Flashcards
B3
Cards in this deck (21)
- 1Impact of Humans *The growth of the human population is increasing rapidly and the improvements in the standard of living is putting strains on the global environment: *Non renewable energy sources are being used up rapidly. *Raw materials are being used up rapidly.*More land is being used up for building and networks, quarrying, farming and dumping waste-reducing the amount of land available to other animals and plants.
*More waste is being produced due to large population causing pollution. - 2Land Pollutions In order to improve the yield (the percentage of crops to go up) of the land, most farmers spray their crops with chemicals including herbicides (kills weeds) and pesticides (kills plant-eating insect).Some of chemicals stay in soil for long periods of time which pollute the land and the sea.
Most rubbish is buried in land fill sites, but some common household items contain toxic chemicals.
Industrial waste is also discharged into the lad. - 3Waste Pollution *Harmful Chemicals into water *Fertilisers are used to make crops bigger, the minerals produced from the fertilisers may run off into the water and cause the algae plants to grow bigger which leads to oxygen depletion, which then causes the death of fishes and invertebrates. This is called eutrophication.*Sewage may also pollute waterways and they have high mineral levels which may promote eutrophication.
*Toxic chemicals from industries and mining can also pollute waterways. - 4Air pollution Most common combustion (process of burning of fire) of fossil fuels *Smoke-From incomplete combustion- gives soots, to buildings and tress causing them to damage and permeates the air-which causes breathing problems.*Sulphur Dioxide-Combustion of fossil fuel with sulphur impurities in them, e.g: coal. It contributes to acid rain-causes weathering in buildings, release of toxic metals, damage to aquatic ecosystems and to forests.
*Carbon dioxide-Combustion of hydrocarbon fuels-greenhouse gas that contributes to global warming.
*Methane-Rice fields, cows, anaerobic decomposition of landfill waste-creates green house gases. - 5Deforestation Trees act like 'carbon sink' by trapping lots of carbon in their biomass (dry part in plant) that was previously absorbed by photosynthesis. Cutting down trees aka deforestation.Reasons for deforestation
*Provides timber as a fuel or building material
*Provides extra land for agriculture due to the increase in demand on food and energy (bio-fuel is also growing there) - 6Consequences for deforestation *Increases rate of CO2 in air as it is not locked away in plant. *As timber is burnt it releases more CO2 which therefore adds to global warming *Forest habitats are destroyed and biodiversity is reduced. *Rice field and Cattle are often put into the land which produce methane which contribute to global warming.Biodiversity
*Means different species and variation in species, habitats and ecosystems in the biosphere-all living thigs on earth.
*reducing biodiversity means we lose possible valuable organisms
*Organisms that can be useful in the future. - 7Destruction of peat bogs Acidic fens (moss lakes) and bogs decay over thousands of years by the growth of other mosses and other plants which absorbs and locks away CO2. *But when moss dies, the bog provides anaerobic conditions mixes with the acidity of the bog preventing the decomposition of the moss. Therefore becomes partially decomposed aka Peat.Peat bogs
2% to 3% in earths surface
* Can be dried and burnt into energy source
*When mixes with oil, it improves Soil structure, mineral retention, and acidity-very valuable in gardening.
*Many peat bogs been drained to extract peat. - 8Problems with Peat bogs *Burning peat release stored carbon out-turns into Co2 in atmosphere *Peat in soil is exposed to aerobic conditions and decomposes releasing the carbon back into the atmosphere. *Destruction of peat blogs destroys habitats and contributes to Global warming.Gardeners using peat
*1950's used Peat
Now increase in Peat-free composts which contain sustainable alternatives to peat.
*Trend been supported by government to reduce gardeners using peat for their plants. - 9Global warming-increase in the earths temperature *2 great contributers of GW are: CO2 and Methane *Levels increasing due to the rise of Co2, whcih is increasing because of: *burning fossil fuels *deforestation *Destroyed Peat bogsMethane levels are increasing because of:
*Increase of cattle due to increase of humans
*Increase of Rice fields produced in water in anaerobic conditions, so when rot methane produced.
*Humans produce more waste which decays anaerobically which produces methane. - 10Green house gases cause global warming *Heat from sun enters earth surface area and warms earth surface *earths surface become hotter and radiates heat out *Some of the heat is absorbed by green house gases which radiates (bounces) back to the earth *As a result, the earth is hotter.Consequences of global warming
*Cause big change in earth climate
*Ice caps melt, rise of sea levels results in flooding
*Reduces biodiversity
*Cause changes in migration for birds
*Organisms move to cooler regions. - 11Sequestration *Oceans, seas and lakes lock away carbon *Process of carbon being locked away is called sequestration this happens due to: *CO2 being soluble and dissolves into water. *Phytoplankton (a sea plant) performs photosynthesis which absorbs CO2, and traps carbon in their biomass (dry part in plant)Some companies and organisation use artificial sequestration to reduce CO2.
