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Human Population Effects On Environment Andrew, Lauren & Wendy. Andrew, Lauren & Wendy.

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Presentation on theme: "Human Population Effects On Environment Andrew, Lauren & Wendy. Andrew, Lauren & Wendy."— Presentation transcript:

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2 Human Population Effects On Environment Andrew, Lauren & Wendy. Andrew, Lauren & Wendy.

3 Number one gimp group =]

4 Number one idiot?

5 / The population reached 6.1 billion in 2000. / The United Nation projects that world population for the year 2050 could range from 7.9 billion to 10.9 billion, depending on the actions we take today. / The population reached 6.1 billion in 2000. / The United Nation projects that world population for the year 2050 could range from 7.9 billion to 10.9 billion, depending on the actions we take today.

6 Human population growth is the number one threat to the world's environment. Human population growth is the number one threat to the world's environment.

7 / Each person requires energy, space and resources to survive, which results in environmental losses. / If the human population were maintained at sustainable levels, it would be possible to balance these environmental losses with renewable resources and regeneration. / Each person requires energy, space and resources to survive, which results in environmental losses. / If the human population were maintained at sustainable levels, it would be possible to balance these environmental losses with renewable resources and regeneration.

8 / But our population is rapidly rising beyond the earth's ability to regenerate and sustain us with a reasonable quality of life. / We are exceeding the carrying capacity of our planet. / But our population is rapidly rising beyond the earth's ability to regenerate and sustain us with a reasonable quality of life. / We are exceeding the carrying capacity of our planet.

9 Food Webs Food Webs Green plants are the starting point in all food chains. Animals depend either directly or indirectly on plants for their energy as it passes along food chains. Many food chains connect to form a food web. These more complex relationships are usually in a very finely balanced state, in equilibrium with the environment. Green plants are the starting point in all food chains. Animals depend either directly or indirectly on plants for their energy as it passes along food chains. Many food chains connect to form a food web. These more complex relationships are usually in a very finely balanced state, in equilibrium with the environment.

10 Disruption of Food Webs Disruption of Food Webs If a factor affects one type of organism in a food web, it is likely to have a knock on effect which disrupts the lives of several other species in the food web.

11 Effects of Chemicals On wildlife  Massive quantities of chemicals are used in agriculture and forestry  Fertilisers: used to improve soil fertility  Pesticides: used to limit damage done to crops by pests  Massive quantities of chemicals are used in agriculture and forestry  Fertilisers: used to improve soil fertility  Pesticides: used to limit damage done to crops by pests

12 Factors Relating to the chemical…  Is the chemical specific in its action or is it poisonous to a wide variety of organisms?  Is it biodegradable or is its molecular structure so stable that it persists for a very long time in the environment?  Is its concentration kept to a minimum or is it used in excess?  Is the chemical specific in its action or is it poisonous to a wide variety of organisms?  Is it biodegradable or is its molecular structure so stable that it persists for a very long time in the environment?  Is its concentration kept to a minimum or is it used in excess?

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14 Nitrogen in the air animal protein dead plants & animals urine & faeces ammonia nitrites nitrates plant made protein decomposition by bacteria & fungi bacteria (nitrifying bacteria) nitrates absorbed denitrifying bacteria root nodules (containing nitrogen fixing bacteria) nitrogen fixing plant eg pea, clover bacteria

15 Nitrogen Cylce  The nitrogen cycle represents one of the most important nutrient cycles found in terrestrial ecosystems.  Nitrogen is used by living organisms to produce a number of complex organic molecules like amino acids, proteins, and nucleic acids.  The store of nitrogen found in the atmosphere, where it exists as a gas (mainly N 2 ), plays an important role for life.  This nitrogen goes through four processes during the nitrogen cycle: nitrogen fixation, decay, nitrification and denitrification.  The nitrogen cycle represents one of the most important nutrient cycles found in terrestrial ecosystems.  Nitrogen is used by living organisms to produce a number of complex organic molecules like amino acids, proteins, and nucleic acids.  The store of nitrogen found in the atmosphere, where it exists as a gas (mainly N 2 ), plays an important role for life.  This nitrogen goes through four processes during the nitrogen cycle: nitrogen fixation, decay, nitrification and denitrification.

16  Plant and animal wastes decompose, adding nitrogen to the soil.  Bacteria in the soil convert those forms of nitrogen into forms plants can use.  Plants use the nitrogen in the soil to grow.  People and animals eat the plants; then animal and plant residues return nitrogen to the soil again, completing the cycle.  Plant and animal wastes decompose, adding nitrogen to the soil.  Bacteria in the soil convert those forms of nitrogen into forms plants can use.  Plants use the nitrogen in the soil to grow.  People and animals eat the plants; then animal and plant residues return nitrogen to the soil again, completing the cycle.

