1
Q
what are the Chemical Spheres?
A
- Biosphere
- Lithosphere
- Atmosphere
- Hydrosphere
2
Q
matter on earth?
A
- Matter on the earth is constant. Energy arrives (Solar energy) and leaves (heat energy)
- Matter must be recycled through the living and nonliving parts of the ecosystem
3
Q
Natural sustainability of the cycles?
A
carbon cycle, water cycle, nitrogen cycle… The global systems on the Earth
4
Q
what is the biosphere?
A
The biosphere consists of all areas of Earth and its atmosphere that contain
life.
5
Q
what is the lithosphere?
A
The lifeless parts of Earth’s crust and upper mantle only (tectonic plates), including continental and oceanic lithospheres and three types of rocks (Metamorphic rocks, Igneous rocks, Sedimentary rocks)
* includes different landforms such as mountains, valleys, rocks, minerals and soil.
* It constantly changes due to forces and pressures such as the sun, wind, ice, water and chemical changes.
6
Q
what is the atmosphere?
A
The atmosphere consists of all the gases above Earth’s surface
* The layer of gases is held in place by gravity and the composition of the atmosphere is influenced by our proximity to the Sun.
7
Q
The Vertical structure of the atmosphere in density?
A
The density of gases decreases, overall, as you move further from the earth’s surface.
8
Q
why is the atmosphere important?
A
These layers allow us and other living things to breathe, protect us from the Sun’s harmful ultraviolet (UV) radiation and keep the surface temperature constant (thermal regulation).
9
Q
layers of the atmosphere?
A
- Exosphere
- Thermosphere: most influenced by solar radiation
- Mesosphere
- Stratosphere: contains Ozone Layer, protects Earth from high-energy UV radiation
released from the Sun - Troposphere: contains the ‘weather’, gaseous composition most influenced by human activity, greenhouse gases.
10
Q
Composition of the atmosphere?
A
Nitrogen 78%
Oxygen 21%
Argon 1%
Trace gases (for example, carbon dioxide, neon, methane, water vapour) <1%
11
Q
what is the hydrosphere?
A
The hydrosphere is made up of all the water in the Earth ‘s environment. (ocean, lakes, rivers, snow and glaciers, water underneath the earth’s surface and even the water vapour)
* It is always in motion
12
Q
why is the hydrosphere important?
A
- Plant and animal organisms rely on the hydrosphere for their survival as water is essential. The hydrosphere is also home to many plants and animals and it believed that the hydrosphere covers approximately 70% of the earth’s surface
13
Q
what is the geosphere?
A
The geosphere includes all the natural and lifeless parts of Earth’s surface, crust and core.
The geosphere is in a constant cycle, with matter constantly moving in the processes involved in the rock cycle.
14
Q
Interaction between spheres?
A
The oceanic lithosphere includes the uppermost layers of mantle which is topped with a thin yet heavy oceanic crust. This is where the hydrosphere and lithosphere meet. The continental lithosphere includes the uppermost layers of mantle which is topped with a thick yet light continental crust. This is where the atmosphere, biosphere and hydrosphere meet the lithosphere. Interaction between spheres
The chemical spheres on Earth interact and affect each other, maintaining a natural balance on Earth. Matter constantly moves between spheres in cycles. The energy driving the movement of matter comes from the Sun and from Earth’s core. It is the flow of this energy and the cycling of matter that produces chemical and physical changes in Earth’s materials.
15
Q
Example: Interaction of Spheres
A
Plants in the biosphere obtain water from the hydrosphere and nutrients from the geosphere via soil. Water vapour is released by plants into the atmosphere.
16
Q
Example: Overlapping Spheres
A
A healthy soil is described as one that contains plenty of water, air, minerals and bacteria, as well as other organic matter. If we were to assign soil to a chemical sphere, you could argue that it belongs to them all: water from the hydrosphere, air from the atmosphere, minerals from the lithosphere and bacteria from the biosphere.
17
Q
what is a sustainable ecosystem?
A
A sustainable ecosystem is a biological environment that is able to support itself without outside assistance.
18
Q
Increase in gases containing carbon compounds in the atmosphere due to human activities?
A
- burning fossil fuels
- deforestation
- changed land use (agriculture)
- production of cement and lime
- waste burning and waste decomposition in landfills
- livestock and rice cultivation
19
Q
where is carbon found on earth?
A
Carbon is found almost everywhere on earth and is the key element of all living things. Carbon is stored in the ocean, atmosphere and crust of the planet, in all four spheres.
20
Q
how long can carbon stay at a carbon cycle stage?
