Submitted: 5 Februari 2013; Accepted: 10 April 2013
Biofuel use is intended to address the ever-increasing demand for and scarcer supply of fossil fuels. The recent Indonesia government policy of imposing 10% mixing of biodiesel into petroleum-based diesel affirms the more important biofuel role in the near future. Palm oil, methane from palm oil mill effluent (POME) and animal wastes are the most prospective agricultural-based biofuels. The production and use of palm oil is interlinked with landuse and landuse change (LULUC), while the use of methane from POME and animal wastes can contribute in reducing emissions. The current European Union (EU) and the potential United States (US) markets are imposing biodiesels’ green house gas (GHG) emission reduction standards (ERS) of 35% and 20%, respectively relative to the emissions of petroleum-based diesel based on using the lifecycle analysis (LCA). EU market will increase the ERS to 50% starting 1 January 2017, which make it more challenging to reach. Despite controversies in the methods and assumptions of GHG emission reduction assessment using LCA, the probability of passing ERS increases as the development of oil palm plantation avoid as much as possible the use of peatland and natural forests. At present, there is no national ERS for bioenergy, but Indonesia should be cautious with the rapid expansion of oil palm plantation on existing agricultural lands, as it threatens food security. Focusing more on increasing palm oil yield, reducing pressure on existing agricultural lands for oil palm expansion and prioritizing the development on low carbon stock lands such as grass- and shrublands on mineral soils will be the way forward in addressing land scarcity, food security, GHG emissions and other environmental problems. Other forms of bioenergy source, such as biochar, promise to a lesser extent GHG emission reduction, and its versatility also requires consideration of its use as a soil ameliorant.
a b s t r a c t
A systematic review and meta-analysis were used to assess the current state of knowledge and quantify the effects of landuse change (LUC) to second generation (2G), non-food bioenergy crops on soil organic carbon (SOC) and greenhousegas (GHG) emissions of relevance to temperate zone agriculture. Following analysis from 138 original studies, transitions from arable to short rotation coppice (SRC, poplar or willow) or perennial grasses (mostly Miscanthus or switchgrass) resulted in increased SOC (þ5.0 ± 7.8% and þ25.7 ± 6.7% respectively). Transitions from grassland to SRC were broadly neutral (þ3.7 ± 14.6%), whilst grassland to perennial grass transitions and forest to SRC both showed a decrease in SOC (10.9 ± 4.3% and 11.4 ± 23.4% respectively). There were insufficient paired data to conduct a strict meta-analysis for GHG emissions but summary figures of general trends in GHGs from 188 original studies revealed increased and decreased soil CO 2 emissions following transition from forests and arable to perennial grasses. We demonstrate that significant knowledge gaps exist surrounding the effects of landuse change to bioenergy on greenhousegas balance, particularly for CH 4 . There is also large uncertainty in quantifying transitions from grasslands and transitions to short rotation forestry. A striking finding of this review is the lack of empirical studies that are available to validate modelled data. Given that models are extensively use in the devel- opment of bioenergy LCA and sustainability criteria, this is an area where further long- term data sets are required.
Adji F.F., Hamada Y., Darang U., Limin S.H., and Hatano R., 2014. Effect of plant-mediated oxygen supply and drainage on greenhousegas emission from a tropical peatland in Central Kalimantan, Indonesia. Soil Sci. Plant Nutrition, 60, 216-230. https://doi.org/10.1080/00380768.2013.872019 Bond-Lamberty B., and Thomson A., 2010. A global database
The establishment of oil palm plantations in Malaysia has rapidly expanded in the past 25 years, especially in the west coast of the Malaysian Peninsula, where soil is most fertile and productive (Henson, 2005). Oil palm has been extensively planted in parts of East Malaysia on newly explored forest land. Generally, oil palm plantations in this country have been devel- oped from logged-over, degraded forest and also as replacement of other crops such as rubber, coconut and cocoa, since these crops have become less prof- itable than oil palm (MPOB, 2001; Henson, 2004). Greenhouse gases (GHG) emissions from landuse change are regularly debated, particularly in relation to biofuels (e.g., establishing new plantations on ag- ricultural land). Emissions are in particular related to changes in aboveground and belowground biomass, as well as soil organic matter (Brinkmann Consultancy, 2009). Specifically, the establishment and operation of a new plantation lead to the removal of the original aboveground and belowground carbon stocks (e.g., forest, grassland, etc.). On the other hand, a plantation stores carbon through the growth of oil palms.
