Climate change and coupling of macronutrient cycles along the atmospheric, terrestrial, freshwater and estuarine continuum

This paper provides an introduction to the Special Issue on “Climate Change and Coupling of Macronutrient
Cycles along the Atmospheric, Terrestrial, Freshwater and Estuarine Continuum”, dedicated to Colin Neal
on his retirement. It is not intended to be a review of this vast subject, but an attempt to synthesize some
of the major findings from the 22 contributions to the Special Issue in the context of what is already
known. The major research challenges involved in understanding coupled macronutrient cycles in these environmental media are highlighted, and the difficulties of making credible predictions of the effects of climate
change are discussed. Of particular concern is the possibility of interactions which will enhance greenhouse
gas concentrations and provide positive feedback to global warming.