mass) from changing sediments of ice sheet pressure

As the oceans have different temperature, thermal expansion will not be uniform

Modelling of ice sheet and glacial contribution

Modelling the contribution of melting ice sheets and glaciers is complex


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Antarctic Ice sheets may increase in size with climate change, because warming could lead to increased snowfall.

However, recent satellite observations suggest that atmospheric and oceanic warming are leading to a melting of both Greenland and Antarctica


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Impacts of climate change on the Arctic – COMPULSORY CASE STUDY

Impacts on natural systems

Vegetation Shifts

Vegetation zones are predicted to shift Northwards Coniferous forests would encroach tundra and ice deserts This shift will destabilise existing food webs The longer, warmer growing season will be a benefit to Arctic agriculture

although soils will be a limiting factor

Thawing of Permafrost

Up to 40% of total permafrost is expected to thaw, especially in Siberia This will release large quantities of methane In some areas, lakes and rivers will drain as the frozen ground beneath them

thaws Rising river flows could create new wetlands in other places These changes will have an impact on species, particularly freshwater fish

Increasing fires and insects

Global warming will increase forest fires and insect-caused tree death This may have an impact on old-growth forest, a value habitat that is rich in

lichens, mosses, fungi and birds Alien species may invade

Ultraviolent Impacts

Increased UV radiation will reach the Earth’s surface as snow and ice cover is lost

Many freshwater ecosystems are highly sensitive to UV radiation, which destroys Phytoplankton at the base of the marine food chain

Carbon cycle changes

The replacement of Arctic vegetation with more forests will lead to higher primary productivity and increased CO2 uptake

However, methane emissions from warming wetlands and thawing permafrost could counterbalance this positive impact

Other impacts

Increased coastal erosion as thawing permafrost weakens the coast More waves and storms surges as sea ice is lost


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Impacts on animal species

Northward species shifts

Species will shift north with forests Some species are likely to suffer major decline

Marine Species

Marine species dependent on sea ice, including polar bears, seals, walruses and some birds will decline

Some may face extinction Birds like geese will have different migration patterns

Land Species

Land species adapted to the Arctic climate such as vole, arctic fox and snowy owl are at risk

Impacts on Society

The ecological and environmental changes described above will mean:

Loss of hunting culture and decline of food security for indigenous people Need for animals to change their migration routes (geese and reindeer) Decline in northern freshwater fisheries (e.g. threatened arctic char), but

enhanced marine fisheries (arrival of cod and herring due to warmer water) Increasing access for marine shipping, but disruption of land-based transport

because of permafrost thawing Enhanced agriculture and forestry Arctic will become vulnerable to exploitation for oil, gas, fish and other

resources due to large areas of snow and ice melting, exposing new land and open sea

Impacts of climate change on Africa – COMPULSORY CASE STUDY

Africa makes the least contribution to global warming, but is the most vulnerable to climate change

It’s population is dependent on climate-sensitive resources such as local water and ecosystems

It has a limited ability to respond to changing climate because of poverty Prediction: Temperature will rise in Africa overall by 3-4°C above the mean

global change Rainfall is likely to increase in the equatorial region, but decrease to the north

and south of that band

Water Issues


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Life in Africa is regulated by access to water for:o Agriculture

o Domestic use

o Hydroelectric power

Many of the larger rivers are internationally shared (e.g. River Nile), which creates potential for conflict between water users

Demand outstrips supply of water for 25% of Africans Poverty is the key reason why millions have no access to safe and reliable

water supplies Water stress could lead to wars, global migrations and famine

Food insecurity

70% of the population are subsistence farmers Many won’t be able to feed themselves should water supplies dry up, pasture

quality deteriorate or crops fail Increased locust plagues may also threaten food supplies

Natural resources

Poor people living in marginal environments depend directly on wild plants and animals to support their way of life

Loss of biodiversity due to climate change will threaten them

Health

Vector-borne diseases (e.g. Malaria) and water-bounre diseases (e.g. Diarrhoea) could increase with climate change

80% of health services rely on wild plants for remedies, which are under threat

Poverty

Africa’s vulnerability is poverty 2/3 of LEDC’s are located in Africa Problem is made worse by conflicts (e.g. in Darfur in the Sudan between

pastoralists and arable farmers) An unjust trading system forces many countries to sell their exports at a low

price to compare with subsidised European and North American products The burden of unpayable debt means that no money is available for the

mitigation of climate impacts and the introduction of adaptive strategies

Desertification

Major destroyer of grasslands


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It is increased by unreliable or decreasing rainfall

