scholarly journals When Biomass Electricity Demand Prompts Thinnings in Southern US Pine Plantations: A Forest Sector Greenhouse Gas Emissions Case Study

2021 ◽  
Vol 4 ◽  
Author(s):  
Thomas Buchholz ◽  
John S. Gunn ◽  
Benktesh Sharma

Increasing demand for woody biomass-derived electricity in the UK and elsewhere has resulted in a rapidly expanding wood pellet manufacturing industry in the southern US. Since this demand is driven by climate concerns and an objective to lower greenhouse gas (GHG) emissions from the electricity sector, it is crucial to understand the full carbon consequences of wood pellet sourcing, processing, and utilization. We performed a comparative carbon life cycle assessment (LCA) for pellets sourced from three mills in the southern US destined for electricity generation in the UK. The baseline assumptions included GHG emissions of the UK’s 2018 and 2025 target electricity grid mix and feedstock supplied primarily from non-industrial private forest (NIPF) pine plantations augmented with a fraction of sawmill residues. Based on regional expert input, we concluded that forest management practices on the NIPF pine plantations would include timely thinning harvest treatments in the presence of pellet demand. The LCA analysis included landscape carbon stock changes based on USDA Forest Service Forest Vegetation Simulator using current USDA Forest Service Forest Inventory and Analysis data as the starting condition of supply areas in Arkansas, Louisiana and Mississippi. We found that GHG emission parity (i.e., the time when accumulated carbon GHG emissions for the bioenergy scenario equal the baseline scenario) is more than 40 years for pellets produced at each individual pellet mill and for all three pellet mills combined when compared to either the UK’s 2018 electricity grid mix or the UK’s targeted electricity grid mix in 2025. The urgency to mitigate climate change with near-term actions as well as increasing uncertainty with longer-term simulations dictated a focus on the next four decades in the analysis. Even at 50% sawmill residues, GHG emission parity was not reached during the 40 years modeled. Results are most likely conservative since we assume a high share of sawmill residues (ranging from 20 to 50%) and did not include limited hardwood feedstocks as reported in the supply chain which are generally associated with delayed GHG emission parity because of lower growth rates.

2014 ◽  
Vol 11 (8) ◽  
pp. 2287-2294 ◽  
Author(s):  
Z. L. Cui ◽  
L. Wu ◽  
Y. L. Ye ◽  
W. Q. Ma ◽  
X. P. Chen ◽  
...  

Abstract. Although the concept of producing higher yields with reduced greenhouse gas (GHG) emissions is a goal that attracts increasing public and scientific attention, the trade-off between high yields and GHG emissions in intensive agricultural production is not well understood. Here, we hypothesize that there exists a mechanistic relationship between wheat grain yield and GHG emission, and that could be transformed into better agronomic management. A total 33 sites of on-farm experiments were investigated to evaluate the relationship between grain yield and GHG emissions using two systems (conventional practice, CP; high-yielding systems, HY) of intensive winter wheat (Triticum aestivum L.) in China. Furthermore, we discussed the potential to produce higher yields with lower GHG emissions based on a survey of 2938 farmers. Compared to the CP system, grain yield was 39% (2352 kg ha−1) higher in the HY system, while GHG emissions increased by only 10%, and GHG emission intensity was reduced by 21%. The current intensive winter wheat system with farmers' practice had a median yield and maximum GHG emission rate of 6050 kg ha−1 and 4783 kg CO2 eq ha−1, respectively; however, this system can be transformed to maintain yields while reducing GHG emissions by 26% (6077 kg ha−1, and 3555 kg CO2 eq ha−1). Further, the HY system was found to increase grain yield by 39% with a simultaneous reduction in GHG emissions by 18% (8429 kg ha−1, and 3905 kg CO2 eq ha−1, respectively). In the future, we suggest moving the trade-off relationships and calculations from grain yield and GHG emissions to new measures of productivity and environmental protection using innovative management technologies.