A
The carbon cycle occurs in many steps, but it is important to note that carbon can stay at one particular stage for thousands of years before moving on to the next step.
21
Q
carbon cycle 7 steps?
A
- Photosynthesis:
Carbon dioxide in Earth’s atmosphere is absorbed by plants during photosynthesis - Transfer of carbon through the food chain:
Animals obtain their carbon by eating plants and other animals. When animals and plants are eaten, their carbon content is transferred through the food chain. - Respiration:
Plants and animals break down glucose using oxygen to form carbon dioxide and water is process is called respiration. e carbon dioxide is added to the atmosphere when organisms breathe out. - Excretion, death and decomposition:
Some of the carbon content of animals and plants enters the soil as waste, such as urine, feces, dead animals and plants and fallen leaves. Dead organic matter is broken down by decomposers, which respire, releasing carbon dioxide back into the atmosphere. - Formation of fossil fuels:
Fossil fuels like coal, oil and gas are composed of the carbon from plants and animals that died millions of years ago. Carbon is stored as fossil fuels for millions of years before re-entering the carbon cycle. - Combustion:
When fossil fuels are burned in oxygen (combustion), carbon dioxide and water are formed. Carbon dioxide is therefore released back into the atmosphere. - Formation of limestone:
Carbon dioxide gas in the atmosphere can dissolve in the oceans, forming carbonic acid. This carbonic acid is used, along with calcium ion mineral deposits, to make calcium carbonate the major component of shells. Shells from dead animals sink to the bottom of the ocean. Over millions of years, the compaction of these shells results in the formation of limestone. The carbon stored in limestone can remain there for millions of years before it re-enters the carbon cycle.
22
Q
why is nitrogen important?
A
Nitrogen is important for all living things as it is the basis of DNA and the subunits of proteins called amino acids.
23
Q
nitrogen cycle 6 steps?
A
- Nitrogen fixation:
Nitrogen fixation makes nitrogen in the atmosphere accessible to the majority of organisms. Lightning converts nitrogen gas in the air by bonding it with oxygen and then dissolving it in rain, which then washes into the soil. Plants can use nitrates directly. Nitrogen gas is also converted to ammonia or ammonium by nitrogen-fixing bacteria that are free-living in soil or trapped in root nodules of plants such as legumes (peas, beans and lentils) or clover. - Transfer through the food chain:
Animals obtain their nitrogen through eating plants and other animals. The nitrogen containing compounds are therefore transferred through the food chain. - Excretion, death and decomposition:
When plants and other organisms that have gained nitrogen during their lifetime
die, they are broken down by decomposers, forming ammonia. These decomposers
convert the nitrogen in the organic matter into ammonia, in a process called ammonication. - Nitrification:
Plants can take up the ammonia formed during the decomposition of nitrogen in organic matter and through nitrogen-fixation .However, nitrogen is of more use to plants
in the form of nitrates.Converting ammonia to nitrates is called nitrication, and is carried out by nitrifying bacteria. - Uptake by plants:
The nitrates formed during nitrification are taken up by plants and used to make DNA and amino acids, the building blocks of proteins. - Denitrification:
The process of denitrification also involves bacteria, in this case denitrifying bacteria.
Denitrification is the conversion of nitrates back into nitrogen gas, which is released back into the atmosphere.
24
Q
How has human activity impacted on the Nitrogen Cycle?
A
- nitrogen-based fertiliser
- Animal and human waste
- Industry
- Smokestack emissions
- burning fossil fuels
25
what is the water cycle important for?
The water cycle is responsible for the recycling of water around the chemical spheres.
26
water cycle 7 steps?
1. Evaporation:
It is a process where water at the surface turns into water vapours. Water absorbs heat energy from the sun and turns into vapours. Water bodies are the main source of evaporation. Through evaporation, water moves from hydrosphere to atmosphere. As water evaporates it reduces the temperature of those water bodies.
2. Condensation:
As water evaporates into water vapour, it rises up in the atmosphere. At high altitudes the water vapour changes into very tiny particles of ice /water droplets because of low temperature. This process is called condensation. These particles come close together and form clouds and fogs in the sky.
3. Sublimation:
Sublimation is a process where ice directly converts into water vapours without converting into liquid water. The main sources of water from sublimation are the ice sheets of the North Pole and the South Pole and the ice caps on the mountains. Sublimation is a rather slower process than evaporation.
4. Precipitation:
The clouds (condensed water vapours) then pour down as precipitation due to wind or temperature change. This occurs because the water droplets combine to make bigger droplets, so when the air cannot hold any more water, it precipitates as rain, snow, sleet, hail, drizzle.
