Climate change

Question 1

Maunder minimum

Answer 1

• Fluctuations in ice-berg drafted debris and 14C suggests that a varying sun may cause millennial climate change
• 1645-1715AD, no sunspot activity, linked to cooling
• Comtemprounos with little Ice Age of 1550-1850AD

Question 2

James Croll

Answer 2

1824, proposed that Ice ages result to changes in Earth’s orbit and movement

Question 3

Eccentricity

Answer 3

• Changes in the path of the Earth’s orbit
• Varies between cyclicial and ellipitical
• 96,000 year cycle
• Affects seasonal variation in amount of heat recieved
• More eccentric, cooler summers

Question 4

Obliquity

Answer 4

• Changes to the Earth’s tilt
• Changes for 21 d to 24 d
• 43,000 year cycle
• A greater angle leds to a greator season contrast
• Less tilt leads to warmer NH winters

Question 5

Precession

Answer 5

• Changes in the wobble
• 26,000 years
• Controls the strength of the tropical monsoons

Question 6

Critisms of MC

Answer 6

• Changes are too small to explain large-scale changes
• Cycles are symmetrical, Ice age are not

Question 7

Thermohaline circulation disruption

Answer 7

• Can be disrupted by the influx of frehswater in N atlantic
• Causes cooling of oceans
• Can be disrupted by Heinrich events where vast masses of ice are released into the sea caused by weaknesses in glaciers.

Question 8

Atmospheric composistion

Answer 8

Lower CO2 and GHGs in glacial periods

Question 9

Volanic eruptions

Answer 9

• Can have a significant noncyclic effect on climate
• 1991, mt Pinatubo led to a 0.5 temp drop
• 73,500 bp, Toba super eruption led to a 3-5 temp drop