1Y11 Geography

Revision Unit C7Revision Unit C7

Fragile environments

2Y11 Geography

Environmental abuse has serious consequences. Its causes need to be tackled to ensure a more

sustainable future.

Only one key idea

3

Section 1Section 1

• The fragile nature of environments; the concept of sustainability.

• Causes of soil erosion and desertification: drought; population pressure; fuel supply; overgrazing; war; migration.

• Consequences (reduced agricultural output; malnutrition; famine; refugees) and management of soil erosion.

• Case studies: 1. A case study of an area affected by desertification (eg the Sahel); including examples of farming practices to alleviate soil erosion.

4

Section 2Section 2

• Causes of deforestation: commercial timber extraction; agriculture; mining; transport; settlement.

• Consequences: loss of biodiversity; contribution to global warming; economic development.

• Managing rainforests in a sustainable way (eg agro-forestry); the need for international co-operation.

• Case studies: 2. A case study of a threatened tropical rainforest

5

Section 3Section 3

• Causes of global warming and climate change: deforestation; use of fossil fuels; air pollution; agricultural change; CFCs.

• Consequences: rising sea levels; more hazards; ecosystem changes; new employment opportunities; changing settlement patterns; health and well being.

• Managing the causes (anti-pollution legislation, alternative energy sources, international cooperation) and adapting to the consequences of global warming and climate change.

• Case studies: 3. A case study of the threats posed by global warming and climate change to one country

• 4. A case study of attempts to tackle the problems of global warming and climate change.

6

In fragile environment studies …In fragile environment studies …

• Ecological foot print [The amount of land, resources etc we need to support

our lifestyle. To find what we use, add the land to give us enough water, food, energy, raw materials and waste disposal. It has been worked out that 1.8 hectare per person is sustainable – the 4.9 hectares per person in the UK is not]

• And• Sustainability

[Activities and forms of progress that meet the needsneeds of the present without reducing the ability of future generations to meet their needs.]

• keep coming up

7

Blues have an OK footprint– does not look good for the Blues have an OK footprint– does not look good for the rest of us! Red is seriously bad, orange and yellow still rest of us! Red is seriously bad, orange and yellow still

above the world average; both greens are below above the world average; both greens are below average (2.7 hectares per person), but only dark green average (2.7 hectares per person), but only dark green is less than the planet can stand (1.8 hectares) - but is less than the planet can stand (1.8 hectares) - but those which are currently sustainable in the main lack those which are currently sustainable in the main lack

essential services - so what do we do?essential services - so what do we do?

8

Causes of soil erosion/desertificationCauses of soil erosion/desertification

• NaturalNatural• Droughts lead to:• Vegetation loss• Which lead to wind

erosion• Or

• Heavy rains lead to:• Sheet erosion (loss of a

thin layer over a wide area)

• Gully erosion (gouging out deep channels)• All of which lead to

• Degraded soil • And in the case of dry

areas• desertification

• Man-madeMan-made• Activities that lead to increased

erosion: Removal of trees for fuel or for

cultivation Allowing more animals to graze

than the land can support Growing crops without replacing

organic matter Compacting (squashing) soil,

which reduces rain infiltration Increasing population putting

more pressure on the land than it can provide for

• All these reduce the plant roots, which can help hold the soil in place in the face of high winds and heavy rainfall

9

Consequences of soil Consequences of soil erosion/desertificationerosion/desertification

• Consequences:Consequences:• Loss of fertility loss of production famines

migration refugees increases in disaster aid

•Management TechniquesManagement Techniques• Maintaining vegetation cover – this reduced wind erosion, as

the roots bind the soil and make it harder to erode. Also roots reduced run-off and increase infiltration of rainfall.

• Use of trees and hedges reduce the effects of wind erosion and steep slopes can be protected from sheet/gully erosion by the roots encouraging infiltration.

• Reduce water erosion by trapping the water before it runs off, either by bunds, terraces.

• Maintaining water in the soil allows plant growth and helps reduce erosion, e.g zai holes

10

Case study - Sahel - why?Case study - Sahel - why?• Includes countries such as Niger,

Burkina Faso, Mali, Sudan, Ethiopia.• Has a wet (June- September) and

dry season that is hot (av. temps 20 -30 deg C)

• Problems have arisen because reasonable rainfall from 1920 -1960 led to an increasing population and greater use of land for pasture and crops.

• Since 1965, the rainfall has become less reliable and several droughts have occurred. This mean that the land could no longer support the population for the farming, which has led to over grazing, over cropping, removal of trees for fuel and markedly increased desertification.

• There have been widespread droughts and famines across the Sahel.