Development of Coastal zones

Movement of environmental refugees from the countryside puts pressure on the coastal zones, especially of north and west Africa

Refugees set up home in shanty towns in cities such as Accra, Freetown and Lagos

60% of Africans live in coastal zones, many of which are at risk of coastal erosion and flooding

The threat from these is likely to increase as a result of rising sea level If the coastal zones were flooded, much of the continent’s infrastructure of

roads, bridges and buildings would also be lost


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Global warming and the future


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A1a Scenario

Technology based on fossil fuels

A1b Scenario

Technology based on non-fossil fuel sources

A1c Scenario

Technology balanced across all energy resources

A2 Scenario

Technological change is very slow

B1 Scenario

Cleaner, more efficient technologies

B2 Scenario

Slow but diverse technological change using wind or solar energy

The concept of tipping point

Tipping point is reached when climate change occurs irreversibly and at an increasing rate

The following are 3 consequences that may already be happening as a result of climate change and global warming:

Rising Sea Levels

Greenpeace estimates that melting of the Arctic ice caps caused a rise in sea level of 10-25cm during the 20th century

In 21st century, they predict further rises of 15-95cm 95cm rise in sea level would

o result in large-scale coral bleaching

o flood huge areas of inhabited land

o threaten the world’s most diverse ecosystem

If the Greenland and west Antarctic ice sheets melt, sea level would rise by 6 metres flooding:

o 1/3 of Florida

o Much of Manhattan

o Most of Eastern England


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o Entire country of Bangladesh

o Almost all of the Netherlands

Shutting down the Atlantic thermohaline Circulation

50% chance that this will shut down within 200 years This would make the land areas of Western Europe colder, even though the

process of global warming would continue to warm the oceans sufficiently to allow further melting of Greenland’s ice sheet

Current melting of Greenland’s ice sheet is causing annual sea level increases of 0.02cm

If global temperatures rise by 2°C more than pre-1750, Greenland’s ice sheet will melt irreversibly

Falling agriculture yields and water shortages

Happening in Africa, Europe, USA & Russia It’s putting the poorest 200 million people in those areas at risk of starvation 2.8 billion people will suffer water shortages for drinking and irrigation

Over the next few decades, there is a possibility that up to 25% of the world’s mammals and 12% of its bird species may be lost to extinction


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SECTION 6 – COPING WITH CLIMATE CHANGE

Mitigation

Reducing the output of GHG’s and increasing the size of GHG sinks (e.g. Rainforest)

Examples of mitigation:o Setting targets to reduce CO2 emissions

o Switching to renewable energy resources

o ‘Capturing’ carbon emissions from power stations and storing them in

spent oil wells


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Adaptation

Changing our lifestyles to cope with a new environment rather than trying to stop climate change

Examples of adaptation:o Managed retreat of coastlines vulnerable to rising sea level

o Developing drought-resistant crops (GM)

o Enlarging existing conservation areas to allow for shifting habitat zones

Human and natural systems may differ in their ability to respond to mitigation and adaptation strategies

Human Systems

For human systems such as the economy, mitigation will involve an upfront cost in reducing GHG emissions.

However, adaptation may allow the cost to be spread over a longer time period

Natural Systems

For natural systems, mitigation could limit damage but adaption strategies could condemn natural environments that cannot adapt to the shift in climate

This would result in species loss and reduced biodiversity as ecosystems become increasingly threatened

Adaptive Capacity to cope

Some countries are better able to implement mitigation and adaptation strategies than others

Wealthier countries have the capital and resources to adapt to climate change But poorer countries in the developing world lack this adaptive capacity to

cope as they already have to overcome a number of ‘non-climatic stresses’, some of which need to be dealt with more urgently, such as:

o Poverty

o Poor infrastructure

o Limited education and skills

o Limited or unequal access to resources

o Conflict and Civil War

o Food Shortages

o Water Stress

o Disease

Scales of Mitigation and Adaptation


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Individual Local National GlobalLifestyles and

consumption choicesLocal government

strategies on planning, recycling, transport etc.

