1. National 4 Biology
Unit 3 – Life on Earth
Section 16 – Human Impact

2. Section 3.16 – Human Impact Pupils should be able to:
Explore reasons for the rapid growth in human population
Explain how rapid growth of human population can affect biodiversity
Explain what is meant by an ecological footprint
Give examples of habitat destruction
Describe the effects of deforestation on biodiversity
Describe what is meant by intensive farming and the effects of this on other species
Describe how pollution from our homes affects ecosystems
Describe the causes of acid rain and its effects on different species
Describes the causes of climate change and its effects on different species
Give examples of natural forms of pollution
Investigate endangered species and conservation
By the end of this section you should be able to:

3. How Many Humans can Live on Earth?
Current World Population - 7,600,000,000!!!
This number is increasing by more than 1.5 million per week - about more mouths to feed during the course of this period
ers.info/world- population/

4. Human Population Growth
Can you think of any reasons why the human population has increased so much in the last 200 years?
What has improved in the last 200 years which means that people are surviving better?
Should we do something?
If we should, what should we do?

5. Human Population Growth
Here are some clues.
Not all countries have access to all of these things, and death rates are much higher, especially in children.
Better sanitation and sewage treatment
Vaccinations against disease
Clean drinking water
More medicines and better healthcare
Better food availability
Better disinfectants

6. What can Governments or People do to Help?

7. Human Demands on the Planet
Humans use up the planet’s resources such as water, energy and land.
We also pollute the planet with our waste.
This effect that humans are having on the planet is called the ecological footprint.

8. Ecological Footprint
The more resources you use and the more waste you produce, the bigger your ecological footprint.
What could you do to reduce your ecological footprint?

9. Reducing your Ecological Footprint
Use less energy – turn the heating down
insulate your home better.
Don’t waste water – turn off a running tap or spend less time in the shower.
Recycle as much waste as you can.

10. Human Effects on Biodiversity
The increasing human population is putting more demands on the planet.
More and more ecosystems are being disrupted or destroyed altogether.
Here are some examples of ways in which humans are affecting ecosystems.
Biodiversity video clip

11. Habitat Destruction
Throughout the world, huge forests are being cut down by humans to provide timber and to create space for farms, houses , factories and roads.
These forests are home to many different species, so when the forest goes they have no food or shelter.
Cutting down large areas of trees by humans is called deforestation.
Deforestation
Deforestation video clip
Ecosystem management video clip

12. Overfishing Fish are an important source of food for humans.
Some of the main fish we capture and eat are
cod, haddock, herring
pollock and tuna.
Overfishing of some fish have caused their numbers to rapidly decline.

13. Overfishing of Atlantic Cod
The graph opposite shows how the numbers of Atlantic cod have seriously declined since the 1970s.
There are now laws in place in many countries to prevent overfishing and conserve valuable species.
This has helped the cod numbers to start recovering.

14. Intensive Farming
In order to feed a large population, it is important that we get the maximum amount of food from an area of land.
This has led to intensive farming techniques.
This involves using huge farms, and using lots of chemicals to encourage growth of plants (fertilisers) and to kill diseases (pesticides).

15. Intensive Farming – Pesticides and Fertilisers
Pesticides kill harmful insect pests, but also kill a lot of useful insects.
Pesticides can leak into rivers and harm animals there.
Fertilisers make plants grow faster.
If fertilisers leak into rivers, they can cause excessive growth of algae, killing other species. This is called eutrophication.

16. Intensive Farming – Animals
Intensive farming of animals can lead to overcrowded conditions.
This affects the health of the animals, and they often need to be given antibiotics to prevent the spread of disease.
These antibiotics can then pass to humans when we eat the animal.
Modern Agriculture
Intensive Dairy farming

17. Intensive Farming of Beef Cattle
(expensive)
(good)
(bad)
(bad)
(bad)

18. Copy Each of the Following into your notes on page 4
Habitat Destruction – Overfishing - Intensive Farming – Pesticides
Huge forests are being cut down by humans to provide timber and to create space for farms, houses, factories and roads.
Fish are an important source of food for humans. Overfishing of some fish have caused their numbers to rapidly decline.
These kill harmful insect pests but also kill a useful insects e.g. bees. Pesticides can leak into rivers and harm animals there.

