Carbon Dioxide Emission Factors Research Articles

Driving Factors of Carbon Dioxide Emissions and the Impact from Kyoto Protocol

In the last two decades increasing attention has been paid to the relationship between environmental degradation and economic development. According to the Environmental Kuznets Curve (EKC) hypothesis this relationship may be described by an inverted-U curve. However, recent evidence rejects the EKC hypothesis for GHG emissions in a broad sense. In this paper we aim to investigate whether the EKC behavior for CO2 emissions could be proved on the behalf of institutional regulations. We analyze the driving factors of CO2 for developed and developing countries to test the theory of the EKC in the context of environmental regulations using a static and dynamic panel data model. We consider the Kyoto Protocol and the Clean Development Mechanism (CDM). The results from this study indicate that the Kyoto obligations have a reducing effect on CO2 emissions in developed and developing countries. JEL Code: Q54, Q56.

Particle and carbon dioxide emissions from passenger vehicles operating on unleaded petrol and LPG fuel

A comprehensive study of the particle and carbon dioxide emissions from a fleet of six dedicated liquefied petroleum gas (LPG) powered and five unleaded petrol (ULP) powered new Ford Falcon Forte passenger vehicles was carried out on a chassis dynamometer at four different vehicle speeds—0 (idle), 40, 60, 80 and 100 km h −1. Emission factors and their relative values between the two fuel types together with a statistical significance for any difference were estimated for each parameter. In general, LPG was found to be a ‘cleaner’ fuel, although in most cases, the differences were not statistically significant owing to the large variations between emissions from different vehicles. The particle number emission factors ranged from 10 11 to 10 13 km −1 and was over 70% less with LPG compared to ULP. Corresponding differences in particle mass emission factor between the two fuels were small and ranged from the order of 10 μg km −1 at 40 to about 1000 μg km −1 at 100 km h −1. The count median particle diameter (CMD) ranged from 20 to 35 nm and was larger with LPG than with ULP in all modes except the idle mode. Carbon dioxide emission factors ranged from about 300 to 400 g km −1 at 40 km h −1, falling with increasing speed to about 200 g km −1 at 100 km h −1. At all speeds, the values were 10% to 18% greater with ULP than with LPG.

CO2 EMISSION FACTOR FOR URBAN TRANSPORT SYSTEM IN CHINA

At present, many Asian countries need a reliable carbon dioxide (CO2) emission factor for transport sector. For instance, though motor vehicles are on the increase rapidly in China, the CO2 emission factor is not published. The purpose of this study is to determine CO2 emission factor and to calculate CO2 emissions for urban transport in China. The method of this study is to analyze existing statistics material of transport and energy in China. The following results were obtained:(1) CO2 emission factors of urban transport were bus 178g-c/km, trolleybus 181g-c/km, subway 535 g-c/km, tramcar 145g-c/km and taxi 85g-c/km.(2) Based on traffic volume, CO2 emissions from urban transport were 1.27 Mt-c (1999) and 1.40Mt-c (2000).(3) CO2 emissions from urban transport were a small minority composing only 1.2 %(1999 and 2000) of the whole transport sector.

Emission factors for human activity

In preparing and justifying transportation policies, it is not uncommon to make use of emission factors. However, such factors are not used for cycling and walking because it is assumed that such activities have zero-valued emissions. This work suggests that this is an invalid approach and estimates UK-based carbon dioxide emission factors for such activities for a large number of individuals. When compared to emission factors for automobiles, the results are surprising.

Calculation of global carbon dioxide emissions: Review of emission factors and a new approach taking fuel quality into consideration

Anthropogenic carbon dioxide emissions resulting from fossil fuel consumption play a major role in the current debate on climate change. Carbon dioxide emissions are calculated on the basis of a carbon dioxide emission factor (CEF) for each type of fuel. Published CEFs are reviewed in this paper. It was found that for nearly all CEFs, fuel quality is not adequately taken into account. This is especially true in the case of the CEFs for coal. Published CEFs are often based on generalized assumptions and inexact conversions. In particular, conversions from gross calorific value to net calorific value were examined. A new method for determining CEFs as a function of calorific value (for coal, peat, and natural gas) and specific gravity (for crude oil) is presented that permits CEFs to be calculated for specific fuel qualities. A review of proportions of fossil fuels that remain unoxidized owing to incomplete combustion or inclusion in petrochemical products, etc., (stored carbon) shows that these figures need to be updated and checked for their applicability on a global scale, since they are mostly based on U.S. data.

Some trace gas emissions from North American biomass fires with an assessment of regional and global fluxes from biomass burning

Emission factors for several trace gases were determined using airborne measurements from 13 biomass fires in North America. Emissions of methane (CH4), nonmethane hydrocarbons (NMHC), hydrogen (H2) and ammonia (NH3) were found to be positively correlated with the ratio of carbon monoxide (CO) to carbon dioxide (CO2) emission factors, both within each fire and between fires. This indicates that these four species are produced predominantly when combustion is inefficient. Methyl chloride (CH3Cl) emission factors were positively correlated with the ratio of CO to CO2 emission factors within the majority of the fires. However, a linear regression of the average CH3Cl emission factor for each fire onto the average ratio of the CO to CO2 emission factors produced a negative correlation coefficient. This indicates that the variance in CH3Cl emissions between fires is not due to differences in overall combustion efficiency. (According to previous research, differences in fuel chlorine content are mainly responsible for the differences in emissions of CH3Cl between fires.) The average NOx emission factors for three biomass fires in southern California were found to be significantly higher than the average NOx emission factors for the remaining 10 fires studied. It is suggested that this difference is due to an enhanced nitrogen content (possibly the result of pollutant deposition and in some cases nitrogen fixation) of the fuels consumed, and the consumption of large amounts of foliage during the three fires. The average NOx/CO2 molar ratio determined from this study (2.1 × 10−3) is consistent with results from other airborne and laboratory studies of biomass burning emissions. However, the N2O/CO2 molar ratios resulting from this study are roughly a factor of 2 larger than N2O/CO2 molar ratios obtained from laboratory studies. It is hypothesized that the higher N2O/CO2 molar ratios presented here are primarily due to emissions of N2O from the soil Overall average emission factors derived from this study were used to estimate the fluxes of several trace gases from temperate and boreal biomass fires. In addition, a new method is outlined for estimating fluxes of CH4, NMHC, H2 and NH3 from global biomass burning. The annual emissions of these four species from worldwide biomass burning are determined by this method to be 39, 17, 21 and 4.5 Tg yr−1, respectively. Our results indicate that the worldwide emissions of CH4, NMHC, H2 and NH3 from biomass burning represent 8%, 17%, 24% and 7%, respectively, of the total global emissions of these four species.