11

Case study - Sahel - managementCase study - Sahel - management

• 1.The Great Green Wall is starting to be planted across the southern margins of the Sahara, 15km wide, and up to 8,000km long from Mali to Ethiopia. The main aim to stop the Sahara encroaching on the Sahel. But it will reduce soil degradation br educing wind erosion as the roots will hold the soil in place, provide fruit from the trees, leguminous trees will fix nitrogen and there will be a good supply of fuel

• 2. Reducing water run off by installing bunds, lines of stone place across a slope, e.g. they were first tried in Ethiopia. They slow the run-off rate which means the water deposits its load of fertile soil, so that it is not washed away, and the water has the opportunity to soak into the ground.

• 3. Zai holes in Burkina Faso. Pits are dug into which manure/compost is placed. Just as the wet season arrives, seed are planted in the pits. As the rain runs down hill, it flows into the pits, depositing the eroded soil and so stopping it being carried off the land. The compost and the shade of the pit reduces evaporation and so allows the plants to reach maturity.

12

Causes/consequences of Causes/consequences of deforestationdeforestation

• CausesCauses• Logging/timber

extraction • Monoculture farming• Cattle ranching• Road building• Mining• Hydroelectric power• Small scale

agriculture

• ConsequencesConsequences• Loss of plant/animal

diversity• Leaching of the soil

(removal of nutrients from the bare earth by rainfall)

• Gully erosion• Rapid water run-off

causing deposition in rivers

• Native people unable to stay on their land

13

Examples of causes of deforestation Examples of causes of deforestation in the Amazonin the Amazon

• Mining for iron ore at Carajas• Road building e.g. Trans-Amazonian Highway• At the time, shanty town dwellers were encourage to

cut down trees along the highway and establish farms.

• Huge cattle ranches• Soya bean estates• Hydroelectric power e.g. the building of the Belo

Monte Dam , the third biggest power scheme in the world is under way and will result in the flooding of an area 1/3 the size of Wales. It will displace more than 20,000 indigenous people.

14

Sustainable managementSustainable management

• Must respect the environment and the local people• Give people control over their land• Use appropriate technology - cheap, easy to use

and do not damage the environment• Protect biodiversity• Reduce the need/ability to cut down trees, which act

as carbon sinks• Provide the opportunity for sustainable livelihoods

for those people who live there• Ensure a fair quality of life for those who live there -

education, medicine etc

15

Examples of sustainable Examples of sustainable managementmanagement

• 1. Agroforestry - a mixed of perennial and annual plants, which reduces soil erosion, increases soil fertility, increases range of food crops, and by growing fuel crops, reduced the need to cut more of the rain forest.

• 2. Helping indigenous people harvest the fruits of the forest rather than destroy it.

• 3. Licence sustainable logging, in which the number and frequency and methods of removing trees are tightly controlled

• 4. Set up national parks and enable locals to set up eco-tourism

16

Examples from the Amazon regionExamples from the Amazon region

• 1.Inga Tree Alley Cropping: Inga trees are legumes (fix nitrogen) and are fast growing. They are planted in lines and in between annual crops are planted. This is method can be used indefinitely and does not require slash-and-burn movement every few years, thus preserving the rainforest. Annual pruning also provides fuel wood

• 2.Local people are given as concessions harvest Brazil nut, called castañeros These are managed by the Peruvian forest servicein privately managed conservation areas that allow harvesters and their families to make an income from intact forest. Brazil nut harvesters sell the nuts to local shelling factories, which pack and export the product overseas. Thus providing economic benefit to the whole area

• 3. Precious Woods log sustainably in Manaus, where they also provide processing work for more employees, which uses sustainable energy sources to run the factory.

• 4.Amazon Charitable Trust (UK charity) in conjunction with Kew Gardens with the help of local people, are building a 6km tree-top walk way, for use by researchers and eco tourists in North Brazil, close to the Venezuelan border.

17

Section 3Section 3

• Causes of global warming and climate change: deforestation; use of fossil fuels; air pollution; agricultural change; CFCs.

• Consequences: rising sea levels; more hazards; ecosystem changes; new employment opportunities; changing settlement patterns; health and well being.

• Managing the causes (anti-pollution legislation, alternative energy sources, international cooperation) and adapting to the consequences of global warming and climate change.

• Case studies: 3. A case study of the threats posed by global warming and climate change to one country

• 4. A case study of attempts to tackle the problems of global warming and climate change.

18

Causes of climate change ands Causes of climate change ands global warmingglobal warming

• They are based on 2 ideas: adding to the greenhouses gases in the environment.

• Reducing the ability of the environment to naturally regulate these gases.

o Burning fossil fuelso Use of fertilizers which release

greenhouse gaseso Burying waste in landfill which

releases methaneo Rice paddies and cattle

release methane

o Reducing plant cover, forests in particular, which can absorb CO2

19

Consequences of climate change Consequences of climate change ands global warmingands global warming

• The average temperatures world wide are increasing more in some place .e.g. Greenland, and less in others e.g. nearer the equator.

