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Winrock International just published a white paper that synthesizes
existing scientific data on greenhouse gas (GHG) emissions related
to the production and expansion of biofuels. It is specifically
focused towards assisting organizations that are developing
sustainability standards for biofuels with the collection and
interpretation of data. 

The member of the Air Resources Board should read this paper --
and future papers that are forthcoming from Winrock -- and ensure
that its findings are taken into consideration during the
implementation of the Low Carbon Fuel Standard.

For instance, the paper points out that, “Sugarcane demonstrates
particularly robust GHG savings through the use of bagasse as an
energy source but potential still exists to improve boiler
efficiency in many instances that would enable greater electricity
production and export which would further improve GHG emissions.” 

As various stakeholders have pointed out, CARB completely miss
that in its GREET and GTAP modeling! For more info, see
http://sugarcaneblog.wordpress.com/?s=LCFS

The Winrock paper is based on peer-reviewed data and published GHG
calculation methodologies and is principally focused on currently
commercial biofuel production from sugarcane, corn, soy, rapeseed,
palm oil and on future feedstocks (lignocellulosic material);
switchgrass, miscanthus, agricultural and woody residues and short
rotation coppice.

The white paper illustrates that:

    * Existing modeling approaches cannot yet effectively and
robustly define the global GHG impact of expanding biofuel
production.

    * Studies with system boundaries that measure “well-to-wheel”
GHG emissions can identify key contributing parameters within the
biofuel supply chain. This approach can be used to develop
appropriate guidelines to reduce GHG emissions.

    * The well-to-wheel system boundaries as currently defined in
many tools could provide future risks of double counting emissions
or reductions e.g. emissions associated with fertilizer production
counted in the chemical industry are also counted in the biofuel
calculation.

    * Reported well-to-wheel GHG emissions can vary according to
methodological decisions, the use of different emission factors and
uncertainties in data e.g. N2O emissions from soil.

    * Well-to-wheel GHG emissions can also vary substantially on
the basis of different cultivation practices and fuels used to
process biofuel. It is not possible to classify biofuel as “good”
or “bad” on the basis of the feedstock they are developed from
alone.

    * The uncertainty associated with N2O emissions from soil is
significant and yet is a key component of the GHG emission profile
of biofuels. Many tools being developed for sustainability
standards rely on default IPCC calculations for N2O emissions.
Detailed models for calculating emissions exist in the US and
Europe.

    * Emissions associated with fertilizer manufacture differ
between different types and play a key role in the emissions
associated with biofuel crop cultivation. Opportunities to
substantially reduce these emissions for ammonium nitrate
production through GHG pricing mechanisms exist and would
positively impact the GHG balance for biofuel.

    * Emissions associated with some types of land use change can
negate GHG savings associated with biofuels and lead to long carbon
payback times?.

    * Co-product treatment method has a large impact on the GHG
savings reported. There is no internationally agreed and consistent
approach.

    * Cultivation management practices to increase soil carbon
sequestration and effective utilization of co-products can play a
role in improving the GHG balance of biofuels, providing they are
maintained long-term. Some emerging co-product markets (food grade
CO2) and their GHG implications have not yet been addressed.

    * The reported GHG savings for biofuels differ depending on
the reference they are compared to. A fuel that demonstrated an 80%
GHG saving against a high carbon intensity reference translates
into greater savings calculated as gCO2eq/MJfuel than if the 80%
GHG saving is related to a lower carbon intensity reference. If GHG
benefits were monetized, this would result in different incentives
depending on regional differences in the reference fuel.

    * Incentives for GHG reduction ($/tCO2eq) are unlikely to
represent a large proportion of net returns ($/ha) at $10/tCO2eq.
In some cases such as sugarcane, the incentives may not be
necessary to establish economically competitive biofuel markets;
however land allocation decisions for advanced biofuel crops could
be influenced by GHG incentives that reduce the breakeven returns
(used as a proxy for land allocation decision). High yields per
hectare and soil carbon sequestration rates are key and incentives
greater than $10/tCO2eq are likely to be required for advanced
biofuels.