emvironmental risks 3.7 Flashcards
Soil erosion
Soil erosion is the wearing away of the topsoil by the action of wind or water
It is a natural process which is made worse by human activities which leave the soil exposed to wind and water
causes of soil erosion
-deforestation
-overgrazing
-over cultivaion
-population increase
-over abstraction of groundwater
-human induced climate change
salinisation
Salinisation is also an increasing issue in many semi-arid areas
Occurs when high rates of evaporation lead to groundwater being drawn to the surface
When the groundwater evaporates salts are left in or on the topsoil
These salts make the land toxic to many crops and so the land can no longer be used
natural causes of desertification
-soil erosion, lead to loss of nutrients, plants cannot grow
-less predictable rainfall leads to droight and vegetation dying
-intense rainfall leads to increased surface run off
-reduced vegetation mean that fewer nutrients are added to the soil
human causes of desertification
-over grazing, reduces the amount of vegetation so the soil is bare and no nutrients are added to the soil
-over cultivation. crops take up all the remaining nutrients
-deforestation, decreases; nutrients added to the soil, infiltration, interception, number of roots which bind to the soil
-population growth
agroforestry
This combines agriculture with forestry, which means some trees remain, which
Decreases deforestation
It 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
afforestation
Tree planting, such as the Great Green Wall across the Sahel, helps to reverse desertification in several ways:
The roots help to bind the soil together, reducing soil erosion
The canopy offers shade, helping to prevent the soil from drying out and also reducing soil erosion from rainfall landing directly on the soil
Nutrients in the soil are replaced by falling leaves and branches
The trees increase animal and insect activity, which helps improve soil quality
contour stones and terraces
These 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
education
Sustainable farming methods, including agroforestry and crop rotation, help to keep the soil healthy
Family planning to reduce population growth
air pollution causes
motor vehicles powered by petrol/diesel
factories
power stations burning fossil fuels
forest fires
open fires and wood-burning stoves
air pollution impacts
There are many impacts of air pollution, including:
It contributes to 12% of annual deaths worldwide
This is highest in middle- and low-income countries
Indoor pollution in LEDCs due to the use of fuelwood for cooking and heating increases health impacts
Increased release of greenhouse gases contributes to the enhanced greenhouse effect
water pollution causes
fuel spillages
agricultural waste/pesticides/fertilisers
leaching of toxic materials from waste
sewage disposal into rivers and seas
boat oil/diesel waste
deforestation leads to soil erosion and soil being washed into waterways
plastic waste—becoming microplastics
radioactive waste
water pollution impacts
Reduction in available clean drinking water
Reduction in crop yields and death of crops
Damage to ecosystems and habitats
Death of wildlife
Abnormalities in fish and other sea/water wildlife
Accumulation of toxins in the food chain
Spread of diseases such as cholera and typhoid
land pollution causes
solid waste—from domestic and industrial sources
agricultural waste/pesticides/fertilisers
mining waste - toxic heavy metals such as mercury
demolition and construction waste
land polluion impacts
reduced crop yields
leaching of toxins into the water system
pollutants entering the food chain through plants
ecosystem and habitat destruction
economic losses
visual pollution causes
buildings
energy production - power stations, wind turbines
signs and advertising (billboards with lights)
power lines and structures (pylons, mobile phone masts)
waste
visual pollution impacts
a lower quality of life
stress and anxiety
an impact on the economy
distraction - may lead to accidents
noise pollution causes
transport - roads and airports
construction
industry
night activities—nightclubs, bars
energy production - wind turbines, power stations
noise pollution impacts
hearing loss
scaring wildlife—affects feeding and breeding
sleep disturbance
stress and anxiety
contributing to high blood pressure, heart disease
negative effects on child development
sustainable managment of air pollution
Improved public transport and electric vehicles to reduce transport emissions
Increase the use of renewable energy
Congestion charges in large cities such as London to reduce the use of vehicles
Use of unleaded and low-sulphur fuels
Filters on the chimneys of factories and power stations
Smokeless fuels
International agreements (Paris and Kyoto) regarding gas emissions
Reduced use of energy to reduce the need for fossil fuel power stations
sustainabale management of water pollution
Regulations on the amounts of fertilisers and pesticides used
Increased use of water treatment works to treat sewage waste before releasing it back into the waterways
Education regarding the disposal of plastic waste
Fines for factories/industries discharging waste into waterways
sustainable management in land pollution
