Time and cost characterisation of emissions from non-road diesel equipment for infrastructure projects

The construction process contributes to pollutant emissions, particularly through the operation of diesel- and gasoline-powered equipment. In the past decade, a series of investigations were undertaken to quantify these emissions for a variety of non-road construction equipment performing different activities and undergoing different duty cycles, and a model to estimate quantities of six types of pollutant was developed. This paper uses that model to estimate emissions for four street and utility construction projects which no one has done previously. We combined information from company records with standard construction industry manuals to estimate total emissions for the projects and to examine the pollution patterns and magnitudes. The street construction projects all had similar emission profiles with a large peak at the beginning and a steady output of emissions throughout the duration of the project. For example, in two of the projects studied, half of all CO₂ emissions were produced before the projects were 40% completed. Results showed that demolition and earthwork are the activities with the largest contribution. The equipment types with the largest contribution are backhoes, front-end loaders, bulldozers and trenchers. Trenchers, for example, produced 30% of all emissions on the projects on which they were used.     

A laboratory study on CO2 emission from asphalt binder and its reduction with the use of warm mix asphalt

Oxidation of hydrocarbon in asphalt binder leads to the production of carbon dioxide (CO₂) during the production of hot mix asphalt. The objective of this laboratory study was to investigate the effects of the asphalt additive Sasobit^®, asphalt content and mixing/placement temperature on CO₂ emissions from binder with laboratory measurements. The isolated effects of Sasobit on asphalt absorption into the aggregate were also looked at. Temperature was found to be the only statistically significant factor on emissions. This would suggest that warm mix asphalt technology, which employs the use of Sasobit in asphalt mixtures, is a very effective way of lowering the industry's CO₂ emission impact, both directly and by the use of less energy for heating. This work predicts that greater than 30% reduction of CO₂ emissions is possible with typically used levels of Sasobit.     

Energy Use and CO2 Production in Tropical Agriculture and Means and Strategies for Reduction or Mitigation

Carbon dioxide emissions due to fossil fuel consumption are well recognized as a major contributor to climate change. In the debate on dealing with this threat, expectations are high that agriculture based economies of the developing world can help alleviate this problem. But, the contribution of agricultural operations to these emissions is fairly small. It is the clearing of native ecosystems for agricultural use in the tropics that is the largest non-fossil fuel source of CO₂ input to the atmosphere. Our calculation show that the use of fossil energy and the concomitant emission of CO₂ in the agricultural operational sector - i.e. the use of farm machinery, irrigation, fertilization and chemical pesticides - amounts to merely 3.9% of the commercial energy use in that part of the world. Of this, 70% is associated with the production and use of chemical fertilizers. In the absence of fertilizer use, the developing world would have converted even more land for cultivation, most of which is completely unsuitable for cultivation. Current expectations are that reforestation in these countries can sequester large quantities of carbon in order to mitigate excessive emissions elsewhere. But, any program that aims to set aside land for the purpose of sequestering carbon must do so without threatening food security in the region. The sole option to liberate the necessary land for carbon sequestration would be the intensification of agricultural production on some of the better lands by increased fertilizer inputs. As our calculations show, the sequestration of carbon far outweighs the emissions that are associated with the production of the extra fertilizer needed. Increasing the fertilizer use in the developing world (without China) by 20%, we calculated an overall net benefit in the carbon budget of between 80 and 206 Mt yr^?1 dependent on the carbon sequestration rate assumed for the regrowing forest. In those regions, where current fertilizer use is low, the relative benefits are the highest as responding yield increases are highest and thus more land can be set aside without harming food security. In Sub-Saharan Africa a 20% fertilizer increase, which amounts to 0.14 Mt of extra fertilizer, can tie up somewhere between 8 and 19 Mt of CO₂ per year (average: 96 t CO₂ per 1 t fertilizer). In the Near East and North Africa with a 20%-increased fertilizer use of 0.4 Mt yr^-1 between 10 and 24 Mt of CO₂ could be sequestered on the land set aside (40 t CO₂ per 1 t fertilizer). In South Asia this is 22–61 Mt CO₂ yr?1 with an annual additional input of 2.15 Mt fertilizer (19 t CO₂ per 1 t fertilizer). In fact, carbon credits may be the only way for some of the farmers in these regions to afford the costly inputs. Additionally, in regions with already relatively high fertilizer inputs such as in South Asia, an efficient use of the extra fertilizer must be warranted. Nevertheless, the net CO₂ benefit through implementation of this measure in the developing world is insignificant compared to the worldwide CO₂ output by human activity. Thus, reforestation is only one mitigating measure and not the solution to unconstrained fossil fuel CO₂ emissions. Carbon emissions should, therefore, first of all be reduced by the avoidance of deforestation in the developing world and moreover by higher energy efficiency and the use of alternative energy sources.     

