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1.
Summary The balance of evidence suggests a perceptible human influence on global ecosystems. Human activities are affecting the global
ecosystem, some directly and some indirectly. If researchers could clarify the extent to which specific human activities affect
global ecosystems, they would be in a much better position to suggest strategies for mitigating against the worst disturbances.
Sophisticated statistical analysis can help in interpreting the influence of specific human activities on global ecosystems
more carefully. This study aims at identifying significant or influential human activities (i.e. factors) on CO2 emissions using statistical analyses. The study was conducted for two cases: (i) developed countries and (ii) developing
countries. In developed countries, this study identified three influential human activities for CO2 emissions: (i) combustion of fossil fuels, (ii) population pressure on natural and terrestrial ecosystems, and (iii) land
use change. In developing countries, the significant human activities causing an upsurge of CO2 emissions are: (i) combustion of fossil fuels, (ii) terrestrial ecosystem strength and (iii) land use change. Among these
factors, combustion of fossil fuels is the most influential human activity for CO2 emissions both in developed and developing countries. Regression analysis based on the factor scores indicated that combustion
of fossil fuels has significant positive influence on CO2 emissions in both developed and developing countries. Terrestrial ecosystem strength has a significant negative influence
on CO2 emissions. Land use change and CO2 emissions are positively related, although regression analysis showed that the influence of land use change on CO2 emissions was still insignificant. It is anticipated, from the findings of this study, that CO2 emissions can be reduced by reducing fossil-fuel consumption and switching to alternative energy sources, preserving exiting
forests, planting trees on abandoned and degraded forest lands, or by planting trees by social/agroforestry on agricultural
lands. 相似文献
2.
Transportation sector is the second largest producer of greenhouse gas in Malaysia next to energy sector. It contributes to nearly 28 % of annual national carbon emissions due to its heavy dependency of hydrocarbons such as gasoline. If not properly managed, carbon dioxide emissions per capita are expected to nearly double in the next 5 years. Lack of interdisciplinary study on this sector has caused proper mitigation initiatives to be delayed, compounding the damage to the ecosystem. The objective of this study is to develop a dynamic probabilistic model to determine emissions and pollutants of transportation system in Malaysia using Analytica software, with focus on passenger cars for its large number over other vehicle classes. Several vehicle fleet management policies based on several key governmental, industrial and stakeholder’s intervention have been constructed and analyzed for a period of 25 years. This analysis found that greenhouse gas emissions and pollutants in 2040 can be reduced by up to 80 %, compared to emissions of 2020, without any adverse effect on vehicle demand nor the economy. However, without proper intervention, personal transportation system in Malaysia will generate nearly 80,000 kilotons of greenhouse gas annually by the year 2040. 相似文献
3.
The selective catalytic reduction (SCR) rate of NO with N-containing reducing agents can be enhanced considerably by converting
part of NO into NO2. The enhanced reaction rate is more pronounced even at lower temperatures by using an equimolar mixture of NO and NO2 (fast SCR reaction). The oxidation characteristics of NO over catalyst Pt/TiO2 have been determined in a fixed bed reactor (8 mm-ID) with different concentrations of oxygen, nitric oxide and nitrogen
dioxide in the presence of 8% water. The conversion of NO to NO2 increases with increasing oxygen (O2) concentration from 3 to 12%, but it levels off at higher O2 concentrations. The NO conversion to NO2 decreases with increasing NO concentration and it also decreases by an addition of NO2 in the feed stream. Therefore, the oxidation of NO over Pt/TiO2 catalyst could be auto-inhibited by the reaction product of NO2. The effects of CO and SO2 on NO oxidation characteristics have also been determined. In fact, the presence of SO2 significantly suppresses oxidation of NO but due to the less stability of sulfate on anatase structure in TiO2, it becomes less significant. On the other hand, the presence of CO increases NO oxidation significantly due to the auto-inhibition
effect by CO. Moreover, the effect of SO2/CO on NO oxidation has also been determined and it was observed that NO oxidation decreases with the increase in SO2/CO ratio. 相似文献
4.
Cosimo Magazzino 《The Environmentalist》2017,37(3):353-366
The aim of this paper is to analyze the relationship among economic growth, carbon dioxide emissions, and energy use for 19 APEC countries over the 1960–2013 years. Using a panel VAR technique, a three-variable VAR is estimated. Empirical findings illustrate that no causal relationship emerges between real GDP and energy use. Thus, our empirical evidence is in line with the “neutrality hypothesis.” Moreover, panel cointegration tests show that a long-run equilibrium relationship is questionable for the APEC countries. Granger causality analyses confirm our previous results, since in nine countries any causal relationship between GDP and energy is found. 相似文献