5. Transpiration:
As water precipitates, some of it is absorbed by the soil. Transpiration is a process where liquid water is turned into water vapour by the plants. The roots of the plants absorb the water and push it toward leaves where it is used for photosynthesis. The extra water is moved out of leaves as water vapour.
6. Runoff:
As the water pours down (in whatever form), it leads to runoff. Runoff is the process where water runs over the surface of earth. When the snow melts into water it also leads to runoff. As water runs over the ground it displaces the top soil with it and moves the minerals along with the stream. This runoff combines to form channels, rivers and ends up into lakes, seas and oceans.
7. Infiltration/Percolation:
Any water that doesn't run directly to bodies of water or get quickly evaporated, will be absorbed by plants and soil, where it may be driven deeper to the earth.The water seeps down and increases the level of the groundwater table.
27
define weather
the conditions in the air above Earth such as temperature, cloud, rain or wind, especially at a particular time over a particular area
28
define climate
the average or prevailing weather conditions of an area over long periods of time
29
Why are there different climates?
- uneven distribution of the Sun’s rays because of the shape of Earth
- land (or sea) surface; compared to water, land temperatures can increase more with the same amount of thermal energy transferred to it compared to water, so land temperatures rise more in the daytime and fall more during the night compared to water
- tilt of Earth’s axis, which causes seasons
- features of the land, such as mountains
- type of soil or plant life
30
What is the climate affected by?
- the way that the Earth’s surface reflects heat (Earth’s surface is heated unevenly. The land absorbs heat from the sun quicker than water. Land temperatures can rise more in the daytime and fall more during the night compared to water.)
- gases in the atmosphere (The amount of greenhouse gases in the atmosphere impacts how much radiation is trapped in the Earth’s atmosphere, thereby influencing global temperatures)
- orientation of the Earth - Seasons (The tilt of the Earth’s axis results in the polar regions
receiving little or no solar radiation for six months of each year.)
- ocean currents (Currents can be at the surface or deep in the ocean.)
- wind circulation
- climate phenomena
31
The main causes of currents are?
* wind
* temperature
* variations in salinity
* the rotation of the Earth on its own axis
* the gravitational pull of the sun and moon
32
surface currents?
Surface currents are affected by wind currents back in the sea and form gyres due to the spin of the earth which causes the air and water to rotate in loop-like patterns.
33
what is thermohaline circulation?
Thermohaline circulation describes the movement of ocean currents due to differences in temperature and salinity in different regions of water
34
what is the global conveyor belt?
The global ocean conveyor belt is a constantly moving system of deep-ocean circulation driven by temperature and salinity.
35
deep currents?
Deep currents move warm water near the equator to the poles. At the poles this water cools and travels back to the warmer areas.
This is because the colder water is heavy (dense) and sinks in the ocean whilst warmer water is lighter (less dense) and moves towards the surface.
This deep-water current is known as the global conveyor belt as it is constantly moving.
* It is driven by density differences in the water.
36
what is the gulf stream?
The Gulf Stream is an ocean current which carries warm water from the equator to the North Atlantic Ocean. This keeps Great Britain, Norway and Iceland warmer than other regions at similar latitudes.
37
the wind/air circulation?
The differences in temperature between the poles and the equator and the rotation of the Earth also influence the wind.
Cold air near the poles is heavy so it sinks towards the surface of the Earth and moves towards the equator. The density of the air creates high pressure and a cool dry climate.
At the equator, the air heats up, rises away from the surface of the Earth and moves towards the poles. As the air is lighter it creates low pressure, creating wet climates.
This air circulation isn't just one big swirl; it's broken down into three important parts called cells in the troposphere. (polar cells, ferrel cells and hadley cell).
38
what are the trade winds?
Winds that blow from east to west across the Pacific Ocean bringing rain to northern Australia in the absence of other phenomena. These winds collect moisture as they move which causes it to rain and storm in areas in their path including Northern Australia
39
what two phenomena is Australia’s climate if affected by?
* The Southern Oscillation (El Niño and La Nina)
* The Indian Ocean Dipole
40
what determines southern oscillation?
It is determined by the atmospheric pressure differences between Tahiti, which is in the South Pacific, and Darwin, which is in northern Australia. These two locations are chosen because they are on opposite sides of the tropical Pacific Ocean.
The differences in pressure either contribute to El Niño conditions, which is the warm phase or La Niña conditions, the cold phase.
41
what is the SOI?
The Southern Oscillation Index (SOI) is a measure of the atmospheric and ocean conditions across the Pacific Ocean.
42
what is the El Niño Southern Oscillation (ENSO)?
