Refine
Year of Publication
- 2012 (7) (remove)
Document Type
- Peer-Reviewed Article (4)
- Part of a Book (1)
- Contribution to Periodical (1)
- Report (1)
Division
Concerns over climate change and the security of industrial feedstock supplies have been opening a growing market for biobased materials. This development, however, also presents a challenge to scientists, policy makers, and industry because the production of biobased materials requires land and is typically associated with adverse environmental effects. This article addresses the environmental impacts of biobased materials in a meta-analysis of 44 life cycle assessment (LCA) studies. The reviewed literature suggests that one metric ton (t) of biobased materials saves, relative to conventional materials, 55 ± 34 gigajoules of primary energy and 3 ± 1 t carbon dioxide equivalents of greenhouse gases. However, biobased materials may increase eutrophication by 5 ± 7 kilograms (kg) phosphate equivalents/t and stratospheric ozone depletion by 1.9 ± 1.8 kg nitrous oxide equivalents/t. Our findings are inconclusive with regard to acidification (savings of 2 ± 20 kg sulfur dioxide equivalents/t) and photochemical ozone formation (savings of 0.3 ± 2.4 kg ethene equivalents/t). The variability in the results of life cycle assessment studies highlights the difficulties in drawing general conclusions. Still, common to most biobased materials are impacts caused by the application of fertilizers and pesticides during industrial biomass cultivation. Additional land use impacts, such as the potential loss of biodiversity, soil carbon depletion, soil erosion, deforestation, as well as greenhouse gas emissions from indirect land use change are not quantified in this review. Clearly these impacts should be considered when evaluating the environmental performance of biobased materials.
Managing solid waste is one of the biggest challenges in urban areas around the world. Technologically advanced economies generate vast amounts of organic waste materials, many of which are disposed to landfills. In the future, efficient use of carbon containing waste and all other waste materials has to be increased to reduce the need for virgin raw materials acquisition, including biomass, and reduce carbon being emitted to the atmosphere therefore mitigating climate change. At end-of-life, carbon-containing waste should not only be treated for energy recovery (e.g. via incineration) but technologies should be applied to recycle the carbon for use as material feedstocks. Thermochemical and biochemical conversion technologies offer the option to utilize organic waste for the production of chemical feedstock and subsequent polymers. The routes towards synthetic materials allow a more closed cycle of materials and can help to reduce dependence on either fossil or biobased raw materials. This chapter summarizes carbon-recycling routes available and investigates how in the long-term they could be applied to enhance waste management in both industrial countries as well as developing and emerging economies. We conclude with a case study looking at the system-wide global warming potential (GWP) and cumulative energy demand (CED) of producing high-density polyethylene (HDPE) from organic waste feedstock via gasification followed by Fischer–Tropsch synthesis (FTS). Results of the analysis indicate that the use of organic waste feedstock is beneficial if greenhouse gas (GHG) emissions associated with landfill diversion are considered.
Material flows induced by national economies can be regarded as indirect pressure indicators for environmental degradation. Economy-wide material flow analysis and indicators have been designed to monitor material and energy flows at the macroeconomic level and to provide indicators, which could contribute to management of resourceuse and output emission flows from both economic, environmental and broader sustainability points of view. These indicators can serve various purposes including monitoring the material basis of national economies and related environmental pressures, assessment of the material and resource productivity and monitoring the implications of trade and globalisation.
The main part of this paper compares the material and resourceuse of the Czech Republic, Germany and the EU-15 by means of DMI and TMR indicators over the period of 1991–2004 (1991–2000 for EU-15). At the aggregate level both indicators in all three economies do not show any clear decreasing or increasing trends over the period considered. This means that environmental pressure related to use of materials for production and consumption purposes remains rather stable. All the economies however, recorded an increase in the efficiency of transforming the material/resource inputs into economic output. The analysis further revealed that most of the dynamics of DMI and TMR in the Czech Republic tended towards a higher similarity with Germany and the EU-15. In the future, further decreases in DMI as well as in TMR of fossils fuels might be expected in the Czech Republic, which could be counteracted by increase in DMI and TMR of metal ores/metal resources and non-metallic minerals/non-metallic resources. The future development of total DMI, TMR and material/resource intensity in both the Czech Republic and Germany will depend on further shifts to less material intensive industries and services and on increasing material efficiency in production and consumption of particular products. This is not only a technological, but also a social challenge, as there are barriers in current mode of governance and in shaping of current economic and social systems to do so.
Global trade is increasingly being challenged by observations of growing burden shifting, in particular of environmental problems. This paper presents the first worldwide calculations of shifted burden based on material flow indicators, in particular direct and indirect physical trade balances. This study covers the period between 1962 and 2005 and includes between 82 and 173 countries per year. The results show that indirect trade flow volumes have increased to around 41 billion tonnes in 2005. The traded resources with the highest share of associated indirect flows are iron, hard coal, copper, tin and increasingly palm oil. Regarding the burden balance between regions, Europe is the biggest shifter whereas Australia and Latin America are the largest takers of environmental burden due to resource extraction. To evaluate the findings from a global perspective, the results are analysed in terms of resource flow induced environmental pressure related to a country's land area in terms of total and per capita area. Resource endowment and population density seem to be more relevant in determining the physical trade balance, including indirect flows, than income level.
Consumption of natural resources should not exceed sustainable levels. The increasing use of biofuels and to some extent biomaterials, on top of rising food and feed demands, is causing countries to use a growing amount of global land, which may lead to land use conflicts and the expansion of cropland and intensive cultivation at the expense of natural ecosystems. Selective product certification cannot control the land use change triggered by growing overall biomass consumption. We propose a comprehensive approach to account for the global land use of countries for their domestic consumption, and assess this level with regard