High Greenhouse Gas Emissions Research Articles

Technological innovation, crude oil volatility, and renewable energy dimensions in N11 countries: Analysis based on advance panel estimation techniques

Deterioration of natural environment is a serious threat to all the communities on earth. However, green and contemporary innovations reduce the adverse environmental outcomes generated through higher greenhouse gas emissions. Therefore, this study examines the role of technological innovationand renewable energy dimensions towards improving environmental quality. At the same time, the role of oil price volatilityis also observed during the study period from 1995 to 2018 for N11 countries with the help of advanced panel estimation. More specifically, this research applies second-generation panel cointegration technique along with continuously updated fully modified and continuously updated bias-corrected (Cup-BC) techniques. The results show that technological innovation and renewable energy dimensions like hydro and thermal power play a major role in reducing environmental threats. However, crude oil price volatility plays a major role in environmental deterioration. Besides, this research offers valuable recommendations for environmentalists.

Whole-system analysis reveals high greenhouse-gas emissions from citywide sanitation in Kampala, Uganda

Global estimates of emissions of greenhouse gasses do not take into account the complex service chain in rapidly growing cities in low- and middle-income countries. This paper presents an end-to-end analysis to estimate emissions from all stages of the sanitation-service chain, using Kampala in Uganda as an example. We show that emissions associated with long periods of storage of faecal waste in sealed anaerobic tanks (49%), discharge from tanks and pits direct to open drains (4%), illegal dumping of faecal waste (2%), leakage from sewers (6%), wastewater bypassing treatment (7%) and uncollected methane emissions at treatment plants (31%), are contributing to high levels of greenhouse-gas emissions. Sanitation in Kampala produces 189 kt CO2 e per year, which may represent more than half of the total city-level emissions. Significant further empirical and modelling work is required to update estimates of greenhouse-gas emissions from sanitation systems globally.

Wetter California Projected by CMIP6 Models With Observational Constraints Under a High GHG Emission Scenario

AbstractAs the world's fifth‐largest economy entity, California (CA) is vulnerable to climate changes especially the magnitude of winter (wet season) precipitation that is closely linked to regional drought severity, vegetation growth, and wildfire activities. However, the fate of CA precipitation in the future remains highly uncertain, for example, the state‐of‐the‐art Earth system models (ESMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) projected −3% to +42% and −27% to +63% precipitation changes in northern and central‐southern CA, respectively, under the high greenhouse gas (GHG) emission scenario (SSP585). In this work, we applied the Pareto optimality concept and used observed teleconnection patterns (causal relationships between ocean regions and CA precipitation) to mechanistically constrain CMIP6 projected CA precipitations. We estimated that precipitation will robustly increase by 0.4–1.3 mm d−1 (10–34%) over northern CA and increase by 0.1–0.5 mm d−1 (7–32%) over central‐southern CA by the end of the 21st century compared with present‐day. Up to 71% of ESM projection uncertainties were reduced mainly due to the strong and consistent causal relationship between North American west coast sea level pressure and CA precipitation in both observations and CMIP6 models. Our results suggest that teleconnection patterns are powerful mechanistic constraints that can help explain and reduce uncertainties in ESM projections.

Republic of Kazakhstan: 2021 Article IV Consultation-Press Release; Staff Report; Staff Statement; and Statement by the Executive Director for Kazakhstan

Activity returned to its pre-COVID level in 2021. Inflation remains well above the NBK’s 4–6 percent target band, and spillovers from sanctions on Russia will exacerbate price pressures and weaken economic growth in 2022. Kazakhstan benefits from strong fiscal and external buffers but risks to the outlook are elevated due to the uncertain impact on Kazakhstan of the sanctions on Russia and heightened domestic tensions since the January social unrest episode. In the medium term, non-oil growth under the baseline is expected to converge to about 4 percent. Sustainable growth will require greater economic diversification. Climate-related challenges are acute for Kazakhstan given its outsized hydrocarbon sector, high per-capita greenhouse gas emissions, and low domestic energy prices.

