CO2 Emission Reduction Targets Research Articles

Decarbonizing Urban Mobility: A Methodology for Shifting Modal Shares to Achieve CO2 Reduction Targets

In most urban areas, mobility is predominantly reliant on automobiles, leading to significant negative environmental impacts, such as noise pollution, air pollution, and greenhouse gas emissions. To meet the objectives of the Paris Agreement, urgent action is required to decarbonize the mobility sector. This necessitates the development of assessment and planning tools to create effective decarbonization scenarios. Urban mobility must evolve to reduce dependency on fossil fuels by increasing public transport options and promoting active modes of transportation. This research presents a methodology to estimate the modal share required to shift car users to active modes and public transport, thereby achieving future CO2 emission reduction targets in the road transport sector. A case study in Braga, Portugal, demonstrates that to meet the 2040 target of 59,150 tons of CO2, 63% of trips must be made using active modes (e.g., walking and cycling) and 32% by public transport.

Enhancing the integration of PV and coal-fired power plant for low-carbon, low-cost, and reliable power supply through various energy storage systems

The integration of photovoltaic (PV) system and coal-fired power plants (CFPP) through various energy storage systems (ESS) presents a promising strategy for achieving a low-carbon, low-cost, and reliable power supply. This study proposes a low-carbon power system that deeply integrates PV and CFPP through battery, thermal, and ammonia energy storage system (BESS, TESS, AESS). Multi-objective optimizations were conducted to minimize both the levelized cost of electricity (LCOE) and specific CO2 emission while considering constraints related to power supply reliability. Additionally, the influence of technological advancements on reducing LCOE was explored, providing insights into the developmental pathways of these energy storage technologies. The results indicate that: (1) The optimal selection of ESS is related to CO2 emission reduction targets. For less restrictive targets, it is economical to abandon ESS and rely entirely on PV and CFPP. As emission reduction targets progress, TESS becomes economically optimal. In scenarios with strict targets, BESS becomes economically optimal. (2) The combination of PV+CFPP+MultiESS demonstrates superior cost-effectiveness under high-reliability constraints, exhibiting a 7.6 % lower LCOE compared to PV+CFPP+SingleESS at a reliability level of ≥ 99 %. (3) Compared to CFPP retrofitted with CCS, the PV+CFPP+ESS integrated system is more economically favorable for less restrictive CO2 emission reduction targets. However, as the CO2 emission limits become stricter, the CCS-retrofitted technology becomes more economically favorable. (4) To enhance cost-competitiveness, developments should be directed toward reducing the unit investment cost of storage for BESS, while reducing the unit investment cost of power conversion system for AESS. As for TESS, technological advancements across various aspects can effectively contribute to its cost-competitiveness.

The effect of considering the real consumption on the assessment of the renovation of social housing buildings

Social housing is a priority within the European Union (EU) for boosting the necessary building renovation. The predicted and real consumption of buildings usually differ, and this is the Energy Performance Gap (EPG). Here, the effect the EPG has on the renovation decision-making process is analysed. The results show that a significant error in energy consumption reduction can occur if real consumption is not considered. Generally, it has been found that the average difference between considering real consumption or not is 22 percentage points. The economic perspective of the renovation is therefore influenced by the tenants’ real consumption and some renovation scenarios can become non-profitable or vice-versa. However, considering real consumption is complex and time consuming, so a simplified methodology intended for use by investors or administrators without considerable effort is proposed. This methodology has been proved to be reliable, accounts for real consumption, and allows a more accurate assessment of building renovation. Particularly, when real consumption is considered, the actual contribution of the building’s renovation regarding CO2 emissions reduction targets can be properly assessed. Finally, the improvement in the dwellings’ indoor conditions is analysed, as a key additional aspect to support the EU priority to renovate social housing.

Research on Regional Economic Growth and CO2 Emissions Reduction Targets: A Decoupling Perspective

Elucidating the relationship between economic growth and CO2 emissions helps promote the coordinated and synergistic development of the economy and the environment. This study utilizes the Tapio decoupling model to analyze the decoupling relationship between economic growth rate and CO2 emissions in 14 cities of Liaoning Province from 2005 to 2020. Additionally, a model is established with the aim of determining CO2 reduction targets for achieving strong or weak decoupling states. Results showed that although most cities showed a strong or weak decoupling state, the decoupling performance in specific year was not ideal, the proportion of negative decoupling increased from 2017 to 2020. Liaoning Province faces significant challenges in decoupling economic growth rate from CO2 emissions, it needs to reduce its CO2 emissions (CE) by 5659.33 107 Kg or 5397.80 107 Kg to achieve strong or weak decoupling, respectively. Among the 14 cities, 8 cities have not achieved strong or weak decoupling. Cities such as Anshan, Yingkou, and Benxi face the greatest challenges, with a minimum required reduction of 25.72% in CE, 41.77% in Carbon Emissions per Capita, and 16.62% in Carbon Emissions per Unit of GDP. The research results can provide theoretical support for improving energy efficiency.

Electrification policy impacts on land system in British Columbia, Canada

British Columbia (BC) is committed to transitioning to a low-carbon energy system to meet its CO2 emission reduction targets, but this shift towards renewable energy sources may have significant implications for land use. This paper investigates the land-use impacts of different electrification pathways and technology choices in BC's energy system using the BC Nexus model. Our analysis highlights the potential increase in land-use requirements associated with transitioning from fossil fuels to renewable energy sources, with the occupied land of the power system potentially increasing up to six times larger than the current total build-up land (depending on the scale of electrification and technology choice). These findings have important implications for policymakers in terms of balancing the trade-offs between energy security, economic development, and environmental sustainability. By understanding the physical footprint of the energy transition, decision-makers can develop more effective climate policies and sustainable development strategies.

Does innovation facilitate meeting the CO2 emission reduction targets of China: A non-linear approach

China has been implementing energy efficiency and CO2 emission reduction schemes at the provincial level that have been embedded in the National Five Year Plans of the country. We set out to investigate the relationship between R&D expenditures and CO2 emissions in China at the province level in the context of the planned emissions reduction targets. We explore the possibility of the existence of a non-linear relationship between R&D expenditures and CO2 emissions with a non-parametric methodology, a fixed effect panel data quantile (FEQR) regression estimator applied to a panel of 30 provinces. We stratify the sample according to the five emissions reduction target tiers of the 12th Five-Year National Plan of China and we investigate the role of R&D expenditures in emissions reduction within each of the tiers. We find an inverse U relationship with different turning points for the three middle tiers and a U-shaped relationship for the tier under the most stringent environmental regulation. We find no effect in the tier with the least stringent emissions reduction targets. A further investigation shows that the above results are attributed to sectors with relatively low energy intensity and not to the sectors of heavy industry. The results allow us to draw broad conclusions about the effectiveness of investment in new technologies as a means of meeting the CO2 targets in China.

The Role of Positive Energy Districts through the Lens of Urban Sustainability Protocols in the Case Studies of Salzburg and Tampere

To achieve the ambitious CO2 emission reduction targets set by the Sustainable Development Goals, it is crucial to act on cities. Indeed, cities are responsible for 67% of the world’s primary energy consumption and about 70% of energy-related CO2 emissions. To support the urban energy transition, a broad implementation of zero-emission districts or, even better, positive energy districts (PEDs) is expected. PEDs can be defined as energy-efficient and energy-flexible urban areas that aim to provide a surplus of clean energy to the city by using renewable energies. However, in developing the PEDs concept, it is necessary to consider not only the technical issue of energy systems but also the environmental, social, and economic spheres. To be effective, it is important to provide decision-makers with tools such as Urban Sustainability protocols for PEDs, which can effectively assess the complexity of the impacts a PED might have on other urban transformations from a multi-stakeholder perspective. LEED for Neighborhood Development, BREEAM Communities, and CASBEE for Cities are the most widely used and known protocols in the world for the evaluation of districts. These certification protocols were established before the concept of PEDs and, therefore, are not considered. However, they exhibit some shared characteristics which permit the evaluation of PEDs’ sustainability. In fact, through this research, an attempt is made to analyze how the implementation of sustainability protocols in existing PED projects can improve sustainability, but also how PED projects can improve evaluation systems through interventions that have not been considered so far. To test a methodology that could be extended in future case studies, an analysis of three of the world’s best-known certification systems, LEED-ND, BREEAM-CM, and CASBEE-UD, was conducted on two completed PEDs case studies, Tampere and Salzburg.

