fragile environments

what is a fragile environment?

an environment that is vulnerable to change and may find it difficult to recover from natural or human-induced change

what are the characterisitics of fragile environments?

- tropical rainforests

- coral reefs

- arid and semi-arid environments

- tundra and alpine areas

why are tropical rainforests fragile environments?

- infertile soil

- rapid deforestation

- vulnerability to climate change

why are coral reefs fragile environments?

vulnerability towards:

- ocean warming

- pollution

- tourism

why are arid and semi-arid environments fragile environments?

there is a lack of moisture so plant regeneration is slower

why are tundra and alpine areas fragile environments?

- plant regeneration is limited due to low temperatures

- there is vulnerability to climate change due to habitat changes

where are fragile environments (tropical rainforests) located?

between the tropics

where are fragile environments (coral reefs) located?

oceans between the tropics

where are fragile environments (arid and semi-arid environments) located?

the savannah and desert areas

where are fragile environments (tundra and alpine areas) located?

mountainous areas and areas with high latitudes

what is an ecological footprint?

a measure of the impact a person or community has on the environment, expressed as the amount of land required to sustain their use of natural resources

what is the global average ecological footprint?

2.8 hectares/person

what is the UK average ecological footprint?

5.5 hectares per person

for a country to be sustainable, what must its global footprint be?

1.73 gha

how are ecological footprints calculated?

- in global hectares

- [resources generated by the planet in a year - resources consumed by each individual in a year]

what are the factors used to calculate ecological footprint?

- carbon footprint

- builtup land

- forest

- cropland and pasture

- fisheries

what makes a high ecological footprint?

- high population/population growth/urbanisation

- high consumption of resources

- high use of fossil fuels

- eating more food

what are some countries with high ecological footprints?

- china

- USA

- india

- russia

- brazil

- japan

- indonesia

what are some countries with low ecological footprints?

- tokelau

- dominica

- madagascar

- sri lanka

- chad

- angola

what is desertification?

the process by which fertile land becomes desert

what are the characteristics of a desertified area?

- absence of surface water

- dried up watercourses

- lowered watertable (groundwater)

- increased salt content in soil

- degraded/lost vegetation

- exposed areas of soil

- presence of dry, loose, or infertile soil

what are the causes of desertification?

- droughts

- population pressure

- fuel supply

- overgrazing

- migration

how do droughts cause desertification?

it is a prolonged period of abnormally low rainfall, leading to severe water shortages

how does population pressure cause desertification?

more people means more deforestation as wood is used for resources, and soil is used to build homes & for fuel

how does fuel supply cause desertification?

more people in arid (dry) areas rely on wood as fuel for cooking, and removal of trees leaves the soil exposed

how does overgrazing cause desertification?

livestock eat plants faster than they can regrow, and trampling by animals erodes the soil

how does migration cause desertification?

more people, especially refugees, leads to increased deforestation, as soil is needed to build homes and for fuel

why are some countries more susceptible to desertification?

- climate

- population

- wealth/technology

- industry/agriculture

why are countries more susceptible to desertification? (climate)

droughts are more common in areas where there is little precipitation and higher evaporation (e.g. sub-saharan africa)

why are countries more susceptible to desertification? (population)

higher populations can increase water consumption, as more water is required to meet people's daily needs (e.g. cooking & cleaning)

why are countries more susceptible to desertification? (wealth/technology)

- more developed countries may have more/better access to technology or infrastructure that can store water, reducing desertification

- they may also have the means to source other energy types (e.g. solar energy), reducing the need for wood as a fuel supply, which can lead to desertification

why are countries more susceptible to desertification? (industry/agriculture)

countries that rely on agriculture as a primary industry may be more vulnerable to desertification due to overgrazing and need for water for livestock and irrigation

what are the social impacts of desertification?

- death

- famine/malnutrition

- lack of medicine (plants needed for medicine)

- migration

what are the economic impacts of desertification?

crop failure makes farmers lose income

what are the environmental impacts of desertification?

crops & livestock die

how can technology resolve water shortages in areas affected by desertification?

- desalination

- water pumps

how can technology resolve water shortages in areas affected by desertification using desalination?

- desalination removes the salt from seawater, producing fresh water that is safe for human consumption and irrigation use

- this can increase the country's water supply and therefore reduce water shortages

how can technology resolve water shortages in areas affected by desertification using water pumps?

sources of water in dry areas include groundwater, which can be brought to the surface using pumps

how can education manage desertification?

- Sustainable farming methods including agroforestry and crop rotation help to keep the soil healthy

- Family planning helps reduce population growth

how can agriculture manage desertification?

- breed livestock which are better adapted to drier conditions

- Reduce herd size

- Use high yield varieties (HYV)

- Crop rotation

how can agroforestry manage desertification?

This combines agriculture with forestry, which means some trees remain, which:

- decreases deforestation

- provides shade as well as increasing infiltration and interception, which reduces soil erosion

- provides organic matter from the trees and adds nutrients to the soil

how can afforestation manage desertification?