El Niño is an extreme of the Southern Oscillation that causes drought in parts of Australia. It is one of the most important influences on the climate in Australia, particularly in QLD and much of NSW. In El Niño years there is little difference in temperature between the western and eastern Pacific, so there is also little air pressure difference. The trade winds that normally blow strongly from South America weaken and the winds carrying a lot of moisture do not reach Australia.
43
effects of El Niño?
- the rainfall over the western Pacific decreases and it becomes dry enough to become a drought in Australia
- the air is pushed upwards above the warm water of the eastern pacific, increasing the rainfall over the pacific
- the eastern pacific becomes warmer than the western pacific
- wind patterns reverse, the winds and ocean current flows east across the pacific
- upwelling weakens or stops altogether
- warm water on top, cold water on the bottom
44
what is the La Niña Southern Oscillation?
The opposite of El Niño is La Niña, an extreme of the Southern Oscillation that causes significant rainfall in parts of Australia.
During a La Niña, the central and eastern Pacific Ocean becomes much cooler than normal. This causes the trade winds to blow more strongly than usual, and Australia experiences more clouds and wetter-than-normal conditions, especially in the north. La Niña events usually last for more than one year.
45
effects of La Niña?
- the air is pushed upwards, clouds form and it rains
- surface winds and ocean currents flow west towards Australia
- winds flow high in the atmosphere back towards Peru
- the cooler air sinks downwards to the ocean surface and the cycle continues
- normal air circulation: the western pacific and north of Australia is warmer than the eastern pacific Peru
- increased upwelling in the eastern pacific with cooler water and warmer water in the western pacific (aus)
- increased convection
46
Normal without southern oscillation?
- trades winds blow westernly across the pacific
- rains in northern eastern australia
- warmer water in western pacific, cooler water in eastern pacific
- upwelling normal
- air circulation goes in whole loop in clockwise direction
47
what is the Indian Ocean Dipole?
The Indian Ocean Dipole is associated with a change in water temperature between the eastern and western Indian ocean.
48
what happens in the positive phase in the Indian Ocean Dipole?
When ocean temperatures are lower near Australia it causes less warm moist air to blow over Australia, resulting in poor rainfall in southern Australia.
(The Indian Ocean is warmer in the west (near the coast of Kenya) than it is in the east (near Sumatra). This reduces tropical moisture availability for Victoria, and can make for a drier spring.)
49
what happens in the negative phase in the Indian Ocean Dipole?
When ocean temperatures are higher near Australia it causes better rainfall in central and southern Australia, during winter. Temperature difference determines the duration of the wet weather.
(The Indian Ocean is warmer in the east than it is in the west. This means that more moisture is available closer to Australia, and can be delivered to Victoria through northwest cloud bands. Typically Indian Ocean Dipole negative events have been associated with wetter seasons in Victoria.)
50
what happens in the normal phase in the Indian Ocean Dipole?
During a normal phase water from the Pacific flows between the islands of Indonesia, keeping seas to Australia's northwest warm. The air rises above this area and falls over the western half of the Indian Ocean basin, blowing westerly winds along the equator.
51
What is climate change?
Climate change has occurred when there has been a significant change to normal weather patterns that has been sustained for a long time – between tens and millions of years. However, Earth has undergone natural cycles of warming and cooling throughout its history.
52
what is a glacial period?
A glacial period is when a reduction in global temperatures is sustained for a long period of time.
53
what is a interglacial period?
An interglacial period is when an increase in global temperatures is sustained for a long period of time. We are currently experiencing an interglacial period.
54
evidence that can be used to support climate change?
- Temperature records for at least 140 years
- Air samples, ice core samples
- Changes to sea ice and arctic ice boundaries and permafrost
- Sea level changes
- Extreme weather events
- Ocean acidification
- Geology – glaciation effects, fossil samples of pollen and other species in
sedimentary rock
55
glaciers as evidence for climate change?
Glaciers develop during periods of cooling and melt during periods of warming.
56
ice cores as evidence for climate change?
Scientists take samples (cylindrical cores) from deep within ice sheets and glaciers. They show the layers of snow that fell thousands of years ago. The snow provides information on the temperature and carbon dioxide levels in that time period.
57
pollen as evidence for climate change?
Pollen which has been fossilised in rock gives an indication of the number and age of species of plants living in that time period.
58
sea levels as evidence for climate change?
The location of sedimentary rocks and fossil distribution can give an indication of past sea level heights.
59
effects of climate change?
- Increased average temperature on Earth.
- Melting polar ice caps
- Rising sea levels
- more drought
- ocean acidification
- Loss of biodiversity as organisms become extinct due to the changing climatic conditions.