19. Copy Each of the Following into your notes on page 4
Intensive Farming – Fertilisers Intensive Farming – Animals
Make plants grow faster. If fertilisers leak into rivers, they can cause excessive growth of algae, killing other species. This is called Eutrophication.
This leads to overcrowding which affects the health of the animals. They often need antibiotics which can then spread to humans when we eat the animal

20. Pollution and Ecosystems
Humans produce a lot of waste which needs to be disposed of.
This includes rubbish and sewage from our homes, as well as harmful chemicals and gas emissions from factories.

21. What is
pollution?
Write you ideas and examples on a white board

22. Pollution from our Homes
Waste in our black bins goes to landfill sites. This can cause toxic chemicals to leak into the soil and kill animals and plants.
Waste water from our house contains soaps and detergents, as well as everything that gets flushed down the toilet!
This water must be treated to make it safe to release into rivers.
Poorly treated sewage can also cause eutrophication in rivers (algae bloom grows)

23. Recycling Domestic Waste
By recycling as much waste as possible, we can avoid damage to the environment.
Waste glass, metal, paper and plastic can be remade into new materials.
Waste food and garden waste can be used to make compost. Some is also used to produce biogas – an alternative fuel.

24. Pollution from Industry
Power stations and factories which burn coal and oil produce acidic gases – sulphur dioxide and nitrogen dioxide.
These then dissolve in the water in rain clouds.
This then leads to acid rain, often hundreds of kilometres away from the source of pollution.
The acid rain can kill trees and other plants. It can also cause death of fish by causing lakes to become acidic.

25. Pollution causes Climate Change
Other gases released from homes, cars and factories are causing climate change.
These gases are causing the earth to slowly heat up – this is called global warming.
The gases involved are mainly carbon dioxide and water vapour. These are called the greenhouse gases.
By using less energy in our homes, switching off appliances not being used, and using cars less we can help to slow down this climate change.

26. Carbon Dioxide Levels

27. Greenhouse Effect
The Greenhouse Effect

28. Effects of climate change on ecosystems and biodiversity
Small changes in sea temperatures are affecting delicate ecosystems like coral reefs, which are dying.
Melting polar ice caps are reducing the area for polar bears to roam and find food.
Rising sea levels are flooding some coastal ecosystems, destroying them.
Some parts of the planet are becoming drier, and the animals living there cannot find enough water to survive.

29. Pollution Campaign! 1. You must include:
Examples of pollution caused by humans and how to reduce pollution.
2. You should include:
Causes of acid rain.
Causes of global warming.
3. You could include:
Describe the effects of acid rain and global warming on plants and animals.

30. Accidental Pollution
Some industries produce harmful chemicals which need to be safely disposed of.
These chemicals sometimes need to be transported to where they will be dumped.
If they accidentally leak into the environment, ecosystems can be seriously affected.
This will reduce biodiversity in that area.
Transporting oil in oil tankers at sea can also affect wildlife if there are any accidental spillages.

31. Natural effects on Biodiversity
Learning Intention: Identify and describe how natural disasters can affect biodiversity
Investigate issues around conservation of endangered species
Success Criteria:
Give examples of natural disasters that can affect ecosystems
Give examples of endangered species
Describe ways of conserving endangered species
Explain the importance of conservation of species.

32. Natural forms of Pollution
Some natural disasters can have negative effects on biodiversity.
Forest fires can start in hot dry countries in the summer months and spread over vast areas, destroying ecosystems.
Earthquakes, volcanos, tsunamis and severe storms can also damage plant and animal life.