Identifying and modeling key trade-offs between hydrogen fuel cell and electric vehicles

Through a sensitivity analysis, the trade-off between vehicle range and CO₂ emissions is investigated as a function of electric emissions coefficient. Various powertrains were analysed for use in a small crossover sport utility vehicle. Gasoline, gasoline electric hybrid, diesel, fuel cell and battery electric vehicles (BEVs) were considered. Using various upstream fuel pathways and a model for vehicle performance, emissions and energy use were estimated. The hydrogen fuel cell vehicle was found preferable to BEVs under conditions of high CO₂ emissions per kW-hr and a high vehicle range requirement. The BEV was preferable for all other conditions.     

Proposing of new building scheme and composite towards global warming mitigation for Malaysia

The building sector has been regarded as a potential sector where there is large capacity to reduce the climate change effect. This study has proposed solutions to mitigate environmental impacts and achieve low CO₂ emission from residential sector. Therefore, full life cycle assessment (LCA) has been run to assess the CO₂ emission and its effect on the atmosphere and climate change. Based on the result, timber scheme is the best choice due to releasing less CO₂ emissions to the atmosphere. However, house builders in Malaysia have almost completely neglected timber as a building material, with timber use as building components reduced to 5%. In this study, LCA Software was used to assess CO₂ emissions from different wall construction. The alternative building scheme has been made by reinforce steel stud, wooden beam and timber wall (S8) to improve the scheme deficiency while releasing less CO₂ emissions compared to other schemes. Therefore, S8 has a decreased CO₂ effect by 85% less than precast concrete frame and 90% less than brick over their lifetime. (S8) increased the load bearing compared to conventional timber beam. Thus, new scheme S8 could be replaced by current scheme and promote more adjustable scheme for Malaysian housing.     

Energy consumption and emission projection for the road transport sector in Malaysia: an application of the LEAP model

This study has attempted to estimate the energy consumption and emission of pollutants namely carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOC) from the road transport sector in Malaysia from the year 2012 till 2040. This was done using the long-range energy alternatives planning (LEAP) model. Estimates of energy consumption and emissions were evaluated and analysed under a business-as-usual scenario and three other alternative fuel policy scenarios of biodiesel vehicles (BIO), natural gas vehicles (NGV) and hybrid electric vehicles (HEV). The aim of this study has been to identify the potential alternative fuel policies that would be effective in reducing the future growth of road transport energy consumption and emission in Malaysia. Results indicate that the NGV scenario contributes towards the highest reduction in road transport energy consumption followed by BIO and HEV. The NGV scenario also achieves highest mitigation of emission of all the four pollutants. In the case of CO₂ emission, BIO scenario attains second highest mitigation, whereas in the event of CO, NOx and NMVOC emission, HEV scenario achieves second highest mitigation.     

Carbon dioxide emissions from cities in China based on high resolution emission gridded data