- Increased frequency of extreme weather events such as fires, storms and floods
- Air and water pollution – release of methane from permafrost
60
what is the natural greenhouse effect?
The process of trapping the Sun’s solar energy in Earth’s atmosphere is called the greenhouse effect. Most of the Sun’s radiation passes through Earth’s atmosphere where the majority heats the ground and the oceans. The remainder is reflected back into space by ice, clouds and water. The ground and oceans emit radiant energy back towards the atmosphere as infrared radiation. However, instead of leaving Earth’s atmosphere, some of this radiation is absorbed and reflected back towards the surface by a layer of gases called greenhouse gases.
61
why is the natural greenhouse effect important?
If the Sun’s radiation was not converted into infrared, we would lose all of the thermal energy back into space, and Earth would be a lot less habitable. Plants, animals and humans would struggle to survive on Earth without the greenhouse effect’s role in maintaining a cosy, consistent average temperature.
62
what is the enhanced greenhouse effect?
The enhanced greenhouse effect is where extra greenhouse gases in our atmosphere trap too much of the Sun's energy. This causes a warming effect, which some people call global warming.
63
cause of enhanced greenhouse effect?
The major cause of the enhanced greenhouse effect is an increase in the concentration of greenhouse gases: carbon dioxide, methane, nitrous oxide and water vapour in the atmosphere.
64
what is the problem with burning fossil fuels?
The problem with burning fossil fuels and releasing the carbon stored in them is that the carbon cycle does not have enough carbon sinks to remove the excess carbon from the atmosphere. Fossil fuels take millions of years to form, and Earth’s carbon sinks cannot remove enough carbon dioxide to prevent it from building up in the atmosphere. The accumulation of carbon dioxide in the atmosphere is increasing Earth’s greenhouse effect.
65
Human impact on climate?
* Burning fossil fuels
* Deforestation
* Agriculture
* Industrial processes – cement production, steel manufacture
* Enhanced greenhouse effect – combustion, agriculture, car emissions
* Ozone Layer
66
How have humans increased greenhouse gases contraction in the atmosphere?
Carbon dioxide - Burning fossils fuels such as coal, oil and gas
Methane - Farming cattle (which produce methane when they digest grass) and growing rice in paddies, Increasing temperatures which is leading to melting of permafrost in the Arctic. Permafrost is frozen soil which contains trapped methane produced from the decomposition of plants and animals.
Nitrous oxide - Using fertilisers, which increases the amount of nitrogen in the nitrogen cycle therefore increasing the production of nitrous oxide
Water vapour - as the concentrations of carbon dioxide, methane and nitrous oxide in the atmosphere increases due to human activity, more heat is trapped which contributes to increasing water vapour concentrations (increased humidity). This has a positive feedback effect on increasing temperatures, enhancing the greenhouse effect.
67
Human influences on climate change and global systems?
Deforestation (Carbon cycle and water cycle) - Fewer trees results in less carbon dioxide being taken in from the atmosphere through photosynthesis. If the wood is burned this contributes further to the greenhouse effect. Trees release large amounts of water
vapour during transpiration. Fewer trees means less water vapour in the atmosphere and less rain.
Agriculture (Carbon cycle) - Cows and sheep produce carbon containing methane when digesting grass. More cattle mean more emissions.
Burning fossil fuels (Carbon and nitrogen cycle) - Burning fossil fuels produces carbon emissions, which alters the carbon cycle. Nitrogen oxides are also produced when fossil fuels burn, causing smog and acid rain.
Fertilisers (Nitrogen cycle) - Adding fertilisers containing nitrates to the soil speeds up their conversion into nitrous oxide, another greenhouse gas.
68
Polar ice affected by climate change?
Melting polar ice caps - As temperatures on Earth rise, polar ice caps
melt, which raises sea levels, endangering low lying areas of land. With less ice cover, more of the ocean is able to absorb sunlight, increasing its temperature. Water expands when it gets warmer. This is an ongoing cycle, ultimately leading to increased ice melting and sea level rise.
Reflecting ice - Ice reflects the Sun’s radiation back into space, which has a cooling effect on the planet. Less ice means less radiation is reflected and an increase in global temperatures.
Ocean density driving currents- When seawater freezes in winter, only the water freezes – the salt is left behind in the unfrozen seawater below. Waters with higher concentrations of salt are denser and are the main cause of ocean currents, circulating seawater around the globe, along with thermal energy and nutrients. With rising temperatures, less seawater is freezing which is reducing the density of the oceans. These global ocean currents could eventually cease all together.
69
Social impacts of climate change?
This disruption will affect food supplies, industry supply chains and financial markets, damage infrastructure and cities, and harm human health and global development.
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