You are here

G-res Tool

UNESCO Chair in Global Environmental Change  

When a reservoir is created, greenhouse gases may be released over time due to the decomposition of organic material in the flooded area. In other conditions, a reservoir may act as carbon sink: absorbing more emissions than it emits. Up until now, however, accurately assessing reservoir emissions has required large-scale and costly multi-year studies.

The GHG Reservoir (G-res) Tool, launched in 2017, allows companies, investors and consultants to report on the carbon footprint of a reservoir. Using readily available input data, the tool provides a cost effective way to more accurately assess net greenhouse gas (GHG) emissions.

The tool was developed by the International Hydropower Association (IHA) in collaboration with the UNESCO Chair for Global Environmental Change.

Assessing the net GHG emissions of a reservoir is now an expectation for sustainability reporting and a requirement for financing a hydropower project through climate finance.

Visit the G-res Tool website:


How it works

The G-res Tool uses a modelling methodology based on current scientific knowledge and over 500 empirical measurements from more than 200 reservoirs worldwide.

It builds on a conceptual framework developed in cooperation with researchers from the University of Quebec at Montreal (UQAM), the Norwegian Foundation for Scientific and Industrial Research (SINTEF) and the Natural Resources Institute of Finland (LUKE).

Using the tool


Supplementary material



In cooperation with:


Sponsored by: