Projection of Greenhouse Gas Emissions for the Road Transport Sector Based on Multivariate Regression and the Double Exponential Smoothing Model

Global greenhouse gas reduction forecasting via machine learning model in the scenario of energy transition

Global warming is becoming increasingly serious, with greenhouse gas (GHGs) emissions identified as a principal contributor. In response to the climate crisis, many countries are actively transitioning to renewable energy. Therefore, it is crucial to forecast GHGs emissions across different countries under varying degrees of energy transition to inform decision-making. Previous studies often focused on single regions and overlooked the developmental variance among countries. To address this problem, this study aims to project GHGs emissions in 39 major carbon-emitting countries globally, distinguishing between developed countries (DCs) and developing countries (LDCs). The results show that a 5.39% increase in global GHGs emissions from 2016 to 2021 and a 327.64% rise in the renewable electricity generation of LDCs. Additionally, this research develops various energy transition scenarios, employs Random Forest (RF) for feature selection, and utilizes an Extreme Gradient Boosting (XGBoost) model enhanced by Bayesian Optimization (BO) to forecast GHGs emission levels in DCs and LDCs. The performance test shows that RF-BO-XGBoost has higher stability and accuracy. The projection results indicate that the total emissions from all DCs and all LDCs will decrease as the scenario shifts from the baseline to the high energy transition scenario, by 1.22% and 5.23% respectively. Further, the study quantifies the impacts of energy transitions on GHGs emissions across individual countries, revealing that not all countries are likely to achieve optimal reduction under the high energy transition scenario. This study underscores the influence of transition costs and supports the climate policymaking.

The impact of fuel cell vehicles deployment on road transport greenhouse gas emissions through 2050: Evidence from 15 G20 countries

As global concern over the negative impacts of global warming, primarily caused by using passenger vehicles (PVs), the transition to hydrogen fuel cell vehicles (HFCVs) is an essential alternative for reducing greenhouse (GHG) emissions. This research employs a bottom-up approach to analyze road vehicle fleet's GHG emissions. We calculated GHG emissions from PVs in 15 Group of Twenty (G20) countries based on four scenarios adopting the global HFCVs from 2024 to 2050. This paper introduces business-as-usual (BaU), moderate, aggressive, and non-HFCVs scenario. The results show that the aggressive scenario has the highest sales, estimated between 62,000 and 29.48 million vehicles by 2050, with global hydrogen market penetration rates 48.48%. Building on countries' respective national strategies, the findings highlight China and India as the leading markets for hydrogen demand, with Germany and Japan also showing significant interest. The aggressive scenario further demonstrates that transitioning from internal combustion engine vehicles (ICEVs) to battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and HFCVs can significantly reduce annual GHG emissions. Ultimately, this study finds that the transition to HFCVs could reduce emissions by up to 67.09% by 2050.

Synergizing economic growth and carbon emission reduction in China: A path to coupling the MFLP and PLUS models for optimizing the territorial spatial functional pattern

Carbon emissions caused by economic growth are the main cause of global warming, but controlling economic growth to reduce carbon emissions does not meet China's conditions. Therefore, how to synergize economic growth and carbon emission reduction is not only a sustainable development issue for China, but also significant for mitigating global warming. The territorial spatial functional pattern (TSFP) is the spatial carrier for coordinating economic development and carbon emissions, but how to establish the TSFP of synergizing economic growth and carbon emission reduction remains unresolved. We propose a decision framework for optimizing TSFP coupled with the multi-objective fuzzy linear programming and the patch-generating land use simulation model, to provide a new path to synergize economic growth and carbon emission reduction in China. To confirm the reliability, we took Qionglai City as the demonstration. The results found a significant spatiotemporal coupling between TSFP and the synergistic states between economic growth and carbon emission reduction (q ≥ 0.8220), which resolves the theoretical uncertainty about synergizing economic growth and carbon emission reduction through the path of TSFP optimization. The urban space of Qionglai City in 2025 and 2030 obtained by the decision framework was 6497.57 hm2 and 6628.72 hm2 respectively, distributed in the central and eastern regions; the rural space was 60,132.92 hm2 and 56,084.97 hm2, concentrated in the east, with a few located in the west; and the ecological space was 71,072.52 hm2 and 74,998.31 hm2, mainly located in the western and southeastern areas. Compared with the TSFP in 2020, the carbon emission intensity of the TSFP obtained by the decision framework was reduced by 0.7 and 4.7 tons/million yuan, respectively, and realized the synergy between economic growth and carbon emission reduction (decoupling index was 0.25 and 0.21). Further confirming that TSFP optimization is an effective way to synergize economic growth and carbon emission reduction, which can provide policy implications for coordinating economic growth and carbon emissions for China and even similar developing countries.

Modeling the Greenhouse Gases Data Series in Europe during 1990-2021

Nowadays, climate change and atmospheric pollution are two of humanity's most significant challenges. Greenhouse gases (GHGs) are responsible for climate change, and they create effects that are mostly irreversible. Therefore, monitoring and reducing such emissions are compulsory for the preservation of the environment for future generations. The European Union took action in this direction. The article presents the evolution of the total GHGs trend, from 1990 to 2021, in the EU countries and their associates. Trend analysis and grouping of the countries using different clustering techniques are performed. The analysis of the existence of greenhouse gases (GHGs) series' trend, in 30 countries from Europe, showed that the GHG emissions decreased from 1990 to 2021 in only 17 countries. The annual series, built using the data reported by each country each year, does not present a specific trend. After grouping the countries in clusters by k-means and hierarchical clustering, the representative series for the annual recorded values in the 30 studied countries, called Regional series (RegS), is built using series selected from the cluster with the highest number of elements. The same algorithm provides the Representative Temporal series (TempS), which selects specific years after clustering the annual GHG series.

A critical review of environmental and public health impacts from the activities of evaporation ponds

Evaporation ponds (EVPs) are among the most cost-effective, and simple wastewater treatment technologies used in many regions/countries with high solar radiation levels. However, its operational limitations, which include the overflow of wastewater, leakages via liners, and large surface area of the EVP that is exposed to atmosphere, creates a negative feedback to the environment. Therefore, the main aim of this review study of more than a hundred works published a little all over the continents is to provide a summary of various contaminations that are associated with EVPs activities through different environmental compartments. In addition, the impacts of EVP on fauna, human health including the current on-site sustainable mitigation strategies were also reviewed. The first conclusion from this study shows that the most commonly contaminants released into surface waters, groundwater, soil and sediments were heavy metals, pesticides, herbicides, selenium, including several major anions and cations. Non-methane hydrocarbons (NMHCs), volatile organic compounds (VOCs), and particulate matters (PMs) were the main air pollutants emitted from the surfaces of an EVP. Limited data is available about the emissions of atmospheric greenhouse gas (GHGs) especially carbon dioxide (CO₂) and methane (CH₄) from EVP surfaces. Migratory birds and aquatic organisms are the most vulnerable fauna as EVP wastewaters can cause obstruction of movements, affect diversity, and causes mortalities following the exposure to the toxic wastewater. The study revealed limited data about the potential health risk associated with occupational and environmental exposure to radiological hazards and contaminated drinking water from EVP activities. On-site EVP treatment strategies using bioremediation and electrochemical treatment technologies have shown to be a promising sustainable mitigation approach. Knowledge gaps in areas of GHGs monitoring/modeling, pollution exposure estimation and health risk assessments are urgently required to gain deeper understanding about the impact of EVP activities, and incorporate them into future EVP designs.

Climate Change-Greenhouse Gas Emissions Analysis and Forecast in Romania

Greenhouse gases (GHG), such as carbon dioxide, methane, nitrous oxide, and other gases, are considered to be the main cause of global climate change, and this problem has received significant global attention. Carbon dioxide has been considered the most significant gas contributing to global climate change. Our paper presents an analysis of the greenhouse gas emissions in Romania along with a forecast for the years to come. For the study, data from the National Institute of Statistics and Eurostat were gathered and used for the analysis in order to present the results. To obtain the results, the data gathered were analyzed using forecasting methods that can be of help in solving some uncertainties that surround the future. The greenhouse gas (GHG) emissions trends in Romania were analyzed both for linear and exponential function methods. The obtained results showed that the linear function analysis of total GHG emissions in Romania had a forecast accuracy higher than the exponential function method. From the analytical methods used we can draw the conclusion that the emissions are on a descending scale and choosing a proper method is important in analyzing data.

1,2—Propanediol Production from Glycerol Derived from Biodiesel’s Production: Technical and Economic Study

For every nine tons of produced biodiesel, there is another ton of glycerol as a byproduct. Therefore, glycerol prices dropped significantly worldwide in recent years; the more significant biodiesel production is, the more glycerol exists as a byproduct. glycerol prices also impact the biodiesel manufacturing business, as it could be sold according to its refinement grade. The primary objective of this work was to evaluate the economic potential of the production of 1,2-propanediol derived from the biodiesel produced in Colombia. A plant to produce 1,2-propanediol via catalytic hydrogenation of glycerol in a trickle-bed reactor was designed. The plant comprised a reaction scheme where non-converted excess hydrogen was recycled, and the heat generated in the reactor was recovered. The reactor effluent was sent to a separation train where 98% m/m purity 1,2-propanediol was attained. Capital and operational costs were estimated from the process simulation. The net present value (NPV) and the modified internal return rate (MIRR) of the plant were used to assess the viability of the process. Their sensitivity to key input variables was evaluated to find the viability limits of the project. The economic potential of the 1,2-propanediol was calculated in USD 1.2/kg; for the base case, the NPV and the MIRR were USD 54.805 million and 22.56%, respectively, showing that, for moderate variations in products and raw material prices, the process is economically viable.

