Determining Earth's conditions in the past - Proxy Data

Question 1

Historical written records

Answer 1

newspapers, diary entries, ships’ logs ‘

thousands of years

bias/subjective

Question 2

Coral

Answer 2

made of calcium carbonate

density of reef changes depending on the availability of carbon (dissolved from the atmosphere)

only grow in certain areas
destroyed in acidic conditions

Question 3

Pollen

Answer 3

determine which plant/species it came from

certain plants are associated with certain climates

there are no flowering plants in some areas

Question 4

Ice cores

Answer 4

date back hundreds of thousands of years

builds up layers annually (thick = wet+warm)

analysis of trapped (greenhouse) gases

oxygen isotope analysis - O18 isotope is heavier meaning H2O molecules require more energy to evaporate - hotter years = more precipitated and preserved

Question 5

Tree rings (dendrochronology)

Answer 5

one per year

wider and lighter= warmer+wetter years

date back few thousand years

preserved as fossilised remains

not all trees have rings
trees don’t grow everywhere

Question 6

Ocean and Lake sediments

Answer 6

certain plants are associated with certain climates

find fossils and their origin

Question 7

What are the limitations of proxy data?

Answer 7

subjective

does not date back very far unless fossilised

only collects data from certain areas

damaging to collect data

Question 8

What data collection methods do we use today?

Answer 8

weather stations
weather balloon
thermometer
satellites - measure ice/cloud cover - weather systems
anemometer - wind speed
rain gauge

Question 9

What methods do we use to collect atmospheric data?

Answer 9

temp - thermometer
air pressure - barometer
humidity - hygrometer
wind speed - anemometer

Question 10

What methods do we use to collect data on land?

Answer 10

temp - thermometer
precipitation - rain gauge
migration - living organisms

Question 11

What methods do we use to collect data from oceans/what data do we collect?

Answer 11

temp - thermometer
sea levels
ocean acidity
species distribution
salinity
ocean currents

Question 12

What information can we collect from space?

Answer 12

cloud cover
ice cover
number/movement of weather systems
colour of oceans - algal blooms
monitor species - movement+distribution

Question 13

Pros of modern methods

Answer 13

more advanced

collects data from across the whole planet

more accurate

Question 14

Cons of modern methods

Answer 14

short history

invasion of privacy

expensive

Question 15

Pros of proxy methods

Answer 15

more data to compare

Question 16

Cons of proxy methods

Answer 16

subjective
only collects data from specific areas
damaging to obtain data