# Corporate Ecological Footprint: New Conversion Factors

Authors: Pablo Coto-Millán; Juan Luis Doménech Quesada; Ingrid Mateo Mantecón
Journal: Research Letters in Ecology
 (2008)

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## Abstract

The first ecological footprint calculation version, applied to companies, appeared in 2003. The said tool provides the possibility of calculating the total impact of a company or organisation in hectares or in equivalent emissions ofCO2. This paper updates carbon absorption rates and improves electricity consumption conversion factors, one of the major footprint generating consumptions in companies. The new rates prove that the footprint estimated to date will be notably increased as, among other aspects, the IPCC has downgraded the amount of carbon that forests are capable of absorbing. These data reveal that companies must make a great effort to adapt to the challenges triggered by climate change.


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## Body

## 1. Introduction

The first version  of the ecological
footprint calculation method applied to companies (corporate ecological
footprint or CEF) was developed between 2003 and 2007  [1–4]. Since then, it has been applied
to an increasing number of organizations, such as ports, dealerships, fishing
companies, the food and agriculture sector.The CEF incorporates all types of
consumptions, as well as waste products, discharges, and emissions. The
different consumption categories are electricity, fuel, general materials,
construction materials (building), services and contracts, farming and
agricultural resources, forestry resources, and water.Most of the data required for the
calculation are taken from account books, meters (electricity, water), and the organization's
annual report. The consumption of energy
and materials is converted to gigajoules (KWh based on the equivalence of1KWh=3.6Mj; fuels based on their calorific value; and materials based on their
energy intensity). Gigajoules, in turn, are converted into CO2 emissions based on the emission factor of the fuel used. Finally, the said
emissions are converted to hectares based on the forest absorption rate. The
latter two steps can be simplified by dividing the Gigajoules consumed by “energy
productivity,” which is obtained by dividing the carbon absorption factor
by the carbon emission factor of the fuel considered. Agricultural, forestry,
or stockbreeding resources are directly converted to hectares based on their
natural productivity levels. For further details on the calculation method,
consult Doménech (2006) [3] and http://www.huellaecologica.com/.However, several of the
above-mentioned consumptions and their conversion factors are still under
development, such as the validity of the system used for the conversion of electricity
consumption, the incorporation of public infrastructures, the incorporation of
dangerous waste products and discharges, the incorporation of fuel life cycles,
or the incorporation of carbon absorption factors for ecosystems other than
forests.Some of the complications concerning
the conversion of electricity consumption into hectares (ecological footprint)
or into carbon emissions (carbon footprint) derive from the different emission
and absorption factors used, according to the sources consulted. This paper
describes the new conversion factors affecting companies' electricity
footprints, which will become part of version 2 of the calculation method and
that is still being prepared.


