Processing National CO2 Inventory Emissions Data and their Total Uncertainty Estimates

The uncertainty of reported greenhouse gases emission inventories obtained by the aggregation of partial emissions from all sources and estimated to date for several countries is very high in comparison with the countries’ emissions limitation and reduction commitments under the Kyoto Protocol. Independent calculation of the estimates could confirm or question the undertainty estimates values obtained thus far. One of the aims of this paper is to propose statistical signal processing methods to enable calculation of the inventory variances. The annual reported emissions are used and temporal smoothness of the emissions curve is assumed. The methods considered are: a spline-function-smoothing procedure; a time-varying parameter model; and the geometric Brownian motion model. These are validated on historical observations of the CO₂ emissions from fossil fuel combustion. The estimates of variances obtained are in a similar range to those obtained from national inventories using TIER1 or TIER2. Additionally, some regularities in the observed curves were noticed.     

Compliance and Emissions Trading under the Kyoto Protocol: Rules for Uncertain Inventories

A solution is proposed for proving compliance with emission targets and for emissions trading in the event of uncertainties in reported emission inventories. The solution is based on the undershooting concept, from which the mathematical conditions for both proving compliance with a risk α and calculating effective emissions for trading are derived. Based on the reported emission units, the number of permits granted is reduced in proportion to the uncertainty in the inventory. A country whose inventory has higher uncertainty is thereby allotted fewer permits than a country with the same inventory but smaller uncertainty.     

Tradable Permit Systems: Considering Uncertainty in Emission Estimates

We simulate the market for emission permits by considering uncertainty in emission inventory reports. The approach taken in this analysis is to enhance the emissions reported in each region by a certain part of their uncertainty when compliance with the Kyoto targets is being proved. While this formulation is not new in the literature, we define the uncertainty component in a way that enables comparison with the approach of effective permits presented in Nahorski, Horabik, and Jonas (2007) Compliance and emissions trading under the Kyoto protocol: Rules for uncertain inventories, (this issue). We show and explain that the transformation to effective permits bears additional costs apart from those resulting from shifting the Kyoto targets.     

A Global Outlook to the Carbon Dioxide Emissions in the World and Emission Factors of the Thermal Power Plants in Turkey

World primary energy demand increases with increases in population and economic development. Within the last 25 yr, the total energy consumption has almost doubled. For the purpose of meeting this demand, fossil energy sources are used and various pollutants are generated. CO₂ is also one of these gases, which cannot be removed like other pollutants, and it causes greenhouse effect and climate change. Reducing the CO₂ emission is very important because of the environmental concerns and regulations, especially the Kyoto Protocol. This paper reviews the estimated world carbon emissions, Turkey's situation in electrical energy production, emission amounts estimated until the year 2020 and emission factors for dust, SO₂, NO_x and CO₂. The estimated results show that CO₂ emissions from thermal power plants in Turkey will make about 0.66 % of the global CO₂ emissions in 2020.     

National Greenhouse Gas Inventories: Understanding Uncertainties versus Potential for Improving Reliability

We investigated the Austrian national greenhouse gas emission inventory to review the reliability and usability of such inventories. The overall uncertainty of the inventory (95% confidence interval) is just over 10% of total emissions, with nitrous oxide (N₂O) from soils clearly providing the largest impact. Trend uncertainty – the difference between 2 years – is only about five percentage points, as important sources like soil N₂O are not expected to show different behavior between the years and thus exhibit a high covariance. The result is very typical for industrialized countries – subjective decisions by individuals during uncertainty assessment are responsible for most of the discrepancies among countries. Thus, uncertainty assessment cannot help to evaluate whether emission targets have been met. Instead, a more rigid emission accounting system that allows little individual flexibility is proposed to provide harmonized evaluation uninfluenced by the respective targets. Such an accounting system may increase uncertainty in terms of greenhouse gas fluxes to the atmosphere. More importantly, however, it will decrease uncertainty in intercountry comparisons and thus allow for fair burden sharing. Setting of post-Kyoto emission targets will require the independent evaluation of achievements. This can partly be achieved by the validation of emission inventories and thorough uncertainty assessment.     

