AP Environmental Science Flashcards: The Carbon Cycle
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
Define a carbon sink.
A carbon sink is a reservoir that absorbs and stores carbon from the atmosphere, such as forests performing photosynthesis or the long-term storage from decomposition.
Card 1 of 11
All Flashcards (11)
Define a carbon sink.
A carbon sink is a reservoir that absorbs and stores carbon from the atmosphere, such as forests performing photosynthesis or the long-term storage from decomposition.
What is a carbon reservoir?
A carbon reservoir is a place where carbon compounds are held for a period of time, such as in living things, fossil fuels, or the atmosphere.
How has decomposition contributed to long-term carbon storage?
Over millions of years, the decomposition of plants and animals has led to the formation of fossil fuels, which are long-term reservoirs of stored carbon.
A factory is built that burns coal for energy. How does this activity interact with carbon reservoirs?
This activity moves carbon from a long-term reservoir (fossil fuels from decomposition) to a short-term reservoir (atmospheric carbon dioxide).
How do carbon reservoirs differ in terms of storage duration?
Some reservoirs, like fossil fuels, hold carbon compounds for long periods of time, while others, like living organisms, hold them for relatively short periods.
Define a carbon source.
A carbon source is a part of the carbon cycle that releases carbon into the atmosphere, such as cellular respiration or the burning of fossil fuels.
What is the primary impact of burning fossil fuels on the carbon cycle?
The burning of fossil fuels rapidly moves carbon that was stored for millions of years into the atmosphere, primarily in the form of carbon dioxide.
Contrast the timescale of carbon storage from decomposition with its release from burning fossil fuels.
Carbon is stored through decomposition over millions of years, while the burning of fossil fuels releases that same carbon back into the atmosphere very quickly.
In what chemical form is carbon released into the atmosphere when fossil fuels are burned?
When fossil fuels are burned, the stored carbon is moved into the atmosphere in the form of carbon dioxide.
What is the carbon cycle?
The carbon cycle is the movement of atoms and molecules containing the element carbon between sources and sinks.
What are the two main biological processes that cycle carbon between living things?
Carbon cycles between photosynthesis, which captures atmospheric carbon, and cellular respiration, which releases it back into the atmosphere.