Direct Land Use Change Research Articles

Modelling greenhouse gas emissions of land use and land-use change using spatially explicit land conversion data for French crops

PurposeGreenhouse gas (GHG) emissions from land use and land-use change (LULUC) are major contributors to the climate change impact of agricultural products. The widely used method recommended by PAS 2050 when the previous land use is unknown has several limitations. The aim of this study was to develop a method to estimate GHG emissions from both direct land-use change (LUC) and land management changes (LMC), to be implemented in the French agricultural and food life cycle inventory database Agribalyse.MethodsThe proposed method uses 50 m × 50 m spatially explicit land conversion data at the departmental scale with a shared-responsibility approach and regionalised carbon (C) stocks, in line with recent advances in LULUC accounting. It also includes GHG emissions associated with changes in hedgerow area and CO2 removals by the soil and biomass. We calculated reference values for five agricultural land-use categories (field crops and temporary grassland, vegetables and flowers, permanent grassland, vineyards, and orchards) in 94 departments of metropolitan France and mean national results for 26 agricultural products. Total net GHG emissions from LULUC at the national scale were calculated for the aggregate land-use category cropland per previous land-use category: cropland, grassland, forest, settlement, hedgerow, and others.Results and discussionTotal net GHG emissions of LULUC from cropland in France in 2020 were equivalent to those estimated by the French National Emissions Inventory Agency, with a large contribution from grassland conversions, followed by forest and hedgerow conversions. Large CO2 removals by the soil were also estimated, associated mainly with LMC. GHG emissions per hectare varied widely among land-use categories and departments, ranging from − 2570 to 4969 kg CO2-eq∙ha−1∙year−1. For products assessed at the national scale, including LMC GHG emissions decreased total net GHG emissions per kilogramme without LULUC by 8–46%, while including LUC GHG emissions increased the latter by 4–68% (except for baled grass from permanent grassland in the north-western lowlands, which decreased from net GHG emissions to net GHG removals).Conclusions and recommendationsWhen data at the farm scale are not available, we recommend using the results of this method, which are in line with IPCC guidelines, instead of those of PAS 2050. For other studies that assess LULUC, we recommend (i) using spatially explicit land conversion data, (ii) using regionalised C stocks, (iii) including changes in hedgerow area, and (iv) including CO2 removals by the soil, especially those associated with LMC and establishment of permanent grassland.

Supplying the ethanol demand for 2030 in Brazil as a land-based climate change mitigation alternative: Implications on greenhouse gases emissions

Transitioning from a fossil-based to a bio-based economy is crucial to climate action and achieving neutrality in greenhouse gas (GHG) emissions. Biofuel production is an essential land-based GHG mitigation alternative. However, it raises concerns about biodiversity conservation, competition with food production, and net GHG emissions associated with direct land-use change (dLUC). This study aims to assess how the location and conversion routes influence GHG emissions for sugarcane expansion in Brazil to supply ethanol demand projections for 2030. A consistent and significant reduction in GHG emissions is achievable by implementing a strategy that prioritizes the spatial distribution for ethanol biorefinery expansions based on georeferenced life cycle emissions, including dLUC emissions associated with sugarcane production. Because of conservative zoning for sugarcane expansion, dLUC emissions are not an overriding factor, representing less than 9.1 % of the total GHG mitigation potential. Despite that, accounting for georeferenced dLUC emissions when prioritizing expansion facilities leads to spatial differences. Regarding conversion routes and land requirements, using cellulosic biorefineries could meet future projected demand based on sugarcane production from 3.1 million hectares, mostly in currently degraded pastureland. Conventional refineries would require 5.5 million hectares to meet the same demand of 71 billion liters. Despite the 77 % higher land demand to produce the same volume of ethanol, conventional refineries with straw recovery could be considered if electricity generation is a priority. This study illustrates how Brazil can achieve GHG mitigation targets while attending to future energy demand and protecting areas with high biodiversity.

