 |
 |
Some quick responses from here. Regarding your thoughts on competition for water, I think your logic is sound where irrigation is used. However, 75% of agricultural land is not irrigated in developing countries (http://www.fao.org/docrep/w5146e/w5146e0a.htm#irrigated%20land), I know a lower percentage of agricultural land is irrigated in the US (I can't find a reference right now) and virtually no forest land is irrigated. So producing biomass doesn't necessarily use irrigation. On the flip side, the likes of Dr. Rockwood in SFRC do research in using reclaimed municipal waste (sewer) water to increase biomass production and provide a service by using the water and removing nutrients from the water, which is non-potable and represents an environmental liability. As populations grow, so does this resource, unfortunately (unless maybe we start using compositing toilets or something, regardless we will still have huge amounts of waste water from some sources). Regarding the combustion question: As biomass and biosolids are burned, they release CO2. However, if the same amount of biomass and biosolids decay naturally, they also emit the same amount of CO2 through decomposition. If the decomposition is above ground, then the return to the atmosphere happens as fast as the decomposition. Some environmental benefits are derived from some resources (mulch from wood, compost from organics, and fertilizer from sludge), though excess resources do accumulate. But ultimately, all organic carbon is going back to the atmosphere in the carbon cycle. Biomass, of course, is not "the" answer, but can be an answer. Regards, and Merry Christmas, Matt Matthew Langholtz Postdoctoral Research Associate School of Forest Resources and Conservation, UF P.O. Box 110410 Gainesville, FL 32611-0410 e-mail: [log in to unmask] Office: (352)846-0892 Pager and Cell: (352)246-7091 Fax: (352)846-1277 Home page: http://plaza.ufl.edu/mateo/ -----Original Message----- From: Bioenergy and Sustainable Technology Society [mailto:[log in to unmask]] On Behalf Of MARTIN,ELIZABETH J Sent: Thursday, December 21, 2006 1:19 AM To: [log in to unmask] Subject: Question about Biofuels overall effects To anyone willing to address my question: I was wondering if someone would mind directing me to some information regarding the pros and cons of biofuel vs. petroleum in terms of land use and water consumption. While I fully agree that there is a dire need to reduce reliance on petroleum and other non-renewable resources, I am concerned as to how it balances out on the other end of the spectrum. Currently over 1 billion people do not have access to safe drinking water, resulting in millions deaths every year due to unsafe and unsanitary water conditions. The main problem is the agricultural techniques used to produce crops such as corn, wheat, soybeans, etc. The largest problem is the net loss of water and the destruction of land due to irrigation. From what I?ve been reading, it appears that the main alternatives to petroleum lie in the use of these organic materials as potential fuels. So my main point is this, even if biofuels replace petroleum and reduce green house gases and air pollution, won?t the result be an even bigger problem due to water scarcity? I understand that no one can know if this will even be a problem, but I can?t help but wondering if biofuels are the answer, or if they are a catch 22. I also have a slight problem with the burning of natural and human wastes. While this does eliminate the growing problem of landfills and the release of methane gas into the atmosphere, isn?t it still slightly retroactive because combustion of any material releases carbon dioxide? I'm terribly sorry if these questions seem ridiculous or completely off base, but I'm having trouble finding answers. Incase anyone was wondering where I got my information on water scarcity: www.blueplanetproject.net There is also a very informative article available at: http://www.qmw.ac.uk/~ugte133/courses/environs/cuttings/water/ Click running.pdf Thanks. Liz -- MARTIN,ELIZABETH J