How much sea level rise is forecast by the end of 2100 by the IPCC?
Between 0.09 m & 0.88 m
Originating with human activity
What do you call an effect due to human activity
Name 4 greenhouse gasses in the atmosphere
Water vapour, Methane, Carbon dioxide & Nitrous Oxide. These are the most important ones
Name 4 things that can skew temperature readings
How much variation in Uncertainty should you give?
Plus/minus half a scale on your measuring equipment
If you can't be sure result is accurate due to equipment or methodology, what is this called?
Experimental uncertainty. (ie a measurement between two marks on the equipment).
What is "Experimental uncertainty"?
When you can't be sure of result due to known equipment or methodology shortcomings. ie a measurement between two marks on the equipment
What is "Random uncertainty"?
When you have a range of values from your results. ie variable factors lead to various results on same measurement
When you have a range of results for the same measurement, what is it called?
Random uncertainty. ie variable factors lead to various results on same measurement
If there is only a small experimental uncertainty, how is the result usually described?
As a precise or high precision result
What is systematic uncertainty?
When, unknown to you, there is error associated with measurements (such as faulty measuring scales)
What type of uncertainty is it if, unknown to you, there is an error with equipment
Why might temp readings in large urban areas be skewed?
Urban heat Island - Temp may be higher than nearby due to human activity, heating systems, vehicles, electrical appliances & number of people. Concrete, glass & metal also impact
What have average temps been increasing by
A) Near the poles
B) Near the equator
A) 1.5 oC
B) 0.1 oC
How do we measure historical temperatures?
By investigating the vegetation of the time. Pollen samples a good way of doing this. We can also use ice cores.
How do we investigate historical pollen records?
By obtaining pollen cores
What type of chart would be used to show results of pollen core samples
How old is the current ice age & how old is the current interglacial?
How much has temp increased in the last 200 years
How much has GMST increased over the last 20 000 years? How much per century is this?
About 10 oC = 0.1 oC century-1
How much has GMST increased in the last centuty?
About 0.5 oC
How fast has GMST been increasing in the last century compared to the last 20 000 years
0.5 oC to 0.1 oC
If temp has increased by 10oc over 500 years, what equation gives you the rate of increase?
What word would describe a result with small random uncertainties?
What are the two catagories of uncertainty?
Random & Experimental (systematic is a form of experimental)
If there is only a small sytematic uncertainty with results, what is this called?
A physical property possessd by an object (such as heat)
Power is the rate at which energy transfer takes place (ie. The amount of energy transferred per unit of time)
What is the SI unit of power?
What is the Watt the SI measure for?
What does 1 watt = in terms of Joules
1 Watt - 1 J s-1
How many Watts = 60 j s-1
What are the main 2 sources of the Earth's surface temperature
Solar Radiation & Earths radiation (solar radiation being 2 000 times stronger)
If GMST is stable what does that tell us about energy on Earth?
That the Earth is in a steady state regarding heat transfers
What is distinct about a Dynamic Steady State as opposed to one that isn't?
A Dynamic state has a continuing input (& thus continuing output).
If Energy is increased to the Earth, what happens to GMST & energy output?
GMST would rise until output had risen sufficiantly for a new steady state to be achieved
What is the scientific term for light we can see?
What two forms of radiation bookend the visible light spectrum?
Ultraviolet radiation (UV)
Infrared radiation (IR)
What emitts Infrared Radiation?
What is Solar Luminosity?
The power emitted by the Sun
What is the power emitted by the sun referred to as?
What is the measured solar radiation reaching the Earth called?
The Solar Constant
What do we mean by the Solar Constant?
The amount of solar radiation that reaches the Earth.
A collection of tiny liquid or solid particles dispersed in gas.
What do we call a collection of tiny liquid or solid particles dispersed in gas
What two process effect the amount of solar radiation that passs through the atmosphere?
Scattering & Absorption
What is the main cause of scattering & reflection by the atmosphere
What are the 2 things that can happen to solar radiation as it hits the Earth's surface?
Relfection or Absorption
What is the Albedo
The mean amount of solar radiation that is refected back to space by the Earh's surface & atmosphere
What is the mean amount of solar radiation refected back to space by the Earh's surface & atmosphere called?
What is the mean Albedo of the Earth?
31% or 0.31 (atmosphere & surface combined)
The mass per unit volume of a substance.
The transfer of heat from a region of higher temperature to a region of lower temperature due to direct contact between the regions.
What term is used to mean the transfer of heat from a region of higher temperature to a region of lower temperature due to direct contact between the regions.
What name is given to the process wherby a substance increases in volume when heated?
What is Thermal Expansion?
The process where wherby a substance expands when heated
Fluid flow in a volume of liquid driven by temperature differences.
Which transfers energy away from a heat source quicker, convection or conduction?
