How information and communication technology drives carbon emissions: A sector-level analysis for China

Understanding the carbon implications of information and communication technology (ICT) is critical for tackling climate change challenges in the digital era. This paper develops an embodied carbon analysis framework by integrating input-output approaches to explore the extent to which and how ICT drives carbon emissions at the sector level. With the proposed framework, we not only assess the carbon emissions embodied in various ICT subsectors but also reveal the formation and changing mechanism by identifying their source sectors, transfer paths, and economic drivers. Using China as a case study, we find that ICT sector is far from being environment-friendly while considering its embodied carbon impacts, which are dozens of times greater than the direct impacts. This is because ICT sector can induce significant amounts of emissions through its requirement for carbon-intensive intermediate inputs from non-ICT sectors. The electricity sector and basic material sectors (e.g. chemicals, metal, and non-metal) are the most important carbon sources, and are involved in major carbon transfer paths. The fast growth of embodied emissions in ICT sector is driven by the large-scale expansion of final demand for ICT products, although improvements in upstream production efficiency have largely slowed the growth. We suggest that integrated carbon management strategies incorporating mitigation measures for specific sectors, supply chains, and economic drivers are particularly required for addressing ICT-related carbon emission issues.     

Effects of a carbon price in the U.S. on economic sectors,resource use,and emissions: An input–output approach

Despite differences in their implementation, most carbon policies aim to have similar outcomes: effectively raising the price of carbon-intensive products relative to non-carbon-intensive products. While it is possible to predict the simple broad-scale economic impacts of raising the price of carbon-intensive products—the demand for non-carbon-intensive products will increase—understanding the economic and environmental impacts of carbon policies throughout the life cycle of both types of products is more difficult. Using the example of a carbon tax, this study proposes a methodology that integrates short-term policy-induced consumer demand changes into the input–output framework to analyze the environmental and economic repercussions of a policy. Environmental repercussions include the direct and the indirect impacts on emissions, materials flow in the economy, and the reliance on various ecosystem goods and services. The approach combines economic data with data about physical flow of fossil fuels between sectors, consumption of natural resources and emissions from each sector. It applies several input–output modeling equations sequentially and uses various levels of aggregation/disaggregation. It is illustrated with the data for the 2002 U.S. economy and physical flows. The framework provides insight into the short-term complex interactions between carbon price and its economic and environmental effects.     

Carbon curse in developed countries

Among the ten countries with the highest carbon intensity, six are natural resource-rich countries. This suggests the existence of a carbon curse: resource-rich countries would tend to follow more carbon-intensive development paths than resource-poor countries. We investigate this assumption empirically using a panel data method covering 29 countries (OECD and BRIC) and seven sectors over the 1995–2009 period. First, at the macroeconomic level, we find that the relationship between national CO₂ emissions per unit of GDP and abundance in natural resources is U-shaped. The carbon curse appears only after the turning point. Second, we measure the impact of resource abundance on sectoral emissions for two groups of countries based on their resource endowments. We show that a country rich in natural resources pollutes relatively more in resource-related sectors as well as all other sectors. Our results suggest that the debate on climate change mitigation should rather focus on a comparison of resource-rich countries versus resource-poor countries than the developed-country versus developing-country debate.     

Allowance allocation matters in China's carbon emissions trading system

China's national carbon emissions trading system (ETS) initially started by covering the power generation sector with a rate-based allocation of emission allowances. This single-sector ETS scheme is a tradable performance standard and loosens the participants' emission abatement effort. Given the stringent emission reduction targets implied by China's Nationally Determined Contributions (NDCs) and the expectation that ETS will cover more sectors in the future, we simulate a national ETS of ten carbon-intensive sectors with mass-based, output-based allocation (OBA) of emission allowances. We uncover the impacts and mechanisms of this ETS by comparing the sectoral abatement behaviors across policy scenarios with varying allocation schemes and numbers of benchmarks. We evaluate if the simulated ETS meets important efficiency principles and exhibits desired features. The results show that this ETS achieves China's NDCs with modest macroeconomic losses. The mass-based OBA leads to evenly distributed emission reduction efforts for all ETS participating sectors. It also limits the emission trading volumes and results in slight to modest impacts on sectoral output, especially for the upstream sectors. OBA with fewer benchmarks enhances emission abatement efforts with the caveats of relatively cleaner participants being subsidized by the ETS and slightly higher impacts on the macroeconomy.     