• Changes in average precipitation, e.g. E England and Spain are getting drier, while some places, those that were wet to start with are getting wetter

• The incidence of unusual events have increased - for example the increase in droughts in dry area like the Sahel, increase in disastrous floods , e.g. Pakistan since 2000. Unusually high winds, up to hurricane force in places outside the usual range of these storms

• Ice melt and warming sea are resulting in rising sea levels. Coastal areas, for example the Netherlands, and small islands will be lost as places to live. Inland areas would have to provide homes for more people.

20

Consequences of climate change Consequences of climate change ands global warming - Bangladeshands global warming - Bangladesh

• Rising sea levels are the most pressing consequence. 75% of Bangladesh is below 10 metres above sea level.

• Any cyclones blowing up the Bay of Bengal are funnelled straight over the low lying deltas of the Ganges- Brahmaputra, destroying the protective mangroves of the world heritage site, the Sunder bans and the rich soil of the delta is then not able to grow rice once salt water has infiltrated it.

• The precipitation brought by the Monsoons and the spring melt from the Himalayas is less reliable than before, which means sometimes there are floods when more turns up that expected, while at other times there are equally unexpected droughts.

• There are concerns that there will soon be climate refugees from the areas of the delta as the land.

21

Consequences of climate change Consequences of climate change ands global warmingands global warming

• Other impacts include the spread of diseases such as malaria to places that previously did not experience it as they were not warm enough.

• Some crops will no longer do as well as they did previously as the temperatures and precipitation change.

• However in certain parts of the world, such as the upper latitudes ( N Canada, N Russia), the area of land in which wheat grows could be greater, and the warmer weather and higher CO2 could provide better yields.

• As fossil fuels run out, it may be necessary for more people to be involved in physical labour. There may be new and different ways of achieving ends - any thoughts?

22

Managing the causes/consequences Managing the causes/consequences of climate change/global warmingof climate change/global warming

• International agreements e.g. Kyoto 1997, the various annual COPs (Conference of the Parties)

• Schemes and mechanisms that were set out to permit progress, e.g. REDD+, Clean Development Mechanism (CDM) etc

• Encouragement of alternative, non-fossil fuel energy, energy conservation etc

23

KyotoKyoto• The aim of the treaty was "stabilization of greenhouse gas

concentrations in the atmosphere at a level that would prevent dangerous human interference with the climate system."

• Concepts: Annex 1 countries - developed countries, who were already

contributing more than their fair share, agreed to cut their GHGs by 5% on their 1990 levels by 2012.

Flexibility mechanisms (FM) - ways in which overall GHGs could be cut by methods other than by countries reducing theirs

Joint implementation - one country pays to help another Annex 1 to reduce GHGs and can claim that reduction in their total (FM)

Clean development mechanism (CDM) - as above but for projects in LICs

24

Other thoughtsOther thoughts• REDD+ - Reducing Emissions from Deforestation and forest

Degradation• The idea is that rainforest areas are paid to keep their forests• But this was really hard to manage as it was difficult to decide if

they were giving money to stop something that might not happen anyway.

• Also who would receive it? How would they keep a check on progress.

• Once monitoring had been establish (mostly satellite), then rules needed to be establish so that the people maintaining an area actually received the funds, not government or big business and that the money was put into an area to give sustainable livelihoods, such as some of those mentioned in managing the Amazon Rain forest

25

May 2005: May 2005: 7. Fragile Environments - 7. Fragile Environments - (a) Study Figure 7a, (a) Study Figure 7a,

which contains information about a particular global threat.which contains information about a particular global threat.

• (i) What has been happening to average world temperatures since early in the last century? (1)

• (ii) What term is used to describe this temperature change? (1)• (iii) Name one greenhouse gas. (1)• (iv) (ii) Global warming may cause climate change. Give two ways in

which the climate of a named country could change. (2)• Named country ____

26

(b) Study Figure 7b, which shows how the (b) Study Figure 7b, which shows how the greenhouse effect works.greenhouse effect works.

• (b) Study Figure 7b, which shows how the greenhouse effect works.

• (i) Annotate fig 7b to show how this works(3)

• (ii) Explain how the increase in greenhouse gases may be warming the atmosphere. (4)

• (iii) Describe two sources which are releasing more greenhouse gases into the atmosphere every year.(4)

27

• (c) Any country’s greenhouse gas emissions are affected by the following factors: heating and cooling requirements transport requirements access to renewable sources of energy level of wealth and economic development

• Choose two of these factors, and for each explain how it affects emissions. (4)

• (d) (i) Describe how the Kyoto Agreement aims to slow down global warming. (5)

• (ii) Explain why the USA’s lack of support for the agreement is such a serious problem.(4)