Dams are not a panacea to the planet’s climate crisis

Since ancient times, water has provided energy. Hydropower was one of the first forms of energy used to power factories. While energy transition has become the mantra of the world to mitigate climate change, hydropower has become an important component in many countries’ strategies to move away from fossil-fuel-based energy production.

In order to meet their climate obligations under the Paris Agreement, more countries, particularly those in Asia and Africa, plan to build larger hydropower dams.

It is clear that increasing renewable energy production is the only way to achieve the goal of net-zero emissions by 2050. The generation of clean energy is essential to the elimination or phasing off of coal. Hydropower constitutes the largest source of renewable electricity — 17% of the global power produced in 2020 with 1,330GW capacity — almost three times of wind power and six times that of solar.

The annual US electricity consumption is about the same as the amount of hydropower that will be produced in 2020. China is already ahead of the pack in hydropower production, with 356GW. The US, Canada and India are next, as well as Norway, Brazil, India, Norway and Norway. Hydropower generation has increased by almost 70% over the past two decades. It is expected to rise another 50% over the next two decades.

There are currently 1,000 dams in construction, mostly in developing countries. China, India and Turkey are currently constructing massive dams. There are many dam projects in Brazil, Nepal, Laos and DRC.

Hydropower is preferred to other renewable sources like solar power, biomass, and wind power because it can effectively store energy, is less climate-dependent, and is less unpredictable. For national energy security, many developing countries have given hydropower generation top priority, as climate change is already threatening the survival on the planet.

International Hydropower Association claims that more than 500GW are currently being built or planned for hydropower projects worldwide. According to the International Hydropower Association, in order to limit global warming below 2 degrees Celsius, hydropower production must increase by 850GW by 2050. If 1.5 degrees Celsius is not achieved, the figure could rise to 1,200GW by 2050.

Hydropower still costs less than electricity from solar or wind. Moreover, political leaders prefer to build large dams as these massive construction projects can be easily portrayed as their achievements in country’s development and gain popular support. Dam building is also a major source of corruption for politicians.

The climate change debate often overlooks hydropower emissions. Despite the common impression about hydropower being ‘good’ energy, people usually forget that the primary hydropower sources are large dams and their reservoirs. However, the massive removal of tree cover is caused by the flooding of large forest areas within the dam reservoirs.

Also, methane and biogenic Carbon are produced by vegetation fermentation in water stored. Research has shown that the greenhouse gases released by the decayed vegetation behind dams account for nearly one billion tonnes of global greenhouse gas emissions each year, or 1.3% of all human-caused global greenhouse gas emissions.

The contribution of dams to greenhouse gases varies from one region to the next. While reservoirs may be useful in the dry and temperate climate zones, they can also serve as carbon sinks. However, in tropical countries such as Africa and Asia, where the majority of dams are being constructed, the carbon footprints are just as large or even more than fossil fuel.

Nearly 80% of the greenhouse gases emitted from dam reservoirs are methane. This is a gas that accelerates global warming and is responsible for almost 80% of all greenhouse gas emissions. Dams have produced more methane in 100 years than biomass burning and rice cultivation.

Dams also have huge environmental consequences as they destroy the free-flowing river ecosystem, block fish migration, erode downstream riverbeds, and adversely affect the river’s aquatic and riparian life. The construction of dams is a huge undertaking. It also causes significant environmental pollution locally due to the large use of cement, steel and rocks.

The hydropower industry has often been criticised for overlooking indigenous people’s rights. A conservative estimate is that dam projects have displaced 80 million people around the world, mostly indigenous and frontline communities who live in forests and rural areas.

India has seen at least 20 million people displaced by dam construction. Only 2 million of these people have received compensation. Even in a country like Sweden, where 45% of electricity generation comes from hydropower, 80% of its large hydropower dams are located on the traditional land of Sami, country’s indigenous minority group.

Additionally, dams are too expensive, especially for poor developing countries. They take too long to construct and can cause major conflicts between nations and groups.

Many countries and regions are already facing dam conflicts. New dam construction has already created threats of armed conflict in the Euphrates-Tigris, Indus and Nile basins.

For countries, it is important that they realize that building new hydropower plants will not bring the same climate benefits. It can accelerate global warming in some cases, especially in the short-term.

Hydropower is a greenhouse gas that produces large amounts of greenhouse gas. It also comes with high social, economic and environmental costs. The countries of Asia and Africa that are at the forefront in this trend should be extra cautious before embracing dam building as a strategy for reducing climate change.