Posted on 02/28/2005 4:41:10 AM PST by nuke rocketeer
Hydro's Dirty Secret Revealed
Hydroelectric dams produce significant amounts of carbon dioxide and methane, and in some cases produce more of these greenhouse gases than power plants running on fossil fuels. by Duncan Graham-Rowe London, UK (SPX) Feb 25, 2005 Contrary to popular belief, hydroelectric power can seriously damage the climate. Proposed changes to the way countries' climate budgets are calculated aim to take greenhouse gas emissions from hydropower reservoirs into account, but some experts worry that they will not go far enough, reports New Scientist. The green image of hydro power as a benign alternative to fossil fuels is false, says Eric Duchemin, a consultant for the Intergovernmental Panel on Climate Change (IPCC). "Everyone thinks hydro is very clean, but this is not the case," he says.
Hydroelectric dams produce significant amounts of carbon dioxide and methane, and in some cases produce more of these greenhouse gases than power plants running on fossil fuels. Carbon emissions vary from dam to dam, says Philip Fearnside from Brazil's National Institute for Research in the Amazon in Manaus.
"But we do know that there are enough emissions to worry about." In a study to be published in Mitigation and Adaptation Strategies for Global Change, Fearnside estimates that in 1990 the greenhouse effect of emissions from the Curua-Una dam in Par‡, Brazil, was more than three-and-a-half times what would have been produced by generating the same amount of electricity from oil.
This is because large amounts of carbon tied up in trees and other plants are released when the reservoir is initially flooded and the plants rot. Then after this first pulse of decay, plant matter settling on the reservoir's bottom decomposes without oxygen, resulting in a build-up of dissolved methane.
This is released into the atmosphere when water passes through the dam's turbines. Seasonal changes in water depth mean there is a continuous supply of decaying material. In the dry season plants colonise the banks of the reservoir only to be engulfed when the water level rises.
For shallow-shelving reservoirs these "drawdown" regions can account for several thousand square kilometres. In effect man-made reservoirs convert carbon dioxide in the atmosphere into methane. This is significant because methane's effect on global warming is 21 times stronger than carbon dioxide's.
Claiming that hydro projects are net producers of greenhouse gases is not new (New Scientist, 3June 2000, p 4) but the issue now appears to be climbing up the political agenda. In the next round of IPCC discussions in 2006 the proposed National Greenhouse Gas Inventory Programme, which calculates each country's carbon budget, will include emissions from artificially flooded regions.
But these guidelines will only take account of the first 10 years of a dam's operation and only include surface emissions. Methane production will go unchecked because climate scientists cannot agree on how significant this is; it will also vary between dams. But if Fearnside gets his way these full emissions would be included.
With the proposed IPCC guidelines, tropical countries that rely heavily on hydroelectricity, such as Brazil, could see their national greenhouse emissions inventories increased by as much as 7 per cent.
Colder countries are less affected, he says, because cold conditions will be less favourable for producing greenhouse gases. Despite a decade of research documenting the carbon emissions from man-made reservoirs, hydroelectric power still has an undeserved reputation for mitigating global warming. "I think it is important these emissions are counted," says Fearnside.
This article appears in New Scientist issue: 26 February 2005
This means that the vaunted electric cars are just as polluting as my much missed '72 Chevelle in the long run. HA.
"...plant matter settling on the reservoir's bottom decomposes without oxygen, resulting in a build-up of dissolved methane... methane's effect on global warming is 21 times stronger than carbon dioxide's."
I wonder if this same dangerous methane is being created in the government funded and built wetland in my community?
Is my organic compost pile that my local government encouraged me to build creating even more of this dangerous methane? Is the healthy high fiber diet that is so heavily promoted causing me to create even more methane yet?
Or is it possible that methane created at the behest of greenies is not the harmful kind.
No, you can't tiptoe through the woods, because then the woods wouldn't be pristine. You just sort of have to sit down where you are (a spot already hopeless) and shiver naked until you die. That's natural, and then your body can feed nature's cycle....
Uh Oh!
"No, you can't tiptoe through the woods, because then the woods wouldn't be pristine. You just sort of have to sit down where you are (a spot already hopeless) and shiver naked until you die. "
HAHAHAHAHAHAHA... I don't know why.. but I got quite a chuckle out of that....
hehehehe...
man, I need more coffee
Bones
If these absolute idiots keep up their good work, soon we will have returned to the accidental common sense of the 1950s!
My SUV generates plant food. I have to drive my SUV a full year to feed five acres of rain forest.
Anthropogenic global warming is a myth: Hydroelectric, Nuclear, Coal - makes no difference.
That's not the goal of the Environmental Whackos.
The goal of the Environmental Whackos is the complete extinction of the human race.
"This is because large amounts of carbon tied up in trees and other plants are released when the reservoir is initially flooded and the plants rot. Then after this first pulse of decay, plant matter settling on the reservoir's bottom decomposes without oxygen, resulting in a build-up of dissolved methane. "
Anybody who has ever had a pond or lake in their yard has seen this. In the South we refer to it as "turning".
When the organic matter on the bottom begins to decay, gasses forming within the matter make it float to the top and release the gasses, making the pond appear to have a thin layer of film on top. The gasses are then released and the remaining matter is either consumed by organisms or falls back to the bottom of the pond as silt. This process is repeated throughout the existence of the body of fresh water.
It is this action that assists in keeping small bodies of water from stagnating. It occurs in nature without any intervention by man, in (I think) every fresh-water body in existence.
What about all that dihydrogen monoxide vapor being released by the lakes behind the hydroelectric dams?
Ban dihydrogen monoixide. Among other things, it is the worst of the "green house" gasses.
They expect me to believe that the energy generated over the life of a hydro dam is LESS than the energy that could be generated by cutting and burning all the trees and other vegetation in the flood basin (plus the annual growth at the margins)?!
That's what they are saying, and I don't believe this bizarre junk for a second.
After all, what do they think would happen to the vegetation growing in a basin if they don't build the dam? Everywhere else, vegetation grows, stands, dies, and decays. Why should it matter whether it is above water or below?
"Ban dihydrogen monoixide. Among other things, it is the worst of the "green house" gasses."
Its even worse than you think! Dihydrogen monoxide vapor is a problem, but it's solid form is taking over the polar regions of the planet.
The envirowhackos are going to attack ANY electricity source. They wish humanity back to a feudal society where they are the masters. The merr fact that this would require the death of 90%+ of humanity makes no difference to them. In fact they want it. Look for more 'exposes" in the near future on solar PV, now that they have pilloried both wind and hydro.
That Stalinland amusement park entrepreneur is on to something...
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