How methods to assess land-use changes influence the resulting global warming potential and cost of optimized diets: a case study on Danish pigs applying life cycle assessment methodology

PurposeMeeting the demands of a growing and increasingly affluent population necessitates a deeper understanding of the environmental and economic implications of production. This implication is most relevant in key production sectors including agriculture and livestock. This article is intended to provide an understanding of the influence of methods of assessing land-use change (LUC) with respect to minimizing both the global warming potential (GWP) and the monetary costs of pig feed formulation.MethodsFeed mixtures intended for slaughter pigs were generated for minimal cost and GWP impacts by applying four differing LUC assessment methods. The objective function was the Danish slaughter pig feed unit, minimized for cost in Danish crowns (DKK), with GWP impacts constrained in multiple steps. Attributional LCA methodology was applied using the Agri-footprint 6.3 database, with GWP impacts calculated excluding land use changes, including direct land-use changes and including the carbon opportunity cost. Analyses of the functional relationship between the optimal cost and the GWP impact were conducted, followed by a comparative LCA of the cost of comparable feed mixture by applying two sets of functional units: 100 slaughter pig feed units and 1 kg of pig live weight.Results and discussionA similar relationship between cost and GWP impact was observed across all methods, although variability of GWP impact magnitude depending on method was observed. Reducing at an equivalent cost, GWP reduction ranged from 5.6 to 27% based on the pig feed functional unit, and 2.4 to 13% based on the pig live weight functional unit. Optimizing feed mixtures for GWP impacts resulted in significantly increased contributions to other impact categories, including a 56% increase in terrestrial ecotoxicity. Despite the increased contributions to other impact categories, all optimized feed mixtures achieved a reduction in endpoint indicators and single score. Endpoint reductions to the feed unit were 2.3–25% for ecosystem damage, 7.4–15% for human health, and 6.0–16% based on a single score value.ConclusionsThe findings emphasize the key importance of addressing LUC when optimizing the GWP of agri-food production. Suggestions are provided for areas of improvement in future optimization studies applying a dietary unit as the objective function, including additional midpoint impact categories and/or extended optimization covering whole areas of protection. The findings suggest that GWP impacts may be reduced at no additional cost if included or embedded in the pig feed formulation procedure.

Spatially-explicit land use change emissions and carbon payback times of biofuels under the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) requires airlines to offset their greenhouse gas (GHG) emissions above 2019 levels by either buying carbon offsets or using Sustainable Aviation Fuels (SAFs). These are drop-in jet fuels made from biomass or other renewable resources that reduce GHG emissions by at least 10 % compared to kerosene and meet certain sustainability criteria. This study assesses the direct land use change (DLUC) emissions of SAF, i.e., GHG emissions from on-site land conversion from previous uses (excluding primary forests, peatlands, wetlands, and protected and biodiversity-rich areas) into alternative feedstocks, considering spatial variability in global yields and land carbon stocks. The results provide DLUC values and carbon payback times at 0.5-degree resolution for six SAF pathways, with and without irrigation and a medium-input intensity, according to CORSIA sustainability criteria. When excluding CORSIA non-compliant areas, soybean SAF shows the highest mean DLUC factor (31.9 ± 20.7 gCO2/MJ), followed by reed canary grass and maize. Jatropha SAF shows the lowest mean DLUC factor (3.6 ± 31.4 gCO2/MJ), followed by miscanthus and switchgrass. The latter feedstocks show potential for reducing GHG emissions over large areas but with relatively greater variability. Country-average DLUC values are higher than accepted ILUC ones for all pathways except for maize. To ensure the GHG benefits of CORSIA, feedstocks must be produced in areas where not only carbon stocks are relatively low but also where attainable yields are sufficiently high. The results help identify locations where the combination of these two factors may be favourable for low-DLUC SAF production. Irrigated miscanthus offers the highest SAF production potential (2.75 EJ globally) if grown on CORSIA-compliant cropland and grassland areas, accounting for ∼1/5 of the total kerosene used in 2019. Quantifying other environmental impacts of SAFs is desirable to understand sustainability trade-offs and financial constraints that may further limit production potentials.

<i>Corrigendum to</i>: Environmental impacts of the Australian poultry industry. 1. Chicken meat production

<sec> Context Steadily increasing consumption of chicken meat (Australia’s most consumed meat protein) has resulted in expanded production. With societal expectations that industries improve sustainability, understanding baseline impacts is vital. </sec> <sec> Aims This study determined carbon footprint (kg CO<sub>2</sub>-e), fossil energy (MJ), fresh water consumption (L), stress (LH<sub>2</sub>O-e) and scarcity (m<sup>3</sup>), and land-occupation (m<sup>2</sup>) impacts for conventional (C) and free-range (FR) production systems, identified hotspots and the implications of changes in production over the past decade, to establish targets for future improvement. </sec> <sec> Methods In the largest study of its kind, attributional life-cycle assessment with data collected for ∼50% of birds processed was used, reporting impacts per kilogram of the typical market mix of chicken products, and boneless chicken. Uncertainty was assessed through Monte Carlo analysis, and results are presented as the means and standard deviation. </sec> <sec> Key results Slightly lower impacts per kilogram of chicken meat product were observed for C production (2.1±0.03kgCO<sub>2</sub>-e, 18.0±0.3MJ, 178.6±22.4L, and 10.2±0.1m<sup>2</sup>) than for FR (2.2±0.03kgCO<sub>2</sub>-e, 18.5±0.3MJ, 189.6±24.6L, and 10.6±0.1m<sup>2</sup>). Feed production was the major hotspot, followed by grow-out and meat processing. Land use (LU) and direct land use-change (dLUC) impacts associated with imported soymeal added 1.7±0.3 and 1.8±0.3kgCO<sub>2</sub>-e to C and FR respectively. FR carbon footprint and land occupation were significantly (<i>P</i><0.05) higher. Since 2010, fossil energy, arable land, and greenhouse-gas emissions have declined. One countertrend was LU and dLUC emissions, which increased due to changed soy imports, resulting in a slightly higher C carbon footprint. </sec> <sec> Conclusions Multi-indicator analysis is fundamental to understanding, communicating, and improving performance, and distinguishing between short-term fluctuations and long-term trends. Since 2010, feed-production impacts have increased (due to imported soymeal in poultry diets), indicating that alternative feed protein sources are a priority. Efficiency improvements reduced per-kilogram impacts across other indicators, demonstrating a positive trend in producing more food from fewer inputs. </sec> <sec> Implications Australian chicken meat is a low-impact animal protein. Future improvements require alternative feed proteins, technology adoption and practice change to maintain or reduce impacts as production expands alongside consumer demand. </sec>

Net greenhouse-gas emissions and reduction opportunities in the Western Australian beef industry

Context The Western Australian (WA) Government has set ambitious emission reduction targets and is developing strategies to reduce emissions across the state economy, including agriculture. Aims This study determined the product carbon footprint (CF) and total emissions of the WA beef industry, to establish a baseline for emission reduction planning. Methods A cradle-to-gate attributional life-cycle assessment with a reconciled livestock inventory of herd numbers and turnoff, was used. Emission reduction strategies were examined and included herd management, enteric-methane mitigation, and removals via carbon sequestration in vegetation and soils. Key results Modelled livestock numbers were found to be 36% higher than reported in the Australian Bureau of Statistics (ABS), resulting in an emission profile of 4.7 million tonnes (Mt) of carbon dioxide equivalent (CO2-e) (excluding land use (LU) and direct LU change (dLUC)). This profile was 26% higher than emissions reported in state inventories. LU and dLUC were estimated to be a greenhouse-gas removal of −2.6 Mt CO2-e, although with high uncertainty. The mean CF for WA was 15.3 kg CO2-e per kg liveweight (LW) (excluding LU and dLUC). State-wide removals from LU and dLUC were estimated to be −8.5 kg CO2-e/kg LW. The CF was 11.7, 19.2 and 18.2 kg CO2-e/kg LW for the Agricultural, Kimberley and Arid regions respectively. The implementation of herd-management strategies and anti-methanogenic supplements resulted in a maximum 25% reduction. Conclusions Herd productivity and market specifications were key drivers of regional differences in CF. Opportunities exist to reduce the CF in northern herds through diverting cattle to Australian backgrounding and feedlot supply chains to reach slaughter weight at a younger age. Adoption of anti-methanogenic feed supplements were important; however, achieving major reductions in the next decade will rely on removals via carbon sequestration in soil and vegetation. Implications Considering the magnitude of removals and elevated uncertainty in this result, further research and new datasets are needed to refine this analysis. New datasets are required to accurately report livestock numbers and track and reduce future GHG emissions from this higher baseline. Technical, cost and adoption barriers will need to be addressed by developing actionable pathways to achieve emission reduction in the mid- to long term.

