Energy-efficient retrofitting and energy consumption in a historic city centre – an example from Lhasa

For thousands of years, cities have evolved with changing needs. Cities are like living organisms, which are exposed to transformations as a result of changing needs and requirements. City centres are one of the attractive, essential, and vital parts of the city that are also affected by these changes. Specifically, historic city centres, which refer to the origins of the city, will be discussed within this context. Urban design aims to shape our cities with better quality and provide better places for everyday life. In addition, urban regeneration can be utilized as generic public policy for solving problems and providing physical improvements for these cities. Although the problems that emerge in each city are similar, sometimes they change circumstantially. As a result, the planning, implementation, and management of urban regeneration projects as well as their sustainability can produce serious complications. This article focuses on the process of urban regeneration, historic city centres, and the Mediterranean region and aims to develop an applicable regeneration framework for historic city centres limited to the Mediterranean region. First, the main problems of these cities are described. Next, characteristics of historic city centres and associated problems of the Mediterranean region are explained. Subsequently, the concept of urban regeneration is clarified, and the processes involved are discussed. Finally, an applicable urban regeneration framework for historic Mediterranean city centres, developed by the authors, is explained with the goal to reduce social segregation while incorporating the contributions of views from both local inhabitants and stakeholders in the process. The methodology of the overall research presented in this article is mainly based on a critical review of primary and secondary documents from the literature through a comparative and exploratory approach.

After more than two decades of negotiation, the China–Russia gas deal represents a new era of energy cooperation between China and Russia. In total, this is a win–win deal for both sides. For China, the deal will decrease energy consumption and carbon emission but will not significantly influence air quality; for Russia, it will provide a new market for its gas resources. In this study, we calculated the energy consumption, carbon emission, and particulate matter pollution (PM2.5 and PM10) in China in 2020, 2030, 2040, and 2050 under four IPCC representative concentration pathways (RCPs 8.5, 6.0, 4.5, and 2.6). We found that energy consumption and carbon emission decreased under the gas deal in RCPs 8.5, 6.0, and 4.5, although the rate of decrease slowed over time; however, in RCP 2.6, the rate of decrease of energy consumption and emission increased over time. PM2.5 and PM10 emission showed similar trends but with increasing rate, although the gas deal would mitigate air pollution in the short term. Although China’s government hopes to reduce carbon and pollutant emission under the deal, our results suggest that additional mitigation measures will be necessary to achieve this goal. Nonetheless, the reduction in carbon emission suggests that the China–Russia gas deal provides a model that other countries can follow to slow climate change.

The historic city centre of Lhasa has preserved special types of historic and cultural heritage for various reasons, including strong religious beliefs, preservation policy, and slow globalisation. In addition to visual cultural heritage, the sound environment represents a cultural heritage that requires preservation. This paper presents an analysis of the sound environment of Lhasa's historic city centre based on field investigations and soundwalk measurements during the tourism high season. First, Lhasa's historic urban form and cultural background are introduced. Second, the relationship between the historic urban space and the sounds is investigated according to the sound sources. The sound taxonomy and the cultural meanings of these sounds are examined and identified. Third, the sound environments are evaluated from the perspectives of sound sources and sound changes with time and frequency. The sound pressure level is found to be high in the historic centre, which might affect the sound sources associated with cultural identities. Additionally, significant variations within the centre—both spatial and temporal—that are indentified in the sound pressure levels and spectrums are reflected in the characteristics of local daily life and social activities. Finally, comparisons are made between Lhasa's historic centre and a number of other historic centres and squares. Possible implications of the results and principles of soundscape preservation are also discussed, based on the case study of Lhasa.

The historical center of the city is the main keeper of the cultural code of the city, since the most important historical and cultural objects are concentrated within its borders, the historical environment is preserved. The appearance of high-rise buildings has become a familiar result of the process of urban reconstruction of historical city centers. As a result, there is a compositional destruction of the historical environment, distortion and spatial destruction of the established historical ensembles. The city of Penza is no exception: dozens of historical buildings have been lost, and their place has been taken by buildings of a larger scale and height that destroy the historical environment. The problem of regulating the height of new buildings in the historical environment of the city of Penza has acquired the most acute character and requires its solution. The purpose of the study is to develop a height regulation for the historical center of Penza as an approbation of the previously proposed "comprehensive methodology for identifying the boundaries of the height of a new development in the historical center of a large city based on landscape-visual analysis." The research is based on the study of the problems of regulating the height of buildings in historical city centers in Russia and abroad, the analysis of scientific works and the legislative framework of the Russian Federation and the city of Penza in the field of height regulation, the systematization of domestic and foreign experience in the formation and regulation of height restrictions in historical city centers, a full-scale survey of the city, retrospective and landscape-visual analysis, graphical modeling. As a result of the conducted research, positive results were obtained: the proposed methodology, as a result of testing, confirmed its effectiveness, made it possible to identify landscape and visual features of the historical center of Penza and to form height restrictions within the boundaries of the historical center of the city, the structure and content of the high-rise regulations for the development of the historical center of the city were formed, options for integrating the high-rise regulations into the urban planning documentation of the municipal level were considered.

