Survey of Energy Resources 2007
Hydropower - Climate Change and Reservoir Emissions
In terms of climate change, hydropower tends to have a very low greenhouse gas footprint. As water carries carbon in the natural cycle, scientists have investigated the extent to which a new reservoir might accelerate carbon emissions. In some very shallow tropical reservoirs, this may be the case, and the factor would need to be taken into consideration in the life-cycle analysis of such schemes. In contrast, many reservoirs around the world have been monitored to test their emissions, confirming that hydropower is one of the cleanest methods of power generation.
Population growth in emerging markets is both a driver and a constraint. The demand for land and water resources increases with population growth. However, water management is key to sustainable development. Many future projects will be multi-purpose, climate-mitigation structures, for drought protection and flood mitigation, in addition to power generation. By storing water, freshwater reservoirs increase water security; by maintaining reserve storage capacity, reservoirs can absorb peak flows during flood events; and, by employing hydropower generation in place of fossil-fuel technologies, a significant offset of greenhouse gas emissions can be achieved.