Prior to Economic Treatment of Emissions and Their Uncertainties Under the Kyoto Protocol: Scientific Uncertainties That Must Be Kept in Mind

In a step-by-step exercise – beginning at full greenhouse gas accounting (FGA) and ending with the temporal detection of emission changes – we specify the relevant physical scientific constraints on carrying out temporal signal detection under the Kyoto Protocol and identify a number of scientific uncertainties that economic experts must consider before dealing with the economic aspects of emissions and their uncertainties under the Protocol. In addition, we answer one of the crucial questions that economic experts might pose: how credible in scientific terms are tradable emissions permits? Our exercise is meant to provide a preliminary basis for economic experts to carry out useful emissions trading assessments and specify the validity of their assessments from the scientific point of view, that is, in the general context of a FGA-uncertainty-verification framework. Such a basis is currently missing.     

Accounting for Climate Change: Introduction

The assessment of greenhouse gases (GHGs) emitted to and removed from the atmosphere is high on both political and scientific agendas internationally. As increasing international concern and cooperation aim at policy-oriented solutions to the climate change problem, several issues have begun to arise regarding verification and compliance under both proposed and legislated schemes meant to reduce the human-induced global climate impact. The approaches to addressing uncertainty introduced in this article attempt to improve national inventories or to provide a basis for the standardization of inventory estimates to enable comparison of emissions and emission changes across countries. Authors of the accompanying articles use detailed uncertainty analyses to enforce the current structure of the emission trading system and attempt to internalize high levels of uncertainty by tailoring the emissions trading market rules. Assessment of uncertainty can help improve inventories and manage risk. Through recognizing the importance of, identifying and quantifying uncertainties, great strides can be made in the process of Accounting for Climate Change.     

Energy and Enviromental Issues in Turkey

The current and future projections of energy utilisation and related environmental impact has been given. Due to the heavy dependance on low grade lignites and imported hard coal, Turkey is going to have problems in the control of CO₂ emissions. Turkey was at first included as an Annex I country according to Kyoto Protocol. Later, it has been removed from the list which is justified considering the previous international environmental impact control applications and relatively much lower energy utilisation in Turkey, compared to Annex I countries. Therefore, Turkey has been removed from the Annex I list.Turkish power generation, industrial and transportation sector will be facing a difficult challenge over the coming 20 yr in complying with environmental impact levels. The developments in the liberalisation of Turkish energy sector since the 1980's is a positive step to overcome the problems.     

Abundance of 14C in biomass fractions of wastes and solid recovered fuels

In recent years thermal utilization of mixed wastes and solid recovered fuels has become of increasing importance in European waste management. Since wastes or solid recovered fuels are generally composed of fossil and biogenic materials, only part of the CO₂ emissions is accounted for in greenhouse gas inventories or emission trading schemes. A promising approach for determining this fraction is the so-called radiocarbon method. It is based on different ratios of the carbon isotopes ¹⁴C and ¹²C in fossil and biogenic fuels. Fossil fuels have zero radiocarbon, whereas biogenic materials are enriched in ¹⁴C and reflect the ¹⁴CO₂ abundance of the ambient atmosphere. Due to nuclear weapons tests in the past century, the radiocarbon content in the atmosphere has not been constant, which has resulted in a varying ¹⁴C content of biogenic matter, depending on the period of growth. In the present paper ¹⁴C contents of different biogenic waste fractions (e.g., kitchen waste, paper, wood), as well as mixtures of different wastes (household, bulky waste, and commercial waste), and solid recovered fuels are determined. The calculated ¹⁴C content of the materials investigated ranges between 98 and 135 pMC.     

European Union waste management strategy and the importance of biogenic waste

In the European Union (EU), waste management is almost totally regulated by EU directives, which supply a framework for national regulations. The main target in view of sustainability is the prevention of direct disposal of reactive waste in landfills. The tools to comply with these principles are recycling and material recovery as well as waste incineration with energy recovery for final inertization. The adaptation of the principles laid down in EU directives is an ongoing process. A number of countries have already enacted respective national regulations and their realization shows that recycling and incineration are not in competition but are both essential parts of integrated waste management systems. In the EU, the amount of residual waste available for energy recovery can supply approximately 1% of the primary energy demand. About 50% of the energy inventory of municipal solid waste (MSW) in most EU countries is of biogenic origin, and MSW is to the same extent to be looked upon as regenerative fuel. Hence part of the CO₂ released from waste incineration is climate neutral. In the EU, this share could produce savings of the order of 1% of annual CO₂ emissions if energy from MSW replaced that derived from fossil fuel.     