Towards a non-ambiguous view of the amortization period for quantifying direct land-use change in LCA

Towards a non-ambiguous view of the amortization period for quantifying direct land-use change in LCA

Uncertainty in life cycle greenhouse gas emissions of sustainable aviation fuels from vegetable oils

Sustainable aviation fuel (SAF) is one of the most promising short-to medium-term term options to mitigate greenhouse gas (GHG) emissions from aviation. Life cycle assessment (LCA) is commonly used to estimate GHG emissions from SAF in comparison to fossil kerosene. While there are several studies reporting the GHG emissions from SAF, uncertainty in the results is not always addressed in a comprehensive way.In this work, GHG emissions of hydroprocessed esters and fatty acids (HEFA) fuels derived from jatropha (Jatropha curcas), pennycress (Thlaspi arvense), castor (Ricinus communis), energy tobacco (Nicotiana tabacum, Solaris) and Salicornia (Salicornia bigelovii) oils were estimated. A stochastic methodology was employed where parametric uncertainty was propagated using Monte Carlo simulations. Uncertainty due to methodological choices was incorporated through scenario analyses. Emissions from direct land use change (DLUC) and the associated uncertainty were assessed under the IPCC Tier 1 approach by considering alternative land use transitions per feedstock.Analyzed HEFA pathways provide GHG emissions benefits (34–65%) in comparison to fossil kerosene when DLUC emissions are not considered. Parametric uncertainty yields up to 26% deviation from the median well-to-wake GHG emissions. Changing the allocation choice for the oil extraction step, from the base assumption of energy-based allocation to mass- or market-based, can impact the results by up to 46%. DLUC is a more significant source of uncertainty than both parametric uncertainty and allocation assumptions in the analysis. DLUC emissions negate any GHG savings from HEFA fuels if forests or natural shrublands are lost.

Land-use change CO2 emissions associated with agricultural products at municipal level in Brazil

Land-use change (LUC) accounted for approximately 66% of CO2 emissions in Brazil in 2020, with significant implications for carbon footprint of Brazilian agricultural products. Accurate LUC estimates associated with agriculture are critical to carbon footprint (CF) and life cycle assessment (LCA) studies and derived measures towards low-carbon supply chains. The aim of the study was to provide direct LUC (dLUC) estimates of CO2 emissions associated with a comprehensive set of agricultural products in Brazil at municipal-level and based on spatially-explicit land conversion data, appropriate for CF and LCA studies. The effect of different dLUC modeling choices on the results are also presented. The modeling followed IPCC guidelines and improved the BRLUC method. MapBiomas spatially-explicit data, municipality-level statistics, regionalized carbon stocks and a shared responsibility approach were combined to obtain dLUC emission rates for 64 crops, plus forestry and planted pastures, in the 5,570 Brazilian municipalities, as well as at state and national levels. It will be open access at www.embrapa.br. The most recent version led to an estimated 911 Mtons of CO2 associated with agriculture in 2019, 81% of that associated with planted pastures. National level dLUC emission rates for corn, pastures, soybean and sugarcane were estimated as 2.0, 4.1, 2.3 and 0.3 tCO2.ha−1.yr−1, respectively. The dLUC emissions are highly heterogeneous across the country and land uses, ranging from positive to negative. In general, they were higher in the Amazon biome, due to deforestation, and lower in Eastern Brazil, where agricultural areas are more consolidated. The resulting data is more consistent with dLUC rationale, IPCC guidelines and PAS2050 when previous land use is known and is recommended to be used, whenever data at farm level are not available. The study also shows the strong effect of different dLUC modeling choices on results and reinforces recommendations for further mitigation options.

