Human impact on the environment

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1. Human Impact on the Environment 2. Homework  Activities  3.6.1 p323 (do after watching the DVD)  3.6.2 p328  3.6.4 p335  3.6.7 p339  3.6.8 p346 …
  • 1. Human Impact on the Environment
  • 2. Homework  Activities  3.6.1 p323 (do after watching the DVD)  3.6.2 p328  3.6.4 p335  3.6.7 p339  3.6.8 p346  3.6.9 p354  3.6.10 p359  3.6.11 p361  3.6.12 p369  3.6.13 p374  3.6.15 p379  3.6.17 p384
  • 3. Definitions anaerobic fungicide megafauna fynbos herbicide monoculture pathogenic pesticide rooibos global warming climate change the greenhouse effect the enhanced greenhouse effect greenhouse gas GHG greenhouse gas emissions(s) carbon footprint methane deforestation ozone depletion desertification biodiversity fossil fuel(s) carbon tax aquifer borehole wetland groundwater surface water algal bloom eutrophication thermal pollution alien invasive species food security food insecurity bio-accumulation crop rotation biological control genetic engineering/modification clone(s) artificial selection natural selection hybrid gene pool extinction event(s) urbanization habitat destruction poaching mechanical control chemical control indigenous endemic endangered species list biodiversity ‘hot-spot’ sterols sterolins landfill site dumpsite phytoremediation
  • 4. Human Impact on the environment: Atmosphere and Climate Change Water: Availability and Quality Food Security Loss of Biodiversity Solid Waste Disposal
  • 5. Key Concepts TERMINOLOGY & DEFINITIONS  Ozone Depletion: the ozone layer which prevents UV light from entering the earth’s surface is being destroyed by CFC’s and pollution  Greenhouse Effect: the UV light is being trapped within the earth’s atmosphere by a “blanket” of mainly carbon dioxide  Greenhouse gases: methane, nitrous oxide, carbon dioxide  Deforestation: removal of natural forests  Fossil Fuels: natural substances made deep within the earth by the decomposition of plant and animal remains over millions of years  Alien invasive species: these are plants and animals that are NOT indigenous to a particular country. They are not native to that area.
  • 6. Atmosphere and Climate Change – The Greenhouse Effect  Gasses bringing about the ‘greenhouse effect’ and leading to global warming and climate change –  water vapour,  carbon dioxide,  methane,  nitrous oxide  and ozone.  The greenhouse effect is termed this way because greenhouses are actually hard polycarbon plastic houses used by market gardeners to grow crops in winter.  These plastic houses allow sunlight to come in and trap heat so that the temperature for the green plants, that grow in these houses, is favourable in winter.  In the same way high CO2 levels trap heat from UV radiation and prevent the UV light from reflecting back into space.
  • 7. The Greenhouse Effect Left - Naturally occurring greenhouse gases—carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)—normally trap some of the sun’s heat, keeping the planet from freezing. Right - Human activities, such as the burning of fossil fuels, are increasing greenhouse gas levels, leading to an enhanced greenhouse effect. The result is global warming and unprecedented rates of climate change. Will Elder, NPS (
  • 8. Greenhouse Gas Contribution to the ‘Greenhouse Effect’ Source of Greenhouse Gas Carbon dioxide (CO2) 53% Respiration; decomposition; burning fossil fuels; forest fires Methane (CH4) 17% Cows; sheep; swamps; rice paddy fields (rice paddies); natural gas leakage; rubbish dumps; landfill sites; water treatment works Nitrous oxide (N2O) 5% Breakdown of organic matter in soil by microbes; nitrogen fertilisers; burning of fossil fuels and wood Ozone (O3) 13% Naturally present in atmosphere; formed when certain substances react in sunlight CFC’s 12% Fridges; foams; aerosol sprays; solvents (See p326)
  • 9. Global warming and Climate Change  Increase in concentration of greenhouse gasses (GHGs)  increase of average temperature on Earth, called global warming.  Global warming  ongoing change in the Earth’s weather patterns, called climate change.
  • 10. Increase in emissions: A) Increase in Carbon emissions  Carbon dioxide – colorless, heavy gas, no smell, about 0.03% of atmosphere. It is the most important greenhouse gas by volume.  Carbon dioxide is produced by:  respiration;  decomposition;  burning fossil fuels  Large volumes are released by power stations burning coal (mostly)  Our demand for electricity for household and commercial use pushes up the need to burn more fuels, increasing the amount of CO2 released into the atmosphere.  The transport of people and goods by motor vehicles burns gasoline( petrol and diesel), which releases CO2 into the atmosphere.  forest and veld fires.