Based on the China high resolution emission gridded data (1 km spatial resolution), this article is aimed to create a Chinese city carbon dioxide (CO₂) emission data set using consolidated data sources as well as normalized and standardized data processing methods. Standard methods were used to calculate city CO₂ emissions, including scope 1 and scope 2. Cities with higher CO₂ emissions are mostly in north, northeast, and eastern coastal areas. Cities with lower CO₂ emissions are in the western region. Cites with higher CO₂ emissions are clustered in the Jing-Jin-Ji Region (such as Beijing, Tianjin, and Tangshan), and the Yangtze River Delta region (such as Shanghai and Suzhou). The city per capita CO₂ emission is larger in the north than the south. There are obvious aggregations of cities with high per capita CO₂ emission in the north. Four cities among the top 10 per capita emissions (Erdos, Wuhai, Shizuishan, and Yinchuan) cluster in the main coal production areas of northern China. This indicates the significant impact of coal resources endowment on city industry and CO₂ emissions. The majority (77%) of cities have annual CO₂ emissions below 50 million tons. The mean annual emission, among all cities, is 37 million tons. Emissions from service-based cities, which include the smallest number of cities, are the highest. Industrial cities are the largest category and the emission distribution from these cities is close to the normal distribution. Emissions and degree of dispersion, in the other cities (excluding industrial cities and service-based cities), are in the lowest level. Per capita CO₂ emissions in these cities are generally below 20 t/person (89%) with a mean value of 11 t/person. The distribution interval of per capita CO₂ emission within industrial cities is the largest among the three city categories. This indicates greater differences among per capita CO₂ emissions of industrial cities. The distribution interval of per capita CO₂ emission of other cities is the lowest, indicating smaller differences of per capita CO₂ emissions among this city category. Three policy suggestions are proposed: first, city CO₂ emission inventory data in China should be increased, especially for prefecture level cities. Second, city responsibility for emission reduction, and partitioning the national goal should be established, using a bottom-up approach based on specific CO₂ emission levels and potential for emission reductions in each city. Third, comparative and benchmarking research on city CO₂ emissions should be conducted, and a Top Runner system of city CO₂ emission reduction should be established.     

Variations of anthropogenic CO2 in urban area deduced by radiocarbon concentration in modern tree rings

Radiocarbon concentration in the atmosphere is significantly lower in areas where man-made emissions of carbon dioxide occur. This phenomenon is known as Suess effect, and is caused by the contamination of clean air with non-radioactive carbon from fossil fuel combustion. The effect is more strongly observed in industrial and densely populated urban areas. Measurements of carbon isotope concentrations in a study area can be compared to those from areas of clear air in order to estimate the amount of carbon dioxide emission from fossil fuel combustion by using a simple mathematical model. This can be calculated using the simple mathematical model. The result of the mathematical model followed in this study suggests that the use of annual rings of trees to obtain the secular variations of ¹⁴C concentration of atmospheric CO₂ can be useful and efficient for environmental monitoring and modeling of the carbon distribution in local scale.     

Dynamic Changes,Regional Differences,and Influencing Factors of CO2 Emission Performance in China

Abstract

This paper proposes to use DEA models with undesirable outputs to construct the Malmquist index that can be use to investigate the dynamic changes of CO₂ emission performance. With the index, the authors have measured the CO₂ emission performance of 28 provinces and autonomous regions in China from 1996 to 2007; with the convergence theory and panel data regression model, the authors analyze the regional differences and the influencing factors. It is found that the performance of CO₂ emissions in China has been continuously improved mainly due to the technological progress, and the average improvement rate is 3.25%, with a cumulative improvement rate of 40.86%. In addition, the CO₂ emission performance varies across four regions. As a whole, the performance score of eastern China is the highest. The northeastern and central China has relatively lower performance scores, and the western China is relatively backward. The regional differences are decreasing, and the performance of CO₂ emissions is convergent. The influence of some factors on the performance of CO₂ emissions is significant, such as the level of economic development, the level of industrial structure, energy intensity, and ownership structure. The influence of some factors, such as opening-up to the outside world, on the performance of CO₂ emissions is not significant.     

Movement towards a low carbon emitted environment: a test of some factors in Malaysia

There exists a high global concern in different nations on environmental sustainability especially at the focal stage of increased economic growth and development process due to high level of environmental degradation and pollution. The major aim of this study was to empirically examine how to minimise carbon emissions (CO₂) in Malaysia which are mainly caused by energy production, fossil fuel consumption, population density and economic growth. The study adopted the method of autoregressive distributed lag bound testing approach to analyse the data for the period 1971–2011. The study found that economic growth in Malaysia has a direct relationship with CO₂ emissions in both the short run and the long run. Similarly, there is a positive relationship between fossil fuel consumption and CO₂ emissions over the same period. Population density was found to have positive impacts on CO₂ emissions. Contrarily, the relationship between the activities of energy production and pollution is negative in the long run. The study recommends that a targeted GDP growth rate should be set with the consideration to avoid more environmental pollution. In addition, the positive impact of fossil fuel consumption on the environmental pollution implies that there is a need to make and implement policies that will encourage the use of public transportation system more than private transportations. That is, the unnecessary use of private vehicles should be discouraged in order to reduce the extent of fossil fuel consumption.     

