Global warming Flashcards
1
Q
How CO2 can be removed long time
A
- CO2 is locked up in trees, trees live for ages
- When trees die, peat forms, fossil fuels form
- carbon sink
2
Q
Net effect of oceanic processes on CO2 content
A
- CO2 taken in by marine animals to create calcium carbonate shell
- CO2 taken in by algae/seaweed for photosynthesis
- marine organisms die and form fossil fuels
- (more CO2 taken in than given out)
3
Q
How to reduce CO2 releases by combustion of fossil fuels
A
- increased use of public transport
- burn biogas
- produce electricity from renewable resources, e.g. wind or solar
- plant trees
- improve fuel efficiency
4
Q
How a forest could be managed sustainably in order to ensure continual supply of wood
A
- replanting after harvesting trees
- selective felling of timber trees, leaving rest of forest intact
- harvesting trees on rotation
- trees cut at ground level and allowed to regrow, leave for 20 years
- plant fast growing trees
5
Q
How pollen analysis is carried out
A
- take a peat core
- peat develops in layers
- the deep the layer, the older the pollen
- identify and analysis species
- certain species grow in certain climates/environmental conditions
- by identifying the specie and climate grown in, you can identify climate when peat was from
- compare pollen to present day species
- radiocarbon date the peat to calculate age of peat
- calculate the density of a specie in the peat to find the relative abundance of specie
6
Q
Why might global warming predictions be inaccurate
A
- they assume that current trends will continue - we cannot be sure they will
- there is only limited amount of long term data used to produce them - older records may have been made with inadequate equipment
- something unforeseeable may happen- not all relevant factors may have been included, e.g. chaos theory
- many factors involved - inadequate computing power
7
Q
What is meant by the term global warming
A
- the rise in the average temperature of the Earth’s surface
- due to the increases in greenhouse gases
- e.g. CO2, methane, CFCS, water vapour
- which trap heat in the atmosphere by reflecting it back
- there is an increased greenhouse effect
8
Q
Why might specie abundance change due to global warming
A
- species have lost their specific habitat
- species have lost their food source
- weather has affected food
- global warming reduces the number of predators
- not able to exploit other habitats
- another species may be better able to adapt and exploit new habitats, larger niche
- one specie might out compete another - moves to avoid intraspecific competition
9
Q
Examples of how CO2 is used
A
- CO2 converted into wood by photosynthesis
- dead wood is converted to other substances by decomposition
- CO2 is released from organisms by respiration
- CO2 is released from wood by combustion
10
Q
Explain why coal reserves represent a carbon sink
A
- coal contains carbon that has been taken from the atmosphere in the past
- the carbon has been taken out of circulation in the carbon cycle
11
Q
Explain why burning wood is considered ‘carbon neutral’
A
- burning wood does not add to the amount of CO2 in the atmosphere (doesn’t cause net increase)
- CO2 taken in equals CO2 given out
- burning wood releases carbon recently absorbed by photosynthesis
12
Q
Why planting extra forest may not be a complete long term solution to rising CO2 levels
A
- not enough room to keep planting enough forests to use up all the surplus CO2
- a mature forest is carbon neutral, only young forests are net absorbers
- the forest will decay (releasing CO2) or be burnt by humans
13
Q
Explain the difference between ‘global warming’ and ‘greenhouse effect’
A
- global warming is a global mean increase in the temperature of the earth’s surface whereas the greenhouse effect explains why global warming is occurring (greenhouse gases, e.g. CO2 and methane trap in heat)
- greenhouse effect is how the sun keeps the Earth warm whereas global warming is an increased greenhouse effect
- Global warming is due to raised CO2 concentration, e.g from the burning of fossil fuels
14
Q
Why might estimates of future temperature be accurate predictions
A
- we assume the trend continues, we do not know it will
- prediction not based on long enough series of data
- data prediction is based on may not be accurate
- some unpredictable event, e.g. volcanic eruption may occur
- there may be a sharper than expected change in fossil fuel consumption
- changes in solar radiation
15
Q
Why might a small increase in temperature have a large effect on the survival of particular species of plants and animals of a particular species
A
- enzymes are temperature sensitive
- rate increases with temperature
- enzymes may be denature by very high temperatures
- this may affect respiration/metabolic activity
- may give competitor an advantage, they will out compete the other specie
- may affect water availability
- may affect supply of food plants/prey species/predators
- change of sex ration in reptiles, e.g. turtles
- photosynthesis affected