CuOx clusters decorated TiO2 for photocatalytic oxidation of nitrogen in air into nitric oxide under ambient conditions

Photocatalytic nitric oxide (NO) synthesis from air is an attractive way to supersede the conventional nitrogen fixation manufacturing technique accompanied by high energy requirements and greenhouse gas emission. The development of efficient photocatalysts for direct solar-driven N2 oxidation to NO without external thermal assistance is highly challenged. Here, CuOx clusters decorated TiO2 nanoflowers with various copper contents are constructed and used for solar-driven air reaction into NO under ambient conditions. When the copper content is 1 wt%, the sample shows the optimal performance with a yield rate of 35.0 mmol m−2 h−1 (7.7 μmol h−1) and an apparent quantum efficiency of 1.77% at 365 nm. A series of in situ and ex situ characterizations reveal Cu2O species and TiO2 support form direct Z-scheme heterojunction over 1%Cu-TiO2. This heterojunction can promote the adsorption and activation of nitrogen and oxygen reactants, leading to the performance enhancement of NO photosynthesis from air. Also, we proposed a possible NO photosynthesis reaction pathway over 1%Cu-TiO2.

Dietary Choices Impact on Greenhouse Gas Emissions: Determinants and Correlates in a Sample of Adults from Eastern Germany

The present study estimated diet-related greenhouse gas emissions (GHGE) and land use (LU) in a sample of adults, examined main dietary contributors of GHGE, and evaluated socio demographic, lifestyle, and wellbeing factors as potential determinants of high environmental impact. A cross-sectional design based on data collected from the European Prospective Investigation into Cancer and Nutrition (EPIC)—Potsdam cohort (2010–2012) was used. Usual diet was assessed using food frequency questionnaires. Diet-related GHGE and LU were calculated using a European-average lifecycle analyses-food-item database (SHARP-ID). Information on potential determinants were collected using self-administered questionnaires. Men (n = 404) and women (n = 401) at an average age of 66.0 ± 8.4 years were included. Dietary-related energy-adjusted GHGE in men was 6.6 ± 0.9 and in women was 7.0 ± 1.1 kg CO2 eq per 2000 kcal. LU in men was 7.8 ± 1.2 and in women was 7.7 ± 1.2 m2/year per 2000 kcal. Food groups contributing to most GHGE included dairy, meat and non-alcoholic beverages. Among women, being single, having a job, being a smoker and having higher BMI were characteristics associated with higher GHGE, whereas for men these included being married, longer sleeping duration and higher BMI. Further studies are warranted to provide insights into population-specific determinants of sustainable dietary choices.

Influence of Ozone Forcing on 21st Century Southern Hemisphere Surface Westerlies in CMIP6 Models

AbstractThe tropospheric westerly jet is a key feature of Southern Hemisphere climate. In recent decades the jet strengthened in austral summer (December–February [DJF]) and moved poleward owing to the Antarctic ozone hole. Future jet trends will be influenced by recovery of the Antarctic ozone hole and greenhouse gas (GHG) forcing. Here, we examine 21st century projections of ozone, temperature and winds in the sixth Coupled Model Intercomparison Project models with (CHEM) and without (NOCHEM) interactive chemistry. NOCHEM models use an ozone data set that was produced with GHG forcings inconsistent with those used by CHEM models, leading to less ozone recovery in the Antarctic springtime lower stratosphere. This propagates to different stratospheric temperature projections and DJF westerly winds: NOCHEM models project a 78 ± 52% stronger increase in DJF westerly wind speeds than CHEM models under the high GHG emissions scenario SSP585. Our results show the importance of simulating stratospheric ozone accurately for Southern Hemisphere climate change projections.

Carbon-neutral building renovation potential with passive house-certified components: Applications for an exemplary apartment building in the Republic of Korea

Building energy consumption for heating and cooling and the comparatively short building lifecycle help account for the increasing ratio of the building sector's greenhouse gas (GHG) emissions. To counteract this increase, sustainable building envelope renovations can minimize GHG emissions through the extension of building lifecycle, saving of construction material, increased energy efficiency, and reduced heating and cooling energy demands. To reduce the GHG emissions of energy efficient building envelope renovation systems, this article compares the Life Cycle Assessment (LCA) results of different Passive House (PH) certified building envelope components regarding their GHG emissions per area unit. Based on PH-certified components, different building envelope renovation components were developed. The LCA facilitated the identification of components with the lowest carbon emissions, which were applied in the PH-conforming renovation model of an exemplary apartment building in Seoul, Republic of Korea. The LCA results over a service life of 50 years illustrate that the highest GHG emissions are associated with the renovated building's primary service energy demand, followed by windows, and the transport of materials. These research findings facilitate the environmental impact determination of multiple PH-standard building renovation systems, and support the planning of building renovations with minimized carbon footprints and service energy demands.