Environmental impacts of the Australian poultry industry. 1. Chicken meat production

Context Steadily increasing consumption of chicken meat (Australia’s most consumed meat protein) has resulted in expanded production. With societal expectations that industries improve sustainability, understanding baseline impacts is vital. Aims This study determined carbon footprint (kg CO2-e), fossil energy (MJ), fresh water consumption (L), stress (L H2O-e) and scarcity (m3), and land-occupation (m2) impacts for conventional (C) and free-range (FR) production systems, identified hotspots and the implications of changes in production over the past decade, to establish targets for future improvement. Methods In the largest study of its kind, attributional life-cycle assessment with data collected for ~50% of birds processed was used, reporting impacts per kilogram of the typical market mix of chicken products, and boneless chicken. Uncertainty was assessed through Monte Carlo analysis, and results are presented as the means and standard deviation. Key results Slightly lower impacts per kilogram of chicken meat product were observed for C production (2.1 ± 0.03 kg CO2-e, 18.0 ± 0.3 MJ, 178.6 ± 22.4 L, and 10.2 ± 0.1 m2) than for FR (2.2 ± 0.03 kg CO2-e, 18.5 ± 0.3 MJ, 189.6 ± 24.6 L, and 10.6 ± 0.1 m2). Feed production was the major hotspot, followed by grow-out and meat processing. Land use (LU) and direct land use-change (dLUC) impacts associated with imported soymeal added 1.7 ± 0.3 and 1.8 ± 0.3 kg CO2-e to C and FR respectively. FR carbon footprint and land occupation were significantly (P < 0.05) higher. Since 2010, fossil energy, arable land, and greenhouse-gas emissions have declined. One countertrend was LU and dLUC emissions, which increased due to changed soy imports, resulting in a slightly higher C carbon footprint. Conclusions Multi-indicator analysis is fundamental to understanding, communicating, and improving performance, and distinguishing between short-term fluctuations and long-term trends. Since 2010, feed-production impacts have increased (due to imported soymeal in poultry diets), indicating that alternative feed protein sources are a priority. Efficiency improvements reduced per-kilogram impacts across other indicators, demonstrating a positive trend in producing more food from fewer inputs. Implications Australian chicken meat is a low-impact animal protein. Future improvements require alternative feed proteins, technology adoption and practice change to maintain or reduce impacts as production expands alongside consumer demand.

Beyond the myths about Indonesia’s deforestation: linking oil palm cultivation to forest degradation and sustainable development goals

Oil palm cultivation is under scrutiny by various stakeholders, arguing that it is the main cause for Indonesia’s deforestation. This paper highlights the decades of forest degradation before the first land clearing for oil palm within the context of Indonesia’s development policies. Using ‘direct photointerpretation’ of ‘Historical Imagery’, it assesses the forest degradation and deforestation caused by oil palm cultivation in Indonesia, particularly in light of the UN Sustainable Development Goals (SDGs). Forest degradation has direct trade-offs with most of the SDGs, with the most affected SDGs being Responsible Consumption and Production (SDG12) and Life on Land (SDG15). Historical satellite imagery indicates that the first land clearing for the 176 Kha of oil palm estates sampled palm occurred around 1994. In contrast, only half of this area contained (natural) forests in 1984- a decade before the first land clearing. None of the remaining forests were (near) intact natural forests; all were (heavily) degraded and their biodiversity was strongly compromised. This indicates that oil palm cultivation is not linked to the degradation of Indonesia’s natural forests. Regarding SDG12, we found significant positive impacts from both the direct and indirect land-use changes by oil palm. For SDG15, we observed major positive impacts from the direct land-use changes and minor positive impacts from the indirect land-use changes. Hence, we conclude that oil palm cultivation in the sampled estates has positive impacts on Indonesia’s SDGs and Indonesia’s development policies align with its SDGs.