Efficiency, sustainability, and resilience a trifecta for a green economic recovery through natural resource markets

This study examines how the current COVID-19 epidemic has impacted Chinese enterprises and how the adjustments to China's sustainable development goals (SDGs) and economic growth objectives have influenced preservation and reduced efforts. Meanwhile, the widespread dissemination of COVID-19 has made the previous approaches useless. The fast global spread of the COVID-19 pandemic has rendered conventional treatments ineffective. With the fast spread of the COVID-19 pandemic, it is more crucial than ever to implement a long-term development plan that does not negatively impact local and regional ecosystems. In the aftermath of the COVID-19 pandemic, the primary purpose of this study is to offer a TNRR map for integrating sustainable energy technologies into existing SDG-related projects. The impact that significant shifts in the energy industry have had on the quest for sustainability is the starting point of this paper's examination. Between 2010 and 2019, energy consumption complexity decreased by 3.33 percentage points and emissions by 4.23 percentage points due to long-term development plans' CO2 emissions reduction targets to save money and reduce pollution. The outcomes and short- and long-term apps The Sustainable Development Goals interface's TNRR suggests they would boost green economic recovery efficiency. In this research, crucial natural resource and green economic recovery strategies are advocated to decrease COVID-19-related global warming.

Techno-Economic Assessment of CO2-Based Power to Heat to Power Systems for Industrial Applications

Abstract The industrial sector is a major source of wealth, producing about one-quarter of the global gross product. However, industry is also a major emitter of CO2 and it represents a key challenge toward achieving the worldwide CO2 emission reduction targets. Nowadays, about 22% of the overall energy demand is heating for the industrial sector, generating about 40% of the global CO2 emissions. Additionally, 30% of the final energy demand of the industrial sector is electricity. Solutions to decarbonize the industrial sector are needed. This work presents the techno-economic assessment of four different molten salts-based power-to-heat-to-heat and power solutions aiming at decarbonizing the industrial sector, requiring medium temperature heat. The systems are studied under different electric markets. Dispatch strategies and system sizing are identified to ensure optimal techno-economic performance. The main performance indicators investigated are the levelized cost of heat and electricity (LCoH and LCoE), the operational expenditure, and the attainable savings with respect to alternative business as usual solutions. The results highlight that the proposed system can be cost-competitive, particularly in markets characterized by low electricity prices and high daily price fluctuations, such as Finland. In these locations, LCoE as low as 100 €/MWh and LCoH lower than 55 €/MWh can be attained by the base system configuration. The introduction of high temperature heat pumps can provide further LCoH reduction of about 50%. This study sets the ground for further power-to-heat-to-heat and power techno-economic investigations addressing different industrial sectors and identifies main system design strategies.

Holistic performance evaluation of a turbofan featuring pressure gain combustion for a short-range mission

Aviation is at the center of public interest because of its environmental impact, such as noise and pollutant emissions. Evolutionary technologies are not expected to be sufficient to contribute significantly to the 2050 CO2 emissions reduction targets. This could change if the constant pressure combustion of the Joule cycle could be replaced with a constant volume combustion (pressure gain combustion, PGC). However, PGC comes with a major drawback of a periodic, highly unsteady process that potentially reduces the stability and efficiency of the adjacent compressor and turbine. Furthermore, changes to the secondary air system (SAS) are required since the driving force of SAS stems from the pressure loss in the conventional combustor. Despite the lasting prevalence of pressure gain combustion, there is no whole system analysis taking into account not only the beneficial aspects of PGC, but also the detrimental effects on the SAS and turbo components. To close that gap, a zero-dimensional whole engine model is created. That model accounts for the individual effects of PGC. A comprehensive design methodology identifies optimum engine specifications for a short-range mission. By comparing the results of the PGC turbofan to a conventional turbofan, an SFC improvement of 3.3% was identified.