Carbon‐neutral jet‐fuel re‐synthesised from sequestrated CO2

A chemical pathway combining reverse water gas shift, Fischer‐Tropsch synthesis and hydro‐cracking was considered to re‐synthesise jet fuel from CO₂ captured at high purity by oxy‐fuelling of a typical coal‐fired power station (Drax, UK). The oxygen for oxy‐fuelling and hydrogen for the fuel re‐synthesis process are sourced by electrolysis of water. According to material and energy balances , 3.1 MT/year of jet fuel and 1.6 MT/year each of gas oil and naphtha can be produced from the Drax annual emissions of 20 MT of CO₂, sufficient to supply 23% of the UK jet fuel requirements. The overall re‐synthesis requires 16.9 GW, to be sourced renewably from (offshore) wind power, and releases 4.4 GW of exothermic energy giving scope for improvements via process integration. The energy re‐synthesis penalty was 82% ideally and 95% on a practical basis. With the cost of offshore wind power predicted to reduce to 2.0 p/kWh by 2020, this ‘re‐syn’ jet fuel would be competitive with conventional jet fuel, especially if carbon taxes apply. The re‐use of CO₂ sequestrated from coal power stations to form jet‐fuel would halve the combined CO₂ emissions from the coal power and aviation sectors.     

Analysis of CO2 emissions peak: China’s objective and strategy

Establishing positive and urgent targets for CO₂ reduction and emission peak, and promoting energy conservation and energy structure adjustment are among the strategies to address global climate change and CO₂ emissions reduction. They are also means to break through the constraints of domestic resources and environment, and internal needs, to achieve sustainable development. Generally speaking, a country's CO₂ emission peak appears after achieving urbanization and industrialization. By then, connotative economic growth will appear, GDP will grow slowly, energy consumption elasticity will decrease, and energy consumption growth will slow down – dependent mainly on new and renewable energies. Fossil fuel consumption will not increase further. When CO₂ emission reaches its peak, the annual reduction rate of CO₂ intensity of GDP is greater than GDP annual growth rate; and the annual reduction rate of CO₂ intensity of energy use is greater than the annual growth rate of energy consumption. Therefore, three important approaches to promotion of CO₂ emission peak can be concluded: maintaining reasonable control of GDP growth, strengthening energy conservation to significantly reduce the GDP energy intensity, and optimizing the energy mix to reduce the CO₂ intensity of energy use. By around 2030, China will basically have completed its rapid development phase of industrialization and urbanization. Connotative economic growth will appear with the acceleration of industrial structure adjustment. The target of GDP energy intensity will still be to maintain an average annual reduction of 3% or higher. The proportion of non-fossil fuels will reach 20–25%, and the aim will be to maintain an average annual growth rate of 6–8%. The total annual energy demand growth of 1.5% will be satisfied by the newly increased supply of non-fossil fuels. The annual decline in CO₂ intensity of GDP will reach 4.5% or higher, which is compatible with an average annual GDP growth rate of approximately 4.5% in order to reach CO₂ emission peak. This corresponds to the level of China's potential economic growth. Achieving CO₂ emission peak will not impose a rigid constraint on economic development, but rather promote economic development and accelerate the transformation of green, low-carbon development. The CO₂ emission peak can be controlled with a cap of 11 billion tons, which means that CO₂ emission will increase by less than 50% compared with 2010. The per capita emission peak will be controlled at a level of less than 8 tons, which is lower than the 9.5 tons in the EU and Japan and much lower than the 20 tons in the US, future economic and social development faces many uncertainties in achieving the CO₂ emission peak discussed above. It depends on current and future strategies and policies, as well as the pace and strength of economic transformation, innovation, and new energy technologies. If the economic transformation pattern fails to meet expectations, the time required to reach CO₂ emission peak would be delayed and the peak level would be higher than expected. Therefore, we need to coordinate thoughts and ideas and deploy these in advance; to highlight the strategic position of low-carbon development and its priorities; to enact mid- to long-term energy development strategies; and to establish and improve a system of laws, regulations, and policies as well as an implementation mechanism for green, low-carbon development. Oriented by positive and urgent CO₂ reduction and peak targets, the government would form a reversed mechanism to promote economic transformation and embark on the path of green, low-carbon development as soon as possible.     

