Good Question and a relevant read can be found Jeffrey Duke's paper "Burning Buried Sunshine: Human Consumption of Ancient Solar Energy" - it appears in Climate Change (2003) 61:31-44. Although he makes numerous assumptions he presents an argument that the fossil fuel consumed in 1997 represent the carbon equivalent of 400 times the earth's NPP
Bob Antibus Robert K. Antibus Chair Science Department Bluffton University -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:[EMAIL PROTECTED] On Behalf Of Ron E. VanNimwegen Sent: Tuesday, January 30, 2007 11:15 AM To: [email protected] Subject: Re: Ethanol (in)efficiency I was considering the physiological growth constraints on the world's flora. Can any fuel-crop grow that fast, and do we have the room to do it? If we're currently dependent on carbon reserves that took millions of years to stockpile, and if we're on a trajectory that will deplete those reserves in a couple centuries, how can we expect the current carbon cycle to "fuel" us, let alone feed us? -R Jane Shevtsov wrote: >Ron E. VanNimwegen wrote: > > >>if we divert our energy harvest from ancient to contemporary carbon sources, >>aren't we still shifting an inordinate amount of carbon from the earth >>to its atmosphere? >> >> > >No, because the carbon in corn or switchgrass was recently fixed from >the atmosphere. Ideally, biofuels are carbon-neutral. In practice, of >course, we use fossil fuels to make them. > > > >>If our entire energy burden were placed on any "bio" source, how long would >>it take us to strip the planet down to bedrock? >> >> > >I'm not sure what you mean here. Are you talking about soil erosion? > > >>Maiken Winter wrote: >> >> >> >> >>>Hi all, >>> >>>We just had a discussion on ethanol on the Tompkins Sustainability >>>listserv, and I would like to share one of the most interesting inputs from >>>an employee of an independent energy firm in our area: >>> >>>At Cornell, a study has shown the inefficiency of ethanol; please see: >>> >>><http://www.news.cornell.edu/stories/July05/ethanol.toocostly.ssl.htm l>http://www.news.cornell.edu/stories/July05/ethanol.toocostly.ssl.html >>> >>>"It seems as if the final word on energy efficiency is still out. >>>Pimental, who is widely and correctly quoted, is viewed as an extremist. >>>( He may still be right), Most research indicates a tiny bit of positive >>>energy produced with corn to ethanol9 10-20%, and a little better for >>>Biodiesel from soybeans. >>> >>>Some interesting articles are listed below: >>> >>>Drunk on Ethanol- Audubon Society: >>><http://magazine.audubon.org/incite/incite0408.html>http://magazine.a udubon.org/incite/incite0408.html >>>"But the reformulated-gasoline program has turned out to be a colossal >>>failure, and the ethanol industry has transmogrified into a sacrosanct, >>>pork-swilling behemoth that gets bigger and hungrier with each feeding. >>>Ethanol dirties the air more than it cleans it. Its production requires >>>vast plantings of corn, which wipe out fish and wildlife by destroying >>>habitat and polluting air, soil, and water. Of all crops grown in the >>>United States, corn demands the most massive fixes of herbicides, >>>insecticides, and chemical fertilizers, while creating the most soil >>>erosion." >>> >>>"Does it take more energy to make ethanol than is contained in ethanol? >>>That question continues to haunt the ethanol industry even after 27 >>>years of expanding production. Over the years more than 20 scientific >>>studies have examined the question. This document contains links to the >>>major studies of the subject completed during the last decade." >>><http://www.newrules.org/agri/netenergy.html>http://www.newrules.org/ agri/netenergy.html >>> >>> >>>Here is a good article from renewable energy access, by LesterBrown of >>>Worldwatch. >>><http://www.renewableenergyaccess.com/rea/news/reinsider/story;jsessi onid>http://www.renewableenergyaccess.com/rea/news/reinsider/story;jsess ionid >>>=DDB1143EA1BF449D5EFC92ADE6723FDE?id=47092 >>> >>>"The U.S. Department of Agriculture (USDA) projects that distilleries >>>will require only 60 million tons of corn from the 2008 harvest. But >>>here at the Earth Policy Institute (EPI), we estimate that distilleries >>>will need 139 million tons -- more than twice as much. If the EPI >>>estimate is at all close to the mark, the emerging competition between >>>cars and people for grain will likely drive world grain prices to levels >>>never seen before. The key questions are: How high will grain prices >>>rise? When will the crunch come? And what will be the worldwide effect >>>of rising food prices? >>>"From an agricultural vantage point, the automotive demand for fuel is >>>insatiable. The grain it takes to fill a 25-gallon tank with ethanol >>>just once will feed one person for a whole year. Converting the entire >>>U.S. grain harvest to ethanol would satisfy only 16 percent of U.S. auto >>>fuel needs. >>> >>>The competition for grain between the world's 800 million motorists who >>>want to maintain their mobility and its 2 billion poorest people who are >>>simply trying to survive is emerging as an epic issue. Soaring food >>>prices could lead to urban food riots in scores of lower-income >>>countries that rely on grain imports, such as Indonesia, Egypt, Algeria, >>>Nigeria, and Mexico." >>> >>>Today's Ithaca Journal has a report on "Mexican President tries to >>>contain tortilla prices" due to a surge in corn prices driven by the US >>>ethanol industry. Seems like the riots are about to start... >>> >>>And Iowa may have to import corn next year, from who knows where? >>><http://www.farmandranchguide.com/articles/2007/01/05/ag_news/letters _and>http://www.farmandranchguide.com/articles/2007/01/05/ag_news/letter s_and >>>_editorial/letter02.txt >>> >>>According to IATP numbers, the biofuel boom - if fulfilled - will >>>require Iowa to import 200 million bu. of corn, rather than export 670 >>>million bu. as it did in 2005/06. Nebraska would need even more, 421 >>>million bu., to fill its ethanol-made hole." >>> >>>Now, here is just one sentence from myself: >>>If - as it seems - ethanol is a hoax, shouldn't we speak up, also for the >>>sake of the remaining prairies that might be at stake? >>>Maiken >>> >>>Maiken Winter >>>Cornell Laboratory of Orntihology >>>Ithaca, NY 14850 >>> >>> >>> >>> >>> >> >> > > >