The political economy of saving the planet

This paper advances a broad program to move the global economy onto a viable climate stabilization path—a trajectory that is consistent with the CO2 emissions reduction targets established by the Intergovernmental Panel on Climate Change (IPCC). The overarching project is straightforward: to achieve the IPCC emissions reduction targets, and to accomplish this in a way that also expands decent job opportunities and raises mass living standards for working people and the poor throughout the world. This overarching aim is captured within the idea of a Global Green New Deal. As I use the term, the Global Green New Deal, includes four major features: phasing out global fossil fuel consumption by 2050; clean energy investments, averaging about 2.5 percent of global GDP per year, including both public and private investments; just transition support for workers and communities that are currently dependent on the fossil fuel industry; and phasing out deforestation and industrial agriculture, to be replaced with afforestation and sustainable agricultural practices. This paper focuses on the first three issues, related to the operations of the global energy system. The main topics covered are: Fossil Fuel Phase-out; Clean Energy Investment Program; Job Creation, Job Losses and Just Transition; Providing Cheap and Accessible Financing; and Ensuring Global Fairness.

Using Carbon Tax to Reach the U.S.’s 2050 NDCs Goals—A CGE Model of Firms, Government, and Households

Our study shows how the United States government can achieve its goal of Nationally Determined Contribution (NDC) in 2025, 2030, and 2050 by reducing energy consumption through a pure carbon tax. To achieve its emissions reduction goals, it is necessary for the U.S. to impose a long-term carbon tax that balances taxes on labour, capital, energy, and carbon. Therefore, in this study, through the two-layer CGE Cobb–Douglas model, the carbon tax rate is set while balancing the production and profit functions of government, businesses, and households. This study concludes that the carbon price will increase from USD 0.4391/kg CO2 in 2020 to USD 2.5671/kg CO2 in 2050, when the CO2 emissions reduction target is increased from 17% reduction in 2020 to 83% reduction in 2050 for the U.S.

Impact of Circular Economy Measures in the European Union Built Environment on a Net-Zero Target

Environmental benefits of circular economy (CE) measures, such as waste reduction, need to be weighed against the urgent need to reduce CO2 emissions to zero, in line with the Paris Agreement climate goals of 1.5–2 °C. Several studies have quantified CO2 emissions associated with CE measures in the construction sector in different EU countries, with the literature’s focus ranging from bricks and insulation products, to individual buildings, to the entire construction sector. We find that there is a lack of synthesis and comparison of such studies to each other and to the EU CO2 emission reduction targets, showing a need for estimating the EU-wide mitigation potential of CE strategies. To evaluate the contribution that CE strategies can make to reducing the EU’s emissions, we scale up the CO2 emission estimates from the existing studies to the EU level and compare them to each other, from both construction-element and sector-wide perspectives. Our analysis shows that average CO2 savings from sector-wide estimates (mean 39.28 Mt CO2 eq./year) slightly exceeded construction-element savings (mean 25.06 Mt CO2 eq./year). We also find that a conservative estimate of 234 Mt CO2 eq./year in combined emission savings from CE strategies targeting construction elements can significantly contribute towards managing the EU’s remaining carbon budget. While this is a significant mitigation potential, our analysis suggests caution as to how the performance and trade-offs of CE strategies are evaluated, in relation to wider sustainability concerns beyond material and waste considerations.

Key influencing factor and future scenario simulation of China's CO2 emissions from road freight transportation

Road freight transportation is a main source of carbon dioxide (CO2) emissions in the transportation sector, and different factors may affect road freight CO2 emissions. However, most studies focus on the influences of a few factors due to the high correlation between factors. Hence, this study adopts a partial least squares regression model to quantify the influences of diverse variables, including pre-treatment variables (which are hard for policy-makers to control) and post-treatment variables (which policy-makers have more control over). Before modeling, road freight CO2 emissions in China for 1999–2019 are estimated. The results show that population growth is a key reason for the increase in road freight CO2 emissions. Among the post-treatment variables, market share, diesel price, and number of freight vehicles play key roles in changes in road freight CO2 emissions. More importantly, road freight CO2 emissions per unit gross domestic product are estimated to be 4.65 g/CNY (Chinese Yuan) in the 2030 business-as-usual scenario, while there remains a 2 g/CNY gap compared to the ideal target. Even in a policy stimulus scenario, all post-treatment variables should be greatly improved to achieve the expected 2030 CO2 emission reduction target for road freight transportation. The above results emphasize the long-term and difficult nature of reducing CO2 emissions from road freight transportation.