17  Another way nitrogen enters the cycle is as inorganic nitrogen from the atmosphere and factories. The concern with these forms is that the incremental amount of nitrates they add to the nitrogen cycle may threaten groundwater. ・ Rain storms contribute atmospheric nitrogen through rain drops that reach the soil. ・ Legumes, such as soybeans, alfalfa and clovers, are plants that can convert atmospheric nitrogen into plant-usable nitrogen. ・ Factories that produce nitrogen fertilizers add nitrogen to the soil when farmers and gardeners "feed" their crops. ・ Nitrogen in sewage sludge from municipal waste plants can be used to fertilize farm fields.  Another way nitrogen enters the cycle is as inorganic nitrogen from the atmosphere and factories. The concern with these forms is that the incremental amount of nitrates they add to the nitrogen cycle may threaten groundwater. ・ Rain storms contribute atmospheric nitrogen through rain drops that reach the soil. ・ Legumes, such as soybeans, alfalfa and clovers, are plants that can convert atmospheric nitrogen into plant-usable nitrogen. ・ Factories that produce nitrogen fertilizers add nitrogen to the soil when farmers and gardeners "feed" their crops. ・ Nitrogen in sewage sludge from municipal waste plants can be used to fertilize farm fields.

18 Eutrophication  Eutrophication is the enrichment of an aquatic environment by nutrients such as nitrate and phosphate.  This is a natural process which normally occurs at a very slow rate.  Levels of eutrophivation have significantly increased in many freshwater and marine ecosystems in recent years.  Eutrophication is the enrichment of an aquatic environment by nutrients such as nitrate and phosphate.  This is a natural process which normally occurs at a very slow rate.  Levels of eutrophivation have significantly increased in many freshwater and marine ecosystems in recent years.  This is because;  Intensive crop growing uses ever increasing quantities of fertilisers containing nitrate and phosphate, much of which have been washed into rivers/lochs by rain.  Intensive livestock farming produces vast amounts of animal sewage, some of which finds its way into waterways adding phosphate and nitrate.  Effluent from sewage treatment works containing nitrate and phosphate is discharged into rivers and canals.  Some forms of detergent are rich in phosphate which is not removed by sewage treatment and ends up in rivers and canals.

19  When sunshine and warm temperatures coincide with an artificially high level of eutrophication, the affected environment is suddenly able to support the enormous number of algae. These tiny plants reproduce prolifically, forming an algal bloom.  A river or canal with slow moving water is more prone to an algal bloom since the excess nutrients are not as well diluted as in fast flowing water.  When sunshine and warm temperatures coincide with an artificially high level of eutrophication, the affected environment is suddenly able to support the enormous number of algae. These tiny plants reproduce prolifically, forming an algal bloom.  A river or canal with slow moving water is more prone to an algal bloom since the excess nutrients are not as well diluted as in fast flowing water.

20 Sewage  Raw sewage contains many different organic chemicals such as protein and urea which are rich in nitrogen.  In developed countries, several species of bacteria are used during the treatment of sewage.  These convert protein to ammonium compounds which are then oxidised to nitrites and nitrates by nitrifying bacteria.  This is basically an intensification of the natural processes that take place during the nitrogen cycle.  Raw sewage contains many different organic chemicals such as protein and urea which are rich in nitrogen.  In developed countries, several species of bacteria are used during the treatment of sewage.  These convert protein to ammonium compounds which are then oxidised to nitrites and nitrates by nitrifying bacteria.  This is basically an intensification of the natural processes that take place during the nitrogen cycle.

21 Overloaded sewage works  If a sewage treatment works becomes overloaded, raw or inadequately treated sewage may be discharged into a river,.  The presence of large amounts of sewage and millions of bacteria cause the water to become cloudy (turbid).  In such conditions of poor illumination, photosynthesis is reduced and the number of algae decreases.  If a sewage treatment works becomes overloaded, raw or inadequately treated sewage may be discharged into a river,.  The presence of large amounts of sewage and millions of bacteria cause the water to become cloudy (turbid).  In such conditions of poor illumination, photosynthesis is reduced and the number of algae decreases.

22 Problems of sewage disposal  As the human population increases so too does the volume of sewage that needs to be disposed of.  This is a particularly serious problem in densely populated countries.  In recent years, much of Britain’s sewage is deposited in the North Sea. However, even this vast volume of water is being badly polluted.  As a result, Britain has agreed to find an alternative; our only one being land fill sites!  As the human population increases so too does the volume of sewage that needs to be disposed of.  This is a particularly serious problem in densely populated countries.  In recent years, much of Britain’s sewage is deposited in the North Sea. However, even this vast volume of water is being badly polluted.  As a result, Britain has agreed to find an alternative; our only one being land fill sites!