Climate change and New Zealand’s groundwater resources: A methodology to support adaptation

Study regionHawke’s Bay and Otago regions, North and South Islands, New Zealand (NZ). Study focusEvidence that climate change affects groundwater is emerging, but a complete understanding of the processes and impacts on the resources remains limited in most countries, including NZ. This paper presents a methodology to explore the potential effects of climate change on groundwater for an envelope of future climate scenarios (i.e., low and high greenhouse gas emissions; mid- and end-century). The methodology uses national and sub-national datasets and models and is applied to two case studies (Hawke’s Bay and Otago). Its structure allows for future implementation in other NZ regions. New hydrological insights for the regionResults are provided as projected changes in precipitation minus evapotranspiration, rainfall recharge to groundwater (RR) and water table elevation. General water quantity reductions are projected for Hawke's Bay (e.g., RR reduced by up to −1.5 mm/d), and more limited and variable changes for Otago (e.g., RR varying between +/- 0.4 mm/d).We then present a discussion about furthering the science of climate change effects on groundwater, characterisation of climate change uncertainty and unique effects, and adaptation in the NZ context. We anticipate that our results, despite limitations and uncertainty, can enable adaptation actions without delay. We recommend integrated and adaptive approaches, including action effectiveness monitoring and community engagement, to develop resilience to climate change threats.

Life cycle assessment and techno-economic analysis of ethanol production via coal and its competitors: A comparative study

The world’s first industrialized coal-based fuel ethanol (CBFE) and emerging second-generation fuel bioethanol (SGFB) routes are promising alternatives and potential competitors to the conventional first-generation fuel bioethanol (FGFB) route. Understanding the comprehensive competitiveness of the three fuel ethanol production routes is important for the development of clean and low-carbon transportation worldwide. However, there is currently a dearth of related knowledge and scientific data. In this study, we identified and compared the strengths and weaknesses of the three fuel ethanol production routes using an assessment framework that integrates life cycle assessment, techno-economic analysis, and entropy weight method. Environmental performance was investigated with the 18 midpoint impact categories of the ReCiPe 2016 method and modeled using the SimaPro software. Economic performance was represented using the net present value, dynamic payback period, and internal rate of return. The results demonstrated the highest comprehensive score in the SGFB route owing to its excellent environmental performance, which will likely address the unsustainability of the FGFB route through the efficient utilization of agricultural residuals. Owing to its considerable economic benefit, the industrialization of the CBFE route not only offers a new downstream chain in the coal industry but also diversifies the sources of fuel ethanol away from biomass. However, such a promising alternative faces a substantial challenge associated with its significant environmental impact, especially with its high greenhouse gas emissions. These results provide valuable information on the relative advantages and disadvantages of the CBFE, FGFB, and SGFB routes for scientific tradeoffs and decisions.

Speed analysis of motorcycle's wheel drive in various road conditions

The usage of the motorcycle as a mode of transportation has led to increased energy consumption in the transportation sector and high emissions of greenhouse gases. Thus, the rapid development of electric motorcycles through the advancement of technology provides the possibility to address the issues of high energy consumption and the emission of pollutants. Despite its convenience in accommodating mobility in an urban area, statistical data show that road accidents involving the motorcyclist in Southeast Asian Nations (ASEAN) countries are very high. The contributing factor to the worrying situation is the failure in controlling the motorcycle speed. One of the solutions is by adjusting the motorcycle speed according to different road conditions. However, a shortcoming is identified based on the numerous studies conducted relating to the electric motorcycle where the studies exclude an analysis of electric motorcycle speed when travelling on different road conditions. Therefore, the slip ratio on the front and the rear wheel has been studied to analyze the suitable electric motorcycle speed when driven on different road conditions. An emphasis is made on two road conditions: dry and wet, and the simulation reveals the suitable speed range for the motorcycle under both road conditions.

The role of seafood in sustainable diets

Recent discussions of healthy and sustainable diets encourage increased consumption of plants and decreased consumption of animal-source foods (ASFs) for both human and environmental health. Seafood is often peripheral in these discussions. This paper examines the relative environmental costs of sourcing key nutrients from different kinds of seafood, other ASFs, and a range of plant-based foods. We linked a nutrient richness index for different foods to life cycle assessments of greenhouse gas (GHG) emissions in the production of these foods to evaluate nutritional benefits relative to this key indicator of environmental impacts. The lowest GHG emissions to meet average nutrient requirement values were found in grains, tubers, roots, seeds, wild-caught small pelagic fish, farmed carp and bivalve shellfish. The highest GHG emissions per nutrient supply are in beef, lamb, wild-caught prawns, farmed crustaceans, and pork. Among ASFs, some fish and shellfish have GHG emissions at least as low as plants and merit inclusion in food systems policymaking for their potential to support a healthy, sustainable diet. However, other aquatic species and production methods deliver nutrition to diets at environmental costs at least as high as land-based meat production. It is important to disaggregate seafood by species and production method in ‘planetary health diet’ advice.

