Dense green tropical forest canopy at Bodiman, Cameroon.

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Preparing the 3D view

Preparing lighting and the first complete frame…

Model scale

Invented closed budget. sphere volume ∝ stored carbon. no geographic distances.

Model year 40.0 · Fossil-fuel combustion: 2.00 Pg C/year. Burned 80.0 Pg C; total 12000.0 Pg C stays fixed.

How to read these results

The selected budget uses 1 Pg C = 10¹² kg of carbon. Each transfer removes the same quantity from one store as it adds to another.

Carbon cycle

Trace carbon between fast and slow stores, and explain how burning fossil fuels transfers carbon into the atmosphere.

Drag to rotate. Hold Ctrl and scroll to zoom, or pinch on a touch screen.

Why it happens

Carbon moves among the atmosphere, organisms, soils, ocean and rocks. Photosynthesis, respiration and other transfers connect stores that operate on very different timescales.

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Tropical forest at Bodiman, Cameroon: living vegetation is a carbon store, exchanging carbon with the air and soil.

Try a comparison

Choose Photosynthesis and Respiration separately. Open the tap, scrub towards 100 model years, and compare source loss with total emitted carbon.

Reading the result

The budget tracks selected stores and transfers; compare its assumptions before interpreting it as a description of the entire global carbon cycle.

A common misunderstanding

Carbon released by burning fossil fuels is immediately removed by the natural carbon cycle.

Burning fossil fuels transfers carbon from long-term geological stores into the atmosphere. Land and oceans absorb some of it, but uptake does not instantly match all emissions. Atmospheric carbon increases when inputs exceed removals, and different stores exchange carbon over very different timescales.

Cases

Exam language

Store

A quantity of material or energy held within part of a system, such as water in a lake or carbon in vegetation. Inputs and outputs change the amount stored. A store is an amount; a flux is a transfer rate.

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Tropical forest at Bodiman, Cameroon: living vegetation is a carbon store, exchanging carbon with the air and soil.

Flux

A rate of transfer of a quantity such as water, carbon or energy; some uses express that rate per unit area.

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NASA CERES observations, 2000–2015 mean. Colours show sunlight reflected by the Earth system in W m⁻². This is outgoing shortwave flux, not incoming solar irradiance or albedo itself.

Photosynthesis

The use of light energy to build organic molecules from carbon dioxide and water. Oxygen-producing photosynthesis transfers carbon into living matter.

Respiration

Processes that release energy from organic matter. Aerobic respiration consumes oxygen and releases carbon dioxide and water.

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White beech leaf litter at Carowiry Creek, New South Wales. Organic material on the forest floor stores carbon and provides material for decomposition.

Weathering

Physical breakdown or chemical alteration of rock at or near Earth's surface, without transporting the material away. Chemical weathering also participates in the carbon cycle.

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Weathered granite documented by GeoDIL. Mineral breakdown and disintegration progressively turn intact rock into weathered material.

Fossil fuel

Coal, oil or natural gas formed from ancient organic material. Burning it transfers carbon from long-term geological stores to the atmosphere.

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Lignite at Chukurovo, Bulgaria. This fossil fuel formed from buried plant material; combustion transfers its stored carbon to the atmosphere.

Fast cycle

Carbon exchanges among the atmosphere, living organisms, soils and upper ocean over relatively short timescales, from days to centuries.

Slow cycle

Carbon transfer through rocks, sediments and the deep Earth, involving weathering, burial, metamorphism and volcanism over geological timescales.

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Layered rocks at Grand Canyon record the geological carbon cycle and deep time. Lithification converts sediment into rock; the canyon also exposes much older basement in its inner gorge. A landscape photograph alone does not date individual beds.

Process0.40Fossil-fuel tap0.20Follow a transfer