The in-use annual energy and carbon saving by switching from a car to an electric bicycle in an urban UK general medical practice: the implication for NHS commuters

The UK Climate Change Act (CCA) mandates an 80 % reduction in CO₂ emissions by 2050. It is estimated that 3.2 M tonnes pa CO₂ results from travel-related NHS business. The acquisition of an electric bicycle to replace a car for both commuting and home visits allowed comparison of fuel use and CO₂ emissions over a 4-year period. The switch to the use of the electric bicycle reduced the average annual petrol use by 329 l, the energy consumption by 3,140 kWh and the CO₂ released by 748 kg a year. Wider adoption of electric bicycles in urban General Practice will contribute to the requirements of the CCA though to have a significant effect on the current estimated commuting-related carbon footprint of the NHS (0.76 MT pa) would require two-thirds of the workforce to abandon their cars in favour of electric bicycles.     

Economic growth and CO<Subscript>2</Subscript> emissions

This article considers a planner’s optimum control exercise with environmental pollution and derives a testable link between the growth rates of consumption and pollution. The link is then empirically estimated for the case of CO₂ emissions for a sample consisting of the union of top 25 countries in terms of CO₂ emissions, population and per capita GNP. The analysis suggests that the interrelationship between the growth rates of CO₂ emission and economic development is mostly significant for countries that have a high level of CO₂ emissions and population.     

A subsystem input–output decomposition analysis of CO<Subscript>2</Subscript> emissions in the service sectors: a case study of Beijing,China

The carbon emissions in service sectors have attracted increasing attention around the world. However, few studies have examined the driving forces for CO₂ emissions from service sectors in developing countries. With the process of accelerating industrialization, China’s service sectors are facing growing pressure to pursue energy savings and emission reductions, especially in several developed regions. In this paper, in order to better understand how CO₂ emissions in Beijing’s service sectors have evolved, we utilized a subsystem input–output decomposition analysis to study the pattern and driving factors of consumption-based emissions in Beijing’s service sectors. The results showed that the transportation sector and the Scientific Studies Technical Services sector caused the most CO₂ emissions in Beijing’s service sectors. The emission intensity effect potentially reduced CO₂ emissions by 10,833 Mt, primarily due to the decreased energy intensity of non-service sectors. Effects of demand and technology were mainly responsible for the increased CO₂ emissions in Beijing’s service sectors. Such influence was mainly related to the external component of service sectors, indicating a strong pull effect exerted by service sectors on non-service sectors. Thus, decarbonizing the supply chain of service sectors and improving the energy intensity are necessary to alleviate CO₂ emissions in Beijing.     

Ecological tax reforms and environmental benefits in Italy and Sweden

The paper calculates the implications of including monetary measurements of environmental emission changes for the welfare impacts of ecological tax reforms in Italy and Sweden. Taxes on emissions of SO₂, NO_x and CO₂ are investigated. Country-specific computable equilibrium models are used for estimating net welfare changes of the introduction of these taxes, the incomes of which are used for reducing distorting labour taxes. The results indicate that the inclusion of environmental benefits reduces the costs of ecological tax reforms considerably for both countries, and may even turn into net welfare gains.     

CO2 emissions in German, Swedish and Colombian manufacturing industries

This study evaluates and compares the trends in CO₂ emissions for the manufacturing industries of three countries: two developed countries (Germany and Sweden) that have applied several measures to promote a shift towards a low-carbon economy and one developing country (Colombia) that has shown substantial improvements in the reduction of CO₂ emissions. This analysis is conducted using panel data cointegration techniques to infer causality between CO₂ emissions, production factors and energy sources. The results indicate a trend of producing more output with less pollution. The trends for these countries’ CO₂ emissions depend on investment levels, energy sources and economic factors. Furthermore, the trends in CO₂ emissions indicate that there are emission level differences between the two developed countries and the developing country. Moreover, the study confirms that it is possible to achieve economic growth and sustainable development while reducing greenhouse gas emissions, as Germany and Sweden demonstrate. In the case of Colombia, it is important to encourage a reduction in CO₂ emissions through policies that combine technical and economic instruments and incentivise the application of new technologies that promote clean and environmentally friendly processes.     

