Long term changes in carbon and water cycle Flashcards
1
Q
How many major glacial cycles were there in the past 400,000 years?
A
4
2
Q
What were average annual UK temps 20,000 years ago?
A
5 degrees below today
3
Q
What were average global temps 250 million years ago?
A
7 to 8 degrees above today.
4
Q
What happens to sea levels during glacials?
A
Fall by 100-130m
5
Q
What happens to the water cycle during glacials?
A
It slows down due to area covered by vegetation shrinking, drier tropics and reduced rates of evapotranspiration.
6
Q
What happens to the amount of Co2 in the atmosphere during glacials?
A
Decreases. Is around 180ppm in warmer times it is around 280ppm.
7
Q
Why does the carbon cycle slow during glacials?
A
Less vegetation cover, fewer forests, lower temps and less precipitation so decrease in NPP.
