scholarly journals Towards Comparable Carbon Credits: Harmonization of LCA Models of Cellulosic Biofuels

2021 ◽  
Vol 13 (18) ◽  
pp. 10371
Author(s):  
Nariê Rinke Dias de Souza ◽  
Bruno Colling Klein ◽  
Mateus Ferreira Chagas ◽  
Otavio Cavalett ◽  
Antonio Bonomi

Decarbonization programs are being proposed worldwide to reduce greenhouse gas (GHG) emissions from transportation fuels, using Life Cycle Assessment (LCA) models or tools. Although such models are broadly accepted, varying results are often observed. This study describes similarities and differences of key decarbonization programs and their GHG calculators and compares established LCA models for assessing 2G ethanol from lignocellulosic feedstock. The selected LCA models were GHGenius, GREET, JRC’s model, and VSB, which originated calculators for British Columbia’s Low Carbon Fuel Standard, California’s Low Carbon Fuel Standard, Renewable Energy Directive, and RenovaBio, respectively. We performed a harmonization of the selected models by inserting data of one model into other ones to illustrate the possibility of obtaining similar results after a few harmonization steps and to determine which parameters have higher contribution to closing the gap between default results. Differences among 2G ethanol from wheat straw were limited to 0.1 gCO2eq. MJ−1, and discrepancies in emissions decreased by 95% and 78% for corn stover and forest residues, respectively. Better understanding of structure, calculation procedures, parameters, and methodological assumptions among the LCA models is a first step towards an improved harmonization that will allow a globally accepted and exchangeable carbon credit system to be created.

Author(s):  
Michael Somers ◽  
Liaw Batan ◽  
Baha Al-Alawi ◽  
Thomas H. Bradley

Abstract The transportation sector accounts for over 20 percent of greenhouse gas (GHG) emissions in Colorado which without intervention will grow to over 30 million metric tons (MMT) of GHG emissions per year. This study seeks to develop a specific characterization of the Colorado fuel and transportation system using a customized life cycle assessment (LCA) model. The model (CO-GT) was developed as an analytical tool to define Colorado’s 2020 baseline life cycle GHG emissions for the transportation sector, and to examine Colorado-specific pathways for GHG reductions through fuel types and volumes changes that might be associated with a state clean fuel standard (CFS). By developing a life cycle assessment of transportation fuels that is specific to the state of Colorado’s geography, fleet makeup, policies, energy sector and more, these tools can evaluate various proposals for the transition towards a more sustainable state transportation system. The results of this study include a quantification of the Colorado-specific roles of clean fuels, electricity, extant policies, and fleet transition in projections of the state’s 2030 transportation sector GHG emissions. Relative to a 2020 baseline, electrification of the vehicle fleet is found to reduce state-wide lifecycle GHG emissions by 7.7 MMT CO2e by 2030, and a model CFS policy able to achieve similar reductions in the carbon intensity of clean fuels as was achieved by California in the first 10 years of its CFS policies is found to only reduce state-wide lifecycle GHG emissions by 0.2 MMT CO2e by 2030. These results illustrate the insensitivity of Colorado’s transportation fleet GHG emissions reductions to the presence of CFS policies, as proposed to date.


Author(s):  
Matthew A. Oehlschlaeger ◽  
Haowei Wang ◽  
Mitra N. Sexton

Biofuels have the potential to be sustainable, secure, low carbon footprint transportation fuels. Primarily due to government mandates, biofuels have become increasingly adopted as transportation fuels over the last decade and are projected to steadily increase in production. Here the prospects of biofuels are summarized in terms of several important performance measures, including: lifecycle greenhouse gas (GHG) emissions, energy return on investment (EROI), land and water requirements, and tailpipe emissions. A review of the literature leads to the conclusion that most first-generation biofuels, including corn ethanol and soybean biodiesel produced in the United States, reduce tailpipe pollutant emissions and GHG emissions—provided their feedstocks do not replace large quantities of fixed carbon. However, their production is perhaps unsustainable due to low EROI and significant land-use and water requirements. Second-generation biofuels; for example ethanol produced from lignocellulosic biomass, have the potential for larger reductions in GHG emissions and can provide sustainable EROI with reasonable land area usage; however, they require water inputs several orders-of-magnitude greater than required by petroleum fuels. Advanced biofuels from algal oils and synthetic biological processes are further from commercial reality and require more assessment but potentially offer better performance due to their orders-of-magnitude greater yields per land area and lower water requirements; at present, the energy costs of such biofuels are uncertain.