- The roots help to bind the soil together, reducing soil erosion

- The canopy offers shade to prevent the soil from drying out and reduces soil erosion from rainfall landing directly on the soil

- Nutrients in the soil are replenished by falling leaves and branches

- The trees increase animal and insect activity which helps improve soil quality

e.g. the Great Green Wall across the Sachel

how can fertilisers, high yield varieties (HYV) and genetically modified (GM) crops manage desertification?

Fertilisers, HYV and GM crops can:

- Increase the yield

- Reduce the amount of land cultivated

HYV and GM crops may also be:

- Drought resistant

- Pest resistant

how can contour stones and terraces manage desertification?

they help to reduce soil erosion by:

- Preventing the soil from being blown or washed away

- Increasing infiltration of water and reducing overland flow

- Ensuring that dead organic matter stays in one place and can decompose, adding nutrients to the soil

what is deforestation?

the cutting down of trees

- can be due to many reasons, but usually for human use

what are the characteristics of a rainforest?

- heavy rainfall

- hot and humid

- infertile soil

- very high biodiversity

what are the causes of deforestation?

- logging (C.T.E)

- agriculture (farming/palm oil)

- transport/road construction

- settlement

- mining/mineral extraction

- dams/hydroelectric power

how does logging cause deforestation?

- Logging is the most widely reported cause of deforestation in rainforests

- The timber is harvested for use as furniture, paper, doors and household utensils

- About half of the wood is used for fuelwood.

- Many companies argue that the use selective logging, but they also damage other trees and the ecosystem in the process.

- In Indonesia, the logging and burning of land has been rapid, with 2 million hectares of forest being lost per year.

how does agriculture cause deforestation?

- Around 80% of Brazil’s deforested areas are used for cattle ranching

- The farmers make a good profit, which is great for the local economy.

- Palm oil is one of the most popular cash crops in developing countries and boosts their economies considerably, allowing for faster development

- It is used in about 50% of all products sold in supermarkets and can also be used for biofuel.

- Indonesia has the world’s largest palm oil plantations, providing employment for 3 million people.

- However, before a plantation can be created, huge areas of forest are cut down and burnt to clear the area, with the resulting ash being spread over the land as fertiliser.

how does transport/road construction cause deforestation?

- Rainforest wilderness is being destroyed by huge road-building projects, which are (arguably) vital to help poor communities gain a better standard of living, as deforestation makes more land available for housing and urban areas.

- e.g. Trans Amazonian Highway

how does settlement cause deforestation?

- Deforestation makes more land available for housing and urban areas generally.

- This can include for hotels and the tourism industry.

- Unsustainable mass tourism results in the building of hotels in vulnerable areas, resulting in deforestation for the resort and for roads to reach it, as well as pollution and waste from the resort itself, once it is up and running.

how does mining/mineral extraction cause deforestation?

- Gold, copper, diamonds and other precious metals are found in rainforests around the world

- In order to mine for these commodities, forests often end up being removed.

- In Peru, silver and zinc are being produced, which gives the country money to improve its infrastructure, such as electricity and roads.

how does the building of dams/hydroelectric power cause deforestation?

- Dam building, for water resources and HEP leads to thousands of people being forced to move from their land and large swathes of forest are flooded upstream of the dam.

- e.g. in Borneo (where 12 dams have been planned), the dams are likely to disrupt the natural river system, holding silt back in the dam, which will impact soil fertility downstream, disrupting the small-scale agriculture carried out by the local communities.

why are areas not equally susceptible to deforestation?

- climate/location

- population density

- economic development

- government policies

why are areas not equally susceptible to deforestation due to climate/location?

the Taiga and the Tropics have more trees, so they are more susceptible to deforestation

why are areas not equally susceptible to deforestation due to population density?

more people need more wood for building etc, leading to more deforestation

why are areas not equally susceptible to deforestation due to economic development?

countries where most jobs are in the primary industry will rely more on deforestation and farming

why are areas not equally susceptible to deforestation due to government policies?

countries whose government is more concerned about the environment are less susceptible to deforestation

what are the social impacts of deforestation?

- indigenous tribes have been forced out of rainforests by road construction, logging, mine building, & plantations/ranches/reservoirs

- disputes arise because people have conflicting views on deforestation e.g. environmental activists and people who dont care

what are the economic impacts of deforestation?

- more jobs are made available from mining, forestry, agriculture and HEP

- increased income from exported goods

- almost 1/4 of brazils gdp comes from activities in the deforested areas of the Amazon

what are the environmental impacts of deforestation?

- river pollution - the mercury used in gold mining enters rivers along with runoff from soil erosion, leading to loss of aquatic animals

- loss of biodiversity - deforestation destroys habitats and endangers species

- there is more co2 in the air as tree canopies absorb co2 and burning of wood also releases co2, contributing to the greenhouse effect and climate change

what are the different approaches to sustainably using and managing rainforests to limit deforestation?

