加拿大油气系统温室气体逃逸排放清单简述

油气系统温室气体逃逸排放是温室气体排放清单的重要组成部分。加拿大在清单中统一考虑了油气系统可能存在的温室气体排放源,因此清单中不仅包括了温室气体的逃逸排放(泄漏、排空),还考虑了能源燃烧中的气体排放,所考虑的温室气体种类既包括甲烷,也包括二氧化碳。采用的是政府间气候变化专门委员会(IPCC)第三层次方法(Tier3),即设备清单法、操作时间法和活动水平法三种计算方法,详细地将排放源分类进行估算。该国对数据的管理、质量控制和质量评估、不确定性分析以及在如何保证数据的持续性方面的作法都值得我们学习和借鉴。     

Application of strategies for sanitation management in wastewater treatment plants in order to control/reduce greenhouse gas emissions

Greenhouse gases (GHG), basically methane (CH(4)), carbon dioxide (CO(2)) and nitrous oxide (N(2)O), occur at atmospheric concentrations of ppbv to ppmv under natural conditions. GHG have long mean lifetimes and are an important factor for the mean temperature of the Earth. However, increasing anthropogenic emissions could produce a scenario of progressive and cumulative effects over time, causing a potential "global climate change". Biological degradation of the organic matter present in wastewater is considered one of the anthropogenic sources of GHG. In this study, GHG emissions for the period 1990-2027 were estimated considering the sanitation process and the official domestic wastewater treatment startup schedule approved for the Metropolitan Region (MR) of Santiago, Chile. The methodology considers selected models proposed by the Intergovernmental Panel on Climate Change (IPCC) and some others published by different authors; these were modified according to national conditions and different sanitation and temporal scenarios. For the end of the modeled period (2027), results show emissions of about 65Tg CO(2) equiv./year (as global warming potential), which represent around 50% of national emissions. These values could be reduced if certain sanitation management strategies were introduced in the environmental management by the sanitation company in charge of wastewater treatment.     

Estimation and Spatiotemporal Analysis of Methane Emissions from Agriculture in China

Estimating and analyzing the temporal and spatial patterns of methane emissions from agriculture (MEA) will help China formulate mitigation and adaptation strategies for the nation’s agricultural sector. Based on the Tier 2 method presented in the 2006 guidelines of the Intergovernmental Panel on Climate Change (IPCC) and on existing reports, this article presents a systematic estimation of MEA in China from 1990 to 2006, with a particular emphasis on trends and spatial distribution. Results from our study indicate that China’s MEA rose from 16.37 Tg yr⁻¹ in 1990 to 19.31 Tg yr⁻¹ in 2006, with an average annual increase of 1.04%. Over the study period, while emissions from field burning of crop residues remained rather low, those from rice cultivation and from livestock typically decreased and increased, respectively, showing extremely opposite trends that chiefly resulted from changes in the cultivated areas for different rice seasons and changes in the populations of different animal species. Over the study period, China’s high-MEA regions shifted generally northward, chiefly as a result of reduced emissions from rice cultivation in most of China’s southern provinces and a substantial growth in emissions from livestock enteric fermentation in most of China’s northern, northeastern, and northwestern provinces. While this article provides significant information on estimates of MEA in China, it also includes some uncertainties in terms of estimating emissions from each source category. We conclude that China’s MEA will likely continue to increase in the future and recommend a demonstration study on MEA mitigation along the middle and lower reaches of the Yellow River. We further recommend enhanced data monitoring and statistical analysis, which will be essential for preparation of the national greenhouse gas (GHG) inventory.     

美国和中国油气系统甲烷排放状况

文章通过调研、分析美国和中国近年来油气系统中甲烷排放状况,对比分析美国与中国应用的主要甲烷计算方法,表明:美国油气系统中对甲烷排放量的计算方法可采用1996IPCC指南中提供的第一层次(Tier1)和第二层次(Tier2)法,计算结果相对比较准确,甲烷的排放呈逐年增加趋势;中国油气系统中甲烷排放量的计算方法目前只限于1996IPCC指南中提供的Tier1法,中国甲烷排放量相对于美国等发达国家较少,但整体呈增长趋势。     

DAYCENT national-scale simulations of nitrous oxide emissions from cropped soils in the United States

