Climate Change And Its Causes

Question 1

Explain carbon dioxide levels as a measure of climate change

Answer 1

Samples from bubbles of carbon dioxide in Antarctica and Greenland
Look at series of carbon dioxide levels in atmosphere

Question 2

Past climate of carbon dioxide levels

Answer 2

Varied naturally between 180 - 280 ppm

Over last 800,000 years

Question 3

Comment on the reliability of carbon dioxide levels

Answer 3

Number of sequences that correlate well suggest that it is reliable

Question 4

How do oxygen isotopes measure climate change

Answer 4

Sampled from ice cores / ocean specimens cores
Ratio indicates past sea levels
16 evaporates easier
-> colder climate

Question 5

Past climate for oxygen isotope records

Answer 5

Correlate well with co2 levels

When cos was low, so we’re sea levels

Question 6

Reliability of oxygen isotopes

Answer 6

Good correlation with co2 levels

Broadly agree on sea levels

Question 7

Explain the technique pollen to measure long term impacts of climate change

Answer 7

Pollen records ecology of past
Extracted from sediment cores
Different plant species grow within certain temperatures

Question 8

Past climate of pollen

Answer 8

Show that ecosystems change due to climate

Question 9

Reliability of pollen

Answer 9

Rely on good preservation of pollen
Long pollen sequences are rare
Vegitation may lag behind

Question 10

Africa ecological impacts

Answer 10

Flora and fauna disappear in Sahel
->10-15% species extinct

5 South African parks lose 40% of animals

Question 11

Economic impacts of Africa

Answer 11

Sea level rise in Egypt -> cost 14% of gdp

Pressure from environmental refugees

1m rise -> Egypt = X 4,000km2 crop land

2*c 80% crop failure

Question 12

Emvironmental impacts of climate change in Africa

Answer 12

97% coral reef bleaching east Africa

Growing period reduced by 20% in Chad
-> vulnerability to floods

2mm sea level rise every year

Question 13

Social impacts of Africa climate change

Answer 13

Malaria double by 2100 in South Africa

300mil water stress in North Africa

20% increase in coastal flood deaths

Less food yields -> import

Question 14

Arctic environment impacts

Answer 14

40% permafrost thawing - melts lakes -> methane

14% loss of ice cover (3x size uk)

Vegetation shift north

Question 15

Ecological impacts Arctic

Answer 15

Veg shift north destabilise food webs

40% permafrost melts - particularly in Siberia Arctic char

Insect species kill trees

Question 16

Social impacts of Arctic

Answer 16

Decline in fresh water fish -> Arctic char to eat

Enhanced agriculture and forestry

More land available for exploitation

Question 17

Ecological impacts Arctic

Answer 17

Veg shift north destabilise food webs40% permafrost melts