mother earth -- our home it is has water, oxygen and a hospitable climate
TRANSCRIPT
Mother Earth -- Our Home
It is has water, oxygen and a hospitable climate
World Population
The Challenge:Sustainable Management of an Ever-Changing Planet
7,010,309,679
Sustainability is the capacity to endure. In ecology the word describes how biological systems remain diverse and productive over time
The Challenge: Sustainable Energy
The Challenge: Food Security
Food production needs to double to meet the needs of an additional 3 billion people in the next 30 years
Climate change is projected to decrease agricultural productivity in the tropics and sub-tropics for almost any amount of warming
The Challenge: Sustainable Forestry
Wood fuel is the only source of fuel for one third of the world’s population
Wood demand will double in next 50 years
Climate change is projected to increase forest productivity, but forest management will become more difficult, due to an increase in pests and fires
The Challenge: Water Security
Water Services
One third of the world’s population is now subject to water scarcity
Population facing water scarcity will more than double over the next 30 years
Climate change is projected to decrease water availability in many arid- and semi-arid regions
The Challenge: Sustainable Fisheries
The Challenge:Sustainable use & conservation of biodiversity
Climate change will intensify the loss of biodiversity
Estimated 10-15% of the world’s species could become extinct over the next 30 years
Biodiversity underlies all ecological goods and services
The Challenge: What Can We Do?
Some human activities that affect the biosphere include:•hunting and gathering•agriculture•industry•urban development
The Green Revolution The green revolution was an effort to increase global food production through modern plant breeding and agricultural techniquesOver the last 50 years, the green revolution has helped world food production double
Hunting and gathering
Agricultural revolution
Industrial revolution
Black Death—the Plague
Industrial revolution
Classifying Resources
–Environmental goods and services may be classified as either renewable or nonrenewable
•Renewable resources can regenerate if they are alive, or can be replenished by biochemical cycles if they are nonliving.
• A tree is an example of a renewable resource because a new tree can be planted in place of an old tree that dies or is cut down
•A nonrenewable resource is one that cannot be replenished by natural processes
• Fossil fuels such as coal, oil, and natural gas are nonrenewable resources - once these fuels are depleted, they are gone forever
•Human activities can affect the quality and supply of renewable resources such as land, forests, fisheries, air, and fresh water
•Desertification is the process by which productive areas are turned into deserts
• Desertification is caused by a combination of farming, overgrazing, and drought
DesertificationDesertification• As a result,
agricultural output decreases, or habitats available to native species are lost
Water PollutionWater PollutionPoint sources occur when harmful substances are emitted directly into a body of water (ex. the Gulf of Mexico oil spill)
A nonpoint source delivers pollutants indirectly through environmental changes (ex. fertilizer from a field is carried into a stream by rain)
Examples of Land Examples of Land PollutionPollution
Soil pollution is mainly due to chemicals in herbicides (weed killers) and pesticides (poisons which kill insects and other invertebrate pests)
Litter is waste material dumped in public places such as streets, parks, picnic areas, at bus stops and near shops
U.S. Oil Field
Land Pollution
Waste Disposal: the accumulation of waste threatens the health of people in residential areas.
Waste decays, encourages household pests and turns urban areas into unsightly, dirty and unhealthy places to live in.
Humans are using up the earth’s resources, including fossil fuels
Global Warming 101
Human impacts on the Environment
Global warmingUse of machinery by humans seems to be increasing CO2 levels in the air. CO2 prevents heat from escaping, causes slight world wide temperature increases
Rising water temperatures causes coral bleaching
Greenhouse Effect
• Burning fossil fuels in cars and power stations produces carbon dioxide, sulphur dioxide, methane and other greenhouse gases
Ozone depletion• Caused by aerosol chemicals called chlorofluorocarbons (CFCs)• CFC’s
– Escape into atmosphere, reacts breaking down the ozone (O3, a protective atmospheric layer)
– UV rays penetrate the atmosphere and cause harm to many organisms (skin cancer)
“HOLE” in the ozone (O3)
Acid RainAcid Rain• The burning of
fossil fuels (such as coal) and other industrial processes release into the air pollutants that contain sulfur dioxide and nitrogen oxide
• When these substances react with water vapor, they produce sulfuric acid and nitric acid.
