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RESOURCES. What is a RESOURCE? source of raw materials, used by the society - includes all types of matter and energy that are used to make the society working. Depletion of resources. When the resource is utilized faster than it is replaced by natural processes e.g. oil
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RESOURCES What is a RESOURCE? • source of raw materials, used by the society - includes all types of matter and energy that are used to make the society working.
Depletion of resources When the resource is utilized faster than it is replaced by natural processes e.g. oil • millions of years to form • extracted and burned in a few years
The City – an open system What does an OPEN SYSTEM means? • it is not self-sustainable; • it needs energy and materials to keep up.
INPUT (from environment) OUTPUT (into environment) Accelerating energy flows litosphere litosphere (energy, minerals) (solid waste) hydrosphere hydrosphere (water pollution) (water) sinks sources society biosphere biosphere (degradation) (agriculture, wildlife) atmosphere atmosphere (air pollution) (air) Accelerating matter cycles depletion problems pollution problems
gas outflow (industry, transportation) respiration 19 t 5.1 t 6 t 0.8 t sewage food end product materials 89 t 61 t 3 t 0.1 t solid waste Solid waste society (towns) is an open system – is not self-sustainable energy is needed energy and material flow has changed due to human activity + 6 t stored temporarily + 0 stored temporarily
Main problems - extra consumption - population increases - urbanization - emission is more dangerous These processes intensify each other
Extra consumption Non-renewable resources • it takes millions of years to form • resource is utilized faster than it is replaced by natural processes • depletion of resources • oil, coal, natural gas, minerals, metals
Extra consumption Renewable resources • can be replaced within a few generations • solar power, wind power, hydro power, biomass, food, timber
Increasing population • more materials and energy is needed • the size of the cities are increasing (horizontally and vertically) =urbanization - too many people are concentrated in a small place (New York, 24000 pe/km2) • original flora and fauna disappear
Population growth In 1800: only 5% in towns Growth rate: 0.8% in developed countries 3.6% in the third world
Emissions • emission values are increasing • high concentration in a small place • all material shows up the wastewater • more dangerous components (chemicals, medicines, etc.)
Towns – built areas original flora and fauna disappear Population growth size of the towns increase (horizontally and vertically) New York: 24 000 pe/m2 psychological, social problems Constructions reshape topography depletion of geological values erosion – soil loss Change in water household
Other effects • change in the water household (surface runoff increases) • communal waste disposal is not solved • air pollution • wastewater must be treated • soil pollution • change in climatic conditions
Towns are the main sources of environmental pollution • Industrial production is concentrated in towns • Communal waste – in lots of towns disposal is not solved • Toxic materials (heavy metals, acids, organic pollutants) • Pathogens (viruses, bacteria) • Artificial materials – plastic – non bio-degradable • Waste dumps without insulation • – water dissolves hazardous matters – groundwater pollution • Air pollution – SO2, NOx, CO, O3, dust
Pollution of soils • Heavy metals (Pb, Ni, Cd), Zn, Mn, Fe • Transportation • Industry • Wastewater • Town with 1 million inhabitants – 0.2-0.5 million m3 sewage • Inorganic, organic pollutants, pathogens • To surface or subsurface recipients – pollution of waters
Change in the climatic conditions • Higher temperature (yearly average +0.5 – 1.2 °C) • Sun radiation is less because of air pollution • Special surfaces - reflection is higher • - surface warms up more easily • Air pollution – greenhouse effect • Heat from houses, industry, transportation • Fast runoff – less evaporation (cooling effect) • Less wind (local wind tunnels between house blocks) • More precipitation • Humidity of air is lower (URBAN DESERT) • Smog
Aim: sustainable resource use • slow down the rate of resource utilization to the point where the resource can be replaced by the nature • in serious cases: stop the current use • the actions above slow depletion and reduce pollution also - historical thinking: rapid exploitation of resources (social, economic, political pressure)
Why do we need to manage resources? • nature is not only a „resource” • growth of population and technology increases the utilization - correct management can help minimize the environmental damage • making decisions about how to use resource is essential to solve the environmental challenges, that global society faces
COSTS OF RESOURCES • increasing resource use provides high short-term economic benefits • any short term benefit of resource use is worthwhile if we ignore environmental costs (clear-cutting a virgin forest yield enormous profits) • more realistic if we include the long-term economic benefits of not using them • less resource use often gives greater economic benefits (tourism, native food, medicines) - thinking in long-term!!
