T5 Climate change

Question 1

Name 5 methods of evidence for climate change

Answer 1

Pollen in peat bogs
CO2 levels
Temperature records
Dendrochronology
Ice cores

Question 2

Explain how studying pollen grains in peat bogs can provide evidence of climate change (4)

Answer 2

M1 Pollen is preserved in peat bogs
M2 Plant species can be identified from its pollen
M3 Climate affects the type of plants growing
M4 The deeper the pollen is found, the longer ago the plant species the pollen is from grew
M5 Changes in pollen over time indicate changes in climate

Question 3

Explain how ice cores can be used to give evidence for climate change

Answer 3

Ice cores contain gas bubbles can be analysed to show temperature and atmospheric composition thousands of years ago

Question 4

Explain how dendrochcronology can be used

Answer 4

When a tree is cut each ring represents a year of growth
Thicker rings indicate warmer, wetter years and vice versa

Question 5

Explain how increasing levels of carbon dioxide are affecting animals in their ecosystems

Answer 5

More carbon dioxide is dissolving into the sea
Decreasing sea pH
Organisms have optimal pH conditions to live in - pH is now outisde optimal
For some organisms their enzymes may denature

Question 6

Explain how anthropogenic factors contributing to higher levels of CO2 in the atmosphere are causing an increase in global temperatures

Answer 6

Humans burn fossil fuels which releases CO2 gas into the atmosphere
So more Infrared radiation is trapped in the atmosphere
Causing a mean increase in the surface/atmospheric temperature

Question 7

Explain why data cannot always be reliable to be used to make predictions about the climate in the future

Answer 7

You cannot assume a trend will continue
Not always enough data collected
Bias from scientists
Don’t know how emissions will change
Unknown natural changes to greenhouse gas levels
Unknown attempts (and their effectiveness) to decrease greenhouse gas levels