Helena Dahlbo

Uncertainty and Sensitivity in the Carbon Footprint of Shopping Bags

Carbon footprints for several shopping bag alternatives (polyethylene, paper, cotton, biodegradable modified starch, and recycled polyethylene) were compared with life cycle assessment. Stochastic uncertainty analysis was used to study the sensitivity of the comparison to scenario and parameter uncertainty. On the basis of the results, we could give only a few robust conclusions without choosing a waste treatment scenario or limiting the parameter space. Given the scenario of current waste infrastructure in Finland, recycled polyethylene bags seem to be the most preferable (−7 to 24 g CO eq./bag) and biodegradable bags the least preferable (38 to 60 g CO eq./bag) option. In each analyzed waste treatment scenario, a few parameters dominated the uncertainty of results. Most of these parameters were downstream of the shopping bag manufacturing (consumer behavior, landfill conditions, method of waste combustion, etc.). The choice of waste treatment scenario had a greater effect on the ranking of bags than parameter uncertainty within scenarios. This result highlights the importance of including several scenarios in comparative life cycle assessments.

Life cycle inventory analyses for five waste management options for discarded newspaper

This paper presents the results of life cycle inventory (LCI) analyses that were carried out to determine the environmental impacts (emissions, resource extractions and land use) of different newspaper waste management options for the Helsinki Metropolitan Area (HMA). LCI analyses were performed for five product systems, in which discarded newspapers were divided into two streams: separately collected newspapers and newspapers in mixed waste. In all the options, the manufacturing and printing processes of newspaper were kept unchanged. The waste management alternatives included combinations of material recycling, energy recovery and landfilling. These product systems were modelled using the current collection rate of newspaper and four additional collection rates. The LCIs of the product systems showed that the life cycle phase causing the most environmental impacts was the paper mill. When comparing the different waste management systems, the energy recovery options were in general superior to landfilling. The ecological implications of the increased energy recovery and decreased material recycling of newspaper were, however, not yet considered in the study. These aspects were assessed in the life cycle impact assessment (LCIA), which was performed after the LCI phase.

Towards a Nordic textile strategy : Collection, sorting, reuse and recycling of textiles

This report is the primary outcome from Part I of the project “Towards a Nordic textile strategy - Collection, sorting, reuse and recycling of textiles” initiated by the Nordic Waste Group (NAG). T ...

A Nordic textile strategy : Part II: A proposal for increased collection, sorting, reuse and recycling of textiles

The proposed strategy for increased reuse and recycling of textiles provides a starting point for the work towards a more sustainable textile and fashion sector in the Nordic region. It is focused ...