When these acids return to the surface of the earth (with rain or snow), they kill plants and
animals in lakes and rivers and on land.
• Acid rain damages trees and pollutes rivers and lakes
DeforestationDeforestation• Clear-cutting of forests
causes erosion, flooding, and changes in weather patterns.
• The slash-and-burn method of clearing forests for agriculture increases atmospheric CO2, which contributes to the greenhouse effect
• Most of the nutrients in a forest are stored in the vegetation, burning the forest destroys the nutrients
Deforestation
• In may countries people are chopping down forests to provide timber or space for agriculture and for the growing population
Haiti vs Dominican RepublicBrown and deforested, Haiti’s terrain (left) contrasts starkly with the green, vegetated landscape of neighboring Dominican Republic. Deforestation has long been a contributing factor to Haiti’s plight: overconsumption of timber resources has led to barren soils and agricultural underproduction, contributing to massive urbanization and economic stagnation
This causes several problems
• Burning wood increases the level of CO2• Less trees means less CO2 for
photosynthesis and less oxygen produced• Soil is eroded as it is exposed to the wind
and rain• Less water is transpired by plant leaves• Many animal and plant habitats are
destroyed causing extinction of species
Human impacts on the environment
Deforestation• Caused by demand for wood products, need for space, farmland, housing, roads • Deforestation causes habitat fragmentation Animals and plants are forced into confined areas, increase in local temperature and reduction of oxygen
Habitat Fragmentation
Overfishing
Overfishing has greatly reduced the amount of fish in parts of the world’s oceans.
Until recently, fisheries seemed to be a renewable resource, but overfishing has limited that resource
Human impacts on the Environment
Fishing activities• Demand for fish and shellfish• Commercial Fishing be harmful to environment in many ways
–Aquaculture•The raising of aquatic animals for human consumption, which is called aquaculture, is also helping to sustain fish resources
Air Pollution
Air Resources•The condition of the air affects people’s health
•Smog is a mixture of chemicals that occurs as a gray-brown haze in the atmosphere
•Smog is:–due to automobile exhausts and industrial emissions
–considered a pollutant because it threatens people’s health
Air Air PollutionPollution
Suspended Particles – made up of soot, smoke, dust and liquid droplets
Nitrogen Dioxide – caused by fuel combustion, aerobic decomposition and nitrogenous fertilizers.
Sulfur Dioxide – produce by the combustion of fossil fuels, with motor vehicles and small and varied sources (such as boilers and stoves) contributing the most.
Associated health hazard: causes acid rain and can be extremely detrimental to the health of the young and elderly.
• Strict automobile emissions standards and clean-air regulations have improved air quality in many cities, and has a positive effect on global environment
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Copyright Pearson Prentice Hall
• Formation of Acid Rain
Air Resources
Emissions to AtmosphereNitrogen oxidesSulfur dioxide
Chemical TransformationNitric acidSulfuric acid
Condensation
Dry FalloutParticulatesGases
PrecipitationAcid rain, fog, snow, and mist
Industry Transportation Ore smelting
Power generation
•Acid rain kills plants by damaging their leaves and changing the chemistry of soils and standing-water ecosystems.
• Acid rain may dissolve and releases toxic elements, such as mercury, from the soil, freeing the elements to enter other portions of the biosphere
What can we Do?
Sustainable Development
•Sustainable development is a way of using natural resources without depleting them, and providing for human needs without causing long-term environmental harm
Sustainability is the capacity to endure. In ecology the word describes how biological systems remain diverse and productive over time
•Improvements in agriculture, health, and medicine have produced a dramatic rise in the human population• This increase in population size
leads to an increase in pollution and higher demand for the world’s resources
Four Scientific Principles of Sustainability
Organic Farming?
• This produces less food and is more expensive but it does not produce the pollution problems of intensive farming
Use farmyard manure as a fertilizer and set aside land for
growth of wild plants
Biological Control of Pests
• This means using natural predators to eat pests instead of pesticides
• It does not have harmful effects
Energy Sources
• Coal provides around 28% of our energy, and oil provides 40%.
