Comments on: Prairie Grasses Can Run Your Car

By: Left_Wing_Fox

Left_Wing_Fox — Tue, 04 Dec 2007 21:52:27 +0000

I can see two problems. First, Forests aren’t permanent methods of sequestering carbon. Forests burn, plants decompose and are metabolized by it’s inhabitants. Eventually those forests reach a level of equilibrium. It’s just not a useful way of dealing with the external source of carbon (fossil fuels) we’re pumping into the cycle, unless we then bury the forests and plant a fresh one on top of it to take it out of the cycle permanently.At least with biofuels, the carbon we put into the atmosphere came out of the atmosphere tin the first place. As long as harvesting, processing and distribution are using green sources of power, the whole system is carbon neutral.The second issue isn’t really one of global warming, but the scarcity of fossil fuels. If indeed the peak oil theorists are right, we can expect to see higher prices, and eventually worldwide shortages. Better to get off those fossil fuels as much as possible while we still have cheap energy, rather than wait until the last second to try and make drastic changes.

By: hibob

hibob — Tue, 04 Dec 2007 20:05:55 +0000

But how does it compare to planting trees on the same acreage and burning normal diesel?from the article:”LIHD biomass removed and sequestered more atmospheric CO2 than was released from fossil fuel combustion during agriculture, transportation, and processing (0.32 Mg haï¿½1 yearï¿½1 of CO2), with net life cycle sequestration of 4.1 Mg haï¿½1 yearï¿½1 of CO2 for the first decade and an estimated 2.7 to 3 Mg haï¿½1 yearï¿½1 for subsequent decades.”So call it 100 Mg of carbon dioxide/ha over 30 years, or about 27 Mg of carbon.An earlier article in Sciencehttp://www.sciencemag.org/cgi/content/full/317/5840/902?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=forest+biofuel&searchid=1&FIRSTINDEX=0&resourcetype=HWCITputs the net sequestration of carbon from reforesting temperate cropland at almost 100 Mg/ha of carbon over 30 years.I’ve probably missed something, but it looks like planting trees and leaving them there still has a three to fourfold advantage over harvesting grasslands for fuel.

By: 6EQUJ5

6EQUJ5 — Tue, 04 Dec 2007 17:53:34 +0000

Food cereals put down roots about a foot. Prairie grasses put roots down about three feet, so they condition much more of the soil, make far better use of water and nutrients, recover faster after being mowed, and they are not just hardy, they are almost impossible to eradicate, unlike monoculture cereals which are much more vulnerable to pests.

By: Left_Wing_Fox

Left_Wing_Fox — Tue, 04 Dec 2007 17:14:27 +0000

I’ve been hearing of a large number of interesting energy developments lately, mostly through CBC’s “Quirks and Quarks” radio program. This week was using bacterial metabolism substantially reduce the amount of electricity required to convert water into Hydrogen and Oxygen. A few months back, it was biodegradable sugar-powered fuel cells.Hydrogen ad Bacteria:http://www.cbc.ca/quirks/archives/07-08/dec01.htmlPower, Sweet Power:http://www.cbc.ca/quirks/archives/06-07/mar31.htmlOlder, not as nigh-practical, but still cool:A New Solar Power:http://www.cbc.ca/quirks/archives/04-05/jan29.html