CRISIS AND OPPORTUNITY - Dams and Development in China - page 24

sustainability. For example, some electricity-generating sources, such as coal-fired power
plants, emit a majority of their greenhouse gases during operation. Others, such as nuclear
power plants, emit almost no greenhouse gases during the process of generating electricity
but entail significant carbon emissions during the mining of raw materials, the construction
of facilities, and the transportation and disposal of waste.
A recent assessment of greenhouse gas emissions from different modes of electricity
generation around the globe used a life-cycle approach, which accounts for emissions from
all phases of a given project and normalizes these emissions by calculating greenhouse
gases per unit of electricity produced. Emissions can be expressed in a simple equation:
CO 2 e / GWh, or the weight of carbon dioxide equivalent per gigawatt hour of electricity.
This gives us a measure of the intensity of greenhouse gas emissions, which is a key focus
of the Intergovernmental Panel on Climate Change and nations around the world as global
attention focuses on carbon emissions as a driver of climate change.
Based on this calculation method, it is clear that all electricity sources are not created
equal. Coal-fired power plants produce, on average, 888 tons of CO 2 e per GWh; natural
gas produces about half that figure. Hydroelectric facilities produce an average of 26 tons
of CO 2 e per GWh, about one-thirtieth the level of coal-fired power plants, making hydro-
power comparable to renewable electricity sources such as solar and wind power (World
Nuclear Association 2013). 2 This underscores the fact that Chinese leaders, like their
counterparts in developed and less-developed countries alike, are often forced to choose
between a set of bad options when it comes to electricity production. 3 Approximately two-
thirds of China's current electricity demands are met by coal-fired power plants (see figure
2.1 ) . China remains the world's leading consumer of coal, using approximately 1.5 billion
metric tons per year for industrial production, energy generation, and, particularly in rural
areas, household heating. The nation's coal stores are vast: at least 100 billion metric tons,
enough to continue current rates of coal combustion throughout the twenty-first century
(Smil 2004).