Impacts of heat stress on global cattle production during the 21st century: a modelling study

Heat stress in animals is one of the major climate change impacts on domesticated livestock raised in both intensive and extensive production systems. At temperatures higher than an animal's thermoneutral zone, heat stress can affect liveweight gain, milk yield, and fertility. Animal welfare may also be negatively affected by heat stress even in the absence of effects on productivity, at least in the short term. We estimated the comparative statics change in the value of cattle milk and meat production from heat stress-induced losses at the global level, using climate scenario outputs for the middle (2045) and end of the century (2085). The loss estimates are based on bioenergetic equations that relate changes in dry matter intake (DMI) to both cold and hot, humid weather. DMI changes were estimated using CMIP6 climate data and linked to a global dataset containing information on livestock production systems, animal numbers, and region-specific and system-specific animal diets. Changes in DMI were converted to changes in milk and meat production and valued using early 20th century world prices (ie, constant 2005 US dollars). For a high greenhouse-gas emission scenario (SSP5-8.5), production losses from heat stress were estimated to amount to $39·94 billion (95% CI 34·39-45·49 billion) per year by the end of the century, or 9·8% of the value of production of meat and milk from cattle in 2005. For a low emission scenario (SSP1-2.6), the value of production losses was $14·89 billion (12·62-16·95 billion) per year, or 3·7% of 2005 value. In both scenarios, losses in most tropical regions were projected to be far greater than they were in temperate regions. Our results highlight the potential magnitude and extent of the adaptation efforts that will be necessary to combat the effects of increasing heat stress on cattle production during this century if food security challenges are to be minimised. Adaptations include switching to more heat-tolerant breeds and provision of shade, ventilation, and cooling systems. CGIAR Trust Fund and bilateral donors.

Water reuse as a strategy for mitigating atmospheric emissions and protecting water resources for the circularity of the swine production chain

High greenhouse gas emissions, high water demand, and waste with high pollution potential are critical points for waste management generated in animal production. With significant contributions in global emissions of air pollutants, sustainable practices for agriculture are fundamental to mitigate global climate change, besides ensuring protection to water resources, which is as critical as climate issues. Despite the importance of these issues, some gaps exist in the literature to develop practices capable of fostering water security and mitigation of greenhouse gas emissions. In this sense, the present study aimed to evaluate the impacts of reusing NO3− rich effluents inside the facilities for cleaning the swine houses and consequent atmospheric emissions of nitrous oxide (N2O) and methane (CH4). In swine manure, the generation of volatile fatty acids (VFA) was strongly influenced by temperature; a change in temperature from 10 to 18 °C increased by ten times the rate of VFA production, reflecting directly in methane emission and availability of organic carbon for the denitrification process. The effluent reuse practice, rich in nitrate, considering the organic carbon bioavailability in the pit storage, decreased methanogenic activity with a consequent VFA use as a bioavailable carbon source for denitrification, reducing greenhouse gas (GHG) emissions and consequently, the environmental impacts of swine production. In this way, the water reuse of 40% can mitigate up to 80% of GHG emission, with a minimum C/N ratio of 20, to ensure that at all temperatures the denitrifying process occurs efficiently since the carbon limitation negatively affected the N2O emission due to incomplete denitrification. Therefore, our results demonstrate the importance of this practice for swine sustainability and the capacity to adopt simple measures in favor of circularity in the swine production chain.

Catalytic Kinetics Regulation for Enhanced Electrochemical Nitrogen Oxidation by Ru-Nanoclusters-Coupled Mn3 O4 Catalysts Decorated with Atomically Dispersed Ru Atoms.

