GEF

Unit 3  |  Water Use and Human Water Systems 73 Many dams are also used to generate hydropower . Taking advantage of the energy inherent in the evaporation and movement of water within the water cycle, dams generate electricity by channeling moving water through turbines. Compared with fossil fuel energy sources, such as coal and natural gas, hydropower has the advantage of producing significantly fewer climate change -causing greenhouse gas emissions, such as carbon dioxide (CO 2 ) . Hydropower is also a renewable energy source, as it relies on the movement of WATER CONCEPTS: BELO MONTE DAM Some cases of dam construction have attracted worldwide attention, such as the construction of the Belo Monte dam on the Xingu River in the Amazon region of Brazil. The Kayapo and other indigenous people in the region near the dam, which is expected to be completed in 2019, are already suffering from loss of fishing grounds, introduced diseases due to an influx of migrants, and cultural disintegration as their natural resources and traditional way of life are threatened. Indigenous communities and environmental groups are struggling against the Brazilian government’s plans to sharply increase energy production to meet the needs of a surging economy. Many other cases of controversial dam construction are playing out in countries around the world as governments look to dams to supply water and hydropower for economic growth. HYDROPOWER Energy produced using run- ning or falling water. FOSSIL FUELS Nonrenewable carbon-based fuels, such as oil, coal, and natural gas, formed from the decomposition, geological compression, and heating of organic material. CLIMATE CHANGE A long-term alteration in the Earth’s weather patterns and temperature, caused primar- ily by human emissions of greenhouse gases. GREENHOUSE GASES (GHGs) Gases, including carbon dioxide, water vapor, and methane that trap heat in the atmosphere. CARBON DIOXIDE (CO 2 ) A gas that is the most com- mon form of atmospheric carbon, used by plants in photosynthesis, and emitted during the combustion of carbon based fuels such as petroleum. RENEWABLE ENERGY Energy produced from resources that can sustain themselves indefinitely, such as wind and solar power.