Indicators for industrial energy efficiency in India

India accounts for 4.5% of industrial energy use worldwide. This share is projected to increase as the economy expands rapidly. The level of industrial energy efficiency in India varies widely. Certain sectors, such as cement, are relatively efficient, while others, such as pulp and paper, are relatively inefficient. Future energy efficiency efforts should focus on direct reduced iron, pulp and paper and small-scale cement kilns because the potentials for improvement are important in both percentage and absolute terms. Under business as usual, industrial energy use is projected to rise faster than total final energy use. A strong focus on energy efficiency can reduce this growth, but CO₂ emissions will still rise substantially. If more substantial CO₂ emissions reductions are to be achieved then energy efficiency will need to be combined with measures that reduce the carbon intensity of the industrial fuel mix.     

CO2 emissions structure of Indian economy

This paper analyses carbon dioxide (CO₂) emissions of the Indian economy by producing sectors and due to household final consumption. The analysis is based on an Input–Output (IO) table and Social Accounting Matrix (SAM) for the year 2003–04 that distinguishes 25 sectors and 10 household classes. Total emissions of the Indian economy in 2003–04 are estimated to be 1217 million tons (MT) of CO₂, of which 57% is due to the use of coal and lignite. The per capita emissions turn out to be about 1.14 tons. The highest direct emissions are due to electricity sector followed by manufacturing, steel and road transportation. Final demands for construction and manufacturing sectors account for the highest emissions considering both direct and indirect emissions as the outputs from almost all the energy-intensive sectors go into the production process of these two sectors. In terms of life style differences across income classes, the urban top 10% accounts for emissions of 3416 kg per year while rural bottom 10% class accounts for only 141 kg per year. The CO₂ emission embodied in the consumption basket of top 10% of the population in urban India is one-sixth of the per capita emission generated in the US.     

Analyses of CO2 emissions embodied in Japan–China trade

This paper examines CO₂ emissions embodied in Japan–China trade. Besides directly quantifying the flow of CO₂ emissions between the two countries by using a traditional input–output (IO) model, this study also estimates the effect of bilateral trade to CO₂ emissions by scenario analysis. The time series of quantifications indicate that CO₂ emissions embodied in exported goods from Japan to China increased overall from 1990 to 2000. The exported CO₂ emissions from China to Japan greatly increased in the first half of the 1990s. However, by 2000, the amount of emissions had reduced from 1995 levels. Regardless, there was a net export of CO₂ emissions from China to Japan during 1990–2000. The scenario comparison shows that the bilateral trade has helped the reduction of CO₂ emissions. On average, the Chinese economy was confirmed to be much more carbon-intensive than Japan. The regression analysis shows a significant but not perfect correlation between the carbon intensities at the sector level of the two countries. In terms of CO₂ emission reduction opportunities, most sectors of Chinese industry could benefit from learning Japanese technologies that produce lower carbon intensities.     

Grey relation performance correlations among economics,energy use and carbon dioxide emission in Taiwan