progressive framework that obliges all countries to formulate climate mitigation strategies and goals to limit global warming to well below 2.0 degrees C ( UNFCCC, 2016 ; Turnhout et al., 2017 ). Countries ’ stra- tegies and actions are formulated in the nationally determined con- tributions (NDCs) and anthropogenic emissions and removals from the AFOLU sector should be communicated with the national GHG in- ventory reports. The accounting mechanism for NDCs includes all ca- tegories of anthropogenic emissions and removals and should comply with the requirement of the Intergovernmental Panel on Climate Change (IPCC) that estimates should be complete, consistent, compar- able, transparent and accurate ( IPCC, 2003 , 2006 , 2014b ). The purpose of the “enhanced transparency framework” of the Paris Agreement ( UNFCCC, 2016 : Article 13) is to provide ‘clear understanding of cli- mate change action’ including ‘clarity and tracking of progress towards achieving Parties’ individual nationally determined contributions’ and ‘Parties’ adaptation actions’ including ‘good practices, priorities, needs and gaps’. With high levels of donor support and engagement of sta- keholders, the Global Environment Facility established the Capacity- building Initiative for Transparency (CBIT) which will assist developing countries, pre- and post-2020 to strengthen their institutional and technical capacities to meet this essential element of the agreement. To understand what is being done and achieved in climate mitigation ac- tion, transparency of biophysical land and emission data and informa- tion in the submitted national communications and NDCs is key. Art. 13 also asks for “a full overview of aggregate ﬁnancial support provided”, but in the present paper we focus on data related to climate change action and do not address the question of ﬁnance data.
In order to fully evaluate the potential impacts of shifting from truck to rail, the state should examine a couple of issues beyond the scope of this study. Differences in circuity between the routes taken by trucks versus those taken by trains should be considered. For example, depending on the layout of the rail and road infrastructures, one mode may take a more direct route between two destination points, leading to more or less efficient transport. In addition, the increased use of drayage trucks (i.e. trucks used to transport goods to and from rail terminals) due to a modal shift from truck to rail freight could reduce the benefits of rail freight. Finally, the state should give some consideration to how this strategy would be implemented, whether via mandate, financial incentives, etc. Policymakers should remember that businesses are drawn to the most cost-effective mode of transportation that fulfills their time-sensitivity needs, regardless of the GHG or air quality impact of those modes; for this reason, businesses may be reluctant to shift to a different mode of shipping without clear legal or financial incentives.
Organic agriculture is often considered to contribute to reducing energy use and greenhousegas (GHG) emissions, also on a per unit product basis. For energy, this is supported by a large number of studies, but the body of evidence for GHGs is smaller. Dutch agriculture is characterized by relatively intensive landuse in both organic and conventional farming, which may affect their performance in terms of energy use and GHG emissions. This paper presents results of a model study on energy use and GHG emissions in Dutch organic and conventional farming systems. Energy use per unit milk in organic dairy is approximately 25% lower than in conventional dairy, while GHG emissions are 5-10% lower. Contrary to dairy farming, energy use and GHG emissions in organic crop production are higher than in conventional crop production. Energy use in organic arable farming is 10-30% and in organic vegetable farming 40-50% higher than in their respective conventional counterparts. GHG emissions in organic arable and vegetable farming are 0-15% and 35-40% higher, respectively. Our results correspond with other studies for dairy farming, but not for crop production. The most likely cause for higher energy use and GHG emissions in Dutch organic crop production is its high intensity level, which is expressed in crop rotations with a large share of high-value crops, relatively high fertiliser inputs and frequent ﬁeld operations related to weeding.
