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How much energy is commonly lost as heat between trophic levels?

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Diagram illustrating Earth's environmental spheres, with labeled sections showing the geosphere (land and crust), biosphere (living things), atmosphere (air), and hydrosphere (water), each extending vertically from the Earth's surface. — Biosphere Earth's environment includes the atmosphere, the hydrosphere, the lithosphere, and the biosphere.

In biological communities, energy is transferred between trophic levels through food chains. As energy moves along these pathways, it is significantly reduced due to the inefficiency of transfer, with as much as 80 to 90 percent of energy being lost as heat.123

This loss occurs because organisms must expend a large portion of the energy they ingest on metabolic processes, such as digestion and maintaining body temperature. According to the laws of thermodynamics, organisms cannot create energy; they transform it, returning a portion to the environment in a less useful form, typically as heat, which cannot perform further work within biological systems.142

Consequently, only a small percentage of energy—estimated on average at about 10 percent—is successfully converted into biomass at each subsequent trophic level. This limited efficiency explains why food chains typically do not extend beyond four or five levels, as there is progressively less energy available to support organisms higher up the trophic pyramid.513