This study explores the inter-relationships among economy, energy and CO₂ emissions of 37 industrial sectors in Taiwan in order to provide insight regarding sustainable development policy making. Grey relation analysis was used to analyse the productivity, aggregate energy consumption, and the use of fuel mix (electricity, coal, oil and gas) in relation to CO₂ emission changes. An innovative evaluative index system was devised to explore grey relation grades among economics, energy and environmental quality. Results indicate that a rapid increase in electricity generation during the past 10 years is the main reason for CO₂ emission increase in Taiwan. The largest CO₂ emitting sectors include iron and steel, transportation, petrochemical materials, commerce and other services. Therefore, it is important to reduce the energy intensity of these sectors by energy conservation, efficiency improvement and adjustment of industrial structure towards high value-added products and services. Economic growth for all industries has a more significant influence, than does total energy consumption, on CO₂ emission increase in Taiwan. It is also important to decouple the energy consumption and production to reduce the impacts of CO₂ on economic growth. Furthermore, most of the sectors examined had increased CO₂ emissions, except for machinery and road transportation. For high energy intensive and CO₂ intensive industries, governmental policies for CO₂ mitigation should be directed towards low carbon fuels as well as towards enhancement of the demand side management mechanism, without loss of the nation's competitiveness.     

The effect of carbon tax on per capita CO2 emissions

As the most efficient market-based mitigation instrument, carbon tax is highly recommended by economists and international organizations. Countries like Denmark, Finland, Sweden, Netherlands and Norway were the first adopters of carbon tax and as such, research on the impacts and problems of carbon tax implementation in these countries will provide great practical significance as well as caution for countries that are to levy the tax. Different from the existing studies that adopt the model simulation approaches, in this article, we comprehensively estimate the real mitigation effects of the five north European countries by employing the method of difference-in-difference (DID). The results indicate that carbon tax in Finland imposes a significant and negative impact on the growth of its per capita CO₂ emissions. Meanwhile, the effects of carbon tax in Denmark, Sweden and Netherlands are negative but not significant. The mitigation effects of carbon tax are weakened due to the tax exemption policies on certain energy intensive industries in these countries. Notwithstanding, in Norway, as the rapid growth of energy products drives a substantial increase of CO₂ emissions in oil drilling and natural gas exploitation sectors, carbon tax actually has not realized its mitigation effects.     

LCA of renewable energy for electricity generation systems—A review

Sustainable development requires methods and tools to measure and compare the environmental impacts of human activities for various products (goods and services). Providing society with goods and services contributes to a wide range of environmental impacts. Environmental impacts include emissions into the environment and the consumption of resources as well as other interventions such as land use, etc. Life cycle assessment (LCA) is a technique for assessing environmental loads of a product or a system. The aim of this paper is to review existing energy and CO₂ life cycle analyses of renewable sources based electricity generation systems.The paper points out that carbon emission from renewable energy (RE) systems are not nil, as is generally assumed while evaluating carbon credits. Further the range of carbon emissions from RE systems have been found out from existing literature and compared with those from fossil fuel based systems, so as to assist in a rational choice of energy supply systems.     

Temporal carbon intensity analysis: renewable versus fossil fuel dominated electricity systems

In order to overcome the negative effects of climate change and ensure a global low-carbon future, decarbonizing the electricity sector has been recognized as an important focus area. Internationally, policymakers use average carbon intensity (in gCO₂-e/kWh) in calculating greenhouse gas (GHG) emissions from the electricity system. However, average carbon intensity is a single rate and a fixed quantity; thus, it does not provide any information about the time-varying nature of carbon intensity. The focus of this paper is to show the usefulness of time-varying carbon intensity estimation, which can provide detailed insights into GHG emissions, and help in identifying potential emission cut opportunities from the electricity sector in order to lessen atmospheric pollution. Time-varying carbon intensity estimation (i) reveals temporal variability of carbon intensity, (ii) explores the interplay between generations and emissions, (iii) identifies peak carbon-intensive hours, and (iv) provides evidence for designing appropriate demand-side management strategies with respect to GHG emission reduction.     

