Comparison of the Embodied Carbon Emissions and Direct Construction Costs for Modular and Conventional Residential Buildings in South Korea

Modular construction is an innovative new construction method that minimizes waste and improves efficiency within the construction industry. However, practitioners are hampered by the lack of environmental and economic sustainability analysis methods in this area. This study analyzes the embodied carbon emissions and direct construction costs incurred during the production phase of a modular residential building and provides comparison to an equivalent conventional residential building. Major drawings and design details for a modular residential building in South Korea were obtained, and the quantity take-off data for the major construction materials were analyzed for a modular construction method and a conventional construction method using a reinforced concrete structure under the same conditions. Focusing on major construction materials during the production phase, the embodied carbon emissions assessment revealed that adopting a modular construction approach reduced the environmental impact by approximately 36%, as compared to the conventional reinforced concrete method. However, in terms of the direct construction cost, the modular construction was approximately 8% more expensive than the conventional reinforced concrete construction method.

Shared Responsibility for Carbon Emission Based on Embodied Carbon Emission in China-US Trade

Traditional Production-Based Accounting (PBA) principle does not consider the embodied carbon emissions in export and import trade. A multiregional input-output (MRIO) model is constructed to estimate the embodied carbon dioxide emissions of 41 countries and regions worldwide, based on the PBA and shared responsibility approach in this paper. The results indicate that the embodied carbon emissions in 2018 in China's export trade were 1326.1 million tons higher than that of import trade. Through the empirical analysis of the embodied carbon emissions in China's import and export trade, it can be seen that China is a major producer of carbon emissions, not a consumer country, and has taken more carbon emissions responsibility for the world. And it is more reasonable and impartial to assign developed and developing country’s carbon emissions responsibility in the light of the shared responsibility method.

Adapting residential envelope assemblies for full circularity

Residential external wall assemblies are among the key contributors to embodied carbon emissions in the building industry. Their design, however, is still largely oriented towards linear consumption trajectories of extraction-use-waste. Within this context, this paper investigates how established material recovery potential assessment metrics could be used to inform design decisions aimed at improving circularity in buildings. A redesign of a typical timber frame assembly is presented and its material recovery performance is compared to standard systems. Results show a 35%-47% improvement in material recovery potential.

Embodied greenhouse gas emissions reduction for structural elements in office buildings

In order to reach the COP21 objectives, mitigation strategies must be identified in all economic sectors. In Austria, the construction sector represents one of the greatest sources of carbon intensive activities. Within this sector, buildings have a significant role to play. Through a systematic literature review, this paper identifies strategies to reduce the embodied carbon emissions of structural building materials. Then, by implementing the most promising alternatives in building case studies and performing a life cycle assessment, up to 15% reduction of the embodied greenhouse gas emissions was observed. This paper, however, intends to show that there is no technology that is intrinsically best at surpassing all others.

Heterogeneous Driving Factors of Carbon Emissions Embedded in China’s Export: An Application of the LASSO Model

With the steady growth of CO2 emissions embedded in trade, the driving forces of emissions have attracted extensive attention. Most of the literature has verified a bundle of the influential factors; however, further analyses are necessary to understand the predominant and heterogeneous driving factors in different economies and/or industries. Accordingly, by applying the multiregional input–output (MRIO) model, this article firstly evaluates the embodied carbon emissions of China’s export from 1992 to 2020 in total volumes and by 14 industries. Then, the Least Absolute Shrinkage and Selection Operator (LASSO) estimations allow us to discover that urbanization, technology update and gross domestic product (GDP) are the leading three prioritizing factors in generating China’s export emissions. Interestingly, this paper discovers that raising the proportion of female parliamentarians contributes to an abatement of emissions. Furthermore, the empirical results suggest that the heterogeneities of those factors do exist among industries. For example, the percentage of females in parliaments turns out to have a larger effect among labor-intensive industries only. In facing with rapid globalization and economic development of China, this paper provides important policy implications towards specific industries in terms of mitigating trade emissions. It guides policy-makers to achieve “carbon neutrality” by avoiding carbon leakage in net-export countries such as China.

Calculation and Decomposition Analysis of Embodied Energy and Embodied Carbon Emissions in China’s Foreign Trade Based on Value-Added Trade

Under the new mode of labor division for global production, the method of calculating a country’s energy consumption and carbon emissions is based on a “production side” principle that disregards the embodied energy and carbon emissions caused by international trade. This method is unfair to China and other large, exporting countries. From the perspective of value-added trade, the multiregional input–output model based on the world input–output table and environmental account from the World Input–Output Database are used to measure the scale of China’s value-added trade; subsequently, the import and export net values of China’s foreigntraderelated embodied energy and carbon emissions are calculated. The results show that: (1) China’s value-added exports in 2009 amounted to US $1,045.37 billion, which constitutes 21% of China’s Gross Domestic Product (GDP) in that year. Nearly half of the value-added exports are to fulfill the final demand from North America and European Union countries; manufacturing and service are the main value-added export industries of China. (2) China has a relatively high unit coefficient for value-added energy consumption and carbon emissions, both representing a net export of embodied energy and embodied carbon emissions in foreign trade. In this regard, energy and mid-level technology manufacturing industries, such as coke, refined oil, and nuclear fuel processing, are the main exporters of embodied energy and embodied carbon.