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The building sector is one of the largest contributors to carbon emissions globally, with high-rise office buildings being a major source due to their energy-intensive operations. This study aims to address the critical issue of carbon emission reductions through the retrofitting of existing high-rise office buildings, focusing on the entire life cycle of these buildings, including the embodied, operational, and demolition phases. Existing research has primarily concentrated on energy consumption and carbon emissions during the operational phase, neglecting the carbon impact of the retrofitting process itself. This research seeks to fill that gap by quantifying the carbon reduction benefits of retrofitting across all life-cycle stages. Using data from 100 high-rise office buildings in Hangzhou's Gongshu District, five typical models were extracted based on their construction eras and architectural features. Retrofitting strategies tailored to these models were developed, and the carbon reduction benefits were calculated using the carbon emission factor method. The primary findings indicated that the shape and orientation of buildings are crucial factors influencing the carbon reduction benefits of retrofitting. Buildings oriented east–west tend to exhibit greater carbon reductions after retrofitting. During the embodied and demolition phases, retrofitting emissions remain similar for models constructed in the same era due to consistent material inputs. However, emissions vary for models from different eras, primarily due to differences in envelope materials and subsequent material consumption. High-rise office buildings constructed between 2007 and 2021 demonstrate higher overall retrofit carbon reduction rates compared to those built before 2007, despite the latter achieving greater reductions during the operational phase. The shorter remaining lifespans of pre-2007 buildings diminish their life-cycle carbon reduction advantages. Notably, complex-shaped buildings from the same era do not necessarily exhibit lower overall retrofit carbon reduction rates compared with rectangular or L-shaped buildings, with comparable reductions per unit area. This suggests that complex-shaped buildings should not be disregarded for retrofitting based solely on shape considerations. Furthermore, the remaining lifespan of a building significantly impacts its post-retrofitting carbon reduction benefits; longer lifespans result in greater benefits, and vice versa. In practical engineering applications, structural reinforcement measures can be implemented prior to retrofitting to extend a building's structural lifespan, ultimately enhancing its carbon reduction benefits. [ABSTRACT FROM AUTHOR]

In a multi-regional integrated energy system (MIES), optimal scheduling under random renewable supply and user demand is crucial to promote the process of carbon neutrality. Further, the total carbon emission of multiple regions is expected to strictly restricted under a threshold, while intensifying the complex coupling of multiple agents. To address the optimal dispatching problem, we establish a typical MIES model with the global carbon emission constraint, which is formulated as a partially observable Markov decision-making process (POMDP). Then we propose an improved multi-agent deep deterministic policy gradient (MADDPG) method, which utilizes a centralized training and decentralized execution (CTDE) framework to effectively improve the multi-agent stationarity. Moreover, an attention mechanism is employed to enhance the efficiency of communication and coordination among agents. Experiments are carried out on multi-regional datasets, and the results certify that the proposed algorithm can decrease system operation costs, reduce carbon emissions, and speed up the convergence of the multi-agent system. • A multi-regional integrated energy system model is formulated as a POMDP. • An improved multi-agent DRL method with CTDE framework is applied. • The total carbon emission is strictly restricted under a threshold. • The stability and robustness of multi-agent optimization strategies is certified. [ABSTRACT FROM AUTHOR]

Excessive carbon emissions have posed a threat to sustainable development. An appropriate market-based low carbon policy becomes the essence of regulating strategy for reducing carbon emissions in the energy sector. This study proposes a Stackelberg game-theoretic model to determine an optimal low carbon policy design in energy market. To encourage fuel switching to low-carbon generating sources, the effects of varying carbon price on generator's profit are evaluated. Meanwhile, to reduce carbon emissions caused by energy consumption, carbon tracing and billing incentive methods for consumers are proposed. The efficiency of low carbon policy is ensured through maximising social welfare and the overall carbon reductions from economic and environmental perspectives. A bi-level multiobjective optimisation immune algorithm is designed to dynamically find optimal policy decisions in the leader level, and optimal generation and consumption decisions in the followers level. Case studies demonstrate that the designed model leads to better carbon mitigation and social welfare in the energy market. The proposed methodology can save up to 26.41% of carbon emissions from the consumption side for the UK power sector and promote 31.45% of more electricity generation from renewable energy sources.

Most environmentalists favor the reduction in CO2 emissions but oppose international trade in emissions permits Although economic theory provides a strong case in favor of trade in permits) there is little empirical evidence of the size of potential benefits. We estimate the benefits of this trade for OECD countries.