Historic City Center Urban Regeneration: Case of Malaga and Kemeraltı, Izmir

In Spain, fifteen cities have been declared World Heritage Cities by UNESCO. This implies a responsibility to conserve all the heritage wealth of these places. However, what is the point of heritage if it cannot be known and visited? In order to be able to do this for all people, in equal and inclusive conditions, it is essential to consider Accessibility and Universal Design principles. This is a challenge that requires a personalised study in places that were precisely built with the idea of being inaccessible. In particular, the study of the urban fabric and pedestrian itineraries are the determining spaces that this article develops. The aim of this study is to determine the keys and possible guidelines for the definition of urban accessibility indicators in the routes of historic city centres. For this purpose, significant routes have been sought in historic centres from the accessibility point of view: areas of high pedestrian traffic (in many cases for tourist reasons). Thus, six of the fifteen historic quarters of the World Heritage Cities in Spain have been selected for the study, with examples of good accessibility practices and difficulties that can be identified in their itineraries. For this analysis, an initial study of the existing documentation on the subject (secondary information sources) is carried out, in addition to a direct analysis (primary information source) of the graphic documentation compiled in each of these places. Subsequently, a complementary analysis will be made of some examples of good practice in pedestrian routes in historic city centres in cities in other countries. On the basis of this preliminary analysis, a comparison will be made to establish common points and singularities among the different case studies first, and then with other cities. This diagnosis provides results that are identified as "keys to consider in the intervention on pedestrian routes in historic centres". These keys not only address issues of mobility, but also location, orientation, understanding, etc., thus addressing a holistic consideration of accessibility as a fundamental principle for all people, and in particular for the elderly sector, which is one of the groups that is clearly growing and which, without necessarily having to have a severe or recognised disability, needs an accessible environment that is easy to use. As a main conclusion, it can be said that the results of this study do not only have an internal application for these cities but can be perfectly extrapolated as a basis for the elaboration of specific indicators for any historic city centre in any city in the world, considering the necessary adaptation to the specific characteristics of each city.

Recycling-Based Reduction of Energy Consumption and Carbon Emission of China’s Electric Vehicles: Overview and Policy Analysis

IntroductionThe construction industry is one of the world’s largest carbon emitters, accounting for around 40% of total emissions. Therefore, reducing carbon emissions from the construction sector is critical to global climate change mitigation. However, traditional architectural design methods have some limitations, such as difficulty in considering complex interaction relationships and a large amount of architectural data, so machine learning can assist architectural design in improving design efficiency and reducing carbon emissions.MethodsThis study aims to reduce carbon emissions in the architectural design by using a Transformer with a cross-attention mechanism model. We aim to use machine learning methods to generate optimized building designs that reduce carbon emissions during their use and construction. We train the model on the building design dataset and its associated carbon emissions dataset and use a cross-attention mechanism to let the model focus on different aspects of the building design to achieve the desired outcome. We also use predictive modelling to predict energy consumption and carbon emissions to help architects make more sustainable decisions.Results and discussionExperimental results demonstrate that our model can generate optimized building designs to reduce carbon emissions during their use and construction. Our model can also predict a building’s energy consumption and carbon emissions, helping architects make more sustainable decisions. Using Transformers with cross-attention mechanism models to reduce carbon emissions in the building design process can contribute to climate change mitigation. This approach could help architects better account for carbon emissions and energy consumption and produce more sustainable building designs. In addition, the method can also guide future building design and decision-making by predicting building energy consumption and carbon emissions.

Does new energy consumption conducive to controlling fossil energy consumption and carbon emissions?-Evidence from China

The unavoidable option for socially sustainable development is a low-carbon economy. One of the essential steps for China to attain high-quality development is reducing carbon emissions. It is necessary to realize low-carbon development in Sichuan, as it is not only an important economic zone but also an ecological protected area. The concurrent relationship among energy consumption, carbon emissions, and economic growth was examined in this study using the Tapio decoupling indicator, and the factors affecting energy consumption and carbon emissions in Sichuan were broken down using the logarithmic mean Divisia indicator (LMDI). The findings demonstrate a fundamental relative decoupling relationship between Sichuan's energy use and carbon emissions. Analysis of energy consumption and carbon emissions in Sichuan Province from 2005 to 2020 shows distinct patterns. From 2005 to 2012, in 2014, and from 2016 to 2020, the relationship between energy use and carbon emissions was relatively decoupled, with decoupling values ranging between 0 and 1. Absolute decoupling occurred in specific years: 2010, from 2013 to 2018, and in 2020. These periods are characterized by economic growth alongside reductions in carbon emissions. Factors affecting energy consumption and carbon emissions were consistently analyzed, showing similar impacts throughout the study periods. We find that population and economic growth are the main driving forces of these effects. The effects of energy intensity and industrial structure mainly play restraining roles, and the latter has a slightly weaker effect than the former.

