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ISSUES & CONCERNS • INTRODUCTION 1) Our earth naturally provides services that: Purify air and water Maintain the global atmosphere Detoxify and decompose wastes Generate and renew soil and soil fertility Pollinate crops and natural vegetation Control the vast majority of agriculture pests Disperse seeds and transfer nutrients Maintain complex sources for our agricultural, medicine, and manufacturing Screen harmful radiation Regulate the climate and sea level Mitigate floods and droughts Moderate temperature extremes and the force of wind and waves Support diverse human cultures However, human activity has made it increasingly difficulty to provide this service ! ! Lectures – Issues & Concerns Page 1 SUSTAINABLE DEVELOPMENT - WHY CONCERNED? STATE OF THE WORLD ENVIRONMENT 1950 - 1997 Population (billions of persons) Megacities (cities of more than 8 million people) Food (ave. daily production in calories/capita) Fisheries (annual fish catch in million tons) Water use (annual water use in cubic kilometres) 1950 1972 1997 2.5 3.8 5.8 2 9 25 1980 2450 2770 19 58 91 1300 2600 4200 Rainforest cover (index of forest cover 1950=100) 100 85 70 Elephants (milions of animals) 6.0 2.0 0.6 CO2 Emissions (billions tons of carbon per annum) 1.6 4.9 7.0 Ozone Layer (atmospheric concentration of CFC’s in parts/billion) - 1.4 3.0 This gives an opportunity to raise some sustainability issues and concepts. • Climate Change – Global Warming/Acid Rain – importance of SOx, NOx, CO2, - Energy and Transport. May need extra material to present • 1/3 of the population lives on less than $1 per day – roughly the cost of a pint a week!! • 25% of the population has no access to healthcare • In Europe 30% of population are OAP’S. In 2030 it will be 70%. Lectures – Issues & Concerns Page 2 WHY CONCERNED? ENVIRONMENT • CLIMATE CHANGE • BIO-DIVERSITY • RESOURCES • POLLUTION CAUSING BOTH ENVIRONMENTAL & PUBLIC HEALTH DAMAGE •Climate Change is recognised by most governments world wide as the major issue facing us all •Often Bio-Diversity is focused on the rare and endangered species, but many local flora & fauna are in decline •Resources can be renewable – plants/trees but others are non-renewable – oil, coal, mineral ores etc. The approach to using these materials has to be different •Every pollutant has a health hazard associated with it Lectures – Issues & Concerns Page 3 1) GLOBAL WARMING What is the greenhouse effect? The earth is surrounded by a layer of gases. These The main gases which contribute to global allow the passage of ultra-violet radiation from the sun warming are: to the earth. The earth radiates back some of this radiation, but at a longer wavelength. This radiation is Carbon dioxide (CO2) absorbed by certain ‘greenhouse’ gases in the atmosphere, leading to a temperature rise. Methane (CH4) This process is known as the greenhouse effect because it involves trapping in heat like glass in a greenhouse Global warming potential Global Warming Without the greenhouse effect, the earth would be about 30oC colder, and life as we know it would not exist. However, it is the enhancement of the effect which causes concern. Man’s activities release extra amounts of greenhouse gases, leading to an increase in atmospheric temperature known as global warming. Why is it called the greenhouse effect? Incoming solar radiation Chlorofluorocarbons (CFCs) Some solar radiation is reflected by the earth’s surface and the atmosphere The contribution of each gas to global warming is a reflection of: The amount generated Its potency as a greenhouse gas, represented as the global warming potential (GWP); this is a measure of the warming resulting from 1 kg of a given gas relative to the warming from 1 kg of carbon dioxide. CFC 12 has a GWP of 7300. This means that 1 kg of CFC 12 will produce warming equivalent to 7300 kg of CO2 – nearly three quarters of a tonne! Greenhouse gases Solar radiation passes Through the clear atmosphere Some solar radiation is absorbed bythe surface and warms it Carbon dioxide (CO2) ATMOSPHERE Infra-red radiation is emitted from the earth’s surface EARTH Some of the infrared radiation is absorbed and reemitted by the greenhouse gases. The effect of this is to warm the surface and the troposphere CO2 contributes around 50% of global warming. It is released by burning fossil fuels such as gas, coal and oil as well as wood. The use of renewable energy will therefore play a major part in reducing CO2 emissions. Industrialised nations such as the UK and USA account for 20% of global population and 80% of global CO2 emissions. The USA produces 22 tonnes of CO2 per person every year, compared to just 0.7 in India Lectures – Issues & Concerns Page 4 We can reduce our CO2 emissions by: Not wasting energy: switch off unnecessary items and use energyefficient equipment both at home and at work Reducing car use: if possible use public transport or