fragile environments

what is a fragile environment

vulnerable to change and may struggle to recover from any changes

examples of fragile environments

arid and semi-arid environments: lack of precipitation and moisture, shallow and infertile soils

tropical rainforest: deforestation and wildfire, infertile soil makes it difficult for plants to re-establish

cold environments: low temperature reduces plants ability to regrow

coral reefs: pollution and damage by tourists

what is desertification

the spread of desert like condition

natural causes of deseritfication

soil erosion: loss of nutrients so plants cant regrow

rainfall patterns: less predictable —> drought

reduced vegetation: nutrients not added to the soil through decomposition of dead organic matter

human causes of desertification

overgrazing: vegetation is gone

over-cultivation: leads to all nutrients in the soil being used

deforestation: removes shade from the soil —> no roots to bind soil together —> soil erosion

population growth: increased pressure on the land

what is deforestation

the felling and clearing of trees

natural causes of deforestation

wildfires

human causes to deforestation

hydropower: building of dams/reservoirs

agriculture: huge areas cleared for plantations or grazing cattle

logging: trees felled for timber

settlements: land cleared for housing

mining: clearance of land to obtain precious minerals

road building

causes of climate change

Milankovitch cycle theory: long-term changes in the Earth’s orbit and position, affecting how much solar radiation the Earth receives

Volcanic eruptions: ash ejected into atmosphere which blocks solar radiation

Sunspot activity: increased activity linked to higher temperatures

Atmospheric dust: asteroids and meteors entering Earth —> dust —> decrease temps

what is the greenhouse effect

greenhouse gases allow short-wave radiation from the Sun through the Earth’s surface. this is absorbed by the atmosphere and Earth’s surface and re-radiated as long-wave radiation. greenhouse gases absorb some of the long-wave radiation (which we feel as heat), stopping it from radiating to space. this maintains Earth’s average temperature and is vital to our survival on Earth

what is the enhanced greenhouse effect

increased amount of greenhouse gases had made it so less long-wave radiation can escape the atmosphere, so more heat is felt, increasing the Earth’s temperatures

statistically how does desertification harm the world

168 countries affected, livelihoods of 2 billion affected, 90% people in developing/emerging countries affected

social impacts of desertification

malnutrition

food shortages: famine if widespread and maintained

migration: due to lack of food

environmental impacts of desertification

reduced plant growth

loss of biodiversity

sedimentation

economic impacts of desertification

decreasing income for farmers as they cannot grow enough crops/raise enough livestock

increased rural poverty

dependence on aid

environmental impacts of deforestation

sedimentation: sediment build up in river beds, increasing flood risk

enhanced greenhouse effect: fewer trees to absorb CO2

monocultures: reduces biodiversity, pollute water sources due to chemical usage

social impacts of deforestation

indigenous communities have less land to sustain their traditional way of life

improved quality of life for some bc increase income and jobs

increased risk of landslides

increased risk of flooding

economic impacts of deforestation

more jobs available in farming, mining etc.

increased income for country through exports

social impacts of climate change

health: increased temp/precipitation can lead to increase spread of disease, heat-waves more frequent (leads to heatstroke, dehydration), stagnant air increases air pollution levels (respiratory diseases increase)

employment: loss of job opportunities —> negative multiplier effect

homes: increased natural disasters will lead to displacement

economic impacts of climate change

agriculture: change crops, reduced water supply, food shortages

employment: decline of tourism, increased risk of natural hazards

settlements: moved

environmental impacts of climate change

sea level rise: warmer temperatures cause water to expand and rise

natural hazards: frequency and severity increases

ecosystem change

response to water shortage from desertification

desalination (expensive)

groundwater from water pumps (don’t over extract)

filtration

other responses to desertification

education: sustainable farming methods

agriculture: crop rotation, reduce herd size

agroforestry: trees remain to provide shade and nutrients

afforestation: tree planting —> prevents soil erosion, provides shade + nutrients

fertilisers, GM crops, HYV

contour stones and terraces: reduce soil erosion by preventing soil from being washed away + ensuring dead organic matter can stay and decompose

deforestation case study

Amazon rainforest in South America covering approx 6.7 km2

international strategies to deforestation case study

UN Forum on Forests

UN sustainable development goals

central amazon conservation complex is a world heritage site protected by international treaties

trade restrictions on endangers species and timer: CITES, ITTA

national strategies to deforestation case study

Brazil’s forest code require landowners to maintain a proportion of their land as forest (50%)

DETER satellite that gave fortnightly reports on forest to stop illegal activity —> 60% decrease in deforestation

Amazonia sustainable landscapes project to restore land

ARPA resulted in 68% increase in protected areas 2004 -2012

local strategies for deforestation

agroforestry

education

marajo project: preserve almost 90,000 hectares of amazon —> tree nursery growing saplings —> new trees

climate change conferences

Earth summit - Rio 1992: stabilise greenhouse gas levels

kyoto protocol 1997: 150 countries agree to reduce greenhouse gas emissions with China + India exempt bc developing

paris agreement 2015: limit global warming to 2 degrees above pre-industrial level, reduce co2 emissions by 60% by 2050

conference of the parties: UN holds annually to discuss climate change

UK response to climate change

responsible for 3% of greenhouse gas emissions, signed up for paris agreement and kyoto protocol

passed climate change act (2008) —> cut emissions + set carbon budgets

adaptation: thames barrier (rising sea levels), Heatwave Plan and Cold weather Plan, reduce water wastage

mitigation: net zero strategy (2021) reduce emissions by 100% by funding electric vehicles, investment of 1.5 bill into green tech research, create 30,000 hectares of woodland. people also encouraged to take their own measures eg. solar panels, energy-efficient appliances