Convection (by some distance)
What is sublimation?
The transfer of a substance directly from gasseous to liquid without going via the solid
What is the transfer of a substance directly from gasseous to liquid without going via the solid
What power causes water to evaporate & rise via convection, leaving a cooler surface behind
How is the air described when it can absorb no more water vapour?
At saturation point
Define 'saturation point'
When the atmosphere can absorb no more water vapour
What term should be used to describe how close the atmosphere is to its saturation point?
Define 'relative humidity'
The term used to describe how close the atmosphere is to its saturation point
What effect can change the atmospheres saturation point
A higher temperature = a higher saturation point (so as it gets colder saturation point drops).
What happens when air is convected up but, due to it getting colder, the saturation point drops below the level of water it's holding
Clouds are formed
How would convection cause clouds to occur?
When air is convected up but, due to it getting colder, the saturation point drops below the level of water it's holding thte water vapour condenses into liquid droplets & forms clouds.
Name the 4 forms of energy gain in the atmosphere.
Name the 3 generalised factors that affect the GMST.
The rate at which the Earth intercepts solar radiation
The properties of the atmosphere
The properties of the Earth's surface
What would happen to the GMST if the atmosphere could absorb more infrared radiation.
More IR would be emitted by the atmosphere so GMST would increase.
Define 'infrared absorptivity'
The amount of IR that the atmosphere can absorb.
Define 'air pressure'
the force of air molecules against another thing, caused by the free movement of the molecules
What is the amount of IR that the air can absorb called?
Why doesn't gravity draw the entire atmosphere down to ground level?
Atmospheric pressure. Air molecules moving with enough force between Earth & atmosphere to keep each subsequent layer up.
What are the two units used to measure pressure?
SI unit is pascal (pa). Bar is also used.
The pascal is the SI unit for what?
To what percentage of the original figure does air pressure drop to at a) 10km & b) 40km above sea level?
Is air pressure lower or higher as you rise above sea level? Why?
Lower because there are fewer molecules of air per unit of volume, hence fewer collisions between them.
How high is the atmosphere?
How high is the troposphere?
What is the layer of atmosphere below 10km called?
What hight is the stratosphere?
Between 10 & 100 km
What is the layer of the atmosphere between 10 & 100 km called?
What is the aproximate ppm of CO2 in the atmosphere?
What is the most significant effect of higher infrared absorptivity?
Higher infrared emissions
Define a 'greenhouse gas'
A gas that absorbs infrared radiation
How would you tell if a gas is a greenhouse gas from its symbol?
A greenhouse gas must have more than 2 molecules (ie H2O) or 2 molecules of different types (ie CO).
What are the main 5 gasses in the atmosphere?
What is the 'residence time' of a substance?
The amount of time a molecule would spend in that state or reservoir
The water cycle of Earth is in a dynamic steady state. What does this mean?
The amount of water on Earth does not change, but the state (or reservoir) individual molecules are in does change.
The process by which plants draw water from the soil & release it into the atmosphere (through evaporation from the stromata)
The water cycle is a closed loop. What does this mean?
Water doesn't get added or subtracted form the cycle it just moves from reservoir to reservoir joining & leaving each reservoir in equal amounts.
Why might there be little or no evaporation despite the temperature being very hot?
The closer the air gets to saturation point, the slower it will absorb more water vapour.
Give an example of a positive feedback related to humidity.
As GMST increases so saturation point rises allowing more humidity into the air. This in turn increases the GMST which increases the saturation point of air.....
What is the difference between positive & negative feedback in relation to the steady state.
With posive feedback the factors operate on each other to push further away from the steady state (& create a new one), with negative feedback the factors counteract each other reinforcing the steady state.
List the 8 individual water reservoirs.
Ice & snow
(in order of mass of water)
Why is underground water the third largest water reservoir?
Because so many rocks are porous & store water that way.
Define 'Organic Carbon'
Carbon that is, or was, part of living things
What would you call carbon that is, or was, part of living things?
What is the largest carbon reservoir
Carbonate rocks (eg limestone, chalk, marble)
Define the Biogeochemical cycle
A cycle where carbon molecules arecycled through both Geological & Biological carbon cycles
Name the Biological carbon reservoirs
Name the Geochemical carbon reservoirs.
Why differentiate between deep & surface ocean?
Surface ocean is a mixed zone, absorbing CO2 etc from air, as well as solar radiation. The deep ocean sees none of these.
Is there more carbon in the biological or geochemical reservoirs?
Geochemical (99.9% of carbon is in rock).
Are residence times longer in the biological or geochemical carbon reservoirs?
Residence times in the biological are under 25years, in the geochemical they are between 1000 & 20 million years.
Does more carbon travel from biological to geochemical cycles or the other way round?
Neither. The amounts balance out over time.
The total mass of living things in a given area.