Local officials’ tenure and CO2 emissions in China

Under China’s unique decentralized governance mechanism, local officials’ career incentive mode and behavioral preferences have an important impact on CO2 emission reduction. Based on a panel data set including local officials’ experience information, this paper investigates the impact and mechanism of local officials’ tenure on CO2 emissions in China. We find that CO2 emissions show an inverted U-shaped trend of rising first and then falling during the governors’ tenure, with the peak occurring in their nearly fourth year in office. The strategic investment and fiscal policies implemented by officials during their tenure provide an explanation for this finding. In particular, introducing CO2 emission reduction targets in the evaluation system of local officials shifts the strategic arrangements implemented by local officials during their tenure, with no significant effect of provincial governors’ tenure on CO2 emissions. Our findings provide empirical evidence for China’s shift from a GDP-based official evaluation system to a green GDP.

Long-term renovation strategy for 2020-2050: assessment from a low-carbon perspective—case Finland

All EU member states have established a long-term renovation strategy (LTRS) and have updated it twice to support renovation of their national building stock to be highly energy efficient and decarbonised by 2050. The new revision of the EPBD is already under way to accelerate progress on climate change mitigation. This paper is an assessment of the third and latest Finnish long-term renovation strategy for 2020–2050 from a low-carbon perspective covering the emissions of energy renovation products as well as heating energy consumption. The renovation strategy of Finland directs measures to structural improvements, more efficient use of building service technologies and changes in heating systems. The measures will reduce CO2 emissions by more than 90% compared to 2020. Only 3–4 percent of emission savings in operational energy are required to offset emissions in accordance with the strategy measures. The measures will meet the CO2 emissions reduction targets of EPBD and Fit for 55 by 2030.

Power-to-heat for the industrial sector: Techno-economic assessment of a molten salt-based solution

The industrial sector is a major source of wealth, producing about one-quarter of the global gross product. However, industry is also a major emitter of CO2 and it represents a key challenge towards achieving the worldwide CO2 emission reduction targets. Nowadays, about 22 % of the overall energy demand is heating for the industrial sector, generating about 40 % of the global CO2 emissions. Solutions to decarbonize the industrial sector are needed. This work presents the techno-economic assessment of a molten salts based power-to-heat solution aiming at decarbonizing the industrial sector, requiring medium temperature heat (150–450 °C). The system is studied under different electric markets considering electricity prices of 2021, future electricity market price modifications are assessed via sensitivity analyses. Dispatch strategies and system sizing are identified to ensure optimal techno-economic performance. The main performance indicators investigated are the levelized cost of heat, the operational expenditure, and the attainable savings with respect to traditional solutions. The system scalability and sizing criteria are investigated accounting for different typical industrial load profile curves and nominal thermal power demands. The results highlight that nominal levelized cost of heat as low as 55 €/MWhth are attainable in cheap electricity markets (i.e. Denmark) and 80 €/MWhth in more expensive scenarios (i.e. United Kingdom). The proposed system can provide operational cost savings between 0.5 and 3 M€/y against traditional non-flexible electric boilers and even wider benefits if fossil fuels-based boilers are considered. Future electricity markets, subjected to higher renewable penetration causing cheaper average electricity prices and higher price volatility, could lead to further reductions of the levelized cost of heat of more than 20 % achieving values below 45 €/MWhth in markets such as Denmark. This study sets the ground for further power-to-heat techno-economic investigations addressing different industrial sectors and identifies main system design strategies.

