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Conversely, the environment affects us in many different ways as well. A simple example is the way we change our clothes in response to cold or hot weather. In this section we will introduce some of the ways in which humans influence their environment and how the environment influences us, both positively and negatively. A good climate, accessible clean water, fertile soil, etc.
However, harsh environments, such as a very hot climate, limited water and infertile land, make it more difficult for people to survive. We are also affected by major environmental events such as earthquakes, floods and drought that damage homes, property and agriculture. These can lead to the displacement of people and can cause injury, loss of life and destruction of livelihoods. They can also damage water sources and pipelines, causing water contamination and spreading waterborne diseases. In Study Session 10 you will learn more about the effects of floods and droughts.
Our relationship with the environment changed with industrialisation, which began in the 18th century in the UK, shortly followed by elsewhere in Europe and North America, and then spreading across the world. Prior to industrialisation, the impacts of human activity were not very significant because the technologies used were not capable of modifying the environment on a large scale.
People at that time lived in agricultural societies using hand tools and simple technologies with limited environmental impact Figure 1.
Industrialisation has allowed for a greater exploitation of resources. For example, we now use powerful chainsaws to cut down trees and industrially produced chemical fertilisers and pesticides for crop production. These changes have rapidly increased the human impact on the environment.
The links between human activity and the environment are complex and varied, but can be grouped into two main types of activity:. We use many different types of natural resources in our daily lives. We depend on food and water for survival and we need energy for many different purposes, from domestic cooking through to major industrial processes.
Our growing population
Our clothes, transport, buildings, tools and all other items we use require many different resources for their production. Think about the resources that have been used to produce a notebook of the type you may be using right now as you study this Module. Manufacturing the paper needed raw materials of wood and water as well as energy for the production process. The trees that supplied the wood required soil, water and land to grow on. There may be ink or metal staples or other components in your notebook that were made from other types of resources.
Our need for resources is vast and it is growing as the population increases and consumption per person increases with socio-economic progress. Depletion of natural resources by extraction and exploitation is especially of concern for non-renewable resources see Box 1. The resources we use can be classified as renewable or non-renewable.
The basic difference between the two is the rate at which they are regenerated back into a usable form, relative to the rate at which they are used by humans. Non-renewable resources cannot be replenished by natural means as quickly as the rate at which they are consumed.
Population and environment: a global challenge - Curious
They include minerals and fossil fuels such as oil, coal and gas, which are formed over millions of years by natural processes from decayed plants and animals. Renewable resources are constantly available or regenerated over short timescales by natural processes.
Some renewable resources, such as solar energy, are not modified or used up by humans. Others, such as water, are altered when we use them and can be over-exploited or damaged such that the resource is no longer available for use. Can you suggest some other renewable resources that are replenished naturally but need to be managed properly and not over-exploited? You may have suggested examples such as wood, animals and plants. For example, trees are cut down to provide wood and they will regrow but they need time to regenerate.
Over that time, the world population increased from 4. Figure 1. The graph shows the extraction of four types of natural resource: fossil fuels, biomass, metals and minerals. Biomass means biological material derived from living organisms such as crops, livestock, fish, wood, etc. Metals are used in the manufacture of a wide range of goods — from cars to computers. Minerals are used in industrial processes and in construction to build our houses and roads.
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Both metals and minerals are obtained from rocks that have been mined and are then processed in various ways to extract the valuable resource. Look at Figure 1. What is the pattern of natural resource extraction from to and what do you think could be the reason? Natural resource extraction shows a steady increase from to , with the greatest amount extracted in the most recent year The most likely reason is the increase in the global population in this period; more people need more resources.
It could also be the case that the amount used by individuals and by wider society is increasing due to changes in behaviour and levels of consumption.
Advances in technology have increased natural resource exploitation by enabling people to reach new resources and to exploit more resources per capita per person. For example, fishermen who use traditional technologies such as small boats are limited in the number of fish they can catch. Modern industrial fishing fleets use very large ships that cover huge areas of ocean at greater depths to catch many more fish. This can lead to overfishing, which means catching fish at a faster rate than they can reproduce. Fish are a renewable resource. However, if fishing is not managed properly and more fish are taken from the water than can be replaced naturally, the fishery will fail.
Overfishing and other examples of over-exploitation of natural resources can result in damage to or the loss of entire ecosystems. An ecosystem includes all the living organisms humans, plants, animals, micro-organisms and their physical environment soil, water, air, land and the interactions between them.
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If one component of the system is removed, this can have knock-on effects on the other parts of the system. One particular problem caused by over-exploitation of natural resources is deforestation , which occurs when forest areas are cleared and the trees are not replanted or allowed to regrow. In Ethiopia, clearing land for agriculture to meet the food needs of the growing population and the demand for fuel and construction materials has resulted in a steady loss of forest area, which is still continuing as you can see from Figure 1. The loss of forest has several undesirable consequences.
Forests are home to many different types of trees, as well as other plants, and a wide range of animals from insects to birds and mammals. The conversion of forests to agriculture greatly reduces biodiversity , which is a measure of the variety of living organisms all life forms. Biodiversity is important for humans because we use other living organisms to provide several essentials:. Deforestation is a significant contributory cause of soil erosion. Once the trees and undergrowth are removed, the underlying ground is exposed.
Without the intercepting effect of the vegetation and the tree roots binding the soil together, the soil is more likely to be washed away when it rains. Loss of forests also has a significant impact on water supply. Tree roots reach deep into the soil and create spaces between the particles which increases soil permeability, allowing rainwater to soak in and replenish groundwater. Permeability means the ease with which water moves through soil or rock. The use of renewable or non-renewable resources is a critical factor when considering energy resources.
Fossil fuels have been the main energy source for global industrialisation, but because they are non-renewable, the quantity is ultimately limited and their use is not sustainable over the long term. Furthermore, burning of fossil fuels is the main cause of climate change. Climate change is discussed fully in later study sessions.
There are several renewable alternatives to fossil fuels.
Wood used as a fuel is renewable in the sense that trees will regrow but there are other disadvantages such as deforestation, as you have read. In Ethiopia, windfarms are harnessing wind power to generate electricity Figure 1. Ethiopia already has several hydropower stations and more are planned, including the Grand Ethiopian Renaissance Dam, currently under construction. Hydroelectric power is renewable because it makes use of the energy of flowing water but does not use up the water in the process.
You may have noticed that the four categories of resources shown in Figure 1. It's no surprise that as the world population continues to grow, the limits of essential global resources such as potable water, fertile land, forests and fisheries are becoming more obvious. Carrying capacity is usually limited by components of the environment e. Debate about the actual human carrying capacity of Earth dates back hundreds of years.
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The range of estimates is enormous, fluctuating from million people to more than one trillion.