Historical climate change Flashcards
1
Q
Quaternary period
A
2.58 million years ago to present
2
Q
What is the quaternary period split up into?
A
- Pleistocene (2.58ma - 12 ka)
- Holocene (12ka - present)
3
Q
Climate change in tropics
A
- 30N to 30S latitude
- Tropics make up nearly 50% of land surface
- Home to 70% of all people
- They export excess solar energy to help warm the rest of the planet
- Intertropical convergence zone (ITCZ) = very wet 20N to 20S
4
Q
Andes vegetation
A
- Data from high plain of Bogota (5N),
- LGM was 5-6 colder
- More perment snow and less forest at high latitudes
5
Q
World vegetation
A
- Global shift toward arid conditions
- 50% drier than modern day
6
Q
CO2
A
- Up to 50% less CO2 in glacial conditinos
- Decline of C3 plants
- Expansion of C4 plants, especailly grasses
7
Q
Refugia theory
A
- Nine main refugees in southern europe
- Trees slowly spread back northward 7-6 ka.
- Oak 500m/year
8
Q
Lake Mega-chad
A
- 15-6ka, many tropical lakes overflowed
- 150% deeper than today nd more extensive
8
Q
Africa humid period
A
- Ground water formation
- Stronger monsoon brought increased rainfall further north
- Green sahara during early/mid holocene
- Very important for modern water supplies
9
Q
Lake Magadi, south kenya
A
- Lake level rose 50 m in 15ka (LGM)
- Desiccation post mid-holocene (5Ka) to weakened monsoon
10
Q
Climate change on humans
A
- Very slow population growth for most of quaternary, increase during holocene
- Pollen evidence of major veg clearance from 6 ka bp
