Okala Impact Factors help design teams to create solutions that abate environmental and human health damage. The listed Okala Impact Factors (OIF) and global warming potentials values supplement the OIF found in Okala Practitioner.1 Okala Practitioner describes in detail how OIF values result from thorough life cycle emissions data and robust impact characterization science. OIF 2014 should not be used in combination with earlier OIF.

The aluminum casting factors indicate the impacts of casting aluminum. They do not include the impacts from the production of aluminum, so aluminum production impacts should be calculated and added separately.

We burn a fuel for its energy. Okala Practitioner reported factors for fuel production, not fuel combustion, so these new factors combine impacts from production and combustion. For this, we modeled representative combustion scenarios: typical vehicles, two-stroke motors (such as lawnmowers), home-scale furnaces and larger boilers.2, 3

For biodiesel, ethanol and wood, we calculated impacts from human-caused (anthropogenic) global warming emissions differently than those from naturally caused (biogenic) global warming emissions. Over a biofuel’s life cycle, the amount of biogenic carbon in the fuel equals the amount of biogenic carbon that is exchanged with the atmosphere. Conforming with protocol, we assigned biogenic combustion emissions a value of zero.4 The resulting global warming values for these combusted biofuels are shown in blue.



1. Philip White, Louise St. Pierre and Steve Belletire, 2013: Okala Practitioner: Integrating Ecological Design, ISBN 978-0-9851674-0-0
2. US EPA, 2014: Greenhouse Gas Emissions from a Typical Passenger Vehicle, Office of Transportation and Air Quality, EPA-420-F-14-040a
3. Roger McDonald, 2009: Gas, Oil and Wood Fueled Heating System Emissions, Brookhaven National laboratory, Upton, NY, USA
4. Philippe Ciais, Christopher Sabine, et al, 2013: Chapter 6. Carbon and Other Biogeochemical Cycles, in Climate Change: The Physical Science Basis, Fifth Report of the IPPC, Cambridge University Press, Cambridge, UK