Carbon flows happen over different time and spatial scales: Fast carbon flows quickly transfer carbon between sources. It only takes a matter of minutes, hours or days. Photosynthesis, respiration, combustion and decomposition are examples of fast carbon flows. Sequestration is a slow carbon flow. It takes millions of years form carbon to be sequestrated in sedimentary rocks. The carbon flow taking place also depend on spatial scale. For example, at a plant scale, respiration and photosynthesis are the main floes. At an ecosystem scale, carbon flows such as combustion and decomposition also occur. At a continental scale, all of the carbon flows including sequestration occur.