Land use leverage points to reduce GHG emissions in U.S. agricultural supply chains

Recognizing the substantial threats climate change poses to agricultural supply chains, companies around the world are committing to reducing greenhouse gas (GHG) emissions. Recent modeling advances have increased the transparency of meat and ethanol industry supply chains, where conventional production practices and associated environmental impacts have been characterized and linked to downstream points of demand. Yet, to date, information and efforts have neglected both the spatial variability of production impacts and land use changes (LUCs) across highly heterogeneous agricultural landscapes. Developing effective mitigation programs and policies requires understanding these spatially-explicit hotspots for targeting GHG mitigation efforts and the links to downstream supply chain actors. Here we integrate, for the first time, spatial estimates of county-scale production practices and observations of direct LUC into company and industry-specific supply chains of beef, pork, chicken, ethanol, soy oil and wheat flour in the U.S., thereby conceptually changing our understanding of the sources, magnitudes and influencers of agricultural GHG emissions. We find that accounting for LUC can increase estimated feedstock emissions per unit of production by a factor of 2- to 5-times that of traditionally used estimates. Substantial variation across companies, sectors, and production regions reveal key opportunities to improve GHG footprints by reducing land conversion within their supply chains.

Biodiversity Impacts of Increased Ethanol Production in Brazil

Growing domestic and international ethanol demand is expected to result in increased sugarcane cultivation in Brazil. Sugarcane expansion currently results in land-use changes mainly in the Cerrado and Atlantic Forest biomes, two severely threatened biodiversity hotspots. This study quantifies potential biodiversity impacts of increased ethanol demand in Brazil in a spatially explicit manner. We project changes in potential total, threatened, endemic, and range-restricted mammals’ species richness up to 2030. Decreased potential species richness due to increased ethanol demand in 2030 was projected for about 19,000 km2 in the Cerrado, 17,000 km2 in the Atlantic Forest, and 7000 km2 in the Pantanal. In the Cerrado and Atlantic Forest, the biodiversity impacts of sugarcane expansion were mainly due to direct land-use change; in the Pantanal, they were largely due to indirect land-use change. The biodiversity impact of increased ethanol demand was projected to be smaller than the impact of other drivers of land-use change. This study provides a first indication of biodiversity impacts related to increased ethanol production in Brazil, which is useful for policy makers and ethanol producers aiming to mitigate impacts. Future research should assess the impact of potential mitigation options, such as nature protection, agroforestry, or agricultural intensification.

Inter-Crops-Allocation (ICA) of CO2 Emissions from Land Use Change

The quantification of CO2 emissions from indirect land use change (ILUC) is proposed by some stakeholders for the inclusion in carbon footprints (CF) of biofuels. The ILUC concept does not appropriately consider so far that each ILUC of a biofuel is direct land use change (DLUC) of another product. This leads to either double counting or free-rider incentives. The articles purpose is to introduce and test inter-crops-allocation (ICA); this new approach allocates CO2 emissions from natural ecosystem conversion between all agricultural activities responsible for the land use change - be it directly or indirectly.

