Synthesis

Abstract

The objectives of this chapter are to present a comprehensive review of the current state of knowledge and to identify the gaps in the greenhouse gas issues in hydroelectric reservoirs and natural ecosystems. It has become essential to integrate our knowledge of the carbon cycle at the larger temporal and spatial scales in order to properly assess the magnitude of GHG fluxes from reservoirs1 and natural ecosystems. The information available comes from small scale and short term (1 to 10 years) studies mostly from boreal regions but also from semi-arid and tropical regions. Natural variability of GHG fluxes due to regional climatic variations and their impacts on whole biological production are far more important than the techniques available to measure them. Therefore, one must keep in mind that the uncertainties in the GHG fluxes are related to natural spatial and temporal variations of fluxes and not necessarily from the measurement techniques themselves. This synthesis is based on the findings of over ten years of studies reported by research teams from many universities, governmental agencies and power utilities.