Until recently, Intergovernmental Panel on Climate Change (IPCC) emission factor methodology, based on simple empirical relationships, has been used to estimate carbon (C) and nitrogen (N) fluxes for regional and national inventories. However, the 2005 USEPA greenhouse gas inventory includes estimates of N2O emissions from cultivated soils derived from simulations using DAYCENT, a process-based biogeochemical model. DAYCENT simulated major U.S. crops at county-level resolution and IPCC emission factor methodology was used to estimate emissions for the approximately 14% of cropped land not simulated by DAYCENT. The methodology used to combine DAYCENT simulations and IPCC methodology to estimate direct and indirect N2O emissions is described in detail. Nitrous oxide emissions from simulations of presettlement native vegetation were subtracted from cropped soil N2O to isolate anthropogenic emissions. Meteorological data required to drive DAYCENT were acquired from DAYMET, an algorithm that uses weather station data and accounts for topography to predict daily temperature and precipitation at 1-km2 resolution. Soils data were acquired from the State Soil Geographic Database (STATSGO). Weather data and dominant soil texture class that lie closest to the geographical center of the largest cluster of cropped land in each county were used to drive DAYCENT. Land management information was implemented at the agricultural-economic region level, as defined by the Agricultural Sector Model. Maps of model-simulated county-level crop yields were compared with yields estimated by the USDA for quality control. Combining results from DAYCENT simulations of major crops and IPCC methodology for remaining cropland yielded estimates of approximately 109 and approximately 70 Tg CO2 equivalents for direct and indirect, respectively, mean annual anthropogenic N2O emissions for 1990-2003.     

The use of guide to the expression of uncertainty in measurement for uncertainty management in National Greenhouse Gas Inventories

Research basis for annual greenhouse gases (GHG) emissions assessment is national and branch statistics data. Quality and confidence of greenhouse gases inventory through assessment methodologies, preparation procedures and processing of data is confirm. Request at National Greenhouse Gases Inventory which contain assessment and analyses uncertainty elements on Intergovernmental Panel on Climate Change-GPG 2000 and IPCC 2006 are determine. Main approaches for uncertainty assessment in environmental and metrological guides are considered. The algorithm of expressing uncertainty and scheme for estimating uncertainty according to GPG 2000 and IPCC 2006 are proposed. The use approaches GUM 1993 for uncertainty assessment for greenhouse gases inventory are proposed.     

有色金属行业CO2排放估算方法研究

通过对国内外有色金属行业温室气体排放估算方法研究现状的分析,将联合国政府间气候变化专门委员会(IPCC)温室气体排放清单指南、国际有色行业协会和环境科学研究中的一些常用算法,总结归纳应用于有色金属行业温室气体的排放量估算,从估算方法和结果上分析各种方法的优缺点和使用条件。以原铝生产CO2排放估算为例,对有色金属温室气体排放进行实证分析,为有色金属行业温室气体排放估算提供参选方法,促进有色金属工业的节能减排。     

有色金属行业CO2排放估算方法研究

通过对国内外有色金属行业温室气体排放估算方法研究现状的分析,将联合国政府间气候变化专门委员会（IPCC）温室气体排放清单指南、国际有色行业协会和环境科学研究中的一些常用算法,总结归纳应用于有色金属行业温室气体的排放量估算,从估算方法和结果上分析各种方法的优缺点和使用条件。以原铝生产CO2排放估算为例,对有色金属温室气体排放进行实证分析,为有色金属行业温室气体排放估算提供参选方法,促进有色金属工业的节能减排。     

Estimating the potential of greenhouse gas mitigation in Kazakhstan

As part of the studies related to the obligations of the UN Framework Convention on Climate Change, the Republic of Kazakhstan started activities to inventory greenhouse gas (GHG) emissions and assess of GHG mitigation options. The objective of this paper is to present an estimate of the possibility of mitigating GHG emissions and determine the mitigation priorities. It presents a compilation of the possible options and their assessment in terms of major criteria and implementation feasibility. Taking into account the structure of GHG emissions in Kazakhstan in 1990, preliminary estimates of the potential for mitigation are presented for eight options for the energy sector and agriculture and forestry sector. The reference scenario prepared by expert assessments assumes a reduction of CO₂ emissions in 1996–1998 by about 26% from the 1990 level due to general economic decline, but then emissions increase. It is estimated that the total potential for the mitigation of CO₂ emissions for the year 2000 is 3% of the CO₂ emissions in the reference scenario. The annual reduction in methane emissions due to the estimated options can amount to 5%–6% of the 1990 level.

     

Climate targets and comprehensive greenhouse gas emissions trading

In June 1992 a Framework on Climate Change Convention was signed in Rio de Janeiro, calling for the control of greenhouse gases, notably in the industrialized countries. Its formulation allows for joint implementation of measures to reach emission targets for greenhouse gases. Such joint implementation covering all greenhouse gases could form the first step towards a system of comprehensive emissions trading. This paper addresses both advantages and disadvantages of comprehensive emissions trading across different gases, sinks and sources. It concludes that in addition to carbon dioxide from fossil fuels, the inclusion of biotic carbon emissions and selected sources of methane is attractive from both the economic and environmental viewpoint. The uncertainties associated with emissions can be overcome by requiring a thorough review of trade proposals by a broad-based international supervisory body, utilizing a consistent methodology such as that being developed by the Intergovernmental Panel on Climate Change (IPCC). Finally, the paper addresses the central objective of the Climate Convention, which implicity sets a limit to greenhouse gases emissions and thus provides a guideline for the total amount of permits that may be made available in a tradeable permit system.     

Bulgaria Country Study to address climate change mitigation

Future developments of the Bulgarian economy, energy demand, energy supply, and greenhouse gas (GHG) emissions are projected and evaluated for baseline and mitigation scenarios. Different methods and approaches are used at different stages of the study with a tendency to incorporate them in a single integrated resource planning tool such as the MARKAL-MACRO model. The results obtained indicate that the aim of Framework Convention of Climate Change to have year 2000 GHG emissions below the base year 1988 emissions will be achieved without further mitigation steps. Reducing the expected increase of GHG emissions in the decade 2000 to 2010 requires a package of mitigation measures to be implemented in the next few years.

     

Changing places, changing emissions: The cross-scale reliability of greenhouse gas emission inventories in the US

Greenhouse gas (GHG) emission inventories, which currently inform abatement policy discussions, are developed mostly from national scale data. Nevertheless, although the policy debate tends to take place in global and national arenas, action to abate GHG emissions is inherently within the provenance of local institutions and communities. The purpose of this paper is to examine how much information is lost by not estimating GHG emissions data at scales finer than the whole US. Such information may be critical in bridging global and local policy. Differences in the composition of GHG emission sources based on GHG emission inventories at three nested spatial scales (national, state, local) for four study sites (in Kansas, North Carolina, Ohio and Pennsylvania) are analysed, drawing upon initial results of a large collaborative study known as the 'Association of American Geographers-Global Change in Local Places (GCLP)' project. The concept of spatial sovereignty of emissions is developed to test the cross-scale reliability of emission inventories. For the test year 1990, close agreement is found in the by-gas composition of GHG emissions among national, state and local inventories. Spatial sovereignty in this case is maintained. However close agreement is not found in the by-source composition of GHG emissions among national, state and local inventories. Spatial sovereignty in this case is not maintained. Regular compilation of state and local emissions source inventories may be necessary to track important spatial and temporal deviations from national trends.     

A reappraisal of WRI's estimates of greenhouse gas emissions

Excessive emissions of certain trace gases such as carbon dioxide, methane, nitrous oxide, carbon monoxide and chlorofluorocarbons are likely to result in global warming due to increased concentration of these greenhouse gases (GHGs). Therefore, measures to control GHG emissions are essential and the current international debate is on how to arrive at optimal GHG limitation strategies. To set emission targets or to distribute the burden of costs of various control measures, it is necessary to identify the major emitters. The World Resources Institute has assessed countrywide contributions to global GHG emissions for 1987. This paper disagrees with the basic approach adopted by WRI because it fails to apportion sinks on a logical basis by keeping in mind equity considerations; it does not account for the residence time of different GHGs; and it uses unreliable and outdated data for estimating the emissions. Using recent and reliable data for India and Brazil as well as the IPCC global warming potential for various GHGs, the shares in global emissions have been recalculated. The paper concludes that if only current emissions are considered there is considerable bias against those countries which are latecomers to the process of industrialization.     

