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Human Impact

Human Impact. Breaking news: World population has reached 7 billion... Can you think of any problems this might cause ?. World Health Organisation. You have been asked by the World Health Organisation to analyse some of the data which has been collected.

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Human Impact

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  1. Human Impact

  2. Breaking news: World population has reached7 billion... Can you think of any problems this might cause?

  3. World Health Organisation You have been asked by the World Health Organisation to analyse some of the data which has been collected. To do this, you will need to use your problem solving skills.

  4. Averages • What has the average population of the world been over the past 60 years? • Following an experiment, why is it better to calculate the average of your results?

  5. Ratio Express the difference in population size between 2000 and 1960 as a whole number ratio. Express the difference in population size between 1980 and 1960 as a whole number ratio.

  6. Percentages • What percentage of the population in 2010, were alive in 1970? • What percentage of the population in 2000 were alive in 1950?

  7. Percentage Change • Calculate the percentage increase in the population size from 1950 to 1990. • Calculate the percentage change in the size of the population from 1970 to 2010.

  8. Converting a percentage • It is predicted that the world population in 2050 will have increased by 20% of 7 billion. By how much will it have increased? • By 2100, it is predicted to have risen by 31% of 7 billion. What size will the population be in 2100?

  9. Plotting a graph. • Plot a graph to demonstrate the data

  10. Human Population Growth • Human population growth can have an impact on biodiversity in many ways; • e.g. Increased demand for food. Carbon dioxide production.

  11. Measuring Human Impact • Human impact on the environment can be calculated by measuring our ecological footprint. • An ecological footprint is a measure of human demand on the Earth’s ecosystems.

  12. Human Impact Research Green - Habitat destruction Orange - Over-fishing Blue - Oil spills

  13. Human Impact Research • Explain the role of humans in your given situation. • Give specific examples of these roles. • Explain how the biodiversity has been affected in each situation. • Give specific examples.

  14. Today we will be learning about; What intensive farming is? The advantages and disadvantages of intensive farming.

  15. Intensive Farming Intensive farming is a method of farming which allows farmers to produce more foodper acre of land. This often involves monoculture, the cultivation of a population of genetically identical crop.

  16. Intensive Farming Intensive farming involves; • Growing high yield plants in monocultures. • Regular use of fertilisers, herbicides and pesticides. • “Battery” farming of animals which reduces energy loss.

  17. Intensive Farming - Advantages • High yield (large quantity of food produced) • Low cost of production • Less labour intensive

  18. Intensive Farming - Disadvantages • Reduces Biodiversity – by clearing ecosystems for monoculture. • Using chemicals kill off weed and insect populations. - Fertilisers can cause pollution. • Unethical • Animals are under high levels of stress and can suffer disease.

  19. Questions • What is intensive farming? • Name an advantage and disadvantage of intensive farming. • What is your own opinion on intensive farming?

  20. Today we will be learning about… • What GM crops are? • How GM crops can be used to produce more food for the growing human population.

  21. GM crops • Genetically modified crops are produced when a useful gene from another organism is inserted into the cells of a plant.

  22. Can you remember the steps of genetic engineering?

  23. GM crops Advantages - enable more food to be produced. - reduce reliance on pesticides. Disadvantages • unethical • insects and weeds can develop a mutation against the resistant plant.

  24. GM crops • Plot a graph to demonstrate the percentage yield of maize per year. • In 1997 GM crops were introduced. Calculate the percentage increase in yield between 1997 and 1999. • Can you suggest a reason for why the yield of maize decreased again between 1999 and 2003?

  25. Fertilisers Give one, get one – what do you know about fertilisers?

  26. Watch the following clip about... Fertilisers – name the 3 minerals found in fertilisers? - What two methods are used on this organic farm instead?

  27. Fertilisers Fertilisers contain nitrogen (N), phosphorus (P) and potassium (K). The absence of any of these minerals will reduce growth in the plant.

  28. Each packet has a ratio which needs to be simplified to a whole number ratio... Miragrow Excellent for leafy green grass and veg. NPK ratio 14:6:2

  29. Supergrow The number one fertiliser for fruit trees and flowers. Each packet has a ratio which needs to be simplified to a whole number ratio... NPK ratio 27-3-9

  30. Greengrow Growing potatoes? This is the fertiliser for you!! Each packet has a ratio which needs to be simplified to a whole number ratio... NPK ratio 4-36-12

  31. Fertilisers • Natural fertilisers include spreading manure and growing clover in the fields. • Artificial fertilisers are chemicals.

  32. Fertilisers

  33. What do you think causes this?

  34. Watch the following clip about... How do fertilisers cause algal blooms?

  35. Put these in order... 1. Chemicals leach into water 2. Fish die 3. Overuse of fertilisers 4. Oxygen levels decrease 5. Algal bloom develops

  36. Today we will be learning about… • The steps of the Nitrogen Cycle. • How feedback can help to improve our learning.

  37. Mind map Create a mind map showing what you already know about feedback.

  38. The Nitrogen Cycle Watch the following clip about the nitrogen cycle and create a sequence of the main steps.

  39. Time for feedback! • Your partner will give you feedback on how to improve your sequence. • Act on the feedback you have received.

  40. Nitrogen gas in the air Nitrogen fixation (by bacteria) Dentrification by bacteria Nitrogen fixation (by bacteria) Excretion and death Nitrogen in animals (protein) Nitrogen in waste and dead bodies (e.g. urine) Nitrogen in plants (protein) Animal Nutrition Absorption by roots Decomposition by bacteria Death Nitrogen in nitrates in the soil Nitrogen in ammonium compounds in soil Nitrogen in nitrites in the soil START HERE Nitrification by bacteria Nitrification by bacteria

  41. Now try the card sort...

  42. Time for feedback! • Your partner will give you oralfeedback on how to improve your sequence. • Be kind, helpful and specific. • Act on the feedback you have received.

  43. Today we will be learning about… • What an indicator species is? • Examples of indicator species and their roles.

  44. Human Impact – Water Pollution Watch the following clip about water pollution and prepare to summarise; 3 ways in which water becomes polluted.

  45. Human Impact – Water Pollution • Water pollution can be caused by substances such as fertilisers, sewage and oil spilling into the water. • Indicator species in the water show the environmental conditions of the water.

  46. Now try... The cut and paste activity using the information provided.

  47. Human Impact – Water Pollution • Sewage leaks into the rivers. • Bacteria feed on the sewage. • The numbers of bacteria in the river increase. • Oxygen concentration in the river decreases. • This causes the fish to die.

  48. Lichens • Lichens are another example of an indicator species. • Healthy lichens are most abundant in areas with low levels of sulphur dioxide.

  49. Lichens Graph

  50. Lichens Graph • Describe the trend shown by the graph. • Explain the trend shown by the graph.

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