• Crude oil (called "petroleum") is easier to get out of the ground than coal, as it can be Pumped from deep wells and flow along pipes. This alsomakes it cheaper to transport
Coal and Uranium
• Natural coal contains trace amounts of uranium, and when it is burned to produce electricity, varying amounts of the radioactive element are left behind in the ash
• This yielding uranium could be reused as a fuel for nuclear reactors
• Natural gas provides around 20% of the world's consumption of energy and can be pumped from deep wells
Advantages to Using Fossil Fuels
• Very large amounts of electricity can be generated in one place using coal, fairly cheaply.
• Transporting oil and gas to the power stations is easy.
• Gas-fired power stations are very efficient.
• A fossil-fuelled power • station can be built • almost anywhere
Oil refinery in U.S. state of Texas
Disadvantages of Using Fossil Fuels
• Basically, the main drawback of fossil fuels is pollution.
• Burning any fossil fuel produces carbon dioxide, which contributes to the "greenhouse effect", warming the Earth.
• Burning coal produces sulphur dioxide, a gas that contributes to acid rain.
• With the United States importing 55% of its oil, oil spills are a serious problem
• Mining coal can be difficult and dangerous. Strip mining destroys large areas of the landscape.
Is it Renewable?
• Once we've burned them all, there isn't any more, and our consumption of fossil fuels has nearly doubled every 20 years since 1900. This is a particular problem for Oil, because we also use it to make plastics and many other products.
Fossil fuels are NOT a renewable energy resource
Solar Power
– Solar Cells really – called photovoltaic"
or "photoelectric" cells) convert light directly into electricity
• In a sunny climate, you can get enough power to run a 100W light bulb from just one square meter of solar panel
Solar Water Heating
• Heat from the Sun is used to heat water in glass panels on your roof.• Solar heating is worthwhile in
places like California and Australia, where you get lots of sunshine.
Advantages to solar power
• Solar energy is free - it needs no fuel and produces no waste or pollution.
• In sunny countries, solar power can be used where there is no easy way to get electricity to a remote place.
• Handy for low-power uses such as solar powered garden lights and battery chargers
Disadvantages to Solar
Power
• Doesn't work at night. • Very expensive to build solar power
stationsSolar cells cost a great deal compared to the amount of electricity they'll produce in their lifetime
• Can be unreliable unless you're in a very sunny climate
Is Solar Power Renewable?
•Solar power is renewable
•The Sun will keep on shining anyway, so it makes sense to use it
Develop alternative energy sources
• Conserve fossil fuel reserves by using solar power, wind power, hydropower, geothermal, etc
Evaluating Energy Resources
• Energy from the sun• Indirect forms of renewable solar
energy– Wind– Hydropower– Biomass
• Commercial energy– Fossil fuels -- nonrenewable
Coal Burning Power Plant
Nuclear Power
• Nuclear power is generated using
Uranium, which is a metal mined in various parts of the world
• Nuclear power produces around 11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel, without the pollution that you'd get from burning fossil fuels
Three-Mile Nuclear Plant
Advantages to Using Nuclear Power
• Nuclear power costs about the same as coal, so it's not expensive to make.
• Does not produce smoke or carbon dioxide, so it does not contribute to the greenhouse effect.
• Produces huge amounts of energy from small amounts of fuel.
• Produces small amounts of waste.
• Nuclear power is reliable.
Disadvantages of Nuclear Power
• Although not much waste is produced, it is very, very dangerous. It must be sealed up and buried for many years to allow the radioactivity to die away.
www.ebaumsworld.com/pictures/view/326426/ http://people.moreheadstate.edu/students/alsimp01/images/chernobyl.jpgjburger.blogspot.com/
LEGACY OF CHERNOBYL
Is it Renewable?
