Climate Change

Question 1

How does the past climate change

Answer 1

Hot and Cold periods

Question 2

Examples of proxy data

Answer 2

Tree rings, ice cores, fossil pollen, ocean sediments, corals and historical data

Question 3

How are corals used to determine the past climate

Answer 3

Corals are made from Calcium Carbonate, Carbonate contains isotopes of oxygen as well as trace metals that can be used to determine the temp of the water om which the coral grew

Question 4

How are tree rings used to determine the past climate

Answer 4

Climatic conditions influence tree growth, patterns in tree-ring widths, density and isotopic composition reflect variations in climate. Trees generally produce one rings a year

Question 5

How are ice cores used to determine the past climate

Answer 5

Snowfall layers contain dust, air bubbles, or isotopes of oxygen, differing year to year based on the surrounding environment

Question 6

Name the two types of earths climate conditions

Answer 6

Greenhouse

Icehouse

Question 7

What occurs during ice house conditions

Answer 7

Glacial and inter-glacial periods occur but on a much shorter timescale

Question 8

Conditions during the mid-Cretaceous (100 million years ago)

Answer 8

Average global temperatures 6-8 degrees higher than today
No polar ice caps
Sub-tropical conditions extended from Antarctica to Alaska

Question 9

What is the new geological period called

Answer 9

Anthropocene

Question 10

What are the three types of natural forcing and explain them

Answer 10

Natural forcings - induce change in climate
External forcing - These are linked to changes in the orbital parameters of the earth
Internal forcing - changes which occur within the Earths system itself

Question 11

External forcing - Milankovitch Cycles what are they

Answer 11

Changes in the earths orbit and axis and the precession of the equinoxes
These changes affect the amount of solar radiation reaching the planets surface

Question 12

Explain Obliquity and what affect it has on climate

Answer 12

Tilt of the Earths axis
More tilt = more seasonality, warmer polar summers, glaciers less likely to survive
Less tilt = the opposite

Question 13

Explain Eccentricity and what affect it has on climate

Answer 13

Eccentricity of Earths orbit
Less eccentricity = less seasonality, cooler polar summers, glaciers more likely to survive
More eccentricity = the opposite

Question 14

Explain precession of the equinoxes

Answer 14

affects seasonality and extent of glaciation

Question 15

What affect does volcanic eruptions have on climate

Answer 15

Sulfur dioxide has a cooling effect

Increased albedo - reflects solar radiation back into space

Question 16

Continental drifts affect on climate

Answer 16

As larger continental areas occupy higher latitudes, the land area with permanent ice cover expands increasing global albedo = positive feedback = forces global cooling

Question 17

Ocean circulation

Answer 17

Vital component in the Earths energy budget, transferring surplus energy

Question 18

Formation of the isthmus of panama consequences

Answer 18

Intensified the gulf stream
Increasing evaporation and precipitation in the North Atlantic
Decreasing the salinity of the North Atlantic and Arctic Oceans
This slowed thermohaline circulation
onset of the glaciation 3 mya

Question 19

Melt water plus consequences

Answer 19

Melting of ice sheets in the Arctic reduces ocean salinity
Weakening the down welling of the North Atlantic Conveyor
Led to the return to glacial periods for 1000 years

Question 20

What have the influences of humans been for climate

Answer 20

Growing population

Technological advances

Question 21

Rising sea level-evidence for climate change

Answer 21

Currently 3 mm per year
Causes: thermal expansion and melting land ice
since 1900 average rise has been 1-2.5 mm/yr
currently at 3 mm/year

Question 22

Shrinking valley glaciers-evidence for climate change

Answer 22

Retreated or disappeared

1961-2005 thickness of valley glaciers reduced by average of 12m

Question 23

Shrinking of ice sheets-evidence for climate change

Answer 23

Antarctic and greenland contain 97 percent if global ice store
both are shrinking fast

Question 24

Losses of ice-evidence for climate change

Answer 24

Warming of atmosphere
Meltwater penetrates the ice and increases the velocity of glacier flow
Ocean warming which accelerates the melting of ice sheets in coastal regions

Question 25

increasing atmospheric water vapour

Answer 25

Most important GHG
Traps huge amounts of energy radiated from Earths surface
Warmer condition=more evaporation=more water vapour
This leads to a positive feedback

Question 26

Decreasing sea ice

Answer 26

Overall decrease since 1997
Summer reduced 8 percent per decade
Winter reduced 3-4 percent per decade
Thickness has also declined

Question 27

Carbon dioxide-Anthropogenic

Answer 27

Second most important GHG
75 percent of anthropogenic GHG
Before 1800 stable at 280 ppm
2015 passed 400ppm, increase in 40 percent in 200 years

Question 28

Methane-Anthropogenic

Answer 28

measured in ppb
1984, 1735ppb
2009, 1890ppb
more potent than CO2, 25 TIMES POTENT
15 percent of all GHG emissions

Question 29

Reasons for rising GHG emissions since the pre-industrial era

Answer 29

Huge surge in demand for energy
Industrialisation and tech advancements
Especially manufacturing and transport
Massive population growth
1800 1 billion, 7.4 billion in 2015
Increase in living standards
Deforestation and drainage of wetlands 
Rely heavy on fossil fuels 87 percent

Question 30

Dependance on fossil fuels

Answer 30

Two thirds of anthropogenic GHG emissions come from burning fossil fuels
10 billion tonnes of CO2 annually

Question 31

Coal

Answer 31

Coal is no longer the leading fossil fuel
China and india are largely powered by coal
Coal is the dirtiest fossil fuel- twice as much co2 as natural gas/20 percent more co2 than oil

Question 32

Cause of the Enhance greenhouse effect

Answer 32

Volume of GHG has increased rapidly in atmosphere

exaggerated by positive feedbacks which led to further warming