Dams-largest human source of methane gas.

 Recent studies have shown dam building worldwide to be extremely destructive to not only river ecosystems but also to people who live on and make their livelihood on river systems around the world and are displaced...often without compensation....by dam construction and flooding.  

Recent studies have also shown that dam building/power generation is not a clean or green way to produce electricity since the reservoirs or flooded areas behind dams produce incredibly high levels of methane gas from rotting vegetation under the reservoir which was killed by the flooding created by the dam....also this dead vegetation can no longer remove CO2 from the atmosphere.

Methane gas is a greenhouse gas which is 25 to 72 times as powerful as CO2 in creating global warming.

Dams/reservoirs are the largest human caused source of this global warming gas on earth. (115 million tons per year.....4-5% of total global warming gases emitted worldwide are methane from dams/reservoirs).

The cost to build and maintain dams as well as the environmental/human costs has been shown to be much more expensive than many alternative energy solutions now available, such as solar, wind, geothermal and natural gas etc.

Recent studies have also shown that many dams create/release into the atmosphere more global warming gases than multiple coal fired power plants that produce equivalent amounts of electricity....and coal is one of the dirtiest fossil fuels out there!!

Also the build up of silt behind dams inevitably renders many dams obsolete after a number of years unless extremely expensive maintenance is done regularly.

Disruption of river flows affect feeding and breeding cycles of fish and other wildlife that lives in or on the river and depend on sediments for nutrients.Their is a frenzy of dam building going on worldwide right now with almost every river on earth dammed multiple times.

This dam building greatly affects temperature of water flowing to the worlds seas, oceans and lakes affecting ocean and lake life which has evolved for millions of years to live in a certain range of temperatures which is determined to a great extent by the cooling or warming (depending on the time of year and location of river) effect of the water of the worlds rivers which flow from the mountains/glaciers etc. into the sea but are now significantly altered as they flow into the sea from dams.

These dams reduce flow and hold water which restricts water flows below dams to almost nothing in some cases...this shallow water is much warmer than normal flow water and in some cases stagnant...in tropical countries this warm water as well as warm reservoir water is prime breeding ground for mosquitoes and increases malaria and other water born diseases and parasites.

Various scientific studies easily accessed on the internet have shown a significant increase of malaria and other water born parasites around dam/dam reservoir sites worldwide.

Malaria is the largest cause of death and sickness in tropical and subtropical countries infecting 500 million people per year and killing 1 million people per year...90% of these deaths are children under 5yrs. old.

Iraq now faces a water/irrigation crisis because of ongoing dam building by Turkey which is severly restricting the flow of the Tigris and Euphrates river threatening peace and stability in Iraq further. 

100 additional dams are in the planning for the Yangtze River on China where the largest dam on earth.....the Three Gorges Dam has already been built and is now causing environmental and human devastation on an astronomical scale as well as not functioning properly.

Many believe this will lead to the extinction of the Yangtze River Dolphin one of the most endangered animals on earth.

Multiple dams are now being planned for major river systems in India which are predicted to cause devastation in Bangladesh as some of Bangladesh's major river systems are dryed up and destroyed by Indian dam building.....will India compensate Bangladesh for this destruction?

10 Ways dams damage rivers:

1.  Dams reduce river levels

By diverting water for power, dams remove water needed for healthy in-stream ecosystems. Stretches below dams are often completely de-watered.

2.  Dams block rivers

Dams prevent the flow of plants and nutrients, impede the migration of fish and other wildlife, and block recreational use. Fish passage structures can enable a percentage of fish to pass around a dam, but multiple dams along a river make safe travel unlikely.

3.  Dams slow rivers

Many fish species, such as salmon, depend on steady flows to flush them downriver early in their life and guide them upstream years later to spawn. Stagnant reservoir pools disorient migrating fish and significantly increase the duration of their migration.

4.  Dams alter water temperatures

By slowing water flow, most dams increase water temperatures. Other dams decrease temperatures by releasing cooled water from the reservoir bottom. Fish and other species are sensitive to these temperature irregularities, which often destroy native populations.

5.  Dams alter timing of flows

By withholding and then releasing water to generate power for peak demand periods, dams cause downstream stretches to alternate between no water and powerful surges that erode soil and vegetation, and flood or strand wildlife. These irregular releases destroy natural seasonal flow variations that trigger natural growth and reproduction cycles in many species.

6.  Dams fluctuate reservoir levels

Peaking power operations can cause dramatic changes in reservoir water levels -- often up to 40 feet -- which degrade shorelines and disturb fisheries, waterfowl, and bottom-dwelling organisms.

7.  Dams decrease oxygen levels in reservoir waters

When oxygen-deprived water is released from behind the dam, it kills fish downstream.
8.  Dams hold back silt, debris, and nutrients

By slowing flows, dams allow silt to collect on river bottoms and bury fish spawning habitat. Silt trapped above dams accumulates heavy metals and other pollutants. Gravel, logs and other debris are also trapped by dams, eliminating their use downstream as food and habitat.
9.  Dam turbines hurt fish

Following currents downstream, fish can be injured or killed by turbines. When fish are trucked or barged around the dams, they experience increased stress and disease and decreased homing instincts.

10.  Dams increase predator risk

Warm, murky reservoirs often favor predators of naturally occurring species. In addition, passage through fish ladders or turbines injure or stun fish, making them easy prey for flying predators like gulls and herons.

"When I visit a dam, I often find a plaque honoring by name the engineer, government leader, contracting firm and the height, size, date, volume of water held or diverted, power generated, flood capacity measurements. And that's fine.

But I don't find a plaque with the names of any species hurt, the names of any people displaced, the cost to taxpayers, the price of maintenance or decommissioning, or why this option was chosen over, say, windmills, solar panels, natural gas, groundwater pumping, demand management or some decentralized tools."

From a World Commission on Dams member    

We the undersigned request the the World Bank restrict further funding for dam building worldwide and redirect this funding into alternative sources of electricity generation such as solar, wind, geothermal, natural gas etc. and as these alternative and less damaging sources are developed to implement a plan to gradually deconstruct and reduce dam building worldwide to restore river/delta/lake/ocean ecosystems.

For more information go to:

http://www.internationalrivers.org/en/global-warming/reservoir-emissions/greenhouse-gas-emissions-dams-faq