self-propulsion Reducing waste production (CO2 is released from landfill sites due to the breakdown of waste), and conserving and planting trees (which absorb CO2 from the atmosphere) Methane (CH4) Major global sources of methane include natural wetlands, rice growing, cattle farming and the escape of natural gas. A quarter of UK methane emissions are derived from landfill, and can be reduced by minimising the waste that we produce. Naturally this will make economic as well as environmental sense Chlorofluorcarbons (CFCs) CFSs are compounds containing chlorine, fluorine and carbon, which have been widely used in foams, propellants and coolants. They are inert, stable and have a high global warming potential; hence the use of international agreements such as the Montreal Protocol which aim to phase our CFS usage. Agriculture and ecosystems Agriculture occurs in bands around the globe. Global warming will force changes to traditional practices, with potential impacts on total global food production. Ecosystems will be forced to adapt, relocate or die out. Sea levels and water resources Sea levels will rise due to thermal expansion of water and melting of land ice. A rise of 20-5cm is expected by 2050, threatening low-lying areas. Patterns of cloud and precipitation will also vary, and many dry areas might receive even less rainfall. Impacts on human population Less developed countries will be less adaptable to changes, and impacts will be especially hard on those currently under stress. Increased temperature may affect health, by altering the availability of water and changing the spread of disease. The effects of global warming o C The impact of global warming average temperature to date. The red line shows the best estimate of predicted temperature rise. 4 3 2 There are, however, still plenty of CFSs in use. These should be recovered, recycled and reused. A domestic refrigerator contains around 120g of CFC in coolant and 180g in the foam insulation. If you replace your appliance, see if shops will take your old one for CFS recovery, and check whether new equipment is CFC-free. Effects of global warming It is estimated that 0.3 – 0.6o C of global warming has occurred in the past century. A further 1.5 – 4.5o C is predicted by 2050, and this will have a variety of effects, outlined below. 1 0 1860 1900 1940 1980 2020 2060 Cm Year Future sea levels The red line shows the predicted sea level rise. The dotted line shows the proportion of this that is due to thermal expansion of the oceans 20 16 12 8 4 0 0 10 20 30 40 50 60 70 Years Lectures – Issues & Concerns Page 5 2) ACID RAIN What is acidity? Acidity is measured on the pH scale. This runs from pH 0, the most acid, to pH 14, the most alkaline. PH 7 is neutral, i.e. neither acid nor alkaline. The pH scale is logarithmic; pH 4 is 10 times more acid than pH 5. Some everyday comparisons include lemon juice (pH 2.3), vinegar (pH 3.3) and baking soda (pH 8.2). Even in the cleanest air rainfall is acidic, with a pH around 5. As water falls through the atmosphere it dissolves a small amount of carbon dioxide and forms a weak carbonic acid. Dry acid gases, or even particular matter to which they are attached, are also deposited on the earth’s surface, in a process called dry deposition. The collective name for all the processes, wet and dry, which result in the transport of acid materials from the atmosphere to the surface of the earth is acid deposition. What is acid rain? The acidification process When the atmosphere contains oxides of sulphur and nitrogen, they too will dissolve in the falling rain and its acidity will rise. Industry and transport emit pollutants such as sulphur dioxide and nitrogen oxides, both of which are acidic. These oxides may be deposited as gases, or fall from the atmosphere attached to particles. This is dry deposition, and it usually occurs close to the pollution source. Formation and deposition of acid rain Chemical conversion SO2 Sulphuric acid Nitric acid NOx NO2 SO2 Dry deposition Wet deposition Alternatively, the oxides may have contact with water in the atmosphere and be converted into sulphuric and nitric acids. These become dissolved in cloud and fall as precipitation (rain, snow, hail, mist or fog). This is wet deposition, the effects of which may occur thousands of miles from the source of the pollution Acid gases Sulphur dioxide (SO2) Nearly all fossil fuels (for example oil, coal and gas) contain sulphur. When these fuels are burnt, sulphur is released which combines with oxygen to form sulphur dioxide. Coal-fired power stations account for over 70% of UK emissions. In one day of full production, a 2000 MW coal-fired power station emits around 400 tonnes of SO2 (equivalent to 600 tonnes of sulphuric acid). Other sources include industrial boilers and coal-burning processes such as smelting. Lectures – Issues & Concerns Page 6 Nitrogen oxides (NOx) What can I do to help? Nitric oxides (NO), nitrous oxide (N20) and nitrogen dioxide (NO2) are usually grouped under the collective term of nitrogen oxides (NOx). These are formed in all types of combustion when air is heated to more than 650o C. Road transport is the largest single contributor to NOx in the UK (51%). There are currently 24 million vehicles in the UK, and this figure is expected to rise to over 50 million by 2025. Power stations and industry are the next most significant contributors. Movement of Pollutants The time-lag between the emission of pollutants and the falling of acid rain means that the wind plays a vital role in dictating where the acid compounds are actually deposited. In Europe the prevailing wind direction is south westerly. Pollutants from the UK and western Europe are therefore frequently carried into central and northern Europe before falling as acid rain. Neutralisation of acidification Rain normally has a pH of 5. This will not usually acidify soils and surface waters with a natural buffering capacity, i.e. an ability to resist change and neutralise the acid. This gives some protection to lakes in lime-rich areas which receive neutralising compounds from the surrounding soil and rock, but lakes and soils which lack a suitable buffer will become acidified. There is a predominance of these features in Scandinavia, which is also where a large proportion of European pollution is blown by the wind, hence the severe problems of acidification in the area Save energy at home and at work (this will lower power station emissions, fossil fuel consumption and your costs) Minimise car use (consider public transport or self-propulsion) Allow catalytic converters to warm up before going at speed (these convert NOx into less harmful compounds) Ensure your car is properly tuned, regularly serviced and the tyres are correctly inflated. 50% of road pollution is caused by only 10% of vehicles The effects of acid deposition on freshwater ecosystems pH 7.0 6.5 6.0 5.5 5.0 4.5 4.0 6.0 Crayfish and shrimps 5.7 Snails and sensitive ephemerid larvae 5.5 Minnows, salmon, roach 5.1 Trout 4.8 Many ephemerids and other small animals Perch, pike 4.4 Hardy insects Effects of acid rain When lakes become acidified, they suffer a decrease in the number of plant and animal species. Acid rain also causes damage to materials, for example structures such as the Parthenon, the Colosseum and, in the UK, many cathedrals Bog moss proliferate Tolerance of acidity by selected freshwater aquatic species Lectures – Issues & Concerns Page 7 3) OZONE What is acidity? Ozone is a gas which occurs naturally in the atmosphere. It is a form of oxygen, each molecule of which consists of 3 oxygen atoms (O3). Ozone is especially important in the upper atmosphere because it forms a protective layer which filters out potentially harmful rays from the sun. This is known as the ozone layer. The process requires still sunny weather, but even so, it is becoming a problem in the UK! It results in a blue/brown haze in the atmosphere and can lead to damage to plants, irritation of the eyes and notes and can aggravate breathing difficulties Low-level ozone Photochemical pollutants In the lower parts of the atmosphere (troposphere) ozone is a damaging pollutant. It is formed by the action of sunlight on pollutants emitted from vehicles and industry, for example nitrogen oxides and volatile organic compounds. This process is known as a photochemical reaction (it requires light) and the ozone that it creates is a major contributor to photochemical smog. Volatile organic compounds (VOCs) are major contributors to photochemical smog. They are released from many sources, including: solvents, for example paints and inks Tropospheric ozone (in the lower atmosphere) Sunlight Ozone (O3) petrol, from storage, distribution and motor vehicles In Europe, around 35% of VOCs are due to road transport, and 30% due to solvent use. VOCs are a cause of other concerns as well, as some are toxic and cancer-causing, some contribute to high-level (stratospheric) ozone depletion, and most contribute to global warming. The other major component of low-level ozone build up, nitrogen oxides, are detailed on Factsheet 1, Global Warming. Photochemical pollutants Photochemical smog formation Pollutants (hydrocarbons oxides of nitrogen, carbon monoxide) Ground-level ozone (O3) The ozone present in the stratosphere forms the ozone layer. This is important to mankind as it absorbs ultra-violet radiation that is emitted from the sun. In the spring around 60% of the ozone over Antarctica is destroyed. This is commonly known as the ‘hole’ in the ozone layer; the depletion is due to the unusual climatic conditions in the area, and has now spread to the edge of Latin America and the Falkland Islands. Those living in such areas will therefore suffer from increased exposure to ultra-violet radiation. Lectures – Issues & Concerns Page 8 Ozone-depleting chemicals Ozone depletion is attributed to a range of chemicals