The Impact of Map and Data Resolution on the Determination of the Agricultural Utilisation of Organic Soils in Germany

Due to its nature, agricultural land use depends on local site characteristics such as production potential, costs and external effects. To assess the relevance of the modifying areal unit problem (MAUP), we investigated as to how a change in the data resolution regarding both soil and land use data influences the results obtained for different land use indicators. For the assessment we use the example of the greenhouse gas (GHG) emissions from agriculturally used organic soils (mainly fens and bogs). Although less than 5 % of the German agricultural area in use is located on organic soils, the drainage of these areas to enable their agricultural utilization causes roughly 37 % of the GHG emissions of the German agricultural sector. The abandonment of the cultivation and rewetting of organic soils would be an effective policy to reduce national GHG emissions. To assess the abatement costs, it is essential to know which commodities, and at what quantities, are actually produced on this land. Furthermore, in order to limit windfall profits, information on the differences of the profitability among farms are needed. However, high-resolution data regarding land use and soil characteristics are often not available, and their generation is costly or the access is strictly limited because of legal constraints. Therefore, in this paper, we analyse how indicators for land use on organic soils respond to changes in the spatial aggregation of the data. In Germany, organic soils are predominantly used for forage cropping. Marked differences between the various regions of Germany are apparent with respect to the dynamics and the intensity of land use. Data resolution mainly impairs the derived extent of agriculturally used peatland and the observed intensity gradient, while its impact on the average value for the investigated set of land-use indicators is generally minor.     

Nitrogen oxide and methane emissions under varying tillage and fertilizer management

Comprehensive assessment of the total greenhouse gas (GHG) budget of reduced tillage agricultural systems must consider emissions of nitrous oxide (N2O) and methane (CH4), each of which have higher global warming potentials than carbon dioxide (CO2). Tillage intensity may also impact nitric oxide (NO) emissions, which can have various environmental and agronomic impacts. In 2003 and 2004, we used chambers to measure N2O, CH4, and NO fluxes from plots that had been managed under differing tillage intensity since 1991. The effect of tillage on non-CO2 GHG emissions varied, in both magnitude and direction, depending on fertilizer practices. Emissions of N2O following broadcast urea (BU) application were higher under no till (NT) and conservation tillage (CsT) compared to conventional tillage (CT). In contrast, following anhydrous ammonia (AA) injection, N2O emissions were higher under CT and CsT compared to NT. Emissions following surface urea ammonium nitrate (UAN) application did not vary with tillage. Total growing season non-CO2 GHG emissions were equivalent to CO2 emissions of 0.15 to 1.9 Mg CO2 ha(-1) yr(-1) or 0.04 to 0.53 Mg soil-C ha(-1) yr(-1). Emissions of N2O from AA-amended plots were two to four times greater than UAN- and BU-amended plots. Total NO + N2O losses in the UAN treatment were approximately 50% lower than AA and BU. This study demonstrates that N2O emissions can represent a substantial component of the total GHG budget of reduced tillage systems, and that interactions between fertilizer and tillage practices can be important in controlling non-CO2 GHG emissions.     

Carbon sequestration potential in reclaimed mine sites in seven east-central states

Terrestrial systems represent a significant potential carbon (C) sink to help mitigate or offset greenhouse gas emissions. Nearly 3.2 Mha are permitted for mining activities in the United States, which are required to be reclaimed with vegetative cover. While site-specific studies have assessed C accumulation on reclaimed mine sites, regional analyses to estimate potential C increases have not been conducted. For this analysis, potential C sequestration is analyzed on 567,000 ha of mine land in a seven-state region reclaimed to cropland, pasture, or forest. Carbon accumulation is estimated for cropland, pasture, and forest soils, forest litter layer, and aboveground biomass by estimating average annual rates of C accumulation from site-specific and general C sequestration studies. The average annual rate of C storage is highest when mine land is reclaimed to forest, where the potential sequestration is 0.7 to 2.2 Tg yr(-1). The C from soils, litter layer, and biomass from mine lands reclaimed to forest represents 0.3 to 1.0% of the 1990 CO2 emissions from the study region (919 Tg CO2). To achieve the greenhouse gas (GHG) emission reduction goal of 7% below the 1990 level as proposed by the Kyoto Treaty requires CO2 emissions in the study area to be reduced by just over 64 Tg CO2. The potential carbon storage in mine sites reclaimed to forest could account for 4 to 12.5% of these required reductions.     