2014 ◽  
pp. 70-91 ◽  
Author(s):  
I. Bashmakov ◽  
A. Myshak

This paper investigates costs and benefits associated with low-carbon economic development pathways realization to the mid XXI century. 30 scenarios covering practically all “visions of the future” were developed by several research groups based on scenario assumptions agreed upon in advance. It is shown that with a very high probability Russian energy-related GHG emissions will reach the peak before 2050, which will be at least 11% below the 1990 emission level. The height of the peak depends on portfolio of GHG emissions mitigation measures. Efforts to keep 2050 GHG emissions 25-30% below the 1990 level bring no GDP losses. GDP impact of deep GHG emission reduction - by 50% of the 1990 level - varies from plus 4% to minus 9%. Finally, very deep GHG emission reduction - by 80% - may bring GDP losses of over 10%.


2021 ◽  
Vol 13 (4) ◽  
pp. 2418
Author(s):  
Ana María Arbeláez Vélez ◽  
Andrius Plepys

Shared mobility options, such as car sharing, are often claimed to be more sustainable, although evidence at an individual or city level may contradict these claims. This study aims to improve understanding of the effects of car sharing on transport-related emissions at an individual and city level. This is done by quantifying the greenhouse gas (GHG) emissions of the travel habits of individuals before and after engaging with car sharing. The analysis uses a well-to-wheel (WTW) approach, including both business-to-consumer (B2C) and peer-to-peer (P2P) car-sharing fleets. Changes in GHG emissions after engaging in car sharing vary among individuals. Transport-related GHG emissions caused by car-free individuals tend to increase after they engage in car sharing, while emissions caused by previous car owners tend to fall. At the city level, GHG emissions savings can be achieved by using more efficient cars in sharing systems and by implementing greener mobility policies. Changes in travel habits might help to reduce GHG emissions, providing individuals migrate to low-carbon transport modes. The findings can be used to support the development and implementation of transport policies that deter car ownership and support shared mobility solutions that are integrated in city transport systems.


2021 ◽  
Vol 292 ◽  
pp. 116878
Author(s):  
Simon H. Roberts ◽  
Barney D. Foran ◽  
Colin J. Axon ◽  
Alice V. Stamp

2021 ◽  
Vol 13 (4) ◽  
pp. 1851
Author(s):  
Alexis Poulhès ◽  
Angèle Brachet

Mid-sized cities are usually considered in the literature to be shrinking cities. Some policies promote right-sizing and others promote revitalization. The relationship between land-use planning and mobility having been established, the present research issue is focused on whether a policy of revitalizing the centers of mid-sized cities is favorable to low-carbon mobility. Our study investigates commuting trips through two indicators: commuting trip distance and car modal share. The increase in total population, the increase in the number of jobs per resident, the decrease in the unemployment rate, the increase in the rate of executives, the increase in the rate of working people in the population and the decrease in the residential vacancy rate all come from the censuses of 2006 and 2016. Statistical models based on individuals in 113 mid-sized cities, in which sociodemographic variables are introduced, show that at the level of agglomerations, no indicator has a simultaneously positive effect in the center and in the urban periphery. No indicator is entirely positive or negative on GHG emissions from commuting trips. While the increase in GHG emissions from commuting trips between 2006 and 2016 is significant in mid-sized cities (18%), a shift toward shrinking city centers is insufficient to change this trajectory.


Author(s):  
Dandan Liu ◽  
Dewei Yang ◽  
Anmin Huang

China has grown into the world’s largest tourist source market and its huge tourism activities and resulting greenhouse gas (GHG) emissions are particularly becoming a concern in the context of global climate warming. To depict the trajectory of carbon emissions, a long-range energy alternatives planning system (LEAP)-Tourist model, consisting of two scenarios and four sub-scenarios, was established for observing and predicting tourism greenhouse gas peaks in China from 2017 to 2040. The results indicate that GHG emissions will peak at 1048.01 million-ton CO2 equivalent (Mt CO2e) in 2033 under the integrated (INT) scenario. Compared with the business as usual (BAU) scenario, INT will save energy by 24.21% in 2040 and reduce energy intensity from 0.4979 tons of CO2 equivalent/104 yuan (TCO2e/104 yuan) to 0.3761 Tce/104 yuan. Although the INT scenario has achieved promising effects of energy saving and carbon reduction, the peak year 2033 in the tourist industry is still later than China’s expected peak year of 2030. This is due to the growth potential and moderate carbon control measures in the tourist industry. Thus, in order to keep the tourist industry in synchronization with China’s peak goals, more stringent measures are needed, e.g., the promotion of clean fuel shuttle buses, the encouragement of low carbon tours, the cancelation of disposable toiletries and the recycling of garbage resources. The results of this simulation study will help set GHG emission peak targets in the tourist industry and formulate a low carbon roadmap to guide carbon reduction actions in the field of GHG emissions with greater certainty.