Catalyst and Elemental Analysis Involving Biodiesel from Various Feedstocks

The world is currently faced with the depletion of fossil fuel energy sources and their use is associated with environmental pollution. This has triggered the need to seek alternative energy sources that are renewable, sustainable and environmentally benign. Biodiesel, an alternative fuel of interest, is obtainable from biomass feedstocks. In existing biodiesel fuel, there are concerns that it is a contaminant due to its elemental contents, which over time also affect its quality. This study aimed to investigate the influence of a bifunctional catalyst on the conversion of free fatty acids and the elemental composition of biodiesel obtained from waste oils of sunflower and palm feedstocks. The synthesised catalyst was characterised using BET, XRD, FTIR and SEM while ICP-OES and Rancimat were used for elemental contents and oxidation in feedstocks and biodiesels. The effect of Cu, Zn and Fe metals on the stability of synthesised biodiesel was further studied. The catalyst showed characteristics of bifunctionality with improved textural properties necessary for the conversion of high free fatty acids feedstocks to biodiesel, despite increasing Ca content within the produced biodiesel. Sunflower biodiesel showed superior fuel quality, although palm biodiesel had more oxidation stability. An increase in the concentration of metals decreased the induction period, with Cu and Fe being more effective than Zn metal.

Modeling Approach of an Air-Based Battery Thermal Management System for an Electric Vehicle

The battery thermal management system is one of the important systems of an electric vehicle with direct effects on its performance. In this regard, this paper proposes a mathematical model that increases the accuracy of data obtained by numerical analysis of the temperature inside battery packs. The activity of the design and development (as accurate as possible) of a battery pack leads to an increase in the life of the battery cells and of the energetic efficiency of the electric vehicle in the specific operating conditions of road traffic. The research methodology of the thermal phenomenon in the battery pack, presented by the authors, is based on an efficient co-simulation concept consisting of steady-state CFD simulations and transient 1D simulations using a new mathematical model for the thermal behavior of a lithium-ion (Li-ion) cylindrical battery and applied in a battery pack’s forced air cooling thermal management system. Comparing the obtained results, it was found that the use of the model provides more accurate calculations of the local thermal performance of the air cooling system, with a direct influence on optimizing its design and construction. It is also highlighted that using the proposed model for higher heat transfer coefficient values (increase in air flow), offers more accurate data compared to other models, with immediate benefits in the proper design and development of the battery’s thermal management system.

CO2 Emissions Reduction Measures for RO-RO Vessels on Non-Profitable Coastal Liner Passenger Transport

Reducing CO2 emissions from ships in unprofitable coastline transport using electricity and hydrogen has potential for island development to improve transport and protect biodiversity and nature. New technologies are a challenge for shipping companies and their introduction should be accompanied by a system of state aid for alternative energy sources. The energy requirements of an electric ferry for a route of up to 6 km were considered, as well as the amount of hydrogen needed to generate the electricity required to charge the ferry batteries to enable a state aid scheme. For a daily ferry operation, a specific fuel consumption of 60.6 g/kWh of liquid hydrogen is required in the system fuel cell with a total of 342.69 kg of hydrogen. Compared to marine diesel, the use of electric ferries leads to a reduction of CO2 emissions by up to 90%, including significantly lower NOx, Sox, and particulate matter (PM) emissions, and operating costs by up to 80%.

Assessment of Petrol and Natural Gas Vehicle Carbon Oxides Emissions in the Laboratory and On-Road Tests

The problem of global warming and the related climate change requires solutions to reduce greenhouse gas emissions, in particular CO2. As a result, newly manufactured cars consume less fuel and emit lower amounts of CO2. In terms of exhaust emissions and fuel consumption, old cars are significantly inferior to the more recent models. In Poland, for instance, the average age of passenger cars is approximately 13 years. Therefore, apart from developing new solutions in the cars produced today, it is important to focus on measures that enable the reduction in CO2 emissions in older vehicles. These methods include the adaptation of used cars to run on gaseous fuels. Natural gas is a hydrocarbon fuel that is particularly preferred in terms of CO2 emissions. The article presents the results of research of carbon oxides emission (CO, CO2) in the exhaust gas of a passenger car fueled by petrol and natural gas. The emissions were measured under the conditions of the New European Driving Cycle (NEDC) test and in real road tests. The test results confirm that compared to petrol, a CNG vehicle allows for a significant reduction in CO2 and CO emissions in a car that is several years old, especially in urban traffic conditions.