What amount of the total biomass is from the animal kingdom?
Less than 0.2%
What is the source of most oxygen on Earth?
Vegetation (via photosynthesis)
Where would you find the greatest biomass on Earth?
Tropical rainforests (20kgC m-2)
Photosynthesis uses carbon (CO2) from the atmosphere. How is some of this carbon returned to the atmosphere.
What is the process of respiration?
Oxygen & organic carbon react to form water & carbon dioxide in order to release energy. CO2 is released as waste
What is the process of photosynthesis?
Carbon dioxide, water & energy (solar radiation) react to form organic carbon & oxygen, the latter being released as waste.
Which way is more energy released, by burning, eating or decomposing a substance?
The same for all.
How much of the carbon absorbed in photosynthesis is subsequently released as CO2 via respiration?
How are decomposition and respiration linked?
Decomposition is another word for the process by which small organisms respirate, using dead organic material as energy
The absence of what prevents the existance of decomposer organisms that resperate on dead material?
Why might atmospheric CO2 be lower in the summer than winter?
More CO2 is needed for photosynthesis in summer than winter.
Where is the carbon in the surface ocean from?
It is 'disolved carbon' obtained by mixing with the atmosphere. (with a small amount that is a result of weathering)
Does temperature affect how gasses can disolve in water?
Yes - More can be disolved into cold water.
Which involves the greater transfer of carbon, degassing or disolving?
They're both the same.
In the ocean, what photosynthesises?
Plankton, particularly Phytoplankton
In what way do phytoplankton move CO2 from the atmosphere to rocks?
Phytoplankton absorb disolved CO2 and convert it into particulate carbon that can drop into the sediment & become sedimentary rock.
In what way do Phytoplankton remove CO2 from the atmosphere?
By absorbing disolved CO2, This then allows for more atmospheric CO2 to be disolved into the sea.
How is calcuium carbonate an important part of the carbon cycle?
Organisms like molluscs & coral mix disolved CO2 with disolved calcium to create calcium carbonate exoskelletons (these often end up in sedimentary rock).
Does respiration happen in the oceans?
For example plankton are eaten, converted into energy, and disolved carbon dioxide is released as waste.
What is the 'biological pump'?
When carbon particulates clump together & sink into the deep ocean reservoir, carrying their carbon with them.
Define 'Sinking' in relation to carbon transfer.
As surface water cools near the polar regions it becomes denser. This can cause it to sink below the lower layers of less dense water.
How much difference is there in disolved carbon betwen the surface and deep oceans? How is this shortfall made up to maintain the steady state when sinking & upswelling occurs?
There is 10% more carbon in the deep ocean.
The biological pump (sinking particulates) replaces the 10% lost to the lower ocean via upswelling.
The process of rock formation.
What are the forces that fuel lithification?
Pressure of overlying layers
Heat from Earth
What process of the carbon cycle was not allowed to occur, causing the formation of coal?
Vegetation living in wetlands died but couldn't be respirated as the decomposing organisms & creatures require oxygen but the materials became trapped under water preventing their natural decomposer organisms from accessing them.
Is there more carbonate or organic sedimentary rock?
There is 4 times as much carbonate sedimentary rock.
What is 'uplifting'?
The geological process that brings deep buried rock to the surface (eg mountain building)
What can 'weather' a rock?
Temp changes (freeze & thaw)
How can carbon in rock be transfered to the surface ocean reservoir?
Weathering by streams & rivers will carry carbon downstream into the sea.
How do volcanoes transfer carbon?
By melting the rock & releasing the carbon alongside gasses directly into the atmosphere.
How would deforestation affect the carbon cycle?
The cutting down of the forest reduces the amount of CO2 that can be taken from the air as photosynthesis.
The burning of the cut wood transfers CO2 into the atmosphere.
Less carbon will be stored in future as biomass.
What is 'coupling'?
The interraction between different equations in a mathamatical model.
What factors affect how clouds impact GMST?
How does longtitude affect climate at a fixed latitude?
Distance fropm sea
Height of land
Winds & Ocean currents
Why can we be confident in saying current warming is anthropogenic?
Models without CO2 factored in don't show a warming Earth
Increases in GMST & atmospheric CO2 show strong correlation
Models accurately predict last 140yrs warming
What temp increases do models predict by 2100?
Between 1.5o & 6oc
Average of 3oc
Assuming CO2 output peaks by 2050, how long will it take for atmospheric CO2 levels to a) stabilise? & b) significantly reduce?
100 years to stabilise & another 100 years to significantly reduce.
What danger would the melting of Arctic permafrost present?
It would release methane into the atmosphere. This would massively increase global warming & lead to more melting & more methane release - a positive feedback.
How much stronger a greenhouse gas is methane than carbon dioxide?
20 times stronger.
What starting assumption do most climate models take about future levels of CO2 emissions?