Virtually unknown in the west, the great Russian geologist and geochemist pioneered scientific study of life’s impact on the Earth.
As we’ve seen, metabolism, a defining feature of all life, always involves exchanges with the world outside the organism. Life cannot exist without ingesting matter and excreting waste. The fact that the Earth is a sphere surrounded by a vacuum, and that we have access only to its outer few kilometers, means that the amount of matter available for life to use is finite, and that life’s wastes have nowhere else to go.
If metabolisms were linear, if inputs were simply consumed, the nutrients needed by living organisms would soon be depleted. Plants could consume all the carbon dioxide in the atmosphere in about 8,000 years, and all the nitrogen in a million years. Life has lasted far longer than that because its support systems are circular. Vast recycling operations endlessly reprocess and reuse essential elements and compounds. Radical biologist Barry Commoner described the Biosphere as “a closed, circular system, [in which] there is no such thing as ‘waste’; everything that is produced in one part of the cycle ‘goes somewhere’ and is used in a later step."