Are dams contributing to global warming?

Answer 1

They're contributing in some ways and offsetting in others.

The large concrete dams use huge quantities of cement in their production, the extraction and processing of cement is one of the biggest emitters of greenhouse gases.

The body of water created by the construction of a dam is stationery in comparison to the river that would ordinarily flow. This allows the surface of the water to warm and evapourate more readily than it would with running water. The increased burden of atmospheric water vapour will contribute to global warming - more so in areas with lower humidity and higher temperatures.

Dams often lead to flooding of vegetated areas, this removes some biomass from the carbon cycle, the consequence of which is areduction in the amount of carbon dioxide sequesteered from the atmosphere for photosynthesis.

On the other hand, water is more reflective than earth and plant material and so reflects sunlight into space more efficiently thus partially offsetting the contribution made to warming.

If the still waters of the reservoir are home to algae this will sequester CO2 from the atmosphere, algae are excellent at doing this.

I guess the answer in respect of any one dam would be arrived at by summing the offsetting and contributory factors of the different components with the result that some dams are contributing to global warming whereas others are.

The purpose of the dam also needs to be taken into account. If that purpose is for hydro-electricity generation then there would be a substantial benefit if it meant a reduction in the burning of fossil fuels to generate the same power in conventional power stations. There would be no net benefit if the alternative were nuclear power as both nuclear and hydro produce almost no greenhouse gas emissions.

Answer 2

apart from deforestation and stress of dams n stored water on ground.... recent studies show that the forest land submerged under water stored releases more methanol into atmoshpere ...n india has the by far largest area covered by dams...although there is a strong contender in china's three gorges dam..

Answer 3

I think they probably do because they interfere with natural drainage patterns and the evaporation cycle's cloud geography. So do massive parking lots, if you concur with my theory; where there used to be indigenous (esp. plant) life, now there are huge tracts of black superheated surface that becomes a drainage management nightmare in areas with rain and/or snow. Of course immense numbers of self-absorbed, passive-aggressively hostile genetic abominations and deviants (particularly fact and science hating amerikans) will cause some sort of cataclysm on their planet, whether it be slow death by global warming and adapting to breathe carbon-dioxide and methane, or nuclear drama. It's attention for the noisy hordes who rightfully should have been abortions, so they intend to bring the greedy and the conscientious to their blaze-of-glory armageddon party. The cost???--- idk, wait 'till it's over and the cleaning bill comes...

Answer 4

no
i dont think so
but may b in one side.when dams r built the forest is cleared.therefore it is a cause.

Answer 5

It is widely accepted that hydro power has more negative environmental impacts than positive.

Answer 6

in a way yes...they lead to afforestation when they are constructed......so in a way they do contribute.....

Answer 7

yup