Potentials for energy efficiency improvement in the US cement industry

This paper reports on an in-depth analysis of the US cement industry, identifying cost-effective energy efficiency measures and potentials. Between 1970 and 1997, primary physical energy intensity for cement production (SIC 324) dropped 30%, from 7.9 GJ/t to 5.6 GJ/t, while specific carbon dioxide emissions due to fuel consumption and clinker calcination dropped 17%, from 0.29 tC/tonne to 0.24 tC/tonne. We examined 30 energy-efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. We constructed an energy conservation supply curve for the US cement industry which found a total cost-effective energy saving of 11% of 1994 energy use for cement making and a saving of 5% of total 1994 carbon dioxide emissions. Assuming the increased production of blended cement, the technical potential for energy efficiency improvement would not change considerably. However, the cost-effective potential would increase to 18% of total energy use, and carbon dioxide emissions would be reduced by 16%. This demonstrates that the use of blended cements is a key cost-effective strategy for energy efficiency improvement and carbon dioxide emission reductions in the US cement industry.     

Contributing to local policy making on GHG emission reduction through inventorying and attribution: A case study of Shenyang,China

Cities consumed 84% of commercial energy in China, which indicates cities should be the main areas for GHG emissions reduction. Our case study of Shenyang in this paper shows how a clear inventory analysis on GHG emissions at city level can help to identify the major industries and societal sectors for reduction efforts so as to facilitate low-carbon policy-making. The results showed total carbon emission in 2007 was 57 Mt CO₂ equivalents (CO₂e), of which 41 Mt CO₂e was in-boundary emissions and 16 Mt CO₂e was out-of-boundary emissions. The energy sector was dominant in the emission inventory, accounting for 93.1% of total emissions. Within energy sector, emissions from energy production industry, manufacturing and construction industry accounted for 88.4% of this sector. Our analysis showed that comparing with geographical boundary, setting system boundary based on single process standard could provide better information to decision makers for carbon emission reduction. After attributing electricity and heating consumption to final users, the resident and commercial sector became the largest emitter, accounting for 28.5% of total emissions. Spatial analysis of emissions showed that industrial districts such as Shenbei and Tiexi had the large potential to reduce their carbon emissions. Implications of results are finally discussed.     

CO2-free hydrogen as a substitute to fossil fuels: What are the targets? Prospective assessment of the hydrogen market attractiveness

Hydrogen is usually presented as a promising energy carrier that has a major role to play in low carbon mobility, through the use of fuel cells. However, such a market is not expected in the short term. In the meantime, hydrogen may also contribute to reduce carbon emissions in diverse sectors: oil refining, low carbon mobility through the industrial deployment of advanced biofuels, natural gas consumption, and methanol production. According to the targeted market, objective costs are rather different; and so is the reachable mitigated CO₂ amount.     

Assessment of the impact of the European CO2 emissions trading scheme on the Portuguese chemical industry

This paper describes an assessment of the impact of the enforcement of the European carbon dioxide (CO₂) emissions trading scheme on the Portuguese chemical industry, based on cost structure, CO₂ emissions, electricity consumption and allocated allowances data from a survey to four Portuguese representative units of the chemical industry sector, and considering scenarios that allow the estimation of increases on both direct and indirect production costs. These estimated cost increases were also compared with similar data from other European Industries, found in the references and with conclusions from simulation studies. Thus, it was possible to ascertain the impact of buying extra CO₂ emission permits, which could be considered as limited. It was also found that this impact is somewhat lower than the impacts for other industrial sectors.     

The forest products industry at an energy/climate crossroads

Transformational energy and climate policies are being debated worldwide that could have significant impact upon the future of the forest products industry. Because woody biomass can produce alternative transportation fuels, low-carbon electricity, and numerous other “green” products in addition to traditional paper and lumber commodities, the future use of forest resources is highly uncertain. Using the National Energy Modeling System (NEMS), this paper assesses the future of the forest products industry under three possible U.S. policy scenarios: (1) a national renewable electricity standard, (2) a national policy of carbon constraints, and (3) incentives for industrial energy efficiency. In addition, we discuss how these policy scenarios might interface with the recently strengthened U.S. renewable fuels standards. The principal focus is on how forest products including residues might be utilized under different policy scenarios, and what such market shifts might mean for electricity and biomass prices, as well as energy consumption and carbon emissions. The results underscore the value of incentivizing energy efficiency in a portfolio of energy and climate policies in order to moderate electricity and biomass price escalation while strengthening energy security and reducing CO₂ emissions.     

