A little more RE: Greenhouse gas production by hydro dams. I followed up on the "A rather balanced view..." that appeared here recently and which was largely based on a New Scientist article. The article does admit that CO2 would spike only initially but goes on to say: ------------------------ "Seasonal changes in water depth mean there is a continuous supply of decaying material. In the dry season plants colonize 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."
http://www.newscientist.com/article.ns?id=dn7046 -------------------------- I have to admit that this concern for methane may have legitimacy. I live next to a man-made bog here in Maine and it is on this bog with its 8 meter head that I wish to install a micro-hydro unit. All summer the bog chokes up with masses of weeds and pond lilies. In the Autumn it all dies and sinks to the bottom. By January the water going over the dam releases putrid gasses from plant decay and minnows that apparently die from the anaerobic conditions. We who believe so much in the practicality of hydropower as renewable energy will have very red faces if it is really true that methane produced from some hydroprojects could actually accelerate the greenhouse gas problem. I believe that this potential for methane is primarily applicable to very shallow reservoirs, but there could be concern from algae precipitating. After all was it not this accumulation of ocean algae (diatoms etc) that is the source of petroleum today? But this must be continuing in all lakes and oceans and somehow Nature has adapted. No one is proposing to drain the worlds great lakes... I hope! -------------------------------- In the comments that NOAA helps to remove old dams, I also found this about NOAA's administrator, CONRAD C. LAUTENBACHER. For those not familiar with NOAA, it runs the massive US weather service and, well everything to do with ocean resources. Lautenbacher sent an open letter to the US Congress part of which is: "May 14, 2004 Dear Member of Congress: I am writing to inform you about the National Oceanic and Atmospheric Administration¹s (NOAA) upcoming proposals to renew listings of Northwest salmon populations under the Endangered Species Act ... At President Bush¹s direction, recovery of salmon is the major focus for NOAA in the Pacific Northwest, an objective widely shared in the region and the nation. We have been pleased to work with you and Congress to direct over $100 million of NOAA¹s budget, and hundreds of millions more from other federal agencies to the cause of salmon recovery this year alone. These substantial resources are enabling the hard work of countless communities to improve hundreds of miles of fish habitat, to enhance fish passage to the habitat, and to rebuild fish stocks in order to re-establish sustainable natural salmon populations...." see: http://www.publicaffairs.noaa.gov/releases2004/may04/noaa04-r910a.html ------------------------------ In march of 2004 I (Chris) submitted an essay to a newspaper here in Maine that concluded: "What is bothersome to me is that I believe that most of the proponents for dam removal are people whose primary motivation is to expand opportunities for their recreational passion of fishing migratory species. Clearly they have no intention of stopping their efforts with [removal of] dams on the Penobscot. The Fort Halifax dam in Winslow appears lost; the demise of hundreds of others are in the planning. These anglers and well-meaning conservationists are educated, politically organized and have deep pockets. I know some of them personally. But do they love their sport so much that it clouds a broader view? The result of hydroelectric dam removal will mean millions of additional tons of carbon dioxide, acid rain precursors, and other pollutants released by the inevitable alternative: combustion of coal, natural gas and oil. It¹s that simple." ------------ What do you bet that President Bush, Mr Cheney et al.. and maybe Mr. Lautenbacher are are all avid salmon fishermen... Chris Beeuwkes [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
