A team of scientists led by the oceanographer Alberto Borges (University of Liège) and Prof. Steven Bouillon (KU Leuven), has just completed a large-scale research project conducted over a five-year period on the African continent. The aim of this study was to compile the first greenhouse gas budget of African rivers. The data from this project both complement and challenge previous knowledge of the overall carbon budget for the continent. 
Covering 12 rivers spread across the entire continent of Africa including the Congo, the second largest river in the world, the study shows that  greenhouse gas emissions from the rivers are very significant. This data constitutes essential information with regards to the management of forestry resources in Africa. An article is due to appear on July 20th 2015 in the prestigious journal Nature Geoscience.

Twelve scientists from the University of Liege, the KU Leuven and the Institute of Research for Development (France) have just completed a five-year large-scale research project financed by Europe (ERC starting Grant), the FNRS, FWO and BELSPO, the aim of which was to compile a previously unknown budget of greenhouse gas emissions (GHG) by the rivers of the African Continent. Under the guidance of Alberto Borges, who is head of the Chemical Oceanography Unit at the University of Liege and who specializes in the GHG of aquatic environments and in close collaboration with Professor Steven Bouillon of KU Leuven, the researchers trawled the African continent in order to analyze the streams of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O), the three main GHG.

The results and analyses, which have now been finalized, are the subject of a publication in Nature Geoscience. This data represents a major contribution to existing knowledge about carbon emissions to the atmosphere from African inland waters . In a broader sense, this data-set contributes to better understand the role of rivers in greenhouse gas global budgets.

"Due to the fact that rivers link continents to the ocean by carrying organic matter that is partly degraded by bacteria, they play a major role in the production and emission of  CO₂  and  CH₄", explains Alberto Borges. "Research concerning GHG emissions in inland waters – rivers, lakes, and reservoirs – began in the 1990s in various developed countries, supported in part by the hydro-electric industry, and supplied valuable information about boreal (Scandinavia, Canada), and temperate (Europe, United States) inland waters. Concerning the tropics which hold 60 % of the freshwaters of the planet, studies were carried out almost exclusively in Brazil, on the Amazon the largest river in the world. But can the data collected in Brazil be applied to the world’s second largest river, the Congo, also located in the tropics ? Similarly, can the data in the Amazon be applied to semi-arid rivers draining savannah rather than tropical forest? There was some important information lacking here. Given that Africa contains 12 % of the world's softwater, this study supplies a missing piece to the puzzle: a very significant and coherent data set in terms of the methodology employed and concerning an entire continent".

(1) Globally significant greenhouse-gas emissions from African inland waters,  A.V. Borges, F. Darchambeau, C.R. Teodoru, T.R. Marwick, F. Tamooh, N. Geeraert, F.O. Omengo, F Guérin, T. Lambert, C. Morana, E. Okuku & S. Bouillon, Nature Geoscience, July 2015.