Effective policies combating global warming and incentivising reduction of greenhouse gases face fundamental collective action problems. States defending short term interests avoid international commitments and seek to benefit from measures combating global warming taken elsewhere. The paper explores the potential of Common Concern as an emerging principle of international law, in particular international environmental law, in addressing collective action problems and the global commons. It expounds the contours of the principle, its relationship to common heritage of mankind, to shared and differentiated responsibility and to public goods. It explores its potential to provide the foundations not only for international cooperation, but also to justify, and delimitate at the same time, unilateral action at home and deploying extraterritorial effects in addressing the challenges of global warming and climate change mitigation. As unilateral measures mainly translate into measures of trade policy, the principle of Common Concern is inherently linked and limited by existing legal disciplines in particular of the law of the World Trade Organization.
Purpose: This research presents a methodology to characterize life cycle impact data (LCIA) of alternative construction materials outside of the European context.
Methods: This methodology was based on the characterization of data and life cycle assessment (LCA) using geographic information systems (GIS), which has been proposed as an effective alternative for this purpose. The data were characterized at three levels: global, represented by different production efficiency of materials; regional, represented by the type of electricity mix used in the production and the national transport at the country level; and local, represented by external factors, such as seismic and wind risk zones at the city level. A comparative LCA was used as case study to test the methodology. The functional unit for the LCA was defined as an 18 m2 core shelter unit consisting of structural elements only. The bill of materials for five designs were calculated, each using a distinctive construction material: bamboo, brick, concrete hollow block, ferro-cement panels, and soil-stabilised bricks. The contributions’ variability and uncertainty analysis were used to validate the consistency of the results. The effect of the external constraints (earthquakes and wind) were analysed, and the environmental impact over the whole life cycle was assessed. Five house designs were calculated in twenty locations based on three levels of production efficiency and three transport distance ranges for each country.
Results and discussion: The results of the bamboo, concrete hollow block and ferro-cement houses overlapped and changed depending on the construction materials’ transport distance. Therefore, the level of impact of an average bamboo house can also be achieved by a high-performance block or ferro-cement house. The results showed that in most cases, the buildings with high technical performance can be achieved with low environmental impacts.
Conclusions: The use of GIS enables the development of characterized LCIA data for construction materials and buildings with a high degree of consistency. Moreover, the proposed approach was able to accurately represent the range of production practices used outside Europe. Finally, the use of the proposed methodology allows for the assessment of building in the early stages of design when uncertainty is at its highest, thereby identifying the improvement potential of each design and recognising the structural needs in specific locations.