Government policies and national tax

frameworks

International agreements for global

actionUsing reusuable bags

Turn off standby

Washing at 30°C

Car sharing

Public Transport

Energy saving bulbs

Switch off lights

Turn off heating

Loft insulation

Recycling household waste

Hybrid cars (Ethical consumerism)

Composting

Take showers instead of baths

Roadside collections

Park and ride

Education

Bus lanes

Congestion Charges

Cycle lanes

Car pool lanes

Return packaging

Stop supermarkets giving out bags

Walking bus – walking all kids together to

school

Waste charging

Pass laws to set carbon reduction

targets and monitor them

Invest in green technologies

Banning of the manufacturing of

filament lightbulbs

Set targets to reduce carbon emissions by

30% by 2020 and 60% by 2050

USA: Encouraging farmers to grow maize

and other crops to have biofuel

Store CO2 underground

Tax on aviation fuels

Recycling of white goods i.e. fridges

Kyoto agreement

Agenda 21

European emissions trading scheme

Mitigation and Adaptation: Key Players

Top down Strategies

Incentives and schemes to reduce GHG emissions are designed and implemented by central government

E.g. Government legislation and targets are filtered down to regional assemblies and implemented by local councils

Bottom up Strategies

Small lifestyle changes made by all individuals within a community can accumulate into large differences and improvements within the environment

E.g. Individual households who recycle to replace traditional light bulbs with energy saving bulbs

Key Players

Key Players Actions and ResponsibilitiesGovernments Organisation and facilitation of strategies to reduce GHG’s

May include strategies developed as a result of International


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Agreements such as the Kyoto Protocol and Agenda 21 (Think global, act local)

Local government/councils will play a large part in implementing central government strategies

Business (Industry &

TNC)

Government legislation may enforce targets to cut emissions, so companies are required/enforced to consider their impact in the

environment when conducting business With increased public awareness on green issues, businesses are

also keen to show their green credentials and portray a caring attitude toward the environment

Non-Governmenta

l Organisation

s (NGOs)

Environmental charities such as Greenpeace and friends of the Earth can lobby governments to pressure them into changing

legislation to protect the environment They can also advise governments on how to develop and

implement sustainable development strategies Small/local environment groups can promote sustainable

development schemes or work to protect and conserve the environment

E.g. Wildlife groups such as North East Wales Wildlife work to create habitats for Great Crested Newts, plants trees and run

education schemes in local schools to raise environmental awareness in future generations

Individuals All individuals can take responsibility for ensuring that sustainable development strategies can be implemented

E.g. Most urban areas have roadside collections for recyclable waste

Using energy saving bulbs, public transport and being an ethical consumer are also examples of what you can do.

European Emissions Trading Scheme (ETS)

Carbon Offsetting

Carbon offsetting is a credit system, called carbon credits, which aims to reduce greenhouse gas emissions

Carbon credits allow companies to pollute, but at a cost Each credit costs money which polluters have to pay, and is in proportion to

the pollution produced The cost encourages companies to look for other ways of production by

polluting less or not at all

Carbon credit forms

Certified:o International exchanges which aim to cut overall emissions

o Companies and/or countries are given targets, allowing them to pollute

a certain amounto Trading is allowed between those with higher or lower levels than they

need Voluntary


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o Payments or projects which offset emissions with equivalent CO2

savingso Used where people or organisations volunteer to offset the pollution

they create

EMS aim

Cut emissions by placing a limit on the total amount emitted Get polluters to pay for damage they cause by introducing credits for the

GHG’s they emit Create incentives for companies to invest in cleaner technology

Failure of the ETS

Manufacturing companies have been moving out of Europe, thus reducing the demand for carbon credits and causing the price to fall

Companies immediately passed the price of the credits on to their customers, and polluters are not absorbing the price of credits

The lost cost of carbon credits means it is cheaper to buy credits rather than to invest in green technology

Carbon offsetting in action

Shell pumps CO2 from an oil refinery in the Netherlands into 500 greenhouses growing fruit and veg. This avoids annual CO2 emissions of 170,000 tonnes

US TNC Bunge, has built lined, enclosed pools to collect the effluent and capture methane from pigs, which farmers can then use to generate electricity

London Congestion charge is an £8 charge per day to drive in the Central London congestion zone:

o Traffic levels have fell by 15%

o Congestion has fell by 30%

o 60% less disruption to bus services

Kyoto Protocol

Global agreement setting targets for reducing GHG emissions 175 countries have signed up

K.P Mechanisms to reduce GHG emissions

Emissions trading – if countries reduce emissions below targets, they can sell their excess emissions credit to others

MEDC’s can finance low emission projects in LEDC’s and receive credits – includes clean technology and planting trees to create extra carbon sinks

How organisations and governments have cut their emissions

Between 1990 and 2000 the UK reduced its GHG emissions by 12.8%


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In 1998, the BP set itself the target of reducing its GHG emissions by 10% within 12 years – it did this within just 3!