Electrochemical N2 oxidation reaction (NOR), using water and N2 in the atmosphere, represents a sustainable approach for nitric production to replace the conventional industrial synthesis with high energy consumption and greenhouse gas emission. Meanwhile, owing to chemical inertness of N2 and sluggish kinetics for 10-electron transfer, emerging electrocatalysts remain largely underexplored. Herein, Ru-nanoclusters-coupled Mn3 O4 catalysts decorated with atomically dispersed Ru atoms (Ru-Mn3 O4 ) are designed and explored as an advanced electrocatalyst for ambient N2 oxidation, with an excellent Faraday efficiency (28.87%) and a remarkable NO3 - yield (35.34µg h-1 mg-1 cat. ), respectively. Experiments and density functional theory calculations reveal that the outstanding activity is ascribed to the coexistence of Ru clusters and single-atom Ru. The synergistic effect between the Ru clusters and Mn3 O4 can effectively activate the chemically inert N2 , lowering the kinetic barrier for the vital breakage of N≡N. The intensive *OH supply and enhanced conductivity are used to regulate the catalytic kinetics for optimized performance. This work provides brand-new ideas for the rational design of electrocatalysts in complicated electrocatalytic reactions with multiple dynamics-different steps.

Rapid surface water expansion due to increasing artificial reservoirs and aquaculture ponds in North China Plain

Water shortage has severely threatened the North China Plain (NCP), a typical grain bowl and highly populated and urbanized area in China. As surface water body area (SWA) is a critical variable for measuring regional water resources, understanding its changes and driving mechanisms is important for sustainable water management. Here, we examine the interannual variations and trends of SWA in the NCP during 1987–2020 by using all the available Landsat imagery, the water indices- and threshold-based water mapping algorithm, and cloud computing platform Google Earth Engine (GEE). The results show that SWA of the NCP significantly (p < 0.05) expanded by 68.0% (from 4740.0 km2 in 1987 to 7963.7 km2 in 2020) at a rate of 101.9 km2/yr. The most remarkable expansion of SWA happened in Shandong Province (75.0 km2/yr), which is an increasingly important aquaculture production region. We find that the increasing artificial reservoirs/lakes due to the implementation of water projects, together with aquaculture development, are the main drivers for the expansion of SWA in the NCP. The expansion of SWA caused a significant increase in water evaporation (0.09 km3/yr) in the NCP as the shallow nature of these artificial reservoirs/lakes and aquaculture ponds could lead to excess evaporation because of the frequent heating and cooling cycles due to their limited abilities to store energy. Similarly, Shandong Province experienced the most rapid increase in water evaporation (0.03 km3/yr), which could accelerate the loss of water storage at a rate of 8.4–14.4 mm/yr in the regions covered by surface water bodies. Continuous temperature rise (0.02–0.06 °C/yr) in the future, as predicted by the climate models (CMIP5) under the two Representative Concentration Pathway (RCP) scenarios of medium (RCP 4.5) and high (RCP 8.5) greenhouse gas emission, could further increase water evaporation, which may add more pressure to regional water shortage. This study warns that, despite an observed significant SWA expansion, water shortage remains a major concern in the NCP.

Greenhouse gas emissions inventory data acquisition and analytics for low carbon cities

This paper studied greenhouse gas inventory data acquisition and analytics for municipalities in Thailand. A complete and transparent GHG inventory of eight municipalities was developed to document the current situation, and to help decision-makers to clarify their priorities for reducing greenhouse gas emissions. The Global Protocol for Community-Scale Greenhouse Gas Emissions Inventories guidelines was used to investigate and calculate the greenhouse gas emissions and assess data accuracy. The results indicated that the data source, data format, and data collection of each municipality are relatively similar. Moreover, the activity data needed to be obtained from several authorities. The results showed that Nonthaburi Municipality had the highest greenhouse gas emissions at 2,286,838 tCO2e/yr and Buriram Municipality, the lowest at 239,795 tCO2e/yr. On a per-capita basis, Lamphun Municipality was the highest with 10.1 tCO2e/capita and Buriram Municipality the lowest with 3.8 tCO2e/capita. The results suggest that the municipalities should continually develop a GHG database by creating a routine procedure. An information management system should be produced in the shape of big data which can lead to state policies, plans, and actions for city development to ensure the reduction of greenhouse gas emissions. This in turn will lead to a low carbon city.