Direct and indirect energy use and carbon emissions in the production phase of buildings: An input–output analysis

There is a considerable disagreement in the literature on the magnitude of primary energy use and CO₂ emissions linked to the production of buildings. In this paper we assess the Swedish building sector using top-down input–output analysis. These top-down results are then disaggregated into sectors and activities, which are compared to results from 18 previous bottom-up studies using process-LCA methodology. The analysis shows almost 90% higher specific energy use (GJ/m²) for the top-down methodology. The differences are only around 20% for the share coupled to production and processing of building materials, while for other involved sectors such as transport, construction activities, production of machines and service sectors, the input–output analysis gives much higher values. Some of these differences can be explained by truncation errors due to the definition of system boundaries in the bottom-up studies. The apparent underestimation of energy use for transport, services etc. in bottom-up studies is only of marginal importance when comparing for example materials choices, but when comparing the production phase to the use phase of buildings such errors are likely to result in an underestimation of the relative importance of the production phase since the use phase is dominated by more easily estimated direct energy use.     

The energy and environmental impacts of Italian households consumptions: An input–output approach

Promoting sustainable consumption and production patterns is a key challenge for the future, in order to use the Earth resources efficiently, to reduce the greenhouse gas emissions, and to decouple the economic growth from the environmental degradation.New or customized methods have to be applied to support decisions makers in the choice of environmental-friendly products, and to select policy priorities and sustainable strategies.A modified input–output model can aid to analyse the relationships among economic growth, energy consumptions and pollutants, in order to assess the energy and environmental impacts due to the actual production and consumption patterns.The following paper introduces an energy and environmental extended input–output model and combines it with the Life Cycle Assessment (LCA) methodology.The authors apply this model to the Italian context in order to assess the energy and environmental impacts related to the consumptions of the Italian households in the period 1999–2006 and to identify the economic sectors involving the highest impacts.The paper represents one of the first Italian studies aimed at identifying those national economic sectors and final goods and services to be assumed prior in the definition of sustainable production and consumption strategies. Results show that about the 70% of the total energy, needed to meet the household final demand of products, is consumed by the productive sectors. In particular tertiary, “electricity, gas and vapour”, road transports and “food and beverage” sectors are the most contributors, accounting for about 75%.Further, the environmental impact analysis associated to Italian households consumptions is carried out, starting from three different data sources The results point out that, to include emissions arising both from energy and non-energy sources, in the assessment of environmental impacts is of paramount importance to obtain reliable simulations of the link between households consumptions and energy and environmental performances.     

Exercising multidisciplinary approach to assess interrelationship between energy use, carbon emission and land use change in a metropolitan city of Pakistan

Population of two cities in Pakistan has already crossed the 10-million figure and for the rest of the areas in the country populations are also increasing rapidly. Urbanization has boosted the use of energy in the cities and so is greenhouse gas (GHG) emissions but the ground situation as to the extent, vulnerability, past trends and future scenarios are not unveiled for the cities of Pakistan. Dearth of data in Pakistan is a huge hindrance to the investigation of energy use and actual GHG emissions. We dared to take steps in addressing this case and put preliminary efforts in compiling baseline sectoral breakdown of energy use, carbon emission and land cover/land use. Furthermore, the relationship of CO₂ source and sink is also explored. This study mainly tries to achieve three objectives. The results illustrate that industrial and residential sectors are vibrant consumers of energy and CO₂ emitters among all other sectors of the city. Sparse trees in the city and reduced agriculture areas by more than one-half in 2009 compared with those in 1975 are the main reasons for increased energy use and reduced CO₂ emissions from agriculture sector as well. However, all the other sectors have increased their CO₂ emissions in an escalating trend. The forecast analysis portrays the same trend too. Therefore, there is a need to make policy makers recognize such vulnerable situation of energy use and GHG emissions for them to take proper and timely actions to cope with the threats of climate change which can occur anytime in the very near future.