Recycling and reuse of materials to reduce the amount of waste
Separation of waste into compostable and recyclable waste by householders
Regulations regarding the use of fertilisers and pesticides
Targets set for local councils and authorities regarding recycling
sustainable management in visual pollution
Reduction in the number of billboards/advertising boards that can be in an area
Planting of trees to screen roads/quarries and other developments
Buildings that blend into the environment
Disguising mobile phone masts
Putting electrical and telephone cables underground
Regular waste collection and provision of bins
sustainale management in noise pollution
Limiting hours of work for construction sites and factories
Noise barriers between houses and main roads
Siting activities away from population centres
Government actions to conserve resources
Congestion charges within cities to reduce traffic
Investment in renewable energy sources
Grants for solar panels
Gas emission limits for vehicles
Charging points for electrical vehicles
Increase in tax on petrol and diesel
Individual actions to conserve resources
Use public transport
Walk or cycle
Reduce, reuse and recycle
Buy energy-efficient appliances
Invest in double glazing and insulation
Wash clothes less often and at lower temperatures
Compost food and garden waste
case study
Pearl River Delta, China
case study location
Located in South-East China, the Pearl River is China’s third longest river
The Pearl River enters the South China Sea to the southeast of Guangzhou
The area surrounding where the river enters the sea is the Pearl River Delta
The greenhouse effect
The greenhouse effect is essential to the survival of life on Earth
Greenhouse gases in the atmosphere allow short-wave radiation from the sun through to the Earth’s surface
This is then radiated back into the atmosphere as long-wave radiation (heat)
The greenhouse gases absorb some of the long-wave radiation (heat) and stop it from radiating out into space
This maintains the Earth’s average temperature
Without the greenhouse effect, the average temperature would be -18°C
Natural causes of climate change
-milankovitch cycles
-volcanic eruptions
-sunspot activity
-atmospheric dust
impact of enahnce greenhouse effect on health
-increased temperatures and lack of precipitation may lead to spread of diseases
-heat waves may become more frequent
-Heat stroke, dehydration and sunburn increase during heat waves
-Stagnant air during heat waves increases air pollution levels:
Respiratory diseases increase and those suffering from respiratory illnesses such as asthma may be more affected
-Increased temperatures negatively affect people with cardiopulmonary diseases
-Diets may be restricted by food shortages leading to malnutrition and famine
impact of enhanced greenhouse effect on home and settlements
Increased flooding due to sea level rise and increased frequency and severity of storms will lead to the displacement of large numbers of people
Settlements in low-lying areas may have to be abandoned or need additional defences against sea level rise
Moving settlements or improving flood defences will be costly
impactof enhanced greenhouse effecrs on agriculture
Farmers may need to change the crop they grow if climate conditions become unsuitable
Coastal flooding may lead to salt intrusion
Reduced availability of water will mean that irrigation is limited or impossible
Food shortages will lead to malnutrition and famine
impact of enhanced greenhouse effect on employment
Job opportunities may change or decrease because:
Tourism may decline in some areas; for example ski resorts may close due to the lack of reliable snow
Coastal resorts may be at risk of flooding leading to the closure
Farmers may have to change the crop they grow or livestock they raise or leave farming
In some areas, agriculture may decline due to rising temperatures or changing rainfall patterns
impact of enhanced greenhouse effect on ecosystem change
-The location of biomes may shift to the north (Northern Hemisphere) and south (Southern Hemisphere) as they rely on specific climate conditions
-Increasing sea temperatures and ocean acidification have resulted in coral bleaching
-Migration and behaviour patterns of animals affected by changing temperatures
-Melting of ice caps/glaciers leading to changing ocean currents
-Mangrove swamps and coral reefs are threatened by rising sea levels
-Loss of habitats through flooding, drought and wildfires
-Food webs breaking as species numbers are reduced and food sources are decreased
-Loss of plants and vegetation
impact of enhanced greenhouse effect on natural hazards
-Changes in climate patterns are likely to increase the frequency and severity of storms
-The frequency and length of droughts are increasing
-Dry conditions lead to the increased risk of wildfires
-Rising sea levels together with increased storms lead to increased flooding risk
Reducing emissions
reducing deforestation
increasing afforestation
improving energy efficiency in industry and domestic appliances
reducing emissions from industry
improving public transport
electric vehicles
use of renewable energy and nuclear power
desertification
the spread of desert like conditions into semi-arid areas