For reducing emissions from deforestation and forest degradation (REDD+) programs, it is particularly important that monitoring for emission reductions is tied to the revenues a developing country receives from REDD+ projects; any estimated uncertainties will have significant impacts on the emission reduction estimation and incentive scheme of REDD+. However, the effects of estimated uncertainties on incentives for developing countries have not been deeply discussed in the current literature. To fill this gap, two estimation approaches for emission reductions are introduced by considering the incentive coefficient by the principle of reliable minimum estimation. The relationship between estimated uncertainties and incentive coefficient is simulated to illustrate the effects of estimated uncertainties on the emission reduction estimation and incentive scheme. Data from six tropical developing countries is used, including Nigeria, Honduras, Indonesia, Kampuchea, Garner, and Brazil. The results indicate that both the errors of referential and actual carbon stock must be considered when estimating and predicting emission reductions. The effects of the error of actual carbon stock on the emission reduction estimation and incentive coefficient were determined to be more influential. The current incentive scheme was more favorable to developing countries with high carbon stock variability, while developing countries with low carbon stock variability had insufficient incentives to implement REDD+ project. [ABSTRACT FROM AUTHOR]

In this paper we present the findings of a qualitative investigation of change trends in urban freight deliveries. The empirical material was gathered with urban freight (courier) company managers and drivers in Aotearoa New Zealand. It presents personal accounts of the everyday lived experiences of those intimately involved in the delivery of goods within the urban environment. Twenty-five interviews were conducted across four urban centres between June and September 2015. We use the four elements of the Energy Cultures Framework to explore what urban freight managers and drivers ‘have’, ‘do’ and ‘think’, and the pressures of an external context. Four interrelated themes are presented. 1. Online shopping and home deliveries, 2. Tracking and transparency, 3. New technologies, and 4. Meeting (changing) expectations, with evidence provided by way of verbatim quotations. The ‘mobility cultures’ concept is used to explore the relationships between the four themes, and to identify the key change trends that may affect the ability of the freight industry to contribute to a low-carbon transport transition. We conclude by signalling some policy implications and future research directions. [ABSTRACT FROM AUTHOR]

This study explores the potential for more sustainable patterns of travel by mobile health professionals. It also explores the relationships between their travel for work and their modal choices in commuting and private travel. It uses as a case study a health trust in the UK that introduced a pioneering scheme involving the use of electric bikes and pool cars designed to reduce the use of employees' own vehicles for work travel. Using self-categorization theory, it explores the role of work group social norms in explaining the differential take-up of the scheme. The study used an online survey completed by 306 staff, telephone interviews, a focus group, and analysis of carbon emissions. The main alternative to private car use was cycling, used by 15% of staff. Several operational constraints were identified, but the differences in participation were also strongly related to work group cultures. Local managers embodying prototypical norms exerted a significant influence on the work groups that had embraced the scheme. A focus group with a team using electric bikes found evidence of increased staff motivation, and benefits to client groups, due to strengthened in-group social identity. The findings suggest considerable potential for modal shift in the travel of mobile health professionals in urban areas. [ABSTRACT FROM PUBLISHER]

Commissioning is arguably the single most cost-effective strategy for reducing energy, costs, and greenhouse gas emissions in buildings today. Although commissioning has earned increased recognition in recent years, it remains an enigmatic practice whose visibility severely lags its potential. The application of commissioning to new buildings ensures that they deliver or exceed the performance and energy savings promised by their design and intended operation. When applied to existing buildings, commissioning identifies deficiencies and the almost inevitable 'drift' from intended performance over time, and carries out interventions to put the building back on course. More formally, commissioning is a systematic, forensic approach to quality assurance and performance risk management, rather than a technology per se. This article presents the world's largest compilation and meta-analysis of commissioning experience and the associated literature, comprising 643 non-residential buildings, 99 million ft of floorspace, $43 million in commissioning expenditures, and the work of 37 commissioning providers. The median normalized cost to deliver commissioning is $0.30/ft ($2009 currencies) for existing buildings and $1.16/ft for new construction (or 0.4% of the overall construction cost). The one third of projects for which data are available reveal over 10,000 energy-related deficiencies, the correction of which resulted in 16% median whole-building energy savings in existing buildings and 13% in new construction, with payback times of 1.1 and 4.2 years, respectively. Because energy savings exceed commissioning costs, the associated reductions in greenhouse gas emissions come at a 'negative' cost of −$110/tonne CO for new buildings and −$25/tonne for new construction. Cases with comprehensive commissioning attained nearly twice the overall median level of savings and five times the savings of the least-thorough projects. Significant non-energy benefits such as improved indoor air quality are also achieved. Applying the median whole-building energy-saving values to the US non-residential buildings stock corresponds to an annual energy-saving potential of $30 billion (and 340 Mt of CO) by the year 2030. [ABSTRACT FROM AUTHOR]

Abstract: SiOC ceramics pyrolyzed from polysiloxanes are usually black because of the formation of excess carbon in the ceramic network. Here we show that the pyrolysis of polysiloxanes in water vapor significantly reduces carbon from SiOC and yields a white SiOC ceramic. Chemical analysis shows the amount of carbon in the white ceramic is only half of that in the black one pyrolyzed in argon. 29Si nuclear magnetic resonance spectral (NMR) analysis indicates the reduction of the carbon-rich [SiC4] and [SiC2O2] units with the enhanced formation of the oxygen-rich [SiO4] and [SiCO3] units by the water pyrolysis. Importantly, this water pyrolysis resultant carbon reduction is realized in a bulk polysiloxane, and the white SiOC ceramic is obtained in a bulk body with the retained shape of the precursor body. The water pyrolysis can be adopted as an effective mean to tailor the structure of PDCs via the simple introduction of water vapor in pyrolysis. [Copyright &y& Elsevier]