which contain chlorine and/or bromine, both of which destroy ozone molecules in the stratosphere. Most important are chlorofluorcarbons (CFSs). These are very stable gases which are eventually transported into the stratosphere. Here they are broken down by radiation from the sun, releasing chlorine which reacts with ozone and destroys it. The chlorine itself is not destroyed, and just one chlorine atom can destroy up to 100,000 ozone molecules. Other ozone depleters include halons, carbon tetrachloride and 1,1,1-trichloroethane. The potential of a given substance to deplete ozone is expressed as the ozone depletion potential (ODP). The higher the ODP, the more destructive the compound. Hydrochlorofluorcarbons (HCFCs) have been introduced as temporary replacements for CFCs. They still deplete ozone, but to a much lesser extent than CFCs. Typically a quantity of HCFC would have an ozone depletion potential of 2-10% of one of the main CFCs. Hydrofluorocarbons are similar to HCFCs, but they do not contain chlorine and therefore do not deplete ozone. However, they still contribute to the enhancement of the greenhouse effect. Scientists believe that a 1% reduction in ozone can lead to a 1-2% increase in ultraviolet radiation and a potential 2-4% increase in skin cancer. Plant cells and aquatic life may be damaged. This has implications for the whole food chain. What can I do to help? Recover, recycle and reuse CFCs. When replacing refrigeration equipment, see if suppliers will take your old appliances and arrange for the CFCs to be recovered. Check that new equipment is CFCfree Ask how your company has addressed the issue When replacing fire extinguishers, look at substitutes for any containing halons. Halons should be recycled for use in specialist processes which cannot yet manage without them. Ozone depletion 450 400 300 250 200 150 Mean monthly ozone levels in Dobson units Ozone-depleting chemicals If the ozone layer is depleted, it cannot absorb as many rays from the sun. This may lead to problems for humans such as: Skin cancer Premature ageing of the skin Damage to eye tissue Reduced immunity to diseases which enter the body through the skin A representation of the ozone hole over the Antarctic, based on a satellite image taken in October 1990 Lectures – Issues & Concerns Page 9 SOCIAL • POPULATION GROWTH 12 BILLION IN 2050 ? • 1 / 3 OF POPULATION LIVE ON LESS THAN $1 PER DAY • 25 % OF POPULATION HAVE NO ACCESS TO HEALTHCARE • IN EUROPE TODAY LESS THAN 30 % OF POPULATION ARE PENSIONERS. IN 2030 IT WILL BE 70 % • SOCIAL EXCLUSION Population growth and the “Quality of Life” of over 30% of the population is low – unacceptable (?) In developed world, the population is growing older, so needs/requirements will change with time. Major opportunity for new designers!! Lectures – Issues & Concerns Page 10 ECONOMIC • POVERTY • INTERNATIONAL COMPANIES • NORTH / SOUTH DIVIDE • STANDARDISATION – PRODUCTS & SERVICES • PRODUCT COSTS TO INCLUDE ENVIRONMENTAL DAMAGE • TAXES, LEVIES, ETC. TO CHANGE CUSTOMER BEHAVIOUR Poverty is seen as the major issue. It is not exclusive to the underdeveloped countries, it happens in the UK and USA Some major concerns regarding behaviour of financial institutions – “uncaring” – many making money – most eminent cultures and religions saw it as not acceptable. On the other hand it can be argued until we pay the “true” cost of a product we will not change our behaviour. Lectures – Issues & Concerns Page 11 SUSTAINABILITY ASPECTS TO CONSIDER ENVIRONMENT •Use of Hazardous Materials •Water usage •Energy usage high •Electricity usage high •Waste generated high •Special/Hazardous Waste •Emissions from process – VOC •Discharges from process – BOD, COD •Generate Nuisances – noise, dust, odour, heat •Transport across the world •Ability to recycle at E.O.L. •Disposal method simple •Global Warming potential •Ozone-depleting substances SOCIAL •Health & Safety at risk •Human rights affected •Community impacted •Community involvement •Site selection •Staff training •Staff development •Skills transfer •Technology transfer •Ease of disposal •Nuisances •Use of child labour (self & suppliers •Extent of distribution •Transport to and from site •Operation close to sensitivity area •Animal testing requirements ECONOMIC •Raw material costs •Manufacturing costs •Distribution costs •Community impact •User costs •Patient costs •Levy/Taxes implication •Economic instruments applies •R & D costs •Other capital investments •Human capital – employee training, community education, customer training/education etc. This list is not exhaustive, but covers most of the issues and concerns. Some will be more important to you than others. Some you may never have considered before!! It is important at the early stage of an assessment a very wide range of issues is considered – it increases awareness for the people involved and brings to the surface hidden issues! Lectures – Issues & Concerns Page 12