Policies the UK government have introduced to reduce GHG’s

Change from coal to cleaner gas-fired power stations Taxation of petrol more higher to cut demand Agricultural practices programme – feeding strategies for animals to reduce

methane The Climate Change Levy (CCL) – a tax on the use of energy in industry,

commerce and the public sector

Countries against the Kyoto Protocol

USA:o Produced 31.6% of 1990 CO2 emissions

o USA won’t sign it as LEDC countries like China have greater leniency

on emissionso The USA are aiming to reduce carbon intensity of its economy by

having domestic policies in place to combat climate change

Failure

The USA, which produces 25% of global emissions, initially singed up but withdrew following the election of GW Bush

Many developing countries have signed up, but did not commit to actual figures

The EU will not meet its target of 8% reduction Spain, Portugal and Ireland have no made progress Climate scientists believe that the Kyoto targets are too much low, and a 60%

cut is needed by industrialised nations, instead of just 5%

Energy use, efficiency and conservation

Up the Chimney

3 main ways in which amounts of energy in the UK are wasted:o Power Stations – waste 65% of generated heat which goes up the

chimney or is lost when hot water is released into riverso Transmission of electricity over a distance loses energy

o At home, huge quantities of heat are lost through roofs, windows, doors

and walls

Combined Heat and Power in Copenhagen

Uses a heat engine to simultaneously generate both electricity and useful heat


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A CHP system uses a combination of:o Waste heat from electricity production

o Surplus heat from waste incineration

o Geothermal energy

o Bio-fuels

o Small amounts of fossil fuels

It supplies many cities (like Copenhagen) with clean, reliable and affordable heating

CHP success in Denmark

By 2005, annual household heating bills in Copenhagen were €1500 less than if oil had been used for heating

Between 1995 and 2000, the cities annual CO2 emissions dropped from 3.5 million tonnes to 2.5 million

SO2 emissions have also been cut by 33%

Use of nuclear energy

Brought about concern from people mainly due to the:o Radioactivity from Uranium

o Nuclear accidents

o How to deal with nuclear waste

1986 Chernobyl technological accident is what has made UK public deeply suspicious about nuclear energy

Carbon Offsetting

The act of mitigating (reducing) GHG emissions E.g. Asking people or companies to pay extra for air travel

Renewable energy sources for the future

Renewable energy is generated from resources which are naturally replenished and cannot run out (like fossil fuels).

Renewable energy Advantage DisadvantageSolar Relatively maintenance

freeLess available solar

energy near the poles of the Earth

Geothermal Running costs are very low

Can only be used where the crust is thin and hot

rocks are near the surfaceWind Cost of the electricity it

generates is fallingWinds are intermittent and

don’t blow all the timeWave Wave turbines are quiet Wave heights vary


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and do not affect wildlife considerably, resulting in an inconsistent supply of

energyTidal Rise and fall of the tide is

constant and not weather dependent

Present designs of tidal energy do not produce a

lot of electricityHydroelectricity Rivers flow continuously

and thus provides a constant source of energy

Building of large dams flood large areas and

destructs habitatsBiomass Energy can be extracted

from wastesCO2 is released into the atmosphere when the

material is burnt

BedZED – Energy Conservation Project

BedZED housing in South London attempt to be carbon neutral by using heat-efficient natural, recycled or reclaimed materials, which absorb heat during warm spells and release it when cooler

It has its own CHP plant, fed by waste wood from tree surgery that would otherwise become landfill

Windows are double-glazed which cuts heat loss by 50% Loft and cavity wall insulation cuts heat lost via these routes by 33% Low-energy lighting and energy-efficient appliances which also cut back on

carbon emissions Although the above initially cost more, the money is repaid back by energy

saved.