23 Contamination of Drinking Water  Nitrate is very soluble in water and does not bind to soil particles.  When the fertiliser is excessively or ill-timed in use, much can wash away and eventually reach water supplies intended for human consumption.  According to medical experts; its harmless to humans. You can have as much as 100ppm in drinking water and pose no threat to health.  However, when nitrate is reduced to nitrite by enzyme action in the gut of babies, the nitrite combines with haemoglobin and hinders the oxygen carrying capacity of the babies blood.  Nitrate is very soluble in water and does not bind to soil particles.  When the fertiliser is excessively or ill-timed in use, much can wash away and eventually reach water supplies intended for human consumption.  According to medical experts; its harmless to humans. You can have as much as 100ppm in drinking water and pose no threat to health.  However, when nitrate is reduced to nitrite by enzyme action in the gut of babies, the nitrite combines with haemoglobin and hinders the oxygen carrying capacity of the babies blood.

24 WHO guidelines…  They recommend a 50ppm limit of nitrate in drinking water  Most of the UK meet this.  In some parts of the world, levels are found to be well above 100ppm.  This excessive level has been linked with gastric ulcers in adults and abnormalities in fetal development.  They recommend a 50ppm limit of nitrate in drinking water  Most of the UK meet this.  In some parts of the world, levels are found to be well above 100ppm.  This excessive level has been linked with gastric ulcers in adults and abnormalities in fetal development.

25 Global warming: Greenhouse Effect  ‘Greenhouse’ gases are; -Carbon dioxide -Methane -Chloroflurocarbons (CFC’s)  ‘Greenhouse’ gases are; -Carbon dioxide -Methane -Chloroflurocarbons (CFC’s)

26  They are referred to as ‘Greenhouse’ gases because they trap infra-red radiation coming from the Earth’s surface and reflect it back to Earth, keeping the planet warm.  This greenhouse effect, appropriately named because the gases play a role similar to the panes of glass in a greenhouse, causes GLOBAL WARMING, which is essential for life on Earth.  Without it, the world would be too cold to support life.  They are referred to as ‘Greenhouse’ gases because they trap infra-red radiation coming from the Earth’s surface and reflect it back to Earth, keeping the planet warm.  This greenhouse effect, appropriately named because the gases play a role similar to the panes of glass in a greenhouse, causes GLOBAL WARMING, which is essential for life on Earth.  Without it, the world would be too cold to support life.

27 Excessive Global Warming  As the concentrations of CO2, CH4 and CFC’s build up in the atmosphere and form an even denser layer, a corresponding increase in the greenhouse effect is expected to occur. This would result in global warming well in excess of the present desirable levels.

28 The Future…  Greenhouse Gases  Increased or constant levels of these gases will result in a significant increase in the greenhouse effect and a major contribution to further global warming  Greenhouse Gases  Increased or constant levels of these gases will result in a significant increase in the greenhouse effect and a major contribution to further global warming

29  Temperature  Experts predict an increase in global temperature of 4-5 degC by 2050.  (NB: a change of a few degrees can make an enormous difference to climatic conditions worldwide)  Rise In Sea Levels  If a rise in global temperature does occur, this could cause partial melting of the polar ice caps, releasing extra water into the worlds oceans  The inevitable result would be a substantial rise in sea level, estimated at 1.5metres in the next 50 years  PROBLEMS: flooding, low lying coastal regions would become submerged  Temperature  Experts predict an increase in global temperature of 4-5 degC by 2050.  (NB: a change of a few degrees can make an enormous difference to climatic conditions worldwide)  Rise In Sea Levels  If a rise in global temperature does occur, this could cause partial melting of the polar ice caps, releasing extra water into the worlds oceans  The inevitable result would be a substantial rise in sea level, estimated at 1.5metres in the next 50 years  PROBLEMS: flooding, low lying coastal regions would become submerged

30 Excessive Global Warming…  Is likely to lead to a decrease in forests, an increase in desertification and a worsening of conditions for the rural poor of the world scraping a loving in marginal farming regions.