Archetypical pathways of direct and indirect land-use change caused by Cambodia’s economic land concessions

In the global South, a rush of large-scale land acquisitions (LSLAs) is occurring by governments and transnational and domestic investors seeking to secure access to land in developing countries to produce food, biofuels, and other agricultural commodities. Complex interactions between regional and global market dynamics and local institutional, socioeconomic, and agro-ecological conditions can lead to widely varying causal processes, land-use change (LUC), and socioeconomic and environmental outcomes. Systematic understanding of how characteristics of LSLAs across multiple social and environmental contexts produce spillover effects on local communities, ranging from employment opportunities to displacement and indirect land-use change (iLUC), is lacking. We conceptualize agricultural commodity production and land-acquisition processes associated with LSLAs as catalyzing causal pathways of direct and indirect land-use changes. Using the case of economic land concessions (ELCs) in Cambodia, we employed a novel synthesis research approach combining remote sensing, spatio-temporal statistics, and case study meta-analysis to construct archetypical pathways of the causes, timing, and consequences of ELC-driven land change. Archetypical pathways generally diverged based on specialized or flex commodity crops and rates of direct LUC, and rapid rates of direct LUC tended to cause displacement and iLUC. In contrast, ELCs producing commodity crops associated with more gradual land-use change and/or organized local resistance lead to less iLUC. Systematic knowledge generated through synthesis of local causes and consequences of LSLA-driven land change is now possible and needed to better address the direct and indirect consequences of LSLAs for commodity crop production.

Life cycle assessment of Jatropha curcas biodiesel production: a case study in Mexico

The potential of liquid biofuels (like bioethanol and biodiesel) to reduce greenhouse gas (GHG) emissions from the transportation sector has generated a great deal of interest in the last few years, with particular attention being given to Jatropha methyl ester (JME). Jatropha curcas (Jc)—a species native to Mexico—shows some promise as a source of oil for biodiesel. A few studies on biodiesel production from Jc have been conducted in Mexico, but just one study involved a life cycle assessment (LCA) of JME. At the international level, most studies dealing with Jc focus on the biodiesel industrial process, while in this paper we also look in detail at the agricultural production phase. This case study provides preliminary results on GHG emissions and energy balances of JME production in Mexico, applying the LCA methodology recommended by the European Renewable Energy Directive (RED). Four production systems (JME 1–4) were studied, resulting in GHG mitigation of between 41 and 53% with regards to diesel if no direct land-use change (dLUC) change occurs. However, when accounting for GHG emissions arising from direct land-use change (dLUC), total emissions increase from 40 to 508 kg CO2e/GJ. The differences between dLUC on tropical dry forest and dLUC on grassland are of lesser importance than those between systems with and without dLUC. Using JME from plantations on lands, previously not cultivated, leads to GHG emissions three or six times higher than using fossil diesel. These results are an approximation to the environmental and energetic impacts of JME production in Mexico. Further studies should be performed before implementing more plantations to produce biofuel from J. curcas.

Land use change implications for large-scale cultivation of algae feedstocks in the United States Gulf Coast

Algae is considered a promising future feedstock for biofuels. Although several studies have been conducted to assess the environmental impact of algae-based fuels, land use change is one area that is commonly overlooked in previous life cycle assessment studies. However, land use change can impact the life cycle greenhouse gas (GHG) emissions of algal biofuels when large tracts of land are converted to algal raceway cultivation systems. This study assesses the impacts of land use change through a variety of means. The Intergovernmental Panel on Climate Change (IPCC) Tier 1 methodology was utilized to assess potential emissions resulting from the conversion of potential algae facility sites in the U.S. Gulf Coast, consisting of grassland, cropland, and forestland in several management conditions. These emission values over a 20-year time horizon were combined with guidance on promising sites for algae raceway development to provide an estimate of industry-wide GHG emissions impacts due to direct land use change (LUC). Direct LUC impacts appear to be important, with average GHG emissions of between 4 and 8 g CO2eq/MJ for grassland and cropland conversion, which is roughly 6.3% and 12.5% of the total GHG emission over the entire algae renewable diesel life cycle without considering the LUC. Emissions due to direct LUC could be even larger if previously forested lands are cleared, averaging 24.7 g CO2eq/MJ across a range of potential algae sites. This article details the methods, assumptions and initial LCA results for these land use change scenarios when considering the algae biofuels life cycle. Results from this LCA can help decision-makers recognize the importance of facility siting in overall environmental performance, and select locations of algae cultivation facilities to minimize direct LUC emissions.

