From the forests we walk through to the oceans that shape our climate, discover the remarkable natural cycle that connects life on Earth.
Carbon is an essential building block of life. It travels between the air, oceans, soil, rocks and living things in a continuous series of natural exchanges.
Understanding the carbon cycle helps explain how ecosystems function, how our planet stores carbon and why changes to atmospheric carbon dioxide matter for the climate.
Understand the process ↗
The carbon cycle is not one single pathway. It is a network of processes happening across different timescales.
Plants take in atmospheric carbon dioxide and turn it into organic matter using sunlight.
Living organisms release carbon dioxide as they use energy.
Decomposers break down organic material, returning carbon to soils and the atmosphere.
Carbon dioxide moves between the atmosphere and oceans, where carbon can be stored.
A closer look at the places and processes that influence our planet's carbon balance.
Explore how trees, plants and soils absorb, release and store carbon.
Discover why marine environments are such important carbon reservoirs.
Learn how rocks, weathering and geological processes move carbon over millions of years.
Natural carbon exchanges have helped regulate Earth's climate over long periods. Human activities, especially fossil fuel combustion, have changed that balance.
Learning about carbon sources, sinks and reservoirs is a useful first step towards understanding climate science and sustainability.
Read the Met Office guide ↗The carbon cycle is the movement of carbon between the atmosphere, oceans, living organisms, soils and rocks.
The carbon cycle supports life and helps regulate Earth's climate by moving carbon between natural reservoirs.
Through photosynthesis, plants absorb carbon dioxide and use carbon to build organic matter.
Oceans exchange carbon dioxide with the atmosphere and store carbon in surface water, deep water and marine sediments.
Burning fossil fuels and changes in land use add carbon dioxide to the atmosphere and alter natural carbon exchanges.
Further reading: British Geological Survey · NASA Earth Observatory