Long term changes in Carbon Cycle Flashcards
What is the most striking feature of the carbon cycle during glacial periods?
The dramatic reduction in CO₂ in the atmosphere.
What is the correlation between temperature and atmospheric CO₂ over the past 400,000 years?
There is a close correlation; CO₂ concentrations fall to around 180 ppm during glacial maxima and are 100 ppm higher in warmer inter-glacial periods.
What is a possible explanation for the drop in atmospheric CO₂ during glacial periods?
Excess CO₂ may find its way from the atmosphere to the deep ocean.
What mechanism may contribute to the reduction of atmospheric CO₂ during glacials?
Changes in ocean circulation that bring nutrients to the surface and stimulate phytoplankton growth.
How do phytoplankton affect CO₂ levels?
Phytoplankton fix large amounts of CO₂ by photosynthesis before dying and sinking to the deep ocean where the carbon is stored.
How do lower ocean temperatures affect CO₂ solubility?
Lower ocean temperatures make CO₂ more soluble in surface waters.
What happens to the carbon pool in vegetation during glacials?
The carbon pool in vegetation shrinks.