One of the reasons frequently cited for the need to amend the biofuels policy is the estimated emissions associated with landuse changes brought about by the expansion of feedstocks used to produce biofuels. A study of landuse change emissions was completed in 2011 by the International Food Policy Institute (IFPRI) for the Directorate General for Trade of the European Commission.  A number of biofuels stakeholders including the European Biodiesel Board (EBB) expressed concerns with this study.  Estimating emissions due to landuse changes using economic models, and predicting the types of land that would be impacted, is a field of much continuing research. A recent (2012) extensive review of the various landuse estimates and models used to estimate landuse changes by Wicke et al concluded, “despite recent improvements and refinements of the models, this review finds large uncertainties, primarily related to the underlying data and assumptions of the market-equilibrium models. Thus there is still considerable scope for further scientific improvements of the modeling efforts.”  Recognizing the need for additional work on landuse changes in the EU and the discussion about possibly modifying biofuel targets, EBB contracted with Air Improvement Resource, Inc. to perform additional LUC modeling. AIR was assisted by by Don O’Connor of (S&T) 2 Consultants, and by Steffen Mueller, University of Illinois, Chicago.
mass balance, and systems models. We do not further develop here the methodological issuesrelated to these assessments. However, it is important to point out the role of temporal, spatial and sectoral scales in the estimation of trade ﬂows and resource consumption per unit commodity. A full range of spatial scales (regional, national, geological) play a role in the links between food trade and environmental issues. Aggre- gation and disaggregation across temporal, spatial and sectoral scales needs to be carried out in a consistent manner and accounting for scale-speci ﬁc constraints. Importantly, comparison across existing studies of a speciﬁc environmental impact of trade (e.g. on water consumption) is limited by the different spatio- temporal scales and product aggregations used.
Reliance on fossil fuels is causing unprecedented climate change and is accelerating environmental degradation and global biodiversity loss. Together, climate change and biodiversity loss, if not averted urgently, may inflict severe damage on ecosystem processes, functions and services that support the welfare of modern societies. Increasing renewable energy deployment and expanding the current protected area network represent key solu- tions to these challenges, but conflicts may arise over the use of limited land for energy production as opposed to biodiversity conservation. Here, we compare recently identified core areas for the expansion of the global pro- tected area network with the renewable energy potential available from land-based solar photovoltaic, wind energy and bioenergy (in the form of Miscanthus 9 giganteus). We show that these energy sources have very dif- ferent biodiversity impacts and net energy contributions. The extent of risks and opportunities deriving from renewable energy development is highly dependent on the type of renewable source harvested, the restrictions imposed on energy harvest and the region considered, with Central America appearing at particularly high potential risk from renewable energy expansion. Without restrictions on power generation due to factors such as production and transport costs, we show that bioenergy production is a major potential threat to biodiversity, while the potential impact of wind and solar appears smaller than that of bioenergy. However, these differences become reduced when energy potential is restricted by external factors including local energy demand. Overall, we found that areas of opportunity for developing solar and wind energy with little harm to biodiversity could exist in several regions of the world, with the magnitude of potential impact being particularly dependent on restrictions imposed by local energy demand. The evidence provided here helps guide sustainable development of renewable energy and contributes to the targeting of global efforts in climate mitigation and biodiversity con- servation.
With most of the exanimated options having higher cumulative emissions than sequestration raises the question of whether bioenergy electricity in this form can support climate change mitigation targets. BECCS might therefore be considered a necessary focus to achieve decarbonisation from forest systems, although viable engineering con- figurations of such systems need to be considered that include the en- ergy demand of carbon separation technologies [ 80–82 ]. Moreover, BECCS could lead to an increasing demand of wood pellets with pos- sible knock-on effects on forest management and feedstock procure- ment (e.g. increased allocation of wood to pellets or expansion of forest area) and possible technology lock-ins. This would affect the cumula- tive net GHG balance and change the system boundaries if there was a displacement of wood for other product. The only option of the in- vestigated variants that can deliver an atmospheric carbon removal without additional technologies like CCS [ 83 , 84 ] is utilising naturally disturbed forests and re-establishing healthy forest instead, in combi- nation with long rotation periods and expanding the forest area (latter could lead to a competition for landuse). Still, this variant has a less favourable GHG performance compared the reference case.
The U.S. Energy Independence and Security Act (EISA) of 2007 mandated annual production of 36 billion liters of biofuels by the year 2022, approximately 20%- 25% of the U.S. transportation fuel requirement, with 16 billion liters from cellulosic ethanol, 15 billion liters from grain ethanol, and 5 billion liters from other advanced fuels. One important issue with large-scale biofuel production is whether high biomass yields can be achieved at limited cost to soil and environmental quality. Optimal balance between high biomass yields and agricultural and environmental sustainability must be attained for successful deployment of biofuel production. Biofuels represent a potential opportunity to provide renewable energy with relatively low greenhousegas (GHG) emissions. However, land conversion to bioenergy crops may deplete soil fertility and increase soil GHG emissions, thereby offsetting the potential global warming benefits associated with biofuel production. The 2007 EISA enhanced research efforts related to cellulosic biofuel production, including various potential feedstocks.
