Land Use Noadswood Science, 2016

Saturday, May 19, 2018 Land Use To understand how we can use organisms as indicators of pollution

Precise Learning Rapid growth in the human population and an increase in the standard of living mean that increasingly more resources are used and more waste is produced. Unless waste and chemical materials are properly handled, more pollution will be caused. Pollution can occur: in water, from sewage, fertiliser or toxic chemicals in air, from smoke and acidic gases on land, from landfill and from toxic chemicals. Pollution kills plants and animals which can reduce biodiversity. Humans reduce the amount of land available for other animals and plants by building, quarrying, farming and dumping waste.

Developing & Developed Look at the following – a recent scene from the Glastonbury festival and a shanty town in South America What issues are involved with this many people?

Developing & Developed In a given area if the population becomes this vast there is a huge strain on resources needed: space / shelter; food; water (and mates) There is also a great strain on removal of waste This impacts not only human populations, but any surrounding flora and fauna

Human Population Projection Human beings compete with other living things for resources and space – as the world’s population continues to increase, and standards of living improve, there is serious danger of a permanent change to the global environment Human activities have led to the pollution of the environment, and a reduction in the amount of land available for other animals and plants, which makes it difficult for some species to survive There is a need to achieve a level of development that also sustains the environment for future generations…

Human Population Projection Like all living things, humans exploit their surroundings for resources – before the beginning of agriculture about 10,000 years ago, small groups of humans wandered across large areas, hunting and gathering just enough food to stay alive Population numbers were kept low because of the difficulty of finding food The development of agriculture led to a population explosion that has accelerated enormously during the past 500 years – unlike other species, humans can adapt to and survive in almost all habitats and climates

Human Population Projection Using the data in the table below plot a graph showing how the human population has changed over the last 10’000 years: - Year Human Population Numbers (Thousands) 8’000 BCE 5’000 6’000 BCE 10’000 4’000 BCE 20’000 2’000 BCE 35’000 200’000 2000 CE 6’000’000

Human Population Projection Human population graph over the past 10’000 years: -

Human Population In the last 200 years or so the human population has grown very quickly – why? We can grow more food We can cure and prevent illness or disease We have no natural predators Standard of living has improved (electricity, fuel, heat, cars etc…)

Standards Of Living People in the developed world enjoy a high standard of living, with abundant food, cars and comfortable housing People in the developing world have a lower standard of living, but many countries are catching up quickly Strains on the global environment include: - Non-renewable energy resources (e.g. coal, oil and natural gas) are being used up rapidly Raw materials are being used up rapidly More waste is being produced More pollution is being caused

Waste Pollution is the addition of substances to the environment that may be harmful to living organisms Population growth and increases in the standard of living cause more waste to be produced – If this waste is not handled correctly, it leads to pollution Pollution can be categorised into the following: - Land pollution Water pollution Air pollution

Land Pollution Most rubbish is buried in landfill sites and not all of it comprises safe materials – even common household items can contain toxic chemicals such as poisonous metals (many smoke alarms contain radioactive americium) Industrial waste is also discharged onto the land – many farmers apply pesticides to improve their crops, but these can damage living things (toxic chemicals can be washed from the land into rivers, lakes and seas causing eutrophication) Eutrophication in the Caspian Sea (turbidity in North)

Fertiliser Problems Fertiliser problems arise when the fertiliser finds its way out of the soil and into rivers and streams This can happen easily if too much fertiliser is applied or it rains immediately after it has been applied The result is called eutrophication Caspian Sea (rapid algae growth can be seen in the northern part increasing the water’s turbidity (cloudiness))

Eutrophication Eutrophication occurs when excess nitrates make their way into rivers and lakes causing rapid growth of some plants and algae Some plants then start dying due increased competition for light which results in micro-organisms feeding on the dead plant (they respire using up lots of oxygen) This increased level of decomposition results in high levels of oxygen being taken from the water, making it very difficult for larger organisms such as fish to survive - a real danger

Eutrophication Excess nitrates make their way into rivers and lakes causing rapid growth of some plants and algae Some plants and algae then start dying due increased competition for light Micro-organisms feed on the dead plant (which respire using up lots of oxygen) A lack of oxygen in the water can be very bad news for larger organisms such as fish

Water Pollution Water pollution is caused by the discharge of harmful substances into rivers, lakes and seas Many aquatic invertebrate animals cannot survive in polluted water, so their presence or absence indicates the extent to which a body of water is polluted Pollutant Typical Effect Fertilisers Damage to aquatic ecosystems Sewage Damage to aquatic ecosystems and humans Toxic chemicals

Air Pollution The most common source of air pollution is the combustion of fossil fuels Pollutant Effect Smoke Deposits soot on buildings and trees, causing them damage – permeates the air, making it difficult for living creatures to breathe Carbon monoxide Poisonous gas Carbon dioxide Greenhouse gas that contributes to global warming Sulphur dioxide Contributes to acid rain

Practice Questions Explain why it is important to have high biodiversity How do humans cause land pollution? The graph shows the amount of waste recycled and the amount sent to landfill in one city for three separate years Describe the trends shown by the graph What percentage of the total waste shown in 2010 was recycled? Suggest why the amount of space taken up by landfill sites around the world is increasing and give a reason why it is important to recycle products such as metal cans

Answers Explain why it is important to have high biodiversity – it makes sure that ecosystems are stable How do humans cause land pollution – toxic chemicals from farming, burying nuclear waste and by creating landfill for other waste Describe the trends shown by the graph – both the amount of waste recycle and the amount sent to landfill has increased each year (but the amount recycled each year has increased by more than the amount sent to landfill) important to recycle products such as metal cans

Answers What percentage of the total waste shown in 2010 was recycled – 40% (100’000 / 250’000)*100 Suggest why the amount of space taken up by landfill sites around the world is increasing and give a reason why it is important to recycle products such as metal cans – world population is increasing and more waste is being produced. Standards of living are also increasing creating even more waste. More raw materials are being used so to prevent running out recycling should take place as much as possible