A geographical assessment of vegetation carbon stocks and greenhouse gas emissions on potential microalgae-based biofuel facilities in the United States

The microalgae biofuels life cycle assessments (LCA) present in the literature have excluded the effects of direct land use change (DLUC) from facility construction under the assumption that DLUC effects are negligible. This study seeks to model the greenhouse gas (GHG) emissions of microalgae biofuels including DLUC by quantifying the CO2 equivalence of carbon released to the atmosphere through the construction of microalgae facilities. The locations and types of biomass and Soil Organic Carbon that are disturbed through microalgae cultivation facility construction are quantified using geographical models of microalgae productivity potential including consideration of land availability. The results of this study demonstrate that previous LCA of microalgae to biofuel processes have overestimated GHG benefits of microalgae-based biofuels production by failing to include the effect of DLUC. Previous estimations of microalgae biofuel production potential have correspondingly overestimated the volume of biofuels that can be produced in compliance with U.S. environmental goals.

Resource use and greenhouse gas emissions from grain-finishing beef cattle in seven Australian feedlots: a life cycle assessment

Grain finishing of cattle has become increasingly common in Australia over the past 30 years. However, interest in the associated environmental impacts and resource use is increasing and requires detailed analysis. In this study we conducted a life cycle assessment (LCA) to investigate impacts of the grain-finishing stage for cattle in seven feedlots in eastern Australia, with a particular focus on the feedlot stage, including the impacts from producing the ration, feedlot operations, transport, and livestock emissions while cattle are in the feedlot (gate-to-gate). The functional unit was 1 kg of liveweight gain (LWG) for the feedlot stage and results are included for the full supply chain (cradle-to-gate), reported per kilogram of liveweight (LW) at the point of slaughter. Three classes of cattle produced for different markets were studied: short-fed domestic market (55–80 days on feed), mid-fed export (108–164 days on feed) and long-fed export (>300 days on feed). In the feedlot stage, mean fresh water consumption was found to vary from 171.9 to 672.6 L/kg LWG and mean stress-weighted water use ranged from 100.9 to 193.2 water stress index eq. L/kg LWG. Irrigation contributed 57–91% of total fresh water consumption with differences mainly related to the availability of irrigation water near the feedlot and the use of irrigated feed inputs in rations. Mean fossil energy demand ranged from 16.5 to 34.2 MJ lower heating values/kg LWG and arable land occupation from 18.7 to 40.5 m2/kg LWG in the feedlot stage. Mean greenhouse gas (GHG) emissions in the feedlot stage ranged from 4.6 to 9.5 kg CO2-e/kg LWG (excluding land use and direct land-use change emissions). Emissions were dominated by enteric methane and contributions from the production, transport and milling of feed inputs. Linear regression analysis showed that the feed conversion ratio was able to explain >86% of the variation in GHG intensity and energy demand. The feedlot stage contributed between 26% and 44% of total slaughter weight for the classes of cattle fed, whereas the contribution of this phase to resource use varied from 4% to 96% showing impacts from the finishing phase varied considerably, compared with the breeding and backgrounding. GHG emissions and total land occupation per kilogram of LWG during the grain finishing phase were lower than emissions from breeding and backgrounding, resulting in lower life-time emissions for grain-finished cattle compared with grass finishing.

Current approaches neglect possible agricultural cutback under large-scale organic farming. A comment to Ponisio et al.

Agricultural productivity is the key to global food security. Modern conventional farming has substantially increased food production, but at the expense of serious environmental harm [[1][1]]. By contrast, organic production is regarded as a suitable and more sustainable alternative owing to its