9 after coppicing and high biomass production in SRC cycles (Grogan & Matthews, 2002; Keoleian & Volk, 2005). There are about 330-500 species of Salix but the main one used for the parent stock of most SRC willow varieties is Salix viminalis (DEFRA, 2004). A number of different varieties of SRC willow are usually planted within a plantation to help prevent spread of disease such as Melampsora rust and pests such as willow beetle (DEFRA, 2004). SRC willow is usually planted in spring either as cuttings or rods with around 15,000 stools ha -1 and is harvested approximately every three years, remaining viable for up to 30 years before replanting becomes necessary (DEFRA, 2004). The high CO 2 -exchange rates, light-use efficiencies, photosynthetic capacities (Karp & Shields, 2008) can result in high yields, typically between 7 and 12 oven dried tonnes ha -1 yr -1 (DEFRA, 2004) but has been shown to reach yields as high as 18 ha -1 in optimum soil conditions (Fischer et al., 2005). There are approximately 6400 ha of SRC willow planted in the UK for the purpose of bioenergy and can be used in dedicated biomass burners or for combined heat and power production (DEFRA, 2009; Rowe et al., 2009). The advantages of SRC willow is that it needs very few inputs, especially of N fertiliser, which can reduce emissions of N 2 O, and can be grown on marginal land or contaminated land (Vervaeke et al., 2003) so that it need not compete for prime agricultural land, both reducing concerns about the sustainability of bioenergy crops.
Biofuels have been promoted to achieve energy security and as a solution to reducing greenhousegas (GHG) emissions from the transportation sector. This dissertation presents a framework to examine the extent to which biofuel policies reduce gasoline consumption and GHG emissions and their implications for land allocation among food and fuel crops, food and fuel prices and social welfare. It first develops a stylized model of the food and fuel sectors linked by a limited land availability to produce food and fuel crops. It then analyzes the mechanisms through which biofuel mandates and subsidies affect consumer choices and differ from a carbon tax policy. A dynamic, multi-market equilibrium model, Biofuel and Environmental Policy Analysis Model (BEPAM), is developed to estimate the welfare costs of these policies and to explore the mix of biofuels from corn and various cellulosic feedstocks that are economically viable over the 2007- 2022 period under alternative policies. It distinguishes biofuels produced from corn and several cellulosic feedstocks including crop residues (corn stover and wheat straw) and bioenergy crops (miscanthus and switchgrass). A crop productivity model MISCANMOD is used to simulate the yields of miscanthus and switchgrass. The biofuel policies considered here include the biofuel mandate under the Renewable Fuel Standard (RFS), various biofuel subsidies and import tariffs. The effects of these policies are compared to those of a carbon tax policy that is directly targeted to reduce GHG emissions.
The results point to the fact that in Europe serious efforts in mitigating the major environmental pro- blems for Europe from agriculture need to address the livestock sector. While technical measures can clearly contribute signiﬁcantly to emission reductions, they cannot alone be sufﬁcient (Bellarby et al 2013 , Bajželj et al 2014 , Eshel et al 2014 , Leip et al 2014a , Witzke et al 2014 , Pierrehumbert and Eshel 2015 , Vanham et al 2015 ). The issues of what European citizens eat and their food waste also need to be addressed. For example, recent scenarios showed that all these actions would be necessary to achieve a stabilization in global N 2 O emissions (UNEP 2013 ).
During the last decades the overall production of red bricks in Sudan has strongly increased from an esti- mated 134 Million in 1975 to 1,804 Million in 2004 and to 2,800 million in 2006 (Hamid, 2002; Alam, 2006). In Sudan the total kiln number increased from 1,750 in 1995 to 3,450 in 2005, of which 2000 are located in Khartoum (Alam & Starr, 2009). Typically BM is a small-scale, labour intensive industry (Jensen & Pep- pard Jr, 2004) and countrywide the number of work- ers employed in this sector amounts to about 35,000 of which 50 % are in Khartoum and 38 % in the Central States (Alam, 2006). Most of the labourers are working on a temporary basis because their payment is based on the quantity produced and not on working hours (Jensen & Peppard Jr, 2004). The health risks related to this ac- tivity, particularly exposure to dust, combustion gases, and to heat, makes it di ﬃ cult to work continuously in a kiln (Alam, 2006). Also, the annual floods of the River Nile, force most of the kilns to stop operation from July to September.
transitions. These data suggest that shifts in microbial communities across these LUC transitions have a greater impact than the direct effect of changes in soil pH.