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SECTION 7 – THE CHALLENGE OF GLOBAL HAZARDS FOR THE FUTURE

1.7.1 The Enormity of the Challenge

The enormity of the challenge

Climate change has implications for economic growth, human security and social wellbeing, especially for the poorest of people

The diagram below shows the vicious cycle of problems generated by climate change

Water Shortages

Physical water scarcity: lack of available supplies to meet demand Economic water scarcity: lack of water because of poverty and poor

governance Colombia and Bolivia: disappearance of glaciers means that people can no

longer rely on glacial meltwater as a water source


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Case Study: Nicaragua’s Miskito Indians

Climate change is having a devastating effect on the Miskito Indians They subsist on crops planted on a few hectares of land 1997, 60 bags of rice a hectare could be harvest In 2007, only 7 bags of rice a hectare were harvest The effect of climate change is likely to hit indigenous communities the

hardest Temperatures across central America are expected to rise by 1-3°C and

rainfall will decrease by 25% by 2070 Droughts, hurricanes and unseasonal flooding will increase The Miskito are isolated from modern farming techniques and hampered by

poverty from years of economic neglect and discrimination.

Food Insecurity

Food security means populations having access to enough food for an active, healthy lifestyle

Food insecurity results from:o A lack of available food due to physical factors (e.g. Climate)

o Adequate food available but the community/individual is too poor to

access it

Impacts of global warming on food security


CaseStud

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Higher temperatures stress crops and reduce yields, HOWEVER, they prolong growing seasons and allow a wider range of crops to be grown

Higher concentrations of CO2 speeds plant growth and increases resilience to water stress

Equatorial areas and East Africa will have more rainfall Higher temperatures can also promote the growth of crop pests and diseases In theory, agriculture is adaptable to global warming and there are

techniques that can overcome water stress Therefore, at a global level, food production and thus food security

should not be adversely affected by climate change Studies have shown that crop yields could drop by up to 10% for every 1°C

temperature rise in some areas of Asia Subsistence farmers in Africa will be badly affected by drought and extreme

events, and malnutrition is likely to get worse

The Challenge

How countries cope with climate change will depend on the wealth Poverty leads to poor health, malnutrition and an inability to cope with

extreme weather events These interconnecting factors are summarised by the poverty bomb:

Climate change is just one of the detonators

1.7.2 – Tackling the Challenge

Sustainable Development


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Sustainable development is ‘development that meets the needs of the present without compromising the ability of future to generations to meet their own needs.’

Green strategies

Tree planting – take in carbon dioxide. However, in the first 10 years of its life, a growing tree releases more CO2 than it absorbs

Microhydro – Small scale hydroelectric scheme generating electricity from running water

Wind turbines – generate electricity for the national grid or isolated communities

Biomass – Plant material burned and used to generate electricity and heat. The CO2 released is the same amount as was removed from the atmosphere during the plant’s lifetime

Geothermal – heat from the Earth is used to fuel power plants and heat water Solar – PV panels convert the sun’s radiation into electricity Tidal wave – generate electricity using tidal barrages or wave energy

Under the Kyoto protocol, countries are not prohibited from deforestation, yet they can claim carbon credits for new planting, when in reality releasing large amounts of CO2

Renewable energy schemes examples/case studies

Community Hydropower in Kenya

2 community hydroelectric schemes provide lighting, radio and telecommunications to over 200 households in the remote areas of Mt. Kenya

It saves 42 tonnes of CO2 emissions each year

Sagan Island

Uses a standalone PV power plant that provides electricity to homes, shops, businesses, schools and hospitals.

Diesel-powered generators have been replaced by this scheme

Community based solutions

Community-based solutions work well because they are ‘bottom up’ – developed by local people for local people instead of being imposed by the government

Community-based green strategies

Wolvercote, Oxfordshire


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The following schemes have been implemented to lower the village’s carbon footprint:

o Each road has waste champions who take surplus rubbish to a

recycling centreo Information is circulated on the 10 most effective ways to reduce CO2

emissionso Green transport strategies have been introduced, including car sharing

and promotion of the use of the local buso Cloth bags are available to cut down on plastic bags

Energy Efficiency

Methods of increasing energy efficiency:o Remodelled factors with cleaner industrial processes and optimum

energy useo Redesigned houses with modern boiler systems and full insulation

o Green transport using green technology (hybrid)

o Greener power stations with lower emissions

The Clean Development Mechanism (CDM) allow developed countries to sponsor GHG cutting projects in developing countries in exchange for carbon credits that can be used to meet their own emissions targets

For example, the UK has made huge investments in scrubbers for Chinese power stations


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Edexcel as Geography - Global Challenges