Page 140 - Materials Chemistry, Second Edition

Climate change responses: carbon offsets, biofuels and the life cycle assessment contribution

financial or operational control, but it does not count those operations in which it has an 127
equity share but no control. These different approaches to determining organisational bound-
aries can produce different results. While the difference is less important for a company volun-
tarily reporting its greenhouse gas emissions, the determination of boundaries can give a
company a financial advantage or disadvantage in a carbon trading or tax scheme. Also,
importantly, there is potential for double counting if two or more companies hold interests in
the same organisation but use different reporting approaches. A functional supply chain
approach would avoid these issues, as the eventual impacts of carbon emissions would belong
appropriately to end consumers of products and services. The reluctance to use this approach
may be linked to the apportionment of blame for emissions. Consumers are reluctant to accept
responsibility for emissions along the supply chains that produce their goods and services. It
may also serve economic interests to encourage an accounting approach where technical solu-
tions rather than changes in consumption patterns are promoted as ‘the way’ to tackle green-
house emissions – despite the constraints inherent in this approach.
These apparent complexities involved in greenhouse gas assessment necessitate clear rules
and accounting systems. Accordingly, in Australia, demand for options to allow companies to
purchase offsets and become ‘carbon neutral’ has led to a specific standard and certification
process. The Greenhouse Friendly™ certification standard aligns with the Greenhouse Gas
Protocol (AGO, 2006; Department of Climate Change, 2008). Greenhouse Friendly™ was
launched in 2001 and has since been expanded as part of the Australian Government’s Green-
house Challenge Plus program. Under the program, credits from abatement projects approved
by the Australian Government under the Greenhouse Friendly™ initiative are available for
purchase by those seeking approved carbon offsets.

10.2 Carbon offsets: assessment problems associated with
bio-sequestration
Bio-sequestration is being used increasingly to offset carbon emissions. By planting trees and
other crops, organisations can ‘neutralise’ their emissions with the assumption that the emis-
sions will be sequestered in plants as carbon. This approach, however, presupposes a sound
knowledge of biomass cycles in the land and plants that are offset. These cycles are complex,
however, as indicated even in the simplified schematic in Figure 10.1. Accordingly, carbon
accounting in agriculture and forestry is plagued with high levels of multiple uncertainties.
A simple description of the generic bio-sequestration system illustrates the key uncertainties
in predicting sequestration offsets. Theoretically, the release of carbon dioxide (CO ) through
2
burning fossil fuels is counterbalanced by the take-up of equivalent carbon through plant
growth under the sequestration program. The first assumption here is that the plants in question
would not be grown if not for the sequestration program and, furthermore, that the land upon
which they are grown would not otherwise fix any carbon (carbon dioxide is referred to here in
shorthand as ‘carbon’). It is problematic to argue that fallow land will remain fallow and inca-
pable of fixing carbon without a sequestration planting. Also, any fossil fuel consumption or
soil carbon losses involved in preparing land and growing plants should also be counted.
It is also assumed that carbon dioxide absorbed during plant growth is ‘locked in’ for a
significant period of time. Indeed, sequestration schemes generally take a land use change
approach, which assumes that the sequestration crop will comprise the new land use in perpe-
tuity, so that over the cycles of plant growth and harvests an average ‘stock’ of carbon will be
maintained. Another key assumption is that the greenhouse gas balance of the soil and sub-
strate remain constant with no net emissions of greenhouse gases. However, the mobilisation
of soil carbon and other greenhouse gases is complex and the balance may not be constant.

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