Changes in the microbial communities observed due to LUC to SRF may be linked to impacts on microclimate and/or litter and root inputs (Prescott & Grayston, 2013) . A study by Vesterdal et al. (2012) found different soil C turnover rates among six tree species (beech, lime, spruce, maple, ash, oak) despite having similar quantities of aboveground litterfall; the authors suggest that tree species have the greatest impact on soil C stocks via the indirect effects of litter quality on microbial activity and decomposition rates. Although not measured, the tree species in this study are likely to have had similar differences in litter quality. The quality of tree inputs from litter and rhizodeposition also vary due to differences in plant chemistry between coniferous and broadleaf species which in turn influences soil microbial composition and more specifically the relative abundance of fungi and bacteria. Clear differences in the abundance of soil fungal and bacterial PLFAs were observed in this study between land uses, with higher concentration per g C of both measured in the broadleaved compared to the coniferous soils. Fungi are considered to promote slower decomposition cycles with increased nutrient retention (Wardle et al., 2004)
The most significant contribution during the industrial phase can be attributed to the production of methanol due to the use of fossil fuel as energy source. GHG emissions from methanol production are highest compared with ancillary material production, mill process and transport. The according proportions of the emissions are 41%, 24%, 15%, 15% and 5% respectively, in Kalimantan. In Sumatra the the production parts similarily contribute to the overall GHG emission accounting for 42%, 24%, 16%, 16%, and 2% respectively. GHG emissions could be avoided by substituting waste stream of raw materials in the production for energy or materials taken from outside the studied system boundary. Emissions can be avoided by using less GHG emitting practices instead of GHG intensive practice to produce energy (Henson, 2009; Brinkman, 2009). A good example is the substitution of the fossil fuels with biofuels or by the incineration of production waste. In addition, emissions can be avoided by material substitution or by changes in the end- of-life treatment.
not possible for oxidation of CH 4 to significantly affect
the net GHG balance.
The permanent grass land-use type used in these simu- lations represents permanent, uncultivated grassland. Grassland, however, may also be temporary, used in rotation with arable crops, and in these circumstances can be regarded as a crop within an arable rotation. Per- manent grassland is the most abundant type of grass- land in the United Kingdom, covering 5.3 million ha in 2010, compared to 1.1 million ha of temporary (mostly rotational) grassland (Khan et al., 2011) at any one time. Rotational grassland in any given year would be catego- rized as arable crops in different years, so the 1.1 mil- lion ha in any year represents a snapshot of the area of rotational grass. As such, rotational grass is not a landuse; it is simply one component of rotational farming, which includes all-arable rotations as well as grass-ara- ble rotations. Rotational grassland is usually repre- sented as a crop within a rotation in most existing soil organic matter models and in ECOSSE is assumed to be a subset of arable rotational land. Permanent grassland represents a separate land-use transition as this land is only used for grass/livestock production. Rotational grass (by definition) occurs on the same land as is used for growing arable crops, so bioenergy conversion on rotational grass is equivalent to removal of land used for arable production. Rotational grassland can there- fore be simulated in ECOSSE in the same way as arable- only rotations.
. Any mechanism would need to be carefully designed so as to function given the UK’s role in the world food economy. Leakage and rebound effects might reduce the mitigation achieved, and increases in global food prices might compromise a land-sparing strategy by creating an incentive to farm, rather than spare, land 19,20 . Integrating our approach with models linking the global agricultural economy, landuse and the changing climate 21 would enable a broader assessment of land sparing in the context of global markets, emissions and food security. Economic considerations will also inform the most appropriate use of spared land. Natural regeneration represents a low-cost option, so any incremental mitigation benefits from managed forestry or bioenergy should be balanced against the additional management costs under these options. Similarly, displacing fossil fuels using bioenergy might not be the best overall strategy: if the UK energy sector could reduce emissions by 80% using other clean energy sources (thereby limiting the mitigation achievable using bioenergy), using spared land to grow forests rather than bioenergy crops would result in greater overall mitigation.