2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Erick P. Massami ◽  
Benitha M. Myamba

The Greenhouse Gas (GHG) emissions due to transport operations have drastically increased in recent years. The sea transport in particular contributes 2.7 to 3 percent of CO2, a major component of GHG emissions globally. Numerous measures have been undertaken locally and internationally to alleviate the sea transport share of Greenhouse Gases. However, most of these measures will be fruitful if ship investors (e.g., ship owners and operators) would fully employ the GHG emission reduction strategies. Due to the scarcity of the statistical data in this respect, this study therefore presents a rough set synthetic assessment (RSSA) model to GHG emission abatement strategies in the Tanzanian shipping sector. The results of the assessment reveal that the Tanzanian shipping companies engaged in Cabotage trade are aware of the abatement strategies and moderately apply them.


2020 ◽  
Author(s):  
Carolyn-Monika Görres ◽  
Claudia Kammann

<p>Arthropods are a major soil fauna group, and have the potential to substantially influence the spatial and temporal variability of soil greenhouse gas (GHG) sinks and sources. The overall effect of soil-inhabiting arthropods on soil GHG fluxes still remains poorly quantified since the majority of the available data comes from laboratory experiments, is often controversial, and has been limited to a few species. The main objective of this study was to provide first insights into field-level carbon dioxide (CO<sub>2</sub>), methane (CH<sub>4</sub>) and nitrous oxide (N<sub>2</sub>O) emissions of soil-inhabiting larvae of the Scarabaeidae family. Larvae of the genus <em>Melolontha</em> were excavated at various grassland and forest sites in west-central and southern Germany, covering a wide range of different larval developmental stages, and larval activity levels. Excavated larvae were immediately incubated in the field to measure their GHG emissions. Gaseous carbon emissions of individual larvae showed a large inter- and intra-site variability which was strongly correlated to larval biomass. This correlation persisted when upscaling CO<sub>2</sub> and CH<sub>4 </sub>emissions to the plot scale. Field emission estimates for <em>Melolontha</em> spp. were subsequently upscaled to the European level to derive the first regional GHG emission estimates for members of the Scarabaeidae family. Estimates ranged between 10.42 and 409.53 kt CO<sub>2</sub> yr<sup>-1</sup>, and 0.01 and 1.36 kt CH<sub>4</sub> yr<sup>-1</sup>. Larval N<sub>2</sub>O emissions were only sporadically observed and not upscaled. For one site, a comparison of field- and laboratory-based GHG emission measurements was conducted to assess potential biases introduced by transferring Scarabaeidae larvae to artificial environments. Emission strength and variability of captive larvae decreased significantly within two weeks and the correlation between larval biomass and gaseous carbon emissions disappeared, highlighting the importance of field measurements. Overall, our data show that Scarabaeidae larvae can be significant soil GHG sources and should not be neglected in soil GHG flux research.</p>


2015 ◽  
Vol 24 (4) ◽  
Author(s):  
Jelena Ariva ◽  
Ants Hannes Viira ◽  
Reet Põldaru ◽  
Jüri Roots

In order to respond to increasing global food demand and provide for national economic growth, the Estonian Dairy Strategy for 2012−2020 aims to achieve a 30% growth in milk production. At the same time, there is a global attempt to reduce greenhouse gas (GHG) emissions. This paper analyses the medium-term (2015−2020) projections for milk production and associated GHG emissions from dairy cows in Estonia. The FAPRI-GOLD type market model of Estonian agriculture, which is used for projections of agricultural production, was supplemented with a module that helps project GHG emissions. The paper demonstrates the endogenisation of GHG emission factors in a relatively general agricultural market model context. The results imply that increasing milk production by 30% by 2020 would jeopardise Estonia’s commitments with regard to agricultural GHG emissions. However, the average GHG emission per tonne of produced milk will decline, thus reducing the “carbon footprint” of milk production.