Evaluation of material recycling for plastics: environmental aspects

“Zero emissions” is a concept envisaging the creation of a sustainable society with minimal disposal of resources. In order to realize zero emissions for plastics, it is important to establish a method for quantitatively evaluating candidate recycling processes. In this study, the principle of the substitution factor (SF) is introduced. A quantitative evaluation of the recycling process for plastics was then carried out. The production process for monofilament plastics was examined. The recycling of plastics discarded during the production process could be substituted in small amounts for virgin materials, giving reduced CO₂ emissions. Furthermore, production using recycled material mixed with virgin material was more effective in reducing CO₂ emissions than when recycled materials only were used. Received: November 19, 1999 / Accepted: November 28, 2000     

Carbon accounting for Japanese petrochemicals

This paper discusses two bottom-up models for the estimation of carbon storage and CO₂ emissions related to the nonenergy use of fossil energy carriers. The models show how material flow accounting can be applied to policy making. The nonenergy use emission accounting tables model is a static model, while the chemical industry environmental strategy assessment program (CHEAP) model is a dynamic model of the flows of synthetic organic materials. Both models provide detailed and more accurate estimates of carbon storage in materials than the accounting method that is currently used in the framework of the Intergovernmental Panel on Climatic Change (IPCC) guidelines. The results for both models suggest that carbon storage in synthetic organic materials has been overestimated, and consequently CO₂ emissions have been underestimated. Japanese CO₂ emissions in 1996 were at least 1.9% higher than reported previously. The CHEAP model results indicate that the net carbon storage (storage − emissions in waste incineration) will decrease during the next few decades. This decrease is mainly driven by changing waste management practice. Received: December 8, 2000 / Accepted: August 15, 2001     

EU strategies and policies on soil and waste management to offset greenhouse gas emissions

Climate change has become an important political priority in the environmental field, and beyond. To revert the increase in the Earth’s temperature, developed country parties to the Kyoto Protocol committed to limit their greenhouse gas emissions. The 15 Member States that made up the European Community in 1997 have a combined reduction target of 8% in CO₂-equivalent emissions in the period 2008–2012 compared to 1990. The role of soil, both as a source and a sink for carbon, is particularly important. How can soil organic matter be maintained or increased? There is no single answer, and a broad range of options need to be explored. Among the different measures proposed, the promotion of organic input on arable land (crop residues, cover crops, farm yard manure, compost, sewage sludge) has been mentioned. The challenge is to ensure that organic wastes of good quality are used to increase soil organic matter in carbon depleted soils and that appropriate monitoring is established. On the waste management front, the European Commission intends to produce guidance for Member States on the management of biowaste that will take into account all related environmental issues, including soil aspects. As for monitoring, the European Commission has put forward legislation according to which Member States would have to identify the areas at risk of soil organic matter decline in their national territory. Such legislation should be regarded as a major step forward for Europe, as it would ensure a high level of soil protection across the Community. This development will have the potential to enable the kind of estimation, measurement or modelling of crop or grazing land management needed for accounting under Article 3.4 of the Kyoto Protocol.     

Greenhouse gases emissions accounting for typical sewage sludge digestion with energy utilization and residue land application in China

About 20 million tonnes of sludge (with 80% moisture content) is discharged by the sewage treatment plants per year in China, which, if not treated properly, can be a significant source of greenhouse gases (GHGs) emissions. Anaerobic digestion is a conventional sewage sludge treatment method and will continue to be one of the main technologies in the following years. This research has taken into consideration GHGs emissions from typical processes of sludge thickening + anaerobic digestion + dewatering + residue land application in China. Fossil CO₂, biogenic CO₂, CH_4, and avoided CO₂ as the main objects is discussed respectively. The results show that the total CO₂-eq is about 1133 kg/t DM (including the biogenic CO₂), while the net CO₂-eq is about 372 kg/t DM (excluding the biogenic CO₂). An anaerobic digestion unit as the main GHGs emission source occupies more than 91% CO₂-eq of the whole process. The use of biogas is important for achieving carbon dioxide emission reductions, which could reach about 24% of the total CO₂-eq reduction.     