As the world's largest country regarding energy consumption and carbon emissions， analyzing China's carbon emissions and emission reduction potential is essential to the fight against global climate change. This study constructs the LEAP-China model to forecast and analyze China's carbon emissions and emission reduction potential in three dimensions： primary energy， end-use industries， and carbon emission contribution. The conclusions are as follows： ① Except for the baseline scenario， the industrial structure emission reduction， technological progress， energy structure emission reduction， and blueprint scenarios were all able to realize the goal of "peaking by 2030." ② From 2022 to 2060， carbon emissions from all industries except industry were declining. ③ The carbon emissions of various industrial sectors varied significantly according to their energy consumption， with chemicals > other industries > non-metallic mineral products industry > ferrous metal smelting and rolling processing industry > non-ferrous metal smelting and rolling processing industry > paper and paper products industry. ④ The optimization of energy structure had apparent emission reduction effects in the short term； the optimization of industrial structure was a continuous driving force for carbon emission reduction， and technological progress was a long-term driving force for carbon emission reduction. The study can provide a decision-making basis for China to realize the medium- and long-term carbon emission reduction path.

As the world grapples with the effects of climate change, there is an urgent need for sustainable solutions to help reduce carbon emissions. Historic urban centres can indicate one possible way forward, and this is because of the way traditional buildings (in this paper centring on the Mediterranean) are built. Their materials and technologies are usually well chosen and adapted to hot climates, while the layout of historic centres, often with quite narrow, winding streets, provide shading and frequently also appropriate direction of cooling winds, especially in marine locations. These often result in these urban cores being cooler than more modern city centres. Traditional roofs, in particular, have over the centuries proved to be reliable and sustainable (when given appropriate maintenance), with layers of porous materials providing inbuilt breathable (evaporative) properties. These lead to a degree of passive cooling and ultimately to less energy consumption (less use of air conditioning for example), thus creating a smaller carbon footprint for each building, and hence also for the urban centre when a number of these buildings are present. This paper is based on a three-year pilot study, where an innovative methodology using a combination of remote data (obtained from Unmanned Aerial Vehicle (UAV) and satellite) with in situ measurements, allows for the remote identification of traditional and modified roofs, as well helping understand the thermal behaviour of such roofs, with this study concentrating on historic centres in the Island of Malta, in the Mediterranean. Ultimately aimed at promoting preservation of these traditional roofs, this study provides data to help address, at least in part, current climatic concerns, whilst also potentially providing some adaptation strategies to address climate change (in particular increased ambient temperatures). Our studies on the behaviour of traditional deffun mortar roofs have shown that they are effective in protecting the internal environment from the external one. This can lead to a reduction in carbon emissions and help create a more carbon-neutral future over an entire historic centre. Therefore, in the long term, with the right management policies in place, traditional roofs on traditional buildings can provide an excellent and cost-effective way of moving towards carbon neutrality in historic urban centres.

Reducing energy consumption and carbon emissions of magnesia refractory products: A life-cycle perspective

This article analyzes the visual and textual representations of the "historical centre" of Bologna before and after 196% the year when the first of the city’s celebrated plans for the preservation of the ancient urban fabric were approved. In spite of the attempts made by architects and planners to precisely and "technically" define the object of the plans, the notion of "historical city centre" remained a vague and ambiguous one. Conflicting images of history, tradition, and centrality shaped the preservation policies, and were in turn reshaped by them. The visual, historical, and political discourse behind the Bologna plans intentionally brought together a multiplicity of local and non-local cultures, resulting in an overall reinvention of both a local identity and an idea of the city of the past.

Compared to general public and residential buildings, large public buildings are often difficult to construct and have a long construction period, creating greater construction energy consumption and carbon emissions on the one hand, while generating a large amount and many types of difficult-to-track process data on the other. As such, it is difficult to measure carbon emissions and analyze various influencing factors. By realizing the simple calculation of energy consumption and carbon emissions, as well as discerning the degree of influence of various factors based on the results of influencing factors research, it is of considerable practical significance to propose energy savings and emission reductions in a targeted manner. In view of the above, this work aimed to establish a more practical calculation method to measure energy consumption and carbon emissions in the construction of large public buildings, as well as to identify the multiple influencing factors related to energy consumption and carbon emissions during the construction process. To demonstrate the practicality of our approach, quantitative calculations are carried out for a new terminal building in a certain place and from the perspective of sustainable urban construction; thus, the driving factors of the traditional STIRPAT model are extended to seven. Based on the calculation results, a modified STIRPAT model is used to analyze the comparative study of impact factors, such as population and construction machinery performance, on energy consumption and carbon emission intensity. The results show the following: (1) The energy consumption value per square meter of this terminal building is 3.43 kgce/m2, and the average carbon emission per square meter is about 13.88 kgCO2/m2, which is much larger than the national average of 6.96 kgCO2/m2, and (2) the type of energy used in the construction process has the greatest degree of influence on energy consumption and carbon emission, and the local GDP, population factor, construction machinery performance specifications, and shift usage also show a positive correlation with the growth of total energy consumption and carbon emissions. Moreover, while the government’s continuous investment in energy conservation and environmental protection has reduced the total energy consumption and carbon emissions in construction, there is still considerable room for improvement. Finally, according to the results, we provide theoretical references and constructive suggestions for the low-carbon construction of large public buildings in the construction stage. Thus, the results of our study will allow policy makers to formulate appropriate policies.