  • 11. Increase in Carbon emissions – South Africa  SA’s Co2 emissions have increased 7 times from 1950-2008  From coal – 85% (119 million metric tons)  From oil use – 11.6%  Remaining 3.4% - Cement manufacture, natural gas, coke-oven gas use  Sa is the 13th largest CO2 emitting country in the world and the largest on the African Continent.  Increase in populations growth leads to:  Greater demand for transported goods;  Increased burning of fossil fuels;  Greater release of CO2 into the atmosphere.  CO2 levels have increased 150% since 1750, form 315 parts per million in 1958 to 360 parts per million in 1990. (see Fig 3.6.5, p328) Population growth
  • 12. Increase in Carbon emissions – South Africa
  • 13. Carbon dioxide levels and Temperature Source:
  • 14. Carbon Footprint  Humans add CO2 to the atmosphere by:  Traveling in motor vehicles using petrol or diesel as fuel;  Using electrical appliances such as stoves and refrigerators;  Using other fuels such as propane, liquid gas or kerosene;  Burning wood and coal (See Table 3.6.2, p329)  Calculate the amount of CO2 released:  amount of energy used per month x emission factor for that energy source.  When we add up the total of CO2 released per month from the use of various energy sources, we get our ‘carbon footprint’.  A heavy carbon footprint – releases a large quantity of CO2, causes much damage to the environment.  A light carbon footprint - releases a small quantity of CO2, causes less damage to the environment.
  • 15. Increase in emissions: B) Increase in Methane Emissions  Methane – 2nd most important greenhouse gas  Sources:  Micro-organisms in the intestines of herbivorous animals undergo anaerobic respiration, release large amounts of methane  Decomposition of organic wastes in land-fill sites  Decomposition bacteria used in the treatment of waste water to break down large particles in the water  Agricultural activities, such as the growth of rice in paddies  Mining releases methane trapped in the lower levels of the Earth  The crystal structures of ice stores methane; when ice melts methane is released  The production, handling, transmission and combustion of fossil fuels release methane  The concentration of methane is much lower than that of CO2, but the effect of global warming is 21 times higher!
  • 16. Increase in emissions: C) Increase in Nitrous Oxide Emissions  The use of chemical fertilisers have increased dramatically.  The use of nitrogen-rich fertilisers release nitrous oxides which have 300 times more heat-trapping capacity per unit of volume than CO2.
  • 17.  Forests cover 1/3 of the total land surface of the Earth.  Forests use CO2 during photosynthesis – they act as CO2 ‘sinks’.  Deforestation – the process of changing land use from natural forests and forestry to a non-forest use, such as agriculture, housing or mining.  Reasons for deforestation:  Many trees are chopped down for fuel  There is a huge demand for wood and paper products  Trees are cleared to provide grazing space for farm animals  Trees are cleared to make space for roads  Forests are cleared for the development of mining  Indigenous forests are cleared and replaced by plantations and agricultural crops, since the bring in more money.  Deforestation increases GHGs in four ways:  Number of plants  − CO2 captured by plants   Farms animals replace trees – methane produced   Wood and paper product production – energy use  and CO2 release   Huge increase in dead tree trunks  – termite population   and methane produced   Increase in emissions: D) Deforestation and Increase in GHGs
  • 18. Increase in emissions: E) Ozone Depletion and Increase in CO2 Levels  Ozone molecule – 3x oxygen atoms (O3)  Thin layer of ozone acts as a protective barrier around the Earth and reduces the amount of dangerous ultraviolet radiation from the sun.  The ozone layer is becoming thinner – Ozone depletion  Ozone depletions is caused by chemicals called chlorofluorocarbons (CFCs) – used in refrigerators and aerosols  Ozone depletion increases CO2 levels by:  More ultraviolet (UV) light from the sun reaches the Earth  Many plants are affected – cannot remove CO2 normally  Some plants die, others cannot photosynthesise normally  More CO2 remains in the atmosphere  So CO2 levels in the atmosphere are increased  Other effects of ozone depletion:  UV light  - skin cancer   UV light  - affects human immune system (early research) Hole in the Ozone over Antarctica
  • 19. Solutions to Ozone depletion  International actions was taken - Montreal Protocol (1989) (p334)  30 Nations world-wide agreed to reduce the use of CFCs  Ozone depletion can be reduced by:  Monitoring the elimination of CFCs as a propellant in aerosols  National monitoring of skin cancer  Increasing public awareness of skin cancer  Investigating new ozone-friendly repellants (and refrigerators)  Which sectors produce the most GHGs? (Figure 3.6.9 p335)  Production and supply of energy – 25.9%  Industry – 19.4%  Forestry – 17.4%  Agriculture – 13.5%