Tillage and field scale controls on greenhouse gas emissions

There is a lack of understanding of how associations among soil properties and management-induced changes control the variability of greenhouse gas (GHG) emissions from soil. We performed a laboratory investigation to quantify relationships between GHG emissions and soil indicators in an irrigated agricultural field under standard tillage (ST) and a field recently converted (2 yr) to no-tillage (NT). Soil cores (15-cm depth) were incubated at 25 degrees C at field moisture content and 75% water holding capacity. Principal component analysis (PCA) identified that most of the variation of the measured soil properties was related to differences in soil C and N and soil water conditions under ST, but soil texture and bulk density under NT. This trend became more apparent after irrigation. However, principal component regression (PCR) suggested that soil physical properties or total C and N were less important in controlling GHG emissions across tillage systems. The CO2 flux was more strongly determined by microbial biomass under ST and inorganic N content under NT than soil physical properties. Similarly, N2O and CH4 fluxes were predominantly controlled by NO3- content and labile C and N availability in both ST and NT soils at field moisture content, and NH4+ content after irrigation. Our study indicates that the field-scale variability of GHG emissions is controlled primarily by biochemical parameters rather than physical parameters. Differences in the availability and type of C and N sources for microbial activity as affected by tillage and irrigation develop different levels and combinations of field-scale controls on GHG emissions.     

Greenhouse gas emissions from forestry operations: a life cycle assessment

Most forest carbon assessments focus only on biomass carbon and assume that greenhouse gas (GHG) emissions from forestry activities are minimal. This study took an in-depth look at the direct and indirect emissions from Pacific Northwest (PNW) Douglas-fir [Pseudotsuga menziesii (Mirbel) Franco] forestry activities to support or deny this claim. Greenhouse gas budgets for 408 "management regimes" were calculated using Life Cycle Assessment (LCA) methodology. These management regimes were comprised of different combinations of three types of seedlings (P + 1, 1 + 1, and large plug), two types of site preparation (pile and burn, and chemical), 17 combinations of management intensity including fertilization, herbicide treatment, pre-commercial thinning (PCT), commercial thinning (CT), and nothing, and four different rotation ages (30, 40, 50, and 60 yr). Normalized to 50 yr, average direct GHG emissions were 8.6 megagrams (Mg) carbon dioxide equivalents (CO2e) ha(-1), which accounted for 84% of total GHG emissions from the average of 408 management regimes. Harvesting (PCT, CT, and clear cutting) contributed the most to total GHG emissions (5.9 Mg CO2e per 700 m3 harvested timber), followed by pile and burn site preparation (4.0 Mg CO2e ha(-1) or 32% of total GHG emissions) and then fertilization (1.9 Mg CO2e ha(-1) or 15% of total GHG emissions). Seedling production, seedling transportation, chemical site preparation, and herbicide treatment each contributed less than 1% of total GHG emissions when assessed per hectare of planted timberland. Total emissions per 100 m3 averaged 1.6 Mg CO2e ha(-1) over all 408 management regimes. An uncertainty analysis using Monte Carlo simulations revealed that there are significant differences between most alternative management regimes.     

Biochar and earthworm effects on soil nitrous oxide and carbon dioxide emissions

Biochar is the product of pyrolysis produced from feedstock of biological origin. Due to its aromatic structure and long residence time, biochar may enable long-term carbon sequestration. At the same time, biochar has the potential to improve soil fertility and reduce greenhouse gas (GHG) emissions from soils. However, the effect of biochar application on GHG fluxes from soil must be investigated before recommendations for field-scale biochar application can be made. A laboratory experiment was designed to measure carbon dioxide (CO) and nitrous oxide (NO) emissions from two Irish soils with the addition of two different biochars, along with endogeic (soil-feeding) earthworms and ammonium sulfate, to assist in the overall evaluation of biochar as a GHG-mitigation tool. A significant reduction in NO emissions was observed from both low and high organic matter soils when biochars were applied at rates of 4% (w/w). Earthworms significantly increased NO fluxes in low and high organic matter soils more than 12.6-fold and 7.8-fold, respectively. The large increase in soil NO emissions in the presence of earthworms was significantly reduced by the addition of both biochars. biochar reduced the large earthworm emissions by 91 and 95% in the low organic matter soil and by 56 and 61% in the high organic matter soil (with and without N fertilization), respectively. With peanut hull biochar, the earthworm emissions reduction was 80 and 70% in the low organic matter soil, and only 20 and 10% in the high organic matter soil (with and without N fertilization), respectively. In high organic matter soil, both biochars reduced CO efflux in the absence of earthworms. However, soil CO efflux increased when peanut hull biochar was applied in the presence of earthworms. This study demonstrated that biochar can potentially reduce earthworm-enhanced soil NO and CO emissions. Hence, biochar application combined with endogeic earthworm activity did not reveal unknown risks for GHG emissions at the pot scale, but field-scale experiments are required to confirm this.