2020 ◽  
Author(s):  
Tao Hu ◽  
Xianqiang Mao ◽  
Xuedu Lu ◽  
Gloria P. Gerilla-Teknomo

Local air pollutants (LAPs), such as carbon monoxide, hydrocarbon, sulfur oxide, nitrogen oxide, ozone, and particulate matter, as well as greenhouse gas (GHG) emissions from the transport sector are rapidly increasing in the People’s Republic of China. Various measures to control LAPs have been implemented in the country, along with the adoption of strategies to mitigate GHG emissions. The connection between LAP and GHG emission control and reduction offers an opportunity to address both problems simultaneously. This paper presents a methodology that measures the benefits of co-control evaluation on mitigating LAP and GHG emissions. It highlights the methodology’s potential to help maximize measures and strategies that have significant co-control effects.


Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 689 ◽  
Author(s):  
She ◽  
Chung ◽  
Han

Harvesting mountain pine beetle-infested forest stands in the northern Colorado Rocky Mountains provides an opportunity to utilize otherwise wasted resources, generate net revenues, and minimize greenhouse gas (GHG) emissions. Timber and bioenergy production are commonly managed separately, and their integration is seldom considered. Yet, degraded wood and logging residues can provide a feedstock for bioenergy, while the sound wood from beetle-killed stands can still be used for traditional timber products. In addition, beneficial greenhouse gas emission (GHG) savings are often realized only by compromising net revenues during salvage harvest where beetle-killed wood has a relatively low market value and high harvesting cost. In this study we compared Sequential and Integrated decision-making scenarios for managing the supply chain from beetle-killed forest salvage operations. In the Sequential scenario, timber and bioenergy production was managed sequentially in two separate processes, where salvage harvest was conducted without considering influences on or from bioenergy production. Biomass availability was assessed next as an outcome from timber production managed to produce bioenergy products. In the Integrated scenario, timber and bioenergy production were managed jointly, where collective decisions were made regarding tree salvage harvest, residue treatment, and bioenergy product selection and production. We applied a multi-objective optimization approach to integrate the economic and environmental objectives of producing timber and bioenergy, and measured results by total net revenues and total net GHG emission savings, respectively. The optimization model results show that distinctively different decisions are made in selecting the harvesting system and residue treatment under the two scenarios. When the optimization is fully economic-oriented, 49.6% more forest areas are harvested under the Integrated scenario than the Sequential scenario, generating 12.3% more net revenues and 50.5% more net GHG emission savings. Comparison of modelled Pareto fronts also indicate the Integrated decision scenario provides more efficient trade-offs between the two objectives and performs better than the Sequential scenario in both objectives.


2020 ◽  
Vol 6 (1) ◽  
pp. 103-112
Author(s):  
Wenjing Wei ◽  
Peter B. Samuelsson ◽  
Anders Tilliander ◽  
Rutger Gyllenram ◽  
Pär G. Jönsson

AbstractMolybdenum is mainly used as an alloy material in the iron and steel industry and typically in the form of ferromolybdenum (FeMo). The current study aims to evaluate the energy consumption and greenhouse gas emissions (GHG) of four ferromolybdenum production cases using inventory inputs from a process model based on mass and energy conservations. The total energy required for producing 1 tonne of FeMo can vary between 29.1 GJ/t FeMo and 188.6 GJ/t FeMo. Furthermore, the corresponding GHG emissions differ from 3.16 tCO2-eq/t FeMo to 14.79 tCO2-eq/t FeMo. The main variances are from the mining and beneficiation stages. The differences in these stages come from the beneficiation degree (ore grade) and the mine type (i.e., co-product from copper mining). Furthermore, the mine type has a larger impact on the total energy consumption and GHG emissions than the beneficiation degree. More specifically, FeMo produced as co-product from copper mining has a lower environmental impact measured as the energy consumption and GHG emission among all the four cases. The inventory, consumed energy or associated GHG emission is independent on the initial ore grade and mine type in the downstream production stages such as roasting and smelting. Also, transport has the least impact on the energy consumption and GHG emission among all production stages.


