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Dams and climate change -

Dams are thought to impact climate change and act as a feeding ground for methane-producing microbes. Greenhouse gases are released from reservoirs and contribute toward the acceleration of global warming.

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Methane emissions from reservoirs -

Methane, a greenhouse gas more potent than CO2, is created when organic matter is trapped underwater in reservoirs. According to research, 1.3% of the world's yearly GHG emissions are caused by reservoirs.

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Fragmentation of rivers -

Dams also interrupt the natural flow of rivers and, ultimately, impact the migration of aquatic species and their habits. As this happens, fish populations decline.

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Impact on river biodiversity -

If fish are prevented from migrating and spawning due to dams, then entire food chains can be disturbed. Many species depend on free-flowing rivers in order to survive.

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Disruption of biogeochemical cycles -

When sediments are trapped in dams, essential nutrients like carbon, nitrogen, and phosphorus can't reach downstream ecosystems, disrupting soil fertility, aquatic life, and oceanic carbon cycles.

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Deforestation and carbon sinks -

The destruction of forests around reservoirs removes crucial carbon sinks that help mitigate climate change. A lack of vegetation can exacerbate carbon emissions.

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Dam failures: mount polley disaster -

In 2014, the collapse of a dam at Canada’s Mount Polley mine released 21 million cubic meters of mining sludge into Quesnel Lake, severely disrupting aquatic life and polluting one of British Columbia’s most important bodies of water.

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Michigan’s midland county floods -

The 2020 failure of the Edenville and Sanford dams in Michigan caused catastrophic flooding, forcing the evacuation of 10,000 people. The incident highlighted the vulnerability of aging dam infrastructure, especially in the face of extreme weather events.

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High frequency of dam failures -

Dams are often considered stable structures. However, failures occur at an alarming rate. When a dam is destroyed, it destroys communities, disrupts ecosystems, and makes society question if dams are worth the potential cost.

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Hydropower and its hidden costs -

Hydropower dams release large amounts of greenhouse gases. Some think it's a clean energy source; however, the decaying organic matter in reservoirs undermines that claim.

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Reservoirs and water loss -

While dams are meant to, and usually do, store large amounts of water, they also lead to massive evaporation losses. Every year, reservoirs worldwide lose about 170 cubic kilometers, or 7% of all freshwater used by humans.

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Sedimentation and declining soil fertility -

Dams deprive downstream soils of essential minerals that are needed for agricultural purposes and can potentially threaten food security in certain regions.

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Tailing dams and toxic waste -

Tailing dams are used to store toxic mining waste. However, they have a high failure rate. Even when intact, they allow toxic metals to leach into the environment through microbial action and acid drainage, contaminating soil, and water sources.

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Dams and increased seismic activity -

Dams built in seismic active regions, such as the Himalayas, add increased pressure to fault lines and can subsequently result in an increased earthquake risk.

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The impact on freshwater species -

Many freshwater creatures, such as Siberian cranes and Yangtze sturgeons, depend on uninterrupted river flow to survive.

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Dams and international water conflicts -

Dams that are built on transboundary rivers can cause tensions between countries. With this setup, upstream nations control the flow of water, while downstream regions are subject to water shortages.

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The Amazon’s dam crisis -

By 2030, 184 new dams are planned to be built along the Amazon River. This will continue to degrade the ecosystem there.

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Why developed nations are removing dams -

In the US and Europe, many older dams are being removed to help restore ecosystems. These dam removals have revived fish populations, improved water quality, and demonstrated the benefits of letting rivers flow without restriction.

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Dams and the decline of fisheries -

When river ecosystems collapse, fish populations do also, which can impact millions of people.

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Dams and economic short-sightedness -

While some economic benefits come from dams through hydropower and irrigation, they often aren't sustainable. In the long run, environmental and social damages outweigh everything else.

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Learning from past mistakes -

Though there is a great deal of evidence regarding dam-related issues, many developing countries are choosing to continue to invest in hydropower.

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Rethinking renewable energy options -

Developing nations, especially, should focus on actual sustainable alternatives such as wind and solar energy. These can provide electricity without significant environmental destruction.

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The illusion of flood control -

Dams are sometimes promoted as flood control infrastructure. However, they can actually worsen when reservoirs overflow. If a dam is poorly managed, then it can also result in a flash flood and widespread problems.

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Policy reform and sustainable water management -

It's important to enhance environmental polices in order to assess the long-term impacts of dams. Options such as decentralized water storage and rainwater harvesting might offer alternatives to dams.

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Individual action and public advocacy -

Pressure from the public can influence policymakers to reevaluate projects involving dams. Individuals can help by signing petitions, reducing water consumption, and much more.

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Why dam removal is the future -

Restoring natural river flow and removing harmful dams can help with environmental conservation and support biodiversity.

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Shifting toward sustainable solutions -

Dams were once seen as impressive engineering feats however, negative consequences now outweigh their benefits. To combat climate change and protect ecosystems, countries must embrace sustainable energy and water management practices.

Sources: (American Rivers) (Earth.org) (Britannica)

See also: World wonders: impressive dams across the globe

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