  • 20. Annual Global GHGs Emissions by Sector Annual South African GHGs Emissions by Sector
  • 21. Effects of Global Warming  Global warming has resulted in the following climate changes:  An increase in the average global temperature  Melting polar ice caps – rising sea-levels and coastal flooding ► Sea-levels are predicted to rise more than 1,5 m by 2050. ► Rising sea-levels cause flooding in coastal and low-lying areas ► Melting ice caps causes the Earth’s temperature to rise: (Fig. 3.6.10 p337) ► Ice reflects most of the sun’s rays, only a little is absorbed ► Water absorbs more of the sun’s rays than ice ► As ice turns to water, the Earth's temperature rises because: 1. The water’s increased ability to absorb heat from the sun’s rays 2. Methane (a GHG), stored in the crystal structure of ice, is released ► As the Earth’s temperature rises – more ice melts – global temperature increases further ► The process continues in a cyclic fashion ► This is an example of positive feedback, a runaway process. The retreat of Pedersen Glacier, Alaska. Left: summer 1917. Right: summer 2005. Credits: NASA
  • 22. Effects of Global Warming(2)  Frequent floods and prolonged draughts ► Changes in rainfall patterns are expected ► Floods and/or draughts are expected ► Floods in low-lying areas, near the coasts and riverbanks (especially in informal settlements) – affect housing and may cause overflow of sewer lines ► Overflow of sewer lines may cause sewage to spill into human settlement areas – increasing the likelihood of water borne diseases like cholera.  Desertification ► Periods of prolonged draught followed by heavy flooding – washes away fertile top soil. ► Frequent loss of top soil – soils unable to support plant life – the land turns into a desert.  Reduced food productivity ► Some food-producing areas – become drier and less fertile ► Some food-producing areas – flooded by rising sea levels ► Food crops destroyed by hurricanes and tornadoes ► Soil erosion – reduces fertility of the soil ► High CO2 concentrations – unfavourable for many crop plants, favourable for many weeds – decreases crop production
  • 23. Effects of Global Warming(3)  Reduced biodiversity (p338) ► Many species cannot adapt to thee climate changes and will become extinct (some are extinct already).  According to the National Climate Change Response White Paper(Oct 2011)  By 2050 – SA coast will warm by 1-2˚C, the interior by 2-3 ˚C.  By 2100 – SA coast will warm by 3-4˚C, the interior by 6-7 ˚C.  Parts of the country – drier and with increased water evaporation – decrease in water availability – will affect human health, agriculture, mining, electricity-generation and the environment in general.  Increase in occurrence and severity of veld and forest fires, extreme weather events, floods and draughts.  Rising sea-levels will negatively impact the coast and its people.  Mass-extinctions of endemic plant- and animal species – will greatly reduce SA’s biodiversity with consequent impacts on eco-system services.
  • 24. Ways to Reduce Global Warming  Reduce the use of fossil fuels  Encourage the use of renewable energy sources – e.g. solar energy, wind power  Use nuclear energy (dangerous radiation for nuclear active waste is still a problem)  Re-plant forests – more trees act as a greater CO2 ‘sink’.  Reduce global greenhouse emissions from various sources  The Kyoto Protocol (Read p340-342)and the annual Conference of Parties (COP) on climate change attempts to get different countries to reduce the release of GHGs according to an agreed-upon plan.  Other possible ways to reduce global warming:  Boost energy efficiency – e.g. look for top energy star appliances  ‘Greening’ transportation – more fuel-efficient vehicles and ‘green’ fuel  Promote recycling and use renewable resources  Ensuring sustainable development and management of natural resources
  • 25. The Kyoto Protocol (1)  The third session of the Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC) took place in Kyoto, Japan in December 1997, resulting in the Kyoto Protocol.  This working agreement of the signatories commits developed countries to reduce their collective emissions of six greenhouse gases by at least 5 per cent of 1990 levels by 2012.  The Kyoto agreement became legally binding on 16 February 2005 when 132 signatory countries agreed to strive to decrease carbon dioxide emissions.  The Kyoto Protocol now covers more than 170 countries globally, but this is only 60% of the countries that release GHGs.  According to the Protocol, governments are separated into two general categories:  Developed countries (referred to as Annex 1 countries)  Developing countries (referred to as Annex 2 countries)  The biggest problem with the discussions is that different countries cannot agree upon how much each country should reduce its green house gas emissions and in what period of time this should happen  The 36 developed countries were required to reduce the release of their own GHGs to levels specified for each as in the agreement.  The United States has not accepted the levels specified for it.