• Nuclear energy from Uranium is NOT renewable
•Once we've dug up all the Earth's uranium and used it, there isn't any more
Wind Power
• We've used the wind as an energy source for a long time• The Babylonians and Chinese were using wind power to pump water for irrigating crops 4,000 years ago, and sailing boats were aaround long before that
• Wind power was used in the Middle Ages, in Europe, to grind corn, which is where the term "windmill" comes from
Advantages to Wind power
• Wind is free, wind farms need no fuel • Produces no waste or greenhouse
gases • The land beneath can usually still be
used for farming • Wind farms can be tourist attractions • A good method of supplying energy
to remote areas
Disadvantages of Wind Power
• The wind is not always predictable some days have no wind • Suitable areas for wind farms are often near the coast, where land is expensive• Some people feel that covering the landscape with these towers is ugly • Can kill birds - migrating flocks tend to likestrong winds. Splat! • Can increase local temperature• Noisy. A wind generator makes a constant,
low,"swooshing" noise day and night
Is Wind Power Renewable?
•Wind power is renewable
•Winds will keep on blowing, it makes sense to use them
Hydroelectricity
• A dam is built to trap water, usually in a valley where there is an existing lake.
• Water is allowed to flow through tunnels in the dam, to turn turbines and thus drive generators.
• Hydro-electricity provides 20% of the world’s power
Advantages of Hydroelectricit
y• Once the dam is built, the
energy is virtually free • No waste or pollution produced• Much more reliable than wind, solar or wave
power and electricity can be generated constantly
• Water can be stored above the dam ready to cope with peaks in demand
• Hydro-electric power stations can increase to full power very quickly, unlike other power stations
•
Disadvantages to Hydro-electricity
The dams are very expensive • Building a large dam will flood a very
large area upstream, causing problems for animals that used to live there
• Finding a suitable site can be difficult - the impact on residents and the environment may be unacceptable
• Water quality and quantity downstream can be affected, which can have an impact on plant life
Is it Renewable?
• Hydro-electric power is renewable.
The Sun provides the water by evaporation from the sea, and will keep on doing so
How Biomass Works• Plant and animal waste is used to produce fuels such as methanol, natural gas, and oil. We can use rubbish, animal manure, woodchips, seaweed, corn stalks, sugar cane husks and other wastes.
Other solid wastes, can be burned to provide heat, or used to make steam for a power station.
Burn fuel>heat water to make steam>steam turns turbine>turbine turns generator>electrical power sent around the country
Advantages to Biomass
• It makes sense to use waste materials where we can
• The fuel tends to be cheap• Less demand on the Earth's
resources
Disadvantages to Using Biomass
• Collecting the waste in sufficient quantities can be difficult• We burn the fuel, so it makes greenhouse gases • Some waste materials are not
available all year round
Is It Renewable?
•Biomass is renewable
•We will always make waste products We can always plant & grow more sugar cane and more trees, so those are renewable too
Geothermal Power
Hot rocks underground heat water to produce steam We drill holes down to the hot region, steam comes up, is purified and used to drive turbines, which drive electric generators
• There may be natural "groundwater" in the hot rocks anyway, or we may need to drill more holes and pump water down to them
Advantages to Geothermal Power
• Geothermal energy does not produce any pollution, and does
not contribute to the greenhouse effect
• The power stations do not take up much room, so there is not much impact on the environment
• No fuel is needed• Once you've built a geothermal power
station, the energy is almost free It may need a little energy to run a pump, but this can be self-generated
Disadvantages to Geothermal
Power• The big problem is that there are not many places
where you can build a geothermal power stationYou need hot rocks of a suitable type, at a depth where we can drill down to them The type of rock above is also important, it must be of a type that we can easily drill through
• Sometimes a geothermal site may "run out of steam", perhaps for decades
• Hazardous gases and minerals may come up from underground, and can be difficult to safely dispose of
Is it Renewable?
•Geothermal energy is renewable
•The energy keeps on coming, as long as we don't pump too much cold water down and cool the rocks too much
Hybrid • A hybrid vehicle is a vehicle that uses two or
more distinct power sources to move the vehicle while reducing/eliminating the use of gasoline
• The gasoline-electric hybrid car is just what it sounds like -- a cross between a gasoline-powered car and an electric car
• An electric car, on the other hand, has a set of batteries that provides electricity to an electric motor. The motor turns a transmission, and the transmission turns the wheels
Electric car – GT Lightning 700 HP nanotechnology battery pack will provide a
200-mile range on a ten-minute charge0-60 in less than 4 sec.
•WHAT ELSE?????????