Addressing food supply chain and consumption inefficiencies: potential for climate change mitigation

Globally, more than 30 % of all food that is produced is ultimately lost and/or wasted through inefficiencies in the food supply chain. In the developed world this wastage is centred on the last stage in the supply chain; the end-consumer throwing away food that is purchased but not eaten. In contrast, in the developing world the bulk of lost food occurs in the early stages of the supply chain (production, harvesting and distribution). Excess food consumption is a similarly inefficient use of global agricultural production; with almost 1 billion people now classed as obese, 842 million people are suffering from chronic hunger. Given the magnitude of greenhouse gas emissions from the agricultural sector, strategies that reduce food loss and wastage, or address excess caloric consumption, have great potential as effective tools in global climate change mitigation. Here, we examine the challenges of robust quantification of food wastage and consumption inefficiencies, and their associated greenhouse gas emissions, along the supply chain. We find that the quality and quantity of data are highly variable within and between geographical regions, with the greatest range tending to be associated with developing nations. Estimation of production-phase GHG emissions for food wastage and excess consumption is found to be similarly challenging on a global scale, with use of IPCC default (Tier 1) emission factors for food production being required in many regions. Where robust food waste data and production-phase emission factors do exist—such as for the UK—we find that avoiding consumer-phase food waste can deliver significant up-stream reductions in GHG emissions from the agricultural sector. Eliminating consumer milk waste in the UK alone could mitigate up to 200 Gg CO₂e year^?1; scaled up globally, we estimate mitigation potential of over 25,000 Gg CO₂e year^?1.     

Energy, environment and growth nexus in South Asia

The present study investigates the energy, environment and growth nexus for a panel of South Asian countries including Bangladesh, India, Pakistan, Sri Lanka and Nepal. The simultaneous analysis of real GDP, energy consumption and CO₂ emissions is conducted for the period 1980–2010. Levin panel unit root test and Im test panel unit root both indicate that all the variables are I (1). In addition, Kao’s panel Cointegration test specifies a stable long-term relationship between all these variables. Empirical findings show that a 1 % increase in energy consumption increases output by 0.81 % in long run whereas for the same increase in CO₂ emission output falls by 0.17 % in long run. Panel Granger causality tests report short-run causality running from energy consumption to CO₂ emissions and from CO₂ emissions to GDP.     

Assessment of uncertainties in greenhouse gas emission profiles of livestock sectors in Africa,Latin America and Europe

The global animal food chain has a large contribution to the global anthropogenic greenhouse gas (GHG) emissions, but its share and sources vary highly across the world. However, the assessment of GHG emissions from livestock production is subject to various uncertainties, which have not yet been well quantified at large spatial scale. We assessed the uncertainties in the relations between animal production (milk, meat, egg) and the CO₂, CH₄, and N₂O emissions in Africa, Latin America and the European Union, using the MITERRA-Global model. The uncertainties in model inputs were derived from time series of statistical data, literature review or expert knowledge. These model inputs and parameters were further divided into nine groups based on type of data and affected greenhouse gas. The final model output uncertainty and the uncertainty contribution of each group of model inputs to the uncertainty were quantified using a Monte Carlo approach, taking into account their spatial and cross-correlation. GHG emissions and their uncertainties were determined per livestock sector, per product and per emission source category. Results show large variation in the GHG emissions and their uncertainties for different continents, livestock sectors products or source categories. The uncertainty of total GHG emissions from livestock sectors is higher in Africa and Latin America than in the European Union. The uncertainty of CH₄ emission is lower than that for N₂O and CO₂. Livestock parameters, CH₄ emission factors and N emission factors contribute most to the uncertainty in the total model output. The reliability of GHG emissions from livestock sectors is relatively high (low uncertainty) at continental level, but could be lower at country level.