31 There are many potential impacts of global warming than hypothetically affect the environment and human life according to the theory of global warming. The main thing is the average temperature increased gradually.From here, there are a number of different effects such as rising sea levels, changes in agricultural ecosystems, the spread of tropical diseases, the increasing intensity of natural phenomena. Some of this phenomenon will produce today, but it is difficult to determine a direct relationship to global warming.potential impacts of global warming There are many potential impacts of global warming than hypothetically affect the environment and human life according to the theory of global warming. The main thing is the average temperature increased gradually.From here, there are a number of different effects such as rising sea levels, changes in agricultural ecosystems, the spread of tropical diseases, the increasing intensity of natural phenomena. Some of this phenomenon will produce today, but it is difficult to determine a direct relationship to global warming.potential impacts of global warming

32 The Consequences of Global Warming  Earths climate is very difficult to predict, because there are many factors to consider: rain, sunshine, wind, temperature ノ So you can not specify what the effects would cause global warming. But it turns out, can be very severe climate change. The first consequence, it is possible, is the improvement of drought: in some places less rainfall. On the other, the rain will increase, causing flooding.Warmer atmosphere can cause the ice near the poles are melting. The amount of water would raise the sea level. Earths climatecause global warming  Earths climate is very difficult to predict, because there are many factors to consider: rain, sunshine, wind, temperature ノ So you can not specify what the effects would cause global warming. But it turns out, can be very severe climate change. The first consequence, it is possible, is the improvement of drought: in some places less rainfall. On the other, the rain will increase, causing flooding.Warmer atmosphere can cause the ice near the poles are melting. The amount of water would raise the sea level. Earths climatecause global warming  Increased by only 60 cm would inundate fertile soil in Bangladesh, India, among them hundreds of thousands of people depend on for food. tropical storms may occur more frequently.The first step to stop the phenomenon In the ユ 70s, many people begin to realize changes that the earth is suffering. By studying them, they could observe how the environment is fragile, and how many people depend on it. Gradually we all realized that it was not possible to continue to pollute the water, earth and air pollution will not go away by itself.

33  Wildlife  Global warming by a few degC would bring about dramatic changes to many natural ecosystems  Many plant and animal species, especially those living in the wild would be unable to adopt to this pace of change  Especially at risk would be those plants and animals highly specialised to suit life in one specific ecosystem  It is certain then that many forms of wildlife will become extinct.  Wildlife  Global warming by a few degC would bring about dramatic changes to many natural ecosystems  Many plant and animal species, especially those living in the wild would be unable to adopt to this pace of change  Especially at risk would be those plants and animals highly specialised to suit life in one specific ecosystem  It is certain then that many forms of wildlife will become extinct.

34  Changes In Climate  A rise in temperature of a few degrees would cause a global shift in climate and rainfall patterns  Agriculture  If equatorial regions were to become even hotter and drier, there would b a shift of thermal limits of agriculture towards the poles  “breadbasket” regions such as the American mid-west would suffer a reduction in salt water and be unable to produce the vast quantities of crops with which they supply the world at present.  This would effect food supply’s on a global scale.  Changes In Climate  A rise in temperature of a few degrees would cause a global shift in climate and rainfall patterns  Agriculture  If equatorial regions were to become even hotter and drier, there would b a shift of thermal limits of agriculture towards the poles  “breadbasket” regions such as the American mid-west would suffer a reduction in salt water and be unable to produce the vast quantities of crops with which they supply the world at present.  This would effect food supply’s on a global scale.

35 Possible Courses of Action  Emission of CO2 could be cut by promoting more efficient use of energy and reducing our reliance on the combustion of fossil fuels by developing alternative sources of energy  Destruction of tropical forest could be reduced by offering financial incentives to the developing countries that possess the forests, in exchange for guaranteed conservation.  Well designed land fill dumps, which allow methane to be collected and put to use instead of escaping to the atmosphere.  Exerting strict control over the use of CFC’s and phasing them out completely as soon as harmless substitutes are found.  International co-operation.  Emission of CO2 could be cut by promoting more efficient use of energy and reducing our reliance on the combustion of fossil fuels by developing alternative sources of energy  Destruction of tropical forest could be reduced by offering financial incentives to the developing countries that possess the forests, in exchange for guaranteed conservation.  Well designed land fill dumps, which allow methane to be collected and put to use instead of escaping to the atmosphere.  Exerting strict control over the use of CFC’s and phasing them out completely as soon as harmless substitutes are found.  International co-operation.

36 Carbon Cycle Carbon dioxide makes up only a very small part of the worlds atmosphere. Prior to the industrial revolution this tended to remain fairly constant due to the activities of the carbon cycle. The volume of CO2 released by the processes of respiration and combustion was absorbed by green plants during photosynthesis. It is thought that any slight imbalances that occurred were corrected by the absorbing or releasing it as required, therefore maintaining an equilibrium Video-carbon cycle

37 Scotland 2050  From Scotland on Sunday, 27 May 1990  By Rob Edwards  From Scotland on Sunday, 27 May 1990  By Rob Edwards


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