LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 3A: LAND USE CHANGE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Table 3. Results for the occupation of 1 ha yr of different land tenure markets (for global average). Further,
in the lower part of the table example results are shown for arable land and rangeland in different countries in
the world. Results are shown when applying the consequential modelling assumption.
Affected land market
Global averages for 1 ha yr
NPP0,
kg C ha-1 yr-1 Expansion, kg CO2-eq.
Result, consequential
Intensification, kg CO2-eq. Total, kg CO2-eq.
Arable 6,110 1,010 6,820 7,830
Forest int. 7,220 3,340 - 3,340
Forest ext. 7,220 1,670 - 1,670
Range
Examples of country specific
results for 1 ha yr
4,860 1,160 - 1,160
Arable, Malaysia 12,000 2,000 13,400 15,400
Arable, Denmark 7,000 1,170 7,800 8,970
Arable, Brazil Amazonas 9,000 1,500 10,000 11,500
Range, Brazil Cerrado savannah 5,000 1,190 - 1,190
Table 3 only shows results using the consequential modelling assumption. If the attributional modelling
assumption is applied, the results for arable land will be around 4% of the results for consequential. Similarly,
the results for forestland and rangeland are significantly lower. The reason for this is that in the attributional
modelling a large market share of the inputs to the land tenure market is comprised by ‘land already in
use’ which is not associated with any emissions.
4. Discussion and conclusion
This paper presents a model of iLUC. The model has the following characteristics; it includes effects on
deforestation and intensification, allocation of deforestation emissions using a chosen amortisation period is
avoided, the model is applicable to any land use type in any location, and the model can handle both consequential
and attributional modelling assumptions.
The results show significant iLUC effects on global warming; crops with yields 5-7 t/ha yr grown on average
yielding land will be associated with iLUC effects at 1 to 1.5 kg CO2-eq./kg crop. For many arable
crops this means a factor 2-4 increase in GHG-emissions. For arable land the effect from intensification
comprises around 87% of the total iLUC where the remaining is related to deforestation. The iLUC from
forestry and rangeland are also significant. Here no intensification is considered. For forestland, the emissions
are caused by transformation of natural forest to cultivated forest, and for rangeland, the emissions
originate from transformation of natural savannah/scrub to grassland.
The major uncertainties in the model are a) the market for land is assumed to be global, b) the determination
of NPP0 as of Haberl et al., (2007) is relative coarse grained, so 10-15% uncertainty is associated with
reading maps which only show intervals, c) the determination of the relative distribution of inputs of expansion
and intensification to the land tenure market is associated with uncertainties since it is based on indirect
estimation methods, d) the modelling of intensification as of Schmidt (2008) only considers additional NPK
fertiliser as an affected mean of intensification, and e) also the dose-response effects in Schmidt (2008) of
crop-yields relative to additional fertiliser are associated with uncertainties.
Despite the uncertainties listed above, the model results are regarded as being within reasonable uncertainty
intervals. It should be noticed, that the model concept is open for improved data input at almost any
level. This means that the presented model can be seen as a proposal for solving the conceptual challenges
with the modelling of iLUC, and that future improvements of the model will focus on improving input data.
6. References
FAOSTAT, 2011. FAOSTAT, Food and agriculture organization of the United Nations. Accessed November 2011:
http://faostat.fao.org/
FAO, 2010. Global Forest Resources Assessment 2010 – main report. FAO, Rome
Haberl H., Heinz Erb K., Krausmann F., Gaube V., Bondeau A., Plutzar C., Gingrich S., Lucht W. and Fischer-Kowalski M., 2007.
Quantifying and mapping the human appropriation of net primary production in earths terrestrial ecosystems. PNAS, vol. 104,
no. 31, pp 12942–12947
IFA, 2011. Production and trade statistics. International Fertilizer Industry Association (IFA). Accessed November 2011:
http://www.fertilizer.org/ifa/Home-Page/STATISTICS
IPCC, 2006. 2006 IPCC Guidelines for national greenhouse gas inventories, Prepared by the National Greenhouse Gas Inventories
Programme, Eggleston H S et al., (eds). IGES, Japan.
Peters G. P., Marland G., Le Quéré C., Boden T., Canadell J. G., Raupach M. R. (2011). Rapid growth in CO2 emissions after the
2008-2009 global financial crisis. Nature Climate Change 2, 2–4
250