CO₂ emission factors for waste incineration: Influence from source separation of recyclable materials

CO₂-loads from combustible waste are important inputs for national CO₂ inventories and life-cycle assessments (LCA). CO₂ emissions from waste incinerators are often expressed by emission factors in kg fossil CO₂ emitted per GJ energy content of the waste. Various studies have shown considerable variations between emission factors for different incinerators, but the background for these variations has not been thoroughly examined. One important reason may be variations in collection of recyclable materials as source separation alters the composition of the residual waste incinerated. The objective of this study was to quantify the importance of source separation for determination of emission factors for incineration of residual household waste. This was done by mimicking various source separation scenarios and based on waste composition data calculating resulting emission factors for residual waste routed to incineration. Emission factors ranged from 27 to 40 kg CO₂/GJ. The results appeared most sensitive towards variations in waste composition and water content. Recycling rates and lower heating values could not be used as simple indicators of the resulting emission factors for residual household waste; however the fossil carbon ratio of the waste after source separation was found to be appropriately correlated with the emission factor. Based on the results, it is recommended to carefully evaluate the source separation and collection systems behind reported literature values when comparing different studies and when using the values for environmental assessment purposes.     

GHG emission factors developed for the collection,transport and landfilling of municipal waste in South African municipalities

Greenhouse gas (GHG) emission factors are used with increased frequency for the accounting and reporting of GHG from waste management. However, these factors have been calculated for developed countries of the Northern Hemisphere and are lacking for developing countries. This paper shows how such factors have been developed for the collection, transport and landfilling of municipal waste in South Africa. As such it presents a model on how international results and methodology can be adapted and used to calculate country-specific GHG emission factors from waste. For the collection and transport of municipal waste in South Africa, the average diesel consumption is around 5 dm³ (litres) per tonne of wet waste and the associated GHG emissions are about 15 kg CO₂ equivalents (CO₂ e). Depending on the type of landfill, the GHG emissions from the landfilling of waste have been calculated to range from ?145 to 1016 kg CO₂ e per tonne of wet waste, when taking into account carbon storage, and from 441 to 2532 kg CO₂ e per tonne of wet waste, when carbon storage is left out. The highest emission factor per unit of wet waste is for landfill sites without landfill gas collection and these are the dominant waste disposal facilities in South Africa. However, cash strapped municipalities in Africa and the developing world will not be able to significantly upgrade these sites and reduce their GHG burdens if there is no equivalent replacement of the Clean Development Mechanism (CDM) resulting from the Kyoto agreement. Other low cost avenues need to be investigated to suit local conditions, in particular landfill covers which enhance methane oxidation.     

Role of waste management with regard to climate protection: a case study.

According to the Kyoto Protocol and the burden-sharing agreement of the European Union, Austria is required to cut greenhouse gas (GHG) emissions during the years 2008 to 2012 in order to achieve an average reduction of 13%, based on the level of emissions for the year 1990. The present contribution gives an overview of the history of GHG emission regulation in Austria and identifies the progress made towards the realization of the national climate strategy to attain the GHG emission targets. The contribution uses Austria as an example of the way in which proper waste management can help to reduce GHG emissions. The GHG inventories show that everything must be done to minimize the carbon input due to waste deposition at landfill sites. The incineration of waste is particularly helpful in reducing GHG emissions. The waste-to-energy by incineration plants and recovery of energy yield an ecologically proper treatment of waste using state-of-the-art techniques of a very high standard. The potential for GHG reduction of conventional waste treatment technologies has been estimated by the authors. A growing number of waste incinerators and intensified co-incineration of waste in Austrian industry will both help to reduce national GHG emissions substantially. By increasing the number and capacity of plants for thermal treatment of waste the contribution of proper waste management to the national target for reduction of GHG emissions will be in the range of 8 to 14%. The GHG inventories also indicate that a potential CO2 reduction of about 500 000 t year(-1) is achievable by co-incineration of waste in Austrian industry.     