  • 26. The Kyoto Protocol (2)  As of January 2008, running through 2012 (referred to the first commitment period), Annex 1 countries have to reduce their GHG emissions by a collective average of 5,2% below their 1990 levels.  For many countries, this is 15% below their expected GHG emissions in 2008.  Milestones in Controlling Climate Change  Yearly meetings of COP – Since the UNFCCC came into force in 1995, The various countries (parties) have met every year to assess progress in dealing with climate change (Conference of Parties (COP))  In 2005, at COP 11 in Montreal, Canada, countries were asked to extend their commitments beyond the end of the first commitment period (2012).  In 2007, at COP 13 in Bali, Indonesia, the Bali Action Plan was launched to extend long-term co-operative action on climate change beyond 2012. The long-term plan was divided into 5 main categories:  Shared vision;  Mitigation; (The action of reducing the severity, seriousness, or painfulness of something)  Adaptation;  Technology;  Financing  The plan was to be agreed upon and accepted at COP 15 in Copenhagen. From the Kyoto Protocol to COP 17
  • 27. From the Kyoto Protocol to COP 17 (2)  In 2009, at COP 15 in Copenhagen, Denmark, many hoped the Bali Action Plan would be finalised and an agreement towards a fair, ambitious and equitable agreement , setting the world towards a path to avoid dangerous climate change would be reached. But the agreement was not formally accepted.  In 2010, at COP 16 in Cancun, Mexico, Governments agreed:  To continue work on identifying a goal for substantially reducing global emissions by 2050.  To work towards identifying a time frame for the peaking of global emissions and wanted a second commitment term for the Kyoto Protocol.  In 2011, at COP 17, Durban, South Africa, the following was looked at:  Details of the Bali Action Plan  Goals for reducing GHG emissions by 2050  Time frames for the peaking of GHGs  A second commitment term for the Kyoto Protocol  Development of a Green Climate Fund.  The main agreements of COP17, known as the Durban Platform, were as follows:  Agreement on a second commitment of the Kyoto Protocol, starting January 2013  Development of a new legal climate change agreement, which will apply to all countries i.e. developed as well as developing countries, to replace the Kyoto Protocol, as soon as possible, but not later than 2015  Establishment of the Green Climate Fund to help developing countries reduce carbon emissions and control global warming (known as mitigation) as well as finding ways and means to manage and adapt to these changes (known as adaptation). Mitigation the action of reducing the severity, seriousness, or painfulness of something. "the identification and mitigation of pollution" Did you know that… • South African Developing Countries (SADC) account for 2% of global emissions. • Africa contributes to around 7% of the world GHG emissions.
  • 28. After COP 17…  2012: COP 18, Doha, Qatar  The Conference produced a package of documents collectively titled The Doha Climate Gateway. The documents collectively contained:  An amendment of the Kyoto Protocol (to be ratified before entering into force) was made featuring a second commitment period running from 2012 until 2020, limited in scope to 15% of the global carbon dioxide emissions.  This limit is due to the lack of commitments of Japan, Russia, Belarus, Ukraine, New Zealand (nor the United States and Canada, who are not parties to the Protocol in that period) and due to the fact that developing countries like China (the world's largest emitter), India and Brazil are not subject to emissions reductions under the Kyoto Protocol.  The conference made little progress towards the funding of the Green Climate Fund.  2013: COP 19, Warsaw, Poland  COP 19 was the 19th yearly session of the Conference of the Parties (COP) to the 1992 United Nations Framework Convention on Climate Change (UNFCCC) and the 9th session of the Meeting of the Parties (CMP) to the 1997 Kyoto Protocol (the protocol having been developed under the UNFCCC's charter).  2014: COP 20, Lima, Peru  From December 1-12, 2014, Lima, Peru will host the 20th yearly session of the Conference of the Parties (COP) to the 1992 United Nations Framework Convention on Climate Change (UNFCCC) and the 10th session of the Meeting of the Parties (CMP) to the 1997 Kyoto Protocol (the protocol having been developed under the UNFCCC's charter).  2015: COP 21, Paris, France (Source:
  • 29. South Africa’s Contribution Towards Controlling Climate Change (p343)  South
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