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Comment by forrestthewoods | Hacker News Reader

I got downvoted in another thread for extolling the ecological consequences of dams.

Dams should not be considered “clean” energy. They’re environmental disasters. Both upstream and downstream.

Dams are incredibly damaging. By contrast, every time we have a nuclear disaster, the no-go zone becomes a wildlife paradise.

Being anti-dam is environmental NIMBYism. A dam focuses externalities on the same communities that benefit from the dam (jobs and revenue). Fossil fuels benefit the producers but everyone suffers the externalities.

> Being anti-dam is environmental NIMBYism.

Hard disagree.

Dams simply need to be categorized as dirty energy. They are probably less dirty than coal or natural gas energy. However dams are dirty and they should be treated as such.

Categorizing an energy source as dirty does not mean we don't use it. It doesn't even mean we don't build more of it. We don't have 100% clean energy today. I hope that someday we do. And when we are 100% clean energy I hope that 0% of it comes from dams. Because dam energy is extremely unclean, damaging, and harmful. And it's not "NIMBY" to say so.

This makes them a rather unique class of dirty renewables.

I have sometimes wondered if we could consider specific solar and wind energy sites as 100% clean if we could calculate their carbon costs and actively take actions to counter carbon release to at least that amount. E.g., if a 1 KM solar farm took 12 Tons of Carbon and 1 tree sequesters 25 Kilos of Carbon per year, then we could start a forest of 500 trees using the Miyawaki Method and keep it thriving.

I have come across messages stating that Trees sequester Carbon for now only to release it all eventually, but Trees provide much more. They provide oxygen, a habitat for animal and insect life, they cool down an area, help attract clouds for rain, hold together the ground soil to prevent erosion, etc.

We ought to be reforesting and afforesting land again to compensate for all the cover that we've lost. Ensuring forests would help carbon-offset the carbon-load required to set up Low Carbon energy sources for locations that need them.

Then is anything clean? As wind and solar both have clear externalities in manufacturing and decommissioning...

Probably well burned wood and other biomass might qualify. Though that is quite complex thing to do at least with particulate emissions...

Do these externalities also affect thermal solar power? It tends to be a bit less efficient than photovoltaic when it comes to power production but probably avoids the rare earth metals.

Does hydro have drawbacks? Yes. They change ecosystems. In many cases the new ecosystems are less desirable from the human perspective, but the reservoirs and rivers that are changed are still plenty viable for all sorts of ecosystems and life. This is highly different from fossil fuels, which produce pollution, toxins, and directly contribute to all of the evils of climate change.

As far as I understand, that’s not even really true in the case of the Three Gorges Dam. The community upstream suffered from the lost of ancestral land, while the cities downstream benefitted the most from the new, cheap electricity (and less risk of flooding).

> A dam focuses externalities on the same communities that benefit from the dam (jobs and revenue)

Baffling. I don't believe for a second that the amount of jobs a dam brings is in any way close to worth the cost of having to move an entire town or village, and the revenue is just laughable - that goes to random pension funds and banks thousands of kms away if its a public company or to some investor's pockets if its not, neither of which benefit locals

I mean, it depends on what the alternative energy source is. Dams have their issues, but when we have the choice between a dam and fossil fuels, the impact of a dam is relatively more acceptable

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