Global Warming?

Question

So i was watching this show of the Niagra Falls and they say that a dam was built to help control errosion of the falls and to help preserve the falls for future generations. The water flow is controlled and is flowing a fraction of what it should be. But why do we care what the flow is. Niagra Falls have been around for a while and I am assuming will be around long after I am long gone. And I understand that we create "Green" energy from the falls, But does this lack of natural flow of water prevent the natural water movement. i.e. all the polar caps melting ... lack of water in Lake Ochachobee ... Mountain with less snow. I am not a republican, just wondering what effects a dam has on the enviroment?

Answer 1

The water is still flowing, but it's passing through generators that create electricity. Since they're bypassing the falls, there is less water going over the falls and therefore less erosion. All the water is still flowing from Lake Erie to Lake Ontario... I don't see the connection to global warming, melting ice caps, etc.

Answer 2

Dams have an effect on the environment but not really in the ways you mentioned. The reservoir created by a dam is effectively static water, the surface can heat up and evapourate more readily then fast flowing water. This evapouration adds to the water cycle and will slightly, ever so slightly, increase precipitation so you'll have more snow on the mountains, more water in the lakes and more ice at the ice caps.

The reflective surface of the water will also reflect sunlight back into space and contribute just a tiny amount to 'global cooling'.

Once the reservoir is full the water flow will continue as normal downstream (less any extraction for irrigation or industrial processes).

The creating of the reservoir in the first place means the flooding of large areas of fauna and flora and the loss of habitat for many species. Possibly the loss of land and homes of people.

The dam will provide environmental benefits if it's used for irrigation pruposes or the generation of hydro electricity - this reduces the need to burn fossil fuels so the existing supplies will last that bit longer and there's no greenhouse gas emissions or other pollutants - better for the environment and anyone or anything that breathes.

The building of a dam involves large scale construction works which obviously have a significant environmental impact and if metal or concrete is used in the construction (some dams are earthen) then much quarrying and mining will be required to source the materials. This has an environmental impact away from the site of the dam as have access roads, power supplies etc.

It's a balancing act, good and bad points.

Answer 3

The falls has been around for a long time but it has been slowly moving upstream as the rocks erode. One reason the dam was built was to slow that (because there's an economic interest in keeping the falls as is). Certainly there is an environmental impact of a dam. It favors life that thrives in still water versus moving water. By controlling flooding it changes how the flood plane will be in the future. It changes evaporation/condensation patterns.

Answer 4

Dams have a variety of effects on the local environment. But very little on global warming.

It's easy to get distracted by small things. But the data clearly shows the main cause of global warming is us, burning fossil fuels. That's big.

http://www.globalwarmingart.com/wiki/Image:Climate_Change_Attribution.png

Answer 5

Global Warming? No such thing!!!

Answer 6

forget it