2020 ◽  
Vol 12 (19) ◽  
pp. 8214
Author(s):  
Toshiro Semba ◽  
Yuji Sakai ◽  
Miku Ishikawa ◽  
Atsushi Inaba

According to the Ellen MacArthur Foundation, 73% of used clothing is landfilled or incinerated globally and greenhouse gas (GHG) emissions from fabric manufacturing in 2015 amounted to 1.2 billion tons. It must be reduced in the future, especially by reusing and recycling used clothing. Based on this perspective, researchers calculated the energy consumption and GHG emissions associated with reusing and recycling used clothing globally with a life cycle assessment (LCA). However, no study was conducted so far to estimate the total GHG emission reductions in Japan by reusing and recycling used clothing. In this study, the amount of used clothing currently discharged from households as combustible and noncombustible waste and their fiber types were estimated using literature. Then, the methods for reusing and recycling of used clothing were categorized into the following 5 types based on fiber type, that is, “reuse overseas,” “textile recycling to wipers,” “fiber recycling,” “chemical recycling” and “thermal recycling.” After that, by applying LCA, the GHG emission reductions by above 5 methods were estimated, based on the annual discharged weights of each fiber type. Consequently, the total GHG emissions reductions by reusing and recycling 6.03 × 108 kg of used clothing totally were estimated around 6.60 × 109 kg CO2e, to range between 6.57 × 109 kg CO2e and 6.64 × 109 kg CO2e, which depended on the type of “chemical recycling.” The largest contribution was “reuse overseas,” which was 4.01 × 109 kg CO2e corresponded to approximately 60% of the total reduction. Where, it was assumed that used clothing were exported from Japan to Malaysia which was currently the largest importing country. In this case, GHG emissions to manufacture new clothing in China, the largest country currently to export them to Japan, can be avoided, which are 29.4 kg CO2e and 32.5 kg CO2e respectively for 1 kg jeans and 1 kg T-shirts. Adding the GHG emissions for overseas transportation to this, on average, 32.0 kg CO2e per kg of used clothing was reduced by “reuse overseas,” which was 19.6 times larger than GHG emissions by incineration, 1.63 kg CO2e per kg, in which carbon neutrality for cotton was not counted. As the result, the total GHG emission reductions above mentioned, around 6.60 × 109 kg CO2e, corresponds to 70% of the GHG emissions by incineration of total household garbage in Japan.


2016 ◽  
Vol 847 ◽  
pp. 321-327
Author(s):  
Yan Cui Cao ◽  
Feng Gao ◽  
Zhi Hong Wang ◽  
Xian Zheng Gong ◽  
Xiao Qing Li

Magnesium is a promising lightweight and green metallic engineering material, but the environmental impact of primary magnesium production stage, especially greenhouse gas (GHG) emissions cannot be ignored. In this study, the life cycle energy consumption and GHG emissions caused by the production of primary magnesium in the years of 2003-2013 in China were calculated; the factor decomposition was conducted to analyze the GHG emissions of magnesium production process by using logarithmic mean Divisia index method (LMDI), including energy GHG emission factors, energy structure, energy consumption per ton of primary magnesium, production, emissions per unit of dolomite and ferrosilicon, and dolomite and ferrosilicon consumptions per ton of primary magnesium. The results showed that GHG emissions of primary magnesium production increased 260.29*104 t CO2eq in total from 2003 to 2013. The variety magnesium production contributed the biggest part of GHG emissions, accounting for 418.17%. The energy structure took second place on the contribution of GHG emissions, accounting for-161.49%. The nest part was energy consumption per ton of primary magnesium, accounting for-138.97%. While, the contribution of energy GHG emission factors, emissions per unit of dolomite and ferrosilicon, and dolomite and ferrosilicon consumptions per ton of primary magnesium was relatively small, which were 0.88%, 0.00% -2.72% -4.73% and-11.13%, respectively. Thus, it is the key methods to reduce GHG emissions by optimizing the energy structure and decreasing the energy consumption.


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