Abstract: With an economic growth in GDP of around 10% per annum in recent years, energy consumption in the building sector in China now accounts for 25% of the total energy use in the whole nation. In large buildings in Beijing and Shanghai the consumption rate, at approximately 190kWh/m2 per annum, is around five times the energy use in residential buildings in those cities. Addressing this ever increasing energy consumption and the consequential green house gas (GHG) emissions must be a priority to achieve low carbon sustainability in China. As part of the Kyoto Protocol the Clean Development Mechanism (CDM) has been used to assist in the finance of GHG reduction projects in developing countries in the context of low carbon sustainable development. However, hitherto the majority of CDM projects of an energy related nature have focussed almost exclusively on renewable energy projects or those which enhance the efficiency of industrial processes. To date the opportunities for using the CDM approach in reducing emissions in large buildings have been largely overlooked in China and other countries. Part of the reason is the lack of an adequate established baseline methodology against which the impact of any proposed CDM project can be judged. This paper explores the barriers to the implementation of carbon reduction strategies in large commercial buildings using China as a particular example. [Copyright &y& Elsevier]

(a–f) Changes of carbon reductions of commercial building operations at the provincial level and (g) the difference with the nation-based results (2001–2016). [Display omitted] • Provincial carbon intensity of commercial building operations grew 2.88 % yr−1 in 2001–2016. • Northeast and north China mitigated the most in carbon intensity and emissions, respectively. • Southwest China showed the highest ratio of carbon reductions to carbon emissions at 29.53%. • The total reduction of China's commercial building operation was 1.38 GtCO 2 in 2001–2016. • Annual provincial reductions peaked in 2013, one year earlier than the national result. The growing energy consumption in commercial building operations has slowed the pace of carbon reduction in the building sector, which has hindered China's movement towards peaking emissions by 2030 and carbon neutrality by mid-century. Considering the technical, socio-economic, climatic, and behavioral factors, this study evaluates the carbon reduction changes of commercial building operations in China's 30 provinces during the period 2001–2016. An assessment framework of the reduction intensity, amount, and efficiency has been built by carbon intensity decomposition. It shows that (1) the average provincial carbon intensity of commercial building operations kept rising by 2.88% per year from 2000 to 2016; (2) provinces of northeast and north China, respectively, took the lead in reduction intensity and amount at 17.09 kg of carbon dioxide per square meter and 73.79 megatonnes of carbon dioxide (MtCO 2) from 2001 to 2016. Meanwhile, the greatest efficiency of carbon reduction was seen in provinces of southwest China with the highest reductions-emissions ratio being 29.53%; (3) compared to the national level results, the annual carbon reductions based on provincial units hit their peak one year earlier at 167.35 MtCO 2 in 2013, although similar emission drivers have been observed. Moreover, effective practices by local governments have been summarized for energy efficiency promotion in commercial building operations. Overall, this study makes a reference for other economies to assess the historical carbon reduction in the building operation, which provides policymakers with insights into balanced and targeted emission reduction strategies towards a low-carbon transition in commercial building sector. [ABSTRACT FROM AUTHOR]

Reaching carbon neutrality would require the retirement of conventional power sources and substitution with renewable energy sources. Given that immediate substitution from conventional to renewable power sources is not feasible in the status quo, we investigate whether adding residential solar photovoltaic (PV) technology in addition to conventional power sources would reduce residential emissions. We use a large survey dataset of more than 300,000 observations and employ a structural equation model (SEM) to validate our findings. Interestingly, emissions increase by 1.75% if residential PV is adopted, and Japanese citizens with residential PV systems end up using 3.02% more electricity. We also find that pro-environmental consumers may also produce more emissions with PVs. As a result, reaching target carbon reductions in the residential sector would necessitate eliminating conventional energy sources. We address the policy implications for pathways to reduce residential emissions. [Display omitted] [ABSTRACT FROM AUTHOR]

National, regional, and international actors can use a range of different policies to increase the demand for forest-based carbon sequestration. Demand for these services has, the potential to significantly impact the decisions of landowners, land managers, and private investors by increasing the incentives for creation or maintenance of forest ecosystems. The Kyoto process is at the center of discussions regarding the market for carbon services although it is not the only relevant source of demand. The authors recommend an approach to climate change regulation that requires actions beyond the current scope and term of the Kyoto Protocol. The four areas addressed in this paper are: (1) increasing regulation-based demand for carbon reductions by improved implementation and increasing coverage, (2) increasing voluntary demand for carbon reductions, (3) increasing the percentage of carbon reduction that derives from land use, land use change, and forestry, and (4) ways to stimulate demand for forest-based carbon sequestration generally by reducing transaction costs and contractual risks and in a particular country by recommending policy changes in Panama. [ABSTRACT FROM AUTHOR]