# Human Impact. Breaking news: World population has reached 7 billion... Can you think of any problems this might cause?

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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. To do this, you will need to use your problem solving skills.

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? YearPopulation (billions) 19502.2 19603 19703.6 19804.2 19904.9 20006 20106.9

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. YearPopulation (billions) 19502.2 19603 19703.6 19804.2 19904.9 20006 20106.9

Percentages What percentage of the population in 2010, were alive in 1970? What percentage of the population in 2000 were alive in 1950? YearPopulation (billions) 19502.2 19603 19703.6 19804.2 19904.9 20006 20106.9

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. YearPopulation (billions) 19502.2 19603 19703.6 19804.2 19904.9 20006 20106.9

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? YearPopulation (billions) 19502.2 19603 19703.6 19804.2 19904.9 20006 20106.9

Plotting a graph. YearPopulation (billions) 19502.2 19603 19703.6 19804.2 19904.9 20006 20106.9 Plot a graph to demonstrate the data

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

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.

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

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.

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

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

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.

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

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.

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

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.

GM crops Genetically modified crops are produced when a useful gene from another organism is inserted into the cells of a plant. Plant typeCharacteristic. MaizeResistant to Insect pests. TomatoSlow to ripen PotatoResistant to fungal blight. Soya beansTolerate herbicide.

Can you remember the steps of genetic engineering?

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.

GM crops YearYield of maize (Tonnes per Hectare) 19978.2 19988.7 19999.4 20007.3 20016.2 20024.8 20032.9 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?

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