Resource management • Principle: less resource use can lead long term economic benefits and reduced environmental costs • some resource use is unavoidable - we try to minimize, where it’s possible
Resource management • used techniques: • preservation • conservation • restoration
Preservation • it means: non-use • try to protect an area in its original, natural state
Conservation • it means: input reduction • minimize the use of a natural resource • improving the efficiency • recycling or reuse • substitution with other resources
Restoration • return a degraded resource to its original state • extremely expensive
supply exceeds demand demand exceeds supply New resource use Resource use time DEPLETION OF RESOURCES resources are exploited very quickly once society discovers their utility • exponential growth of population and technology indicates exponential use of the resources as long as supply exceeds demand • resources on Earth are finite - limits to growth occur • society intensifies its effort to obtain more of the resources through further exploitation and increased technological application
supply exceeds demand demand exceeds supply Resource use New resource use time DEPLETION OF RESOURCES • at the end increasing efforts to extract the resource produce progressively smaller amounts (law of diminishing returns) • production declines exponentially because the most easily extracted concentrations of the resource become exhausted • rise of the prices or switching to an other source (wood - coal - oil)
TYPES OF RESOURCES • MINERAL RESOURCES • FOOD • SOIL • ENERGY • LAND RESOURCES • BIOLOGICAL RESOURCES • WATER • AIR • ...
MINERAL RESOURCES • Economic minerals = minerals used in manufacturing • METALS • iron and steel (740 million tons used annually) • manganese (22.4 million t) • copper (8 million t) • chromium (8 million t) • aluminum (4,6 million t) • nickel (0,7 million t)
METALS important because economic and social stability consumers: • USA • Japan • Europe producers: • South America • South Africa • former Soviet Union
NON -METALS silicate minerals (asbestos, talc) sand, gravel salts limestone soils gypsum (calcium-sulphate) sulphur fertilizers (potassium-sulphates, potassium-chloride) …..
Importance of recycling - some minerals are in short supply tin, platinum, gold, silver, lead - recycling - reduce the amount of waste - reduce the land lost to mining - reduce the consumption of energy, water resources, money
Non-renewable energy sources Fossil fuels Coal Oil Natural gas 90% of all commercial energy is provided by fossil fuels Resources are not infinite! Oil supply: 35 years (at present rate of use) Gas supply: 60 years Coal supply: 300 years
Renewable energy sources Wind and water power were the main energy sources before industrial revolution • Hydroelectric • Wind • Biomass methane • Solar electric • Geothermal
Energy sources • Non-renewable energy sources • Finite • Cause pollution • Renewable energy sources • High initial cost • Difficult to store the energy • Less pollution
Food - food supplies grow more rapidly than human population - there is enough food to meet the minimum diatery requirements of everyone now living - 750 million people suffer from undernutrition or malnutrition - 20 million people die each year from diseases related to undernutrition
FOOD - Thousands of edible plants and animals - We eat: - a dozen types of seeds and grains - three root crops - twenty common fruits - six mammals - two domestic fowl - few fish
Soil and agriculture - fertile, tillable soil is needed for the crops - in a healthy ecosystem soil is a renewable resource - it can accumulate 1 mm deep per year - human-caused erosion is generating soil losses (25 billion tons each year) - diminished crop production - many alternative methods to reduce erosion, avoid dangerous chemicals and improve yields
BIOLOGICAL RESOURCES Estimations: 3-30 million different species on the Earth 1,7 million species have been identified food medicine clothing building materials other potential use - if we can prevent their destruction
BIOLOGICAL DIVERSITY Biodiversity = species diversity How many kinds of organisms occur in a community Ecosystem stability is strongly affected by species diversity: elimination of one species would have smaller effect on a complex ecosystem
BIOLOGICAL DIVERSITY A very simple example: • there is only one type of grass, • one type of rabbit eating the grass, • one type of predator eating the rabbit • If there comes any effect degrading this type of grass (pest, environmental change, etc.) -it also degrades the rabbit and its predator • While having more types of grass, there might be some species of grass that is resistant to that specific environmental change – rabbits and the predators will still have something to eat
HUMANS THREATEN WILDLIFE DIRECTLY • overharvesting animals and plants for food and commerce • using pesticides INDIRECTLY • altering or destroying wildlife habitats • exotic species • diseases • pollution
HUMANS THREATEN WILDLIFE normally these changes take thousands or millions of years –ecosystem have time for adaptation human activity causes very quick (immediate) changes –ecosystem does not have time for the natural selection Response: vanishing species (those disappear who can not adapt these strong and quick changes)
HUMANS THREATEN WILDLIFE Humans can not kill all kinds of life-forms Nature will survive Problem is that humans may not survive the degradation of natural environment (not enough food, clean water, clean air, etc.)
AIR RESOURCES Necessary for the survival of all higher forms of life Human can survive 5 minutes without air Seems to be vast in volume Earth = an apple Atmosphere = apple's skin
WATER RESOURCES • Earth is very rich in water: >70% of the planet`s surface • More than 97 % of this is salt water • 30 % of the world`s renewable fresh water supplies are already being used • Enough fresh water is available to support over 20 billion people, if it were evenly distributed. • Because of variable climatic and geologic condition it is available to 6 billion people.
Atmosphere, rivers, plants, animals 0,001% Fresh water 2,6% Groundwater0,59% 0,014% Soil moisture 0,005% Salt water in oceans and seas 97,4% Ice caps and glaciers 1,98% Lakes 0,007%
WATER DEMAND • human’s need (2-4 l/day) • agriculture (41% of the water) • cool power generators (38%) • industrial manufacturing (11%) • USA (1993)