- 12Bio fuels * theoretically carbon neutral-as made by plants which carbon and then used as fuel which releases carbon.Bio Ethanol
*A type of alcohol also used as fuel.
*Made by a process called fermentation-converts sugar into ethanol and co2 if conditions are anaerobic.
*The catalyst used is a single celled fungi (aka yeast) which speeds up the reaction - 13Ethanol *Some countries get sugar from sugar cane. *Others use maize which is starch but need the breakdown of the enzyme amylase to occur. *In order for it to become more sufficient for use, ethanol is distilled.Disadvantages of Bio-ethanol
*Increase of demand in ethanol means greater demand for the rain forest land.
*Some people morally object towards it as it could cause an increase in food shortage and higher prices for food.
*Theoretically bio-neutral, however ethanol does not take account of the co2 emissions associated with growing, harvesting and transporting crops. So therefore, contributes to global warming. - 14Biogas *Biogas is produced from anaerobic fermentation of carbohydrates in plant material or waste, (so basically produced from poo and vegetable peelings in an area with no oxygen) by bacteria *Lots of methane in it *If oxygen present, bacteria will respire aerobically (with oxygen) and produce a gas with more CO2 and less methane. *Can be produced in a biogas generator/digester *Waste settles at the moment and used as a fertilizer for the land
- 15Optimum Temperature *Optimum temperature 32 to 35 degrees *Temperatures below the optimum rate slows down the rate of respiration with bacteria resulting in slower biogas production (time consuming), however biogas generator can be buried under ground, with thick walls to insulate the generator and keep it warm inside. E.G: U.KOptimum Temperature
*Optimum temperature 32 to 35 degrees
*Temperatures above optimum temperature begin to denature (destroy) bacterial enzyme resulting in slower biogas production. However, bury generator underground, as it helps insulates the biogas generator by keeping it cool at day and warm at night. - 16More facts about...Biogas *Bigger more sophisticated biogas generator used. *Naturally produced in landfill sites-as bacteria anaerobically breaks down-but normally methane escapes to atmosphere and contributes to global warming.Pipe network
*If a pipe network with holes in it can be built, it can stop methane from escaping.
*Can be used as a fuel to generate electricity or heat buildings. - 17Efficiency of Bio mass of food production *Decreases as it goes up food chain *Can be improved by reducing the number of levels in the foodchain. *Moving animals around so much so energy is not lost *Keeping surroundings warm, preserves energy used to maintain body temp, so that it can be used to increase biomass.Advantages and Disadvantages
*Advantage-keeping animal in warm cages in little space gives more efficient food production, therefore cheaper food.
*Disadvantages-Increase risk of disease (such as salmonella among chickens) and injury. - 18Energy Efficiency *The energyMyco-protein
*High-protein food produced from a fungus called fusarium.
*Low in fat, no cholesterol and high fibre
*Grown in a fermenter - 19How to make Myco-protein? *Fermenter filled aseptically-(there is no disease or bacteria) with a sterile containing glucose syrup which comes down from the breakdown of plant starch by amylase enzymes. *A small starter 'culture' of the fusarium fungus.How to make Myco-protein?
*Sterilised glucose syrup, ammonia-produces amino acids (building blocks of protein)- and air containing oxygen (so aerobic conditions) is added continuously for 6 weeks, so fungus has correct nutrients and conditions to grow.
*Fungus grows and doubles it's bio-mass every five hours. - 20How to make Myco-protein? *Cooking coil removes excess heat generated by the fungus during respiration keeping temperature at optimum level. *At the end of 6 weeks, the fungal biomass is harvested and purified by heating it at 65 degrees to remove harmful substances and spinning it dry with a centrifuge. *Yellow solid substance can then be flavoured and shaped into different products.Sustainable fishing
*using fishing quotas
*Making smaller size nets - 21Food miles *The distance where the food is transported from one country to another usually an LIC to an HIC. *The greater the distance the more impact it has on the environment-due to pollution from CO2 produced from the transportTHE END
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- Flashcards on B3, created by Lamisha Chowdhury on 26/04/2016.
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- Lamisha Chowdhury
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