Biogeochemistry: now and into the future

Biogeochemistry can be defined as the mutual interactions (two-way) between the biology and chemistry of the Earth system, and as such is clearly an important component of the broader discipline of geobiology. It is a well-developed field, having a dedicated journal and textbook, and many hundreds of publications appearing in the scientific literature each year. Perhaps the best example of biogeochemistry is the balance between photosynthesis and respiration, autotrophy and heterotrophy, on Earth, the so-called Redfield equation. The modern practice of biogeochemical research has been focused on present-day processes such as those in the Redfield equation, but new tools and approaches are beginning to explore the biogeochemistry of the ancient Earth; this is the challenge for biogeochemists in the future.