## 2. Results: Changes to the Electricity Footprint Calculation Method

Substantial  changes have been made
to the method used to convert the electric energy consumed intoCO2 emissions or hectares—the CO2 emission factors have been adjusted
in accordance with the document “España. Informe Inventarios GEI 1990–2004 (mayo 2006)” (http://portal.aragon.es/portal/page/portal/MEDIOAM-BIENTE/CALIDAD_AMBIENTAL/CCLIMA/INFORMES/INVENTARIOEMISIONESGEI_1990–2004.PDF)
“(Spain. GHG Inventory Report 1990–2004 (May 2006),” which is mainly based on IPCC data from 1996
and, especially, on changes made to the carbon absorption rate of forests,
adopting the rate issued by the IPCC in 2001, which was 1 tC/ha/year.The classic energy productivity of
71 Gj/ha/year generally applied to liquid fuels in previous versions is now of
51 Gj/ha/year (average of gas-oil, gasoline, and fuel oil). The 55 Gj/ha/year
usually used for coal, is now 37 Gj/ha/year, and the 93 Gj/ha/year for gases is
now 65.5 Gj/ha/year. This reduction in energy productivity results in higher
footprints than in the previous version. In other words, the environmental
impact of companies is greater than estimated to date.Table2 displays a company's
electricity footprint calculation, obtained based on three different fuel
sources: coal, liquid fuel, and gas. Three different data sources are also
compared (1) those used to date in previous versions (CEF version 1); (2) those
calculated directly based on KWh consumed, taken from Meier et al. (2005) [6],
which include the entire life cycle in the emission factors (extraction,
infrastructures, transport, waste, etc.); this variant is described by Álvarez et al. (2008) [5]; (3) those calculated in this paper based on
national inventory data.The “energy productivity” (emission
factor/absorption factor) is also calculated based on two different carbon
absorption factors: the most recent from the IPCC in 2001 (1 tC/ha/year or 3.66tCO2/ha/year) and the one we have been using to date (1.42 tC/ha/year or 5.2 tCO2/ha/year).Table1 displays a list of fuels and
updated emission factors and the new forest CO2 absorption rate.Table 1
New fuel conversion indices used to calculate corporate ecological footprints.
FuelForest absorption rate
(tCO2/ha/year)Emission factor with oxidation factor
(tCO2/Gj)“Energy
productivity” of forests (Gj/ha/year)SolidsAnthracite3.66660.097337.7Lignite3.66660.100236.6Coal
for coke making3.66660.093739.1Other
bitumen. coal3.66660.093739.1Tyres
(cement factories)3.66660.082044.7LiquidsGas-oil3.66660.073749.8Gasoline3.66660.069053.1Fuel
oil3.66660.076048.2General LPG3.66660.065056.4Kerosene (not for aircraft)3.66660.071551.3Oil
coke3.66660.098337.3Oils & lubricants3.66660.072950.3Solvents (cement factories)3.66660.083044.2Used oil (cement factories)3.66660.073050.2GasNatural gas (dry)3.66660.056065.5Butane3.66660.066255.4Methane3.66660.054667.2Propane3.66660.063657.7Carbon
Monoxide3.66660.154023.8Hydrogen3.66660.00000Source:
“España. Informe Inventarios” GEI 1990–2004 (May 2006).
http://portal.aragon.es/portal/page/portal/MEDIOAMBIENTE/CALIDAD_AMBIENTAL/CCLIMA/INFORMES/INVENTARIOEMISIONESGEI_1990–2004.PDF (last access: June/2008).Table 2
Method used to convert electricity consumption toCO2 emission
and hectares based on three different data sources and two different
absorption factors.
(1) Spread sheet for CEF version 1
(Doménech, 2006)(2) Direct conversion
with LCA (*)
(Álvarez et al. 2008)(3) GHG inventories 1990–2004Electricity obtained from a coal fired power stationAssumed electric consumption
as an example1 GWh (12,000 Gj)1 GWh (12,000 Gj)1 GWh (12,000 Gj)Emission factor0.026 tC/Gj (1)1006tCO2/GWh (1)0.0973tCO2/Gj (2)t carbon emitted312274.4318.4tCO2 emitted1,144.010061,167.6Conversion to hectares
(5.20tCO2/ha/year) &
“energy productivity”220 ha/year193.5 ha/year224.5 ha/year—54.6 Gj/ha/year53.4 Gj/ha/yearConversion
to hectares
(3.66tCO2/ha/year) &
“energy
productivity”312.6 ha/year274.9 ha/year319.0 ha/year—38.5 Gj/ha/year37.6 Gj/ha/yearElectricity
obtained from a power station fired by liquid fossil fuelsElectricity
consumption1 GWh (12,000 Gj)1 GWh (12,000 Gj)1 GWh (12,000 Gj)Emission factor0.020 tC/Gj (3)742tCO2/GWh (4)0.076tCO2/Gj (4)t carbon emitted240202.4248.7tCO2 emitted880742912Conversion
to hectares
(5.20tCO2/ha/year) &
“energy productivity”169.2 ha/year142.7 ha/year175.4 ha/year—71 Gj/ha/year68.6 Gj/ha/yearConversion
to hectares
(3.66tCO2/ha/year) &
“energy
productivity”240.4 ha/year202.7 ha/year249.7 ha/year—50 Gj/ha/year48.3 Gj/ha/yearElectricity
obtained from a gas fired power stationElectricity
consumption1 GWh (12,000 Gj)1 GWh (12,000 Gj)1 GWh (12,000 Gj)Emission factor0.0153 tC/Gj466tCO2/GWh0.056tCO2/Gjt carbon emitted183.6127.1183.3tCO2 emitted673.2466672Conversion
to hectares
(5.20tCO2/ha/year) &
“energy productivity”129.5 ha/year89.6 ha/year129.2 ha/year—92.8 Gj/ha/year92.8 Gj/ha/yearConversion
to hectares
(3.66tCO2/ha/year) &
“energy productivity”183.9 ha/year127.3 ha/year183.6 ha/year—65.4 Gj/ha/year65.4 Gj/ha/year(*)
Life cycle assessment.
(1)
Referred to coal in general (includes several times); (2) anthracite; (3) fuel oil
and gas-oil; (4)
fuel oil.
Source:
own preparation.


## 3. Discussion and Conclusions

Attention must be paid to the fact
that variant 2 (Table2) provides the lowest carbon footprint for the three
types of fuel considered, even in spite of including the entire fuel life cycle
from extraction to combustion and the treatment of waste products. On the other
hand, the emission factors in cases 1 and 3 are very similar or slightly higher
in case 3 (it seems advisable to choose the one that results in the highest
footprint). Therefore, with a view to avoid the dispersion of data and to
facilitate comparisons, subsequent corporate ecological footprint versions will
use the official data provided by the national inventory. The new forest mass
emission factor of (1 tC/ha/year), included in the IPCC 2001 report, will also
be used as it is more recent than the one used in previous versions (1.42 tC/ha/year).These new conversion factors,
especially the new forest absorption rate, will substantially increase the
ecological and carbon footprints attributed to companies to date. This will make it even more difficult for
companies to face the challenges presented by climate change. The European
Union carbon reduction objective for the year 2020 (20% less than in 1990) and
the growing tendency toward a low-carbon economy leads us to suggest that
companies should add proactive carbon reduction policies to their main
strategic targets.



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*Source: 415934-2008-10-21.xml*