African heritage sites threatened as sea-level rise accelerates

The African coast contains heritage sites of ‘Outstanding Universal Value’ that face increasing risk from anthropogenic climate change. Here, we generated a database of 213 natural and 71 cultural African heritage sites to assess exposure to coastal flooding and erosion under moderate (RCP 4.5) and high (RCP 8.5) greenhouse gas emission scenarios. Currently, 56 sites (20%) are at risk from a 1-in-100-year coastal extreme event, including the iconic ruins of Tipasa (Algeria) and the North Sinai Archaeological Sites Zone (Egypt). By 2050, the number of exposed sites is projected to more than triple, reaching almost 200 sites under high emissions. Emissions mitigation from RCP 8.5 to RCP 4.5 reduces the number of very highly exposed sites by 25%. These findings highlight the urgent need for increased climate change adaptation for heritage sites in Africa, including governance and management approaches, site-specific vulnerability assessments, exposure monitoring, and protection strategies.

Influence of waste glass powder as a supplementary cementitious material (SCM) on physical and mechanical properties of cement paste under high temperatures

Supplementary cementitious materials (SCMs) have attracted increasing research interests due to the energy-intensive process and high greenhouse gases emissions of conventional cement. Meanwhile, large amounts of domestic wastes such as waste glass are causing serious environmental issues due to their nonbiodegradable characteristic. Thus, recycling waste glass is a sustainable way to mitigate the environmental problem, conserve natural materials, minimize landfill spaces, and save energy during the recycling production process. This paper experimentally studied the effect of using waste glass powder (WGP) as an ordinary Portland cement (OPC) supplementary material on the paste specimens at ambient temperature and after exposure to high temperatures (800 °C, 1000 °C, and 1200 °C). The physical-mechanical properties such as workability, setting time, compressive strength, and bonding strength of the OPC paste samples containing different mass contents of WGP (0%, 10%, 20%, and 30%) were investigated and discussed. The potential alkaline aggregate reaction (ASR) effect of WGP on OPC was investigated by the accelerated mortar-bar method. The results show that the addition of WGP contributed to the workability but led to prolonged setting time of the OPC paste. On the other hand, the introduction of WGP in OPC mitigated the degradation of the OPC matrix under high temperatures and could reduce the ASR effect. Therefore, the WGP could be regarded as a feasible SCM to OPC to improve the safety of OPC-based structures both at ambient and under high temperatures.

Well-to-wheel greenhouse gas emissions of electric versus combustion vehicles from 2018 to 2030 in the US

Concise abstractElectric vehicles (EVs) can reduce transportation-related greenhouse gas (GHG) emissions, given the planned electric grid decarbonization. Regulations can also reduce internal combustion engine vehicle's (ICEVs) emissions by mandating increased fuel economies or ethanol-gasoline mixes. Factors such as fuel economy, electricity grid mix, vehicle choice, and temperature affect EV GHG emissions relative to ICEVs, and successfully decarbonizing the transportation sector depends on understanding their combined effects. We use life-cycle assessment to compare the EV and ICEV well-to-wheel GHG emissions in the United States and four other states from 2018 to 2030. We found lower emissions for EVs than ICEVs in most conditions considered. In New York state, where natural gas power plants replace nuclear energy, GHG emissions of electricity generation increase over time after 2020. Future ICEVs can have comparable emissions to EVs due to fuel economy increase. Therefore, EV and ICEV can together lower transportation GHG emissions at a faster pace. Extended abstractTransportation-related greenhouse gas (GHG) emissions can be reduced by (a) increasing the share of electric vehicles (EVs) and (b) reducing GHG emissions of internal combustion engine vehicles (ICEVs) by mandating increased fuel economies or ethanol-gasoline mixes. Factors, such as fuel economy, electricity grid mix, vehicle choice, and temperature affect EVs' relative GHG emissions compared to ICEVs, and understanding their combined effect is necessary for a successful decarbonization of the transportation sector. We used life-cycle assessment to evaluate the simultaneous effect of the above-mentioned factors on the well-to-wheel GHG emissions of EVs and ICEVs from 2018 to 2030. The analysis was performed for the United States (US) average and state-level for Arizona, California, New York, and Oregon.Our results showed lower GHG emissions for EVs than ICEVs for most conditions considered. GHG emissions are expected to decrease in the US on average by 5% for EVs and 27% for ICEVs in 2030 compared to 2018. In 2030, the ICEV well-to-wheel GHG emissions were comparable to those of the EVs in the US average and Arizona. EVs perform best in California and Oregon throughout the considered period. In regions, such as New York, EVs driven 2021 and after will have higher GHG emissions than ICEVs, as natural gas power plants are replacing nuclear energy. While EV GHG emissions decrease over time due to grid decarbonization, future ICEVs can lower the GHG emissions, especially for larger vehicles, where EVs might not be the best option. Therefore, EV and ICEV can together lower transportation GHG emissions at a faster pace.