The Carbon Cycle

“One atom can move from air to leaf, ocean, shell, and rock across very different histories.”

01 / PLAINLY

What it means, plainly

The carbon cycle exchanges carbon among the atmosphere, life, oceans, soils, rocks, and fuels across many timescales.

02 / CONTEXT

A little more

Photosynthesis, respiration, decomposition, and ocean mixing move carbon relatively quickly; weathering, sedimentation, and tectonics operate much longer. Burning fossil fuels transfers within decades carbon stored over geological ages.

03 / WHY IT MATTERS

Why it matters

It connects metabolism, ecosystems, ocean acidity, and climate and shows why both the amount and speed of a transfer matter.

04 / EXAMPLE

A familiar example

The ocean absorbs part of atmospheric carbon dioxide; as it dissolves, it changes chemical equilibria and lowers seawater pH.

05 / LIMIT

What it does not mean

A carbon sink does not destroy carbon or necessarily store it forever; it can saturate, change, or release carbon again.

06 / NOTICE

Notice it in your day

Trace carbon in a meal from the atmosphere to your breath. Add an alternative route that ends stored in soil or sediment.

FINAL NOTE

The idea worth keeping

Identify the reservoir, flow, rate, and residence time before judging a change.

QUESTIONS / 02

Questions people still have

Where is most of Earth's carbon stored?

A large share is held in rocks and sediments rather than in the atmosphere or living organisms.

What changes when fossil fuels are burned?

Geological carbon moves rapidly into the atmosphere, altering flows that usually operate over much longer scales.