Do material efficiency improvements backfire?: Insights from an index decomposition analysis about the link between CO2 emissions and material use for Austria

Decomposition Analysis of the Carbon Footprint of Primary Metals

This study investigates how different technological and socioeconomic drivers have impacted the carbon footprint of primary metals. It analyzes the historical evidence from 1995 to 2018 using new metal production, energy use, and greenhouse gas (GHG) emission extensions made for the multiregional input-output model EXIOBASE. A combination of established input-output methods (index decomposition analysis, hypothetical extraction method, and footprint analysis) is used to dissect the drivers of the change in the upstream emissions occurring due to the production of metals demanded by other (downstream) economic activities. On a global level, GHG emissions from metal production have increased at a similar pace as the GDP but have decreased in high-income countries in the most recent 6 year period studied. This absolute decoupling in industrialized countries is mainly driven by reduced metal consumption intensity and improved energy efficiency. However, in emerging economies increasing metal consumption intensity and affluency have driven up emissions, more than offsetting any reductions due to improved energy efficiency.

Life cycle assessment of material footprint in recycling: A case of concrete recycling

Meeting the current demand for concrete requires not only mining tons of gravel and sand, but also burning large amounts of fossil fuel resources in cement kilning. Consequently, concrete recycling is crucial to achieving a material-efficient society, especially with the application of various categories of concrete and the goal of phasing out fossil fuels. A comparative life cycle assessment (LCA) is used to assess the engineering material footprint (EMF) and the fossil fuel material footprint (FMF) in closed-loop recycling of three types of concrete: siliceous concrete, limestone concrete, and lightweight aggregate concrete. This study aims to investigate the impact of (i) concrete categories, (ii) methods to model recycling, and (iii) using renewable energy sources on the material footprint in concrete recycling. The results highlight that the concrete recycling system can reduce 99% of the EMF and 66-93% of the FMF compared with the baseline system, in which concrete waste is landfilled. All three recycling modeling approaches indicate that concrete recycling can considerably reduce EMF and FMF compared with the baseline system, primarily resulting from the displacement of virgin raw materials. Using alternative diesels is more sensitive than adopting renewable electricity in reduction of the FMF in concrete recycling. Replacing diesel with electrolysis- and coal-based synthetic diesel for concrete recycling could even increase the FMF, while using biodiesel made from rapeseed and wood-based synthetic diesel can reduce 47-51% and 84-89% of the FMF, respectively, compared to the virgin diesel-based recycling system. Finally, we discussed the multifunctionality and rebound effects of recycling, and double-counting risk in material and energy accounting.

Green Information System (GIS) Model in the Conference Sector: Exploring Attendees' Adoption Behaviors for Conference Apps

Introduction

Academic conferences are carbon-intensive. Conference travel by air contributes to huge amount of global greenhouse gas emissions, which can be reduced by adopting green information systems (green IS or GIS). This study aims to investigate attendees' behaviors for adopting green IS (such as conference apps) from an ecological perspective.

Methods

For this research, a survey method was used. Survey instrument had 29 items adapted from existing scales. Data was collected using Mturk's panel of respondents on online Qualtrics. Exploratory and confirmatory factor analysis were conducted on 403 responses for data analysis and validation of the results using SPSS AMOS ver. 24.

Findings

This study provides empirical evidence to add ecological beliefs as a key predictor of green IS adoption models. Findings demonstrate that attitudes and ecological beliefs play an essential role in conference app adoption, in comparison with performance expectations, social impacts, and facilitation conditions, as presented in the traditional technology acceptance literature. Findings assist conference owners develop essential communication strategies for green attendees.