33. Pollution and Ecosystems
Type of Domestic Waste
Where it Goes
Effect of Environment
Sewage
Sewage Treatment
Poorly treated sewage can also cause eutrophication in rivers (algal bloom grows)
Recycled glass, metal and plastic
Recycling Centre
Remade into new materials e.g. fleece, new glass and plastic bottes
Garden waste and waste food
Biogas generator or composting plant
Can be made into compost or used as biofuels
General Waste
Landfill site
Can cause toxic chemicals to leak into the soil and kill animals and plants

34. Pollution from Industry
Name two gases that contribute to acid rain.
Give two effects of acid rain on living things
Name two greenhouse gases
Explain why these gases are causing global warming
What can be done to reduce global warming?
Describe the effects of global warming on biodiversity
Sulfur Dioxide
Nitrogen Dioxide
Kill trees and plants/lakes become more acidic – causing death of fish
Methane, Carbon dioxide and water vapour
These gases absorb radiant energy from the sun which heats up the earth
Use less energy in our homes, so burn less fossil fuels, use public transport, cycle or walk
Changes in the temperature of the sea affects coral reefs and melts polar ice caps causing the sea levels to rise. Some parts of the world are becoming dryer e.g. desertification.

35. Endangered Species
The numbers of many animals on the planet are declining due to overhunting and habitat destruction.
Some of these species could soon become extinct. These are called endangered species.

36. Endangered Species

38. Conservation of Endangered Species
Governments throughout the world have taken steps to protect endangered species by:
passing laws making it illegal to hunt or kill certain animals.
making it illegal to pick or destroy certain plants

39. Conservation of Endangered Species
Creating protected areas like wildlife reserves and national parks, where animal and plant numbers are monitored and rangers patrol to ensure that animals are not harmed. Its illegal to hunt or kill the animals
Having captive breeding programmes, where endangered animals are fed well and encouraged to breed, and the young animals are protected from natural predators.

40. Case Study of an Endangered Species
Choose an endangered animal from the list on the next slide, or come up with your own suggestion for an endangered species.
Create a powerpoint presentation or a word document about the animal.
Include where the animal’s natural habitat is, why the animal is in danger of becoming extinct and what steps are being taken to conserve the species
Make it bright and colourful with lots of pictures.

41. Case study of an Endangered Species
Amur Leopard
Black Rhino
Hawksbill Turtle
Javan Rhino
Leatherback Turtle
Mountain Gorilla
South China Tiger
Sumatran Elephant
Sumatran Orangutan
Sumatran Rhino
Sumatran Tiger
Amur Tiger
Asian Elephant

42. Humans use up the planet’s resources such as water, energy and land.
Term
Definition
Water Pollution
The contamination of water bodies (lakes, lochs, rivers etc), usually as a result of human activities.
Ecological Footprint
Humans use up the planet’s resources such as water, energy and land.
Overfishing
Overfishing is the removal of fish from the sea at a rate that the species cannot replenish in time, resulting in those species either becoming depleted or very underpopulated in that given area.
Habitat Destruction
Huge forests are being cut down by humans to provide timber and to create space for farms, houses , factories and roads.
Intensive Farming
This involves using huge farms, and using lots of chemicals to encourage growth of plants (fertilisers) and to kill diseases (pesticides).

43. Term Definition Global Warming
The observed century-scale rise in the average temperature of the Earth's climate system and its related effects.
Air Pollution
The contamination of the air and atmosphere, usually as a result of human activities.
Accidental Pollution
The result of sudden events, independent of human will. It may, for example, occur following the rupture of a pipeline, a fire or a shipwrecking
Acid Rain
Rainfall made so acidic by atmospheric pollution that it causes environmental harm, chiefly to forests and lakes.
Climate Change
A change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.

44. The destruction of forests by humans for non-forest use
Pesticides
Pesticides kill harmful insect pests, but also kill a lot of useful insects.
Deforestation
The destruction of forests by humans for non-forest use
Fertilisers
Fertilisers make plants grow faster.
Endangered Species
The numbers of many animals on the planet are declining due to overhunting and habitat destruction.

45. Success Criteria By the end of this section you should be able to:
I can explore reasons for the rapid growth in human population
I can explain how rapid growth of human population can affect biodiversity
I can explain what is meant by an ecological footprint
I can give examples of habitat destruction
I can describe the effects of deforestation on biodiversity
I can describe what is meant by intensive farming and the effects of this on other species
I can describe how pollution from our homes affects ecosystems
I can describe the causes of acid rain and its effects on different species
I can describes the causes of climate change and its effects on different species
I can give examples of natural forms of pollution
I can investigate endangered species and conservation
By the end of this section you should be able to: