PhD defence: Modelling the origin and fate of carbon in the aquatic continuum


In the climate change and carbon cycling science community there is a need for quantifiable insights into the fate of the most important greenhouse gas, carbon dioxide, emitted to the atmosphere through human activities. A puzzle piece in that research is to quantify the pathways of carbon in freshwater systems such as rivers and lakes.

This Phd project developed a new computer model that simulates delivery to, burial, emissions and transport of carbon by freshwaters. Over the course of the 20th century delivery of carbon increased from 3.3 to 3.5 Petagram (Pg) carbon per year, retention increased from 0.3 to 0.4 Pg carbon per year, carbon dioxide emissions increased from 2.1 to 2.2 Pg carbon per year and transport to the ocean remained equal with 0.9 Pg carbon per year. All fluxes in the freshwater carbon cycle increased, but these changes are limited when compared to changes in the land carbon storage (from 0.4 to 2.2 Pg carbon per year), atmosphere carbon storage (from 0.6 to 3.1 Pg carbon per year) and ocean carbon storage (from 0.5 to 2.0 Pg carbon per year).

Therefore this research concludes that the sensitivity of the freshwater carbon cycle to human interference is lower than that of other components of earth system. Note that eutrophication is not included here. Still it is important not to omit freshwaters in global carbon cycle models as they impact the magnitude of the carbon fluxes from atmosphere to land and ocean.

Start date and time
End date and time
Utrecht University Hall, Domplein 29
PhD candidate
Wim Joost van Hoek
Modelling the origin and fate of carbon in the aquatic continuum
PhD supervisor(s)
Prof. Dr Jack Middelburg
Prof. Dr Lex Bouwman