Transcript Y11GeUC7 Fragile PPwk26 - the InterHigh IGCSE Geography

Revision Unit C7
Fragile environments
Y11 Geography
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Only one key idea
Environmental abuse has serious
consequences. Its causes need
to be tackled to ensure a more
sustainable future.
Y11 Geography
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Section 1
• The fragile nature of environments; the concept of
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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.
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Section 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 cooperation.
• Case studies: 2. A case study of a threatened
tropical rainforest
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Section 3
• Causes of global warming and climate change: deforestation;
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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.
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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]
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• Sustainability
 [Activities and forms of progress that meet the needs of
the present without reducing the ability of future
generations to meet their needs.]
• keep coming up
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Blues have an OK footprint– does not look good for the
rest of us! Red is seriously bad, orange and yellow still
above the world average; both greens are below
average (2.7 hectares per person), but only dark green
is less than the planet can stand (1.8 hectares) - but
those which are currently sustainable in the main lack
essential services - so what do we do?
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Causes of soil erosion/desertification
• Natural
• Droughts lead to:
• Vegetation loss
• Which lead to wind
erosion
• Man-made
• Activities that lead to increased
• Or
• Heavy rains lead to:
• Sheet erosion (loss of a
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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
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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
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Consequences of soil
erosion/desertification
• Consequences:
• Loss of fertility loss of production famines
migration refugees  increases in disaster aid
• Management 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
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Case study - Sahel - why?
• Includes countries such as Niger,
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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
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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.
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Case 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.
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Causes/consequences of
deforestation
• Causes
• Consequences
• Logging/timber
• Loss of plant/animal
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extraction
Monoculture farming
Cattle ranching
Road building
Mining
Hydroelectric power
Small scale
agriculture
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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
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Examples of causes of deforestation
in the Amazon
• Mining for iron ore at Carajas
• Road building e.g. Trans-Amazonian Highway
• At the time, shanty town dwellers were encourage to
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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.
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Sustainable management
• Must respect the environment and the local people
• Give people control over their land
• Use appropriate technology - cheap, easy to use
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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
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Examples of sustainable
management
• 1. Agroforestry - a mixed of perennial and annual
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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
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Examples 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.
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Section 3
• Causes of global warming and climate change: deforestation;
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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.
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Causes of climate change ands
global warming
• They are based on 2 ideas: adding to the greenhouses
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gases in the environment.
Reducing the ability of the environment to naturally regulate
these gases.
o Burning fossil fuels
o Use of fertilizers which release
greenhouse gases
o Burying waste in landfill which
releases methane
o Rice paddies and cattle
release methane
o Reducing plant
cover, forests in
particular, which
can absorb CO2
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Consequences of climate change
ands global warming
• The average temperatures world wide are increasing more
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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.
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Consequences of climate change
ands global warming - Bangladesh
• Rising sea levels are the most pressing consequence. 75%
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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 GangesBrahmaputra, 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.
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Consequences of climate change
ands global warming
• Other impacts include the spread of diseases such as
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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?
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Managing the causes/consequences
of 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
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Kyoto
• The aim of the treaty was "stabilization of greenhouse gas
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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
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Other thoughts
• REDD+ - Reducing Emissions from Deforestation and forest
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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
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May 2005: 7. Fragile Environments - (a) Study Figure 7a,
which contains information about a particular global threat.
• (i) What has been happening to average world temperatures since early
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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 ____
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(b) Study Figure 7b, which shows how the
greenhouse effect works.
• (b) Study Figure 7b,
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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)
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• (c) Any country’s greenhouse gas emissions are
affected by the following factors:
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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
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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)
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