Life-cycle maintenance strategy of bridges considering reliability, environment, cost and failure probability CO2 emission reduction: A bridge study with climate scenarios

Climate change significantly affects existing infrastructure by enhancing the deterioration of concrete structures. As the number of repairs and strengthening increases during the service life of a bridge, the cost and environmental impact gradually increase as well. This study aims to propose a framework with climate adaptability considering reliability, environment, and cost, to realize the optimization of the life-cycle maintenance strategy of bridges under climate change. In this study, four preventive maintenance and four essential maintenance of bridges were comprehensively considered, and the reliability, environmental impacts and cost of the bridge at the maintenance stage were quantitatively analyzed. By using the decision tree method, the optimal strategy of bridge life cycle maintenance and reinforcement under climate change scenario was proposed, with the environmental impacts, environmental cost, economic cost and comprehensive cost as the optimization objectives, respectively. Finally, a failure probability calculation model of emission reduction target of bridges was estimated, based on the CO2 emission reduction targets by China in the Paris agreement. To demonstrate the applicability of the proposed framework, a typical highway bridge was taken as an example. It can be observed from the results that the maintenance strategies determined with different optimization objectives show great differences in environmental and economic costs. With the deepening of climate scenario, the failure probability of bridge emission reduction of maintenance strategies with diverse optimization objectives will increase by 10%–20%. The findings highlight the climate adaptability assessment framework is of significant for optimizing the maintenance budget and environmental impact of aging bridge structures in China, and is expected to support decision-making for bridge maintenance under the influence of climate change.

A cost-effective and reliable pipelines layout of carbon capture and storage for achieving China's carbon neutrality target

Carbon capture, utilization, and storage (CCUS) is a crucial technology for global climate mitigation. To implement large-scale CCUS, decisions about where and how to build a CO2 transportation network are urgently required. However, previous studies are limited in proposing the economical transportation network for CCUS that considered comprehensive risks from socio-economic, geographical and geological factors. Here, we develop a pipeline layout planning model to investigate the cost-effective and reliable transportation network for CCUS. Results show that to meet the annual CO2 emission reduction target of 654 million tons for CCUS in the coal-fired power sector under China's carbon neutral goal, pipelines with a total length of 17,589 km need to be constructed. The emission sources can be transported in pipelines with an average radius of 58 km, and with diameters of 8, 12, and 16 inches. Northeast, north, and northwest China are the main areas suitable for pipeline construction.

A new inverse DEA model with frontier changes for analyzing the achievement path of CO2 emissions target of China in 2030

China has promised to reduce its CO2 emissions per gross domestic product (GDP) by 60–65% relative to 2005 emissions by 2030, which puts higher requirements for the quality of China's future economic development. Meanwhile, using current methods to scientifically analyze the realization path of CO2 emission reduction while ensuring future economic development remains a challenge. This study develops a new inverse data envelopment analysis (DEA) method to analyze the annual realization path of CO2 emission reduction and economic growth targets in China from 2020 to 2030. This method not only considers undesirable output and frontier changes but also analyzes the realization path of CO2 emission reduction on the premise of ensuring economic growth. Moreover, the proposed method can analyze resource optimization allocation to achieve the corresponding goals, and its contributions to sustainable development are discussed. The results indicate that (1) In terms of CO2 emission reduction, the eastern region will face the largest pressure of CO2 emission reduction, accounting for 52.85% of the total CO2 emission reduction, followed by the central region, accounting for 37.2%, and the western region will face the least pressure, accounting for 9.95%; whereas in terms of the change trend of CO2 emission reduction, the eastern and central regions show opposite CO2 emission reduction trends, while the trend in the western region is relatively stable. (2) At provincial level, CO2 emission reduction shows a polarized distribution. Many provinces, such as Jiangsu, Guangdong, Hunan, and Chongqing, undertake great pressure to reduce CO2 emission. However, some provinces, such as Shandong, Shanxi, and Yunnan, almost have no potential to reduce CO2 emission while maintaining economic growth. (3) The increasement of human and energy resources input in the future is key to achieving CO2 emission reduction and economic development goals. Finally, some useful implications are summarized by analyzing the results to provide powerful decision support for achieving CO2 emission reduction and economic growth targets of China in 2030.