Increasing Demand for Natural Resources (OCR GCSE Geography B)
Revision Note
Written by: Bridgette Barrett
Reviewed by: Jenna Quinn
Factors Increasing Demand
The demand for resources is increasing rapidly
Demand is outstripping supply in many areas of the world for food, water, and energy
There are a number of reasons for this:
Population growth
Economic development
Lack of supply
Population growth
In 2022 the world's population increased to over 8 billion people
World population total and growth rate
The world population is predicted to reach 9.2 billion by 2040
This is a rapid increase since the early 1900s when the population was below 2 billion people
The more people there are, the higher the demands for food, energy, and water
Economic development
As countries develop, the people have increased incomes
This increases the demand for consumer goods, energy and water
Increased demand for products also leads to more industry to produce the goods, both factories and agriculture.
These industries also require energy and water, further increasing the demand
Lack of supply
Many natural resources are finite - they are being used faster than they can be replenished:
Fossil fuels (coal, oil, and gas)
Freshwater
Minerals such as copper, iron,
Even for those resources which are not finite it may be difficult to meet the demand
There is a decreasing amount of land available for food growth due to expanding settlements, the use of land for growing biofuels and desertification
Exploitation of Ecosystems
Environments and ecosystems are used and modified by humans
The scale of this has increased as the demand for resources rises
Food supply
As countries develop the impact of farming systems on the environment increases
In LIDCs subsistence farming dominates
In ACs commercial farming dominates
Commercial farming relies on improvements in technology to produce high yields which can be sold for profit. These technologies include:
Mechanisation - the use of tractors, combine harvesters
Artificial chemicals - pesticides, herbicides, and fertilisers
Greenhouses - using artificial heat and light
Commercial fishing also uses improvements in technology to catch large quantities of fish
Trawlers use large nets which are dragged along the seabed this is called bottom trawling
Blast or dynamite fishing uses explosives to stun or kill large quantities of fish in an area
These lead to overfishing which is when so many fish are caught the fish population is unable to repopulate fast enough
Impacts of Farming Systems
All farming systems impact the ecosystem in which they are located
Some have more impact than others such as:
Monocultures which reduce diversity because the animals have no access to a wide range of foods
Soil nutrients are depleted because nutrient cycling becomes dependent on fertilisers added to the soil, this may be natural (manure) or artificial fertilisers
When the ecosystem is modified with inputs of seed, fertiliser, pesticides, herbicides, and the use of machines
Fertilisers, pesticides, and herbicides pollute the water and soil
Food webs are reduced due to lower biodiversity levels
Removal of trees and hedgerows to create larger fields reduces the amount of biomass
Soil erosion increases because the soil is exposed to the wind and rain
Worked Example
Describe two ways in which the mechanisation of farming has impacted on ecosystems
(2 marks)
Answer
Hedges have been removed from fields so that tractors can be more easily used in fields [1].
(Spraying) pesticides which can kill insects [1].
Farms take up larger areas providing less food for wildlife/ reducing biodiversity [1].
The use of tractors will produce more carbon dioxide which can lead to climate change [1].
(Sprayed) Fertilisers can run off the fields into rivers/ lead to eutrophication [1].
Combine harvesters can compact soil leading to increased soil erosion [1].
Deforestation to create fields will reduce habitats for animals [1].
Energy supply
Fuelwood and fossil fuels are the main sources of energy across the world
Fuelwood - deforestation
It is estimated that more than between 2 and 3 billion people across the world rely on fuelwood for heating and cooking usually because they do not have access to other forms of energy
Approximately 13% of the world's population does not have access to electricity
This is mostly an issue in LIDCs within Sub-Saharan Africa and Asia
The use of fuelwood leads to deforestation
The amount of wood cut each year is greater than the rate of replanting and regrowth
This impacts on ecosystems, reducing biodiversity because plants and animal habitats are destroyed
Fossil fuels - mining
Over 80% of the world's energy is provided by fossil fuels
These fuels, oil, gas, and coal, are obtained by mining and drilling
This leads to deforestation as areas have to be cleared for buildings and roads
Habitats are destroyed, which impacts the ecosystem
Waste material leaches into the soil and water sources, leading to soil and water pollution
Water supply
The two main ways in which the demand for water is met is via:
Reservoirs
Water transfer schemes
Reservoirs
Reservoirs are created to store water
A dam is placed across a river, and this causes the land behind the dam to flood creating the reservoir
Over 60% of the world's major rivers are impacted by dam construction
The impact of a dam and reservoir occurs both upstream and downstream
Upstream:
The flooding of the valley destroys habitats
The water may be polluted by any housing or industry which was located in the area flooded
Fish migration routes may be blocked, and fish may be disorientated
The depth of water reduces oxygen levels because the water is too deep for photosynthesis and the mixing of air and water at the surface
The lack of oxygen reduces the biodiversity
Downstream
Water lacking oxygen enters the river, this can affect fish and other wildlife
Sediment is trapped by the dam, which means less sediment is deposited downstream which affects the fertility of the floodplain and the supply of sediment to deltas
Water transfer schemes
Water transfer schemes are found in many parts of the world
Water is transferred from one area to another using pipes, canals, and rivers
This can affect the ecosystems in both areas. Impacts include:
Over-abstraction of water from the donor area which reduces the availability of water in that ecosystem
Water pollution may spread over a greater area
Ecosystems and food webs may be disrupted
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