2021 ◽  
Author(s):  
Deepthi Swamy ◽  
Apurba Mitra ◽  
Varun Agarwal ◽  
Megan Mahajan ◽  
Robbie Orvis

India is currently the world’s third-largest emitter of greenhouse gases (GHGs) after China and the United States and is set to experience continued growth in its population, economy, and energy consumption. Exploring low-carbon development pathways for India is therefore crucial for achieving the goal of global decarbonization. India has pledged to reduce the emission intensity of its gross domestic product (GDP) by 33–35 per cent relative to 2005 levels by 2030 through its Nationally Determined Contribution (NDC), among other related targets for the renewable energy and forestry sectors. Further, countries, including India, are expected to respond to the invitation of the Conference of the Parties (COP) to the Paris Agreement to communicate new or updated NDCs with enhanced ambition and long-term low-GHG development strategies for 2050. To design effective policy packages to support the planning and achievement of such climate targets, policymakers need to identify policies that can reduce GHG emissions in a timely and cost-effective manner, while meeting development-related and other national objectives. The India Energy Policy Simulator (India EPS), an open-source, system dynamics model, can enable an integrated quantitative assessment of different cross-sectoral climate policy packages for India through 2050 and their implications for key variables of interest such as emissions, GDP, and jobs. The tool was developed by Energy Innovation LLC and adapted for India in partnership with World Resources Institute. It is available for open access through a Web interface as well as a downloadable application. This technical note describes the structure, input data sources, assumptions, and limitations of the India EPS, as well as the setup and key results of its reference scenario, referred to as the business-as-usual (BAU) scenario in the model. It is intended as an update to the first technical note on the India EPS (Mangan et al. 2019) and accounts for the changes incorporated into the model since the first version.


2017 ◽  
Vol 30 (1) ◽  
pp. 191-214 ◽  
Author(s):  
Meryl Jagarnath ◽  
Tirusha Thambiran

Because current emissions accounting approaches focus on an entire city, cities are often considered to be large emitters of greenhouse gas (GHG) emissions, with no attention to the variation within them. This makes it more difficult to identify climate change mitigation strategies that can simultaneously reduce emissions and address place-specific development challenges. In response to this gap, a bottom-up emissions inventory study was undertaken to identify high emission zones and development goals for the Durban metropolitan area (eThekwini Municipality). The study is the first attempt at creating a spatially disaggregated emissions inventory for key sectors in Durban. The results indicate that particular groups and economic activities are responsible for more emissions, and socio-spatial development and emission inequalities are found both within the city and within the high emission zone. This is valuable information for the municipality in tailoring mitigation efforts to reduce emissions and address development gaps for low-carbon spatial planning whilst contributing to objectives for social justice.


2017 ◽  
Vol 9 (5) ◽  
pp. 107
Author(s):  
Seied Mohsen Taghavi ◽  
Teodoro C. Mendoza ◽  
Bart Acero Jr ◽  
Tao Li ◽  
Sameer Ali Siddiq ◽  
...  

Breeding of rice varieties with low carbon dioxide equivalent (CO2e) emission is essential in reducing global greenhouse gas (GHG) emissions. In this study, we compared the gross CO2e emission of two newly developed green super rice (GSR) varieties with elite hybrids and nationally released farmer-cultivated varieties from production to post-production in the dry and wet seasons in Laguna, Philippines. The average gross CO2e emission was 17.9 tons CO2e ha-1 or 2.98 tons CO2e ton-1 rice (production 82%, post-production 18%). Contributing to this total were soil emissions at 72%, the use of chemicals at 5%, burning of rice straw at 3%, cooking at 12%, and transportation at 5%. The average social cost of carbon (SCC) per ton of rice was estimated at $119. Increasing grain yield per unit area with shorter growth duration decreased CO2e emission of rice per unit of weight. Cultivation of rice varieties GSR8 and GSR2 emitted 37.0% lower CO2e than the popular inbred varieties.


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