Climate change

Question 1

evidence for climate change

Answer 1

1. CO2 concentration which can be determined from the past from bubbles of air trapped in extracted ice cores
2. temperature records from 1659 however we don’t know how reliable the measuring equipment was.
3. pollen in peat bogs gives an indication of their relative abundance and climate at the time
4. dendrochronology gives information about the climate at the time each ring of the tree was formed

Question 2

correlation

Answer 2

when two variables change at the same time but the change in one is not directly caused by the other

Question 3

causation

Answer 3

when the change in one variable is as direct result of the change in the other variable

Question 4

how does pollen in peat bogs explain past climates

Answer 4

1. wind-pollenated plants produce vast amounts of pollen so some is likely to be preserved
2. pollen is only produced by mature trees so they would be surviving successfully in the climate at the time
3. pollen has a tough outer coating that is resistant to decay
4. each species of plant has a distinctive type of pollen allowing for identification of the plant species they came from
5. peats form layers where the deeper the layer the other the peat - C14 dating allows the age of the peat to be established
6. plant species have specific ecological conditions they thrive in so the pollen found from a plant species tat favours warm climate can be show that the peat was laid down when the climate was warm.

Question 5

how does dendrochronology provide information on past climates

Answer 5

every year trees produce a new layer of xylem vessels and the diameter varies depending on the season in which they grew, wide vessels are produced in warm and wet conditions, the width of rings indicate the climate conditions pf the time period.

Question 6

what is the greenhouse effect

Answer 6

• UV radiation is emitted by the sun and absorbed by the earths surface
• the earths surface warms up and emits infra-red radiation
• some of this radiation is absorbed by greenhouse gases like C02 or methane
• this results in an increase in mean atmospheric temperature

Question 7

cause of climate change

Answer 7

• CO2 from combustion and methane from ruminant farm animals are being increasingly release into the atmosphere by human activities
• CO2 and methane trap heat in the atmosphere causing it to warm mote than it would naturally do so the more CO2 and methane the warmer the atmosphere gets.

Question 8

assumptions that need to be made to extrapolate a curve

Answer 8

1. we have enough data to establish the trend accurately
2. present trends continue

Question 9

climate change effect of animals

Answer 9

• changing temperatures will have an effect on the rate of enzyme reactions
• this can effect hatching times, seed germination and growth of animals and plants