- protection of forests - e.g. National Park

- carefully planned and controlled logging & selective logging

- replanting forest areas that have been felled (cut down)

- restricting logging licenses

what is global climate change?

the long term change in the average weather/atmospheric conditions of the earth

what is the greenhouse effect?

a natural process where greenhouse gases in the earth's atmosphere trap heat from the sun, allowing the planet to maintain a suitable temp. for life

however, human activities are increasing greenhouse gas levels in the atmosphere, leading to the 'enhanced greenhouse effect' and global warming

what are the natural causes of climate change?

- milankovitch cycles (the change in shape of the earth's orbit around the sun)

- volcanic activity

- solar energy changes

- the natural greenhouse effect

how do milankovitch cycles cause climate change?

it leads to natural warming and cooling periods on earth because the earths orbit around the sun varies - stretch,tilt,wobble

how does volcanic activity cause climate change?

large eruptions cause ash/dust clouds which can cool the earths surface as some of the sun's rays are reflected back out to space by the ash particles

- e.g. the earth cooled by around 0.5C after Mount Pinatubo erupted in 1991

how do solar energy changes cause climate change?

increases in the sun's output leads to higher temps. and vice versa

how does the natural greenhouse effect cause climate change?

when heat is trapped by greenhouse gases it radiates heat back toward earth, making it warmer

what are the human causes of climate change?

- burning fossil fuels

- farming

- cement production

- deforestation

how does burning fossil fuels cause climate change?

co2 is released when they are burnt

how does farming cause climate change?

- livestock (esp. cows) produce a lot of methane

- flooded fields of rice paddies emit methane, contributing to global warming

how does cement production cause climate change?

cement is made from limestone, which contains carbon, so when cement is produced, lots of co2 is released

how does deforestation cause climate change?

- plants take in co2, so when plants are cut down, less co2 is removed

- burning trees as fuel also releases co2

why do some people/countries produce more greenhouse gases than others?

increased wealth leads to:

- more car ownership burning petrol, leading to more co2

- more consumption of meat and dairy, leading to more methane

- greater use of energy and electricity, leading to more co2

what causes co2 and methane in the atmosphere?

- deforestation

- fossil fuels

- fire

- transport

- electricity generation & consumption

- building & construction

how does deforestation cause co2 and methane in the atmosphere?

as plants grow, they use co2 to build and maintain their biomass, so deforestation increases co2 levels

how do fossil fuels cause co2 and methane in the atmosphere?

burning fossil fuels transfers carbon to the atmosphere, increasing co2 levels

how does fire cause co2 and methane in the atmosphere?

fire adds co2 to the atmosphere

how does transport cause co2 and methane in the atmosphere?

burning fuel in cars for petrol releases co2

how does electricity generation & consumption cause co2 and methane in the atmosphere?

burning fuels for electricity releases co2

how does building & construction cause co2 and methane in the atmosphere?

this leads to deforestation and higher consumption of energy like fossil fuels

what are the positive feedback cycles of climate change?

global temps. rise -> ice melts -> more dark surfaces (dark oceans instead of white ice)

what is a positive feedback cycle?

a series of events where an initial change in a system leads to further changes that amplify the original change, creating a continuous cycle that progressively intensifies the effect

- this often leads to instability within the system

what is a tipping point?

the threshold that when exceeded, significant change within a system is triggered

why might data from climate change not be accurate?

- technology that accurately measures climate change has only recently been developed, so it is hard to detect concrete patterns and trends

- only some places in the world measure climate data, so the data may not be reflective for patterns in the whole world

what are the negative environmental effects of climate change?

- warmer temps. are causing glaciers shrink and ice sheets to melt (e.g. in the antarctic & greenland), causing sea levels to rise

- sea levels rising will lead to more flooding and coastal erosion, destroying habitats

- sea ice is shrinking, destroying habitats

- species declining (e.g. the great barrier reef is suffering from bleaching, killing marine life)

- this decreases biodiversity

- global warming is also changing precipitation patterns

what are the negative effects that climate change has on people?

• affects low-lying costal areas; becomes uninhabitable which leads to mitigation and overcrowding in other areas

• some areas are struggling water availability caused by changing rainfall patterns; leads to political tensions

• decreases crop yield e.g. Argentina - leads to malnutrition and famine esp. in areas with lower altitudes

what is mitigation?

mitigation strategies aim to reduce the impacts of climate change

what are some mitigation strategies?

• carbon capture

• international agreements

• planting trees

• alternative energy production e.g. renewable energy

Case study: UK has more offshore wind farms

what is adaptation?

adaptation strategies aim to respond to the effects of climate change

what are some adaptation strategies?

• changing agricultural systems e.g. using biotechnology to create new crop varieties which are more resistant to extreme weather events

Case Study: Kenya- drought-resistant millet

• managing water supply - installing water metres, recycle and collect rainwater/waste water

• coping with sea levels

Case Study: Thames Barrier in London can be closed to prevent flooding in the city

Case Study 2: Bangladesh people are building houses on embankments