Whenever I write about what a lousy building material concrete is from an environmental point of view, and why I love wood, I take a lot of abuse. However this little drawing by Austrian architect Christoph Wassmann says it all: a cubic meter of concrete (which doesn't go very far in construction and is not readily recyclable) puts out 385 kg of CO2. A cubic meter of steel (which goes a long way and is recyclable) puts out a lot at 12,200 kg CO2/m2, but that is virgin steel and much of it now is recycled so it should be lower. Wood? it binds CO2 and has a negative rating, sucking in 900Kg of CO2 in its "manufacture" or growth. A cubic meter of wood contains 411 board-feet, or about 100 8' long 2x4s, which is a fair pile.::Anarchitecture
He figured this out using the Global Emission Model for Integrated Systems (GEMIS) Version 4.4 free software that "was developed in 1987-1989 as a tool for the comparative assessment of environmental effects of energy by Öko-Institut and Gesamthochschule Kassel (GhK). Since then, the model was continuously upgraded and updated."
It looks really useful for doing life-cycle analyses:
"GEMIS includes the total life-cycle in its calculation of impacts - i.e. fuel delivery, materials used for construction, waste treatment, and transports/auxiliaries.
The GEMIS database covers for each process:
* efficiency, power, capacity factor, lifetime
* direct air pollutants (SO2, NOx, halogens, particulates, CO, NMVOC)
* greenhouse-gas emissions (CO2, CH4, N2O, SF6, all other Kioto gases)
* solid wastes (ashes, overburden, FGD residuals, process wastes)
* liquid pollutants (AOX, BOD5, COD, N, P, inorganic salts)
* land use."
I have downloaded it and will try and figure it out; at first glance it looks like a complicated but valuable tool for designers. ::GEMIS