The properties of organisms are not tunable parameters selected because they create maximum entropy production on the biosphere scale: A by-product framework in response to Kleidon

Research output: Contribution to journalReview article


Axel Kleidon (Clim Change 66:271-319, 2004) proposed that the organisms that constitute Earth's biota have free parameters that can be selected to create states of maximum entropy production (MEP) on various scales, from the biota to the planetary radiation balance of the Earth system. I show that Kleidon's concept, here called the biotic-MEP hypothesis, is fundamentally mistaken. A thought experiment with a life form that would be selected against even though it would generate a higher degree of entropy demonstrates my case: A hypothetical tree that puts forth a non-productive but high-entropy producing black carpet of tissue clearly separates out entropy production from other biological processes and shows that entropy production is not a functional adaptation and therefore it cannot be selected for. A real world example comes from dimethyl sulfide-emitting plankton, which, by increasing cloud albedo, do not raise but rather lower the entropy flux of the Earth system. I provide a number of other examples of biotic processes that individually either decrease or increase the environmental entropy production. It is argued that biological effects on environmental entropy production can be expected to include both positive and negative examples, because these effects are merely by-products of the actual processes that are selected for by evolution. Given my framework of entropy production as a by-product of the true processes that are being selected for, the concept of MEP on environmental scales has no great relevance for discussions of biological evolution or the time history of the effects of life on the global system.

Original languageEnglish (US)
Pages (from-to)251-258
Number of pages8
JournalClimatic Change
Issue number3-4
StatePublished - Dec 1 2007


ASJC Scopus subject areas

  • Global and Planetary Change
  • Atmospheric Science

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