Spatial GHG Inventory: Analysis of Uncertainty Sources. A Case Study for Ukraine

A geoinformation technology for creating spatially distributed greenhouse gas inventories based on a methodology provided by the Intergovernmental Panel on Climate Change and special software linking input data, inventory models, and a means for visualization are proposed. This technology opens up new possibilities for qualitative and quantitative spatially distributed presentations of inventory uncertainty at the regional level. Problems concerning uncertainty and verification of the distributed inventory are discussed. A Monte Carlo analysis of uncertainties in the energy sector at the regional level is performed, and a number of simulations concerning the effectiveness of uncertainty reduction in some regions are carried out. Uncertainties in activity data have a considerable influence on overall inventory uncertainty, for example, the inventory uncertainty in the energy sector declines from 3.2 to 2.0% when the uncertainty of energy-related statistical data on fuels combusted in the energy industries declines from 10 to 5%. Within the energy sector, the ‘energy industries’ subsector has the greatest impact on inventory uncertainty. The relative uncertainty in the energy sector inventory can be reduced from 2.19 to 1.47% if the uncertainty of specific statistical data on fuel consumption decreases from 10 to 5%. The ‘energy industries’ subsector has the greatest influence in the Donetsk oblast. Reducing the uncertainty of statistical data on electricity generation in just three regions – the Donetsk, Dnipropetrovsk, and Luhansk oblasts – from 7.5 to 4.0% results in a decline from 2.6 to 1.6% in the uncertainty in the national energy sector inventory.     

Characteristics of MSW and heat energy recovery between residential and commercial areas in Seoul

This paper analyzes the amount and characteristics of municipal solid waste (MSW) according to the inhabitant density of population and the business concentration in 25 districts in Seoul. Further, the heat energy recovery and avoided CO₂ emissions of four incineration plants located in residential and commercial areas in Seoul are examined. The amount of residential waste per capita tended to increase as the density of inhabitants decreased. The amount of commercial waste per capita tended to increase as the business concentration increased. The examination of the heat energy recovery characteristics indicated that the four incineration plants produced heat energy that depended on residential or commercial areas based on population and business. The most important result regarding avoided CO₂ emissions was that commercial areas with many office-type businesses had the most effective CO₂ emission savings by combusting 1 kg of waste. Assuming the full-scale operation of the four incineration plants, the amount of saved CO₂ emissions per year was 444 Gg CO₂ and 57,006 households in Seoul can be provided with heat energy equivalent to 542,711 Nm³ of LNG.     

Artificial carbonation for controlling the mobility of critical elements in bottom ash

In municipal solid waste incineration (MSWI), bottom ash, generated at a stoker grate type incinerator, the critical elements were identified in terms of EU regulation. The stabilizing effect of moderate carbonation (pH 8.28 ± 0.03) on critical contaminants was studied through availability and diffusion leaching protocols. Data from the performed tests were evaluated with the goal of reusing MSWI bottom ash as secondary construction material. To investigate the mobilizing effect of CO₂, suspended MSWI bottom ash was severely carbonated (pH 6.40 ± 0.07). The effect of CO₂ and its interaction with other leaching factors, such as liquid/solid (L/S) ratio, leaching time, pH, ultrasound treatment, and leaching temperature, were examined using a reduced 2^6-1 experimental design. Contaminants identified as critical were Cr, Cu, Mo, Sb, Cl⁻, and SO₄ ²⁻. Although moderate carbonation decreased the release of Cr, Cu, Mo, and Sb from compacted bottom ash, the main disadvantage remains its inability to demobilize Cl⁻ and SO₄ ²⁻. The hypothesized mobilizing effect of severe carbonation was proven. The treatment enhanced the separation of critical components (α = 0.05) (except for Cl⁻), i.e., about fivefold for Sb and about twofold for Cr, Cu, and S. Nevertheless, the prospect is good that severe carbonation could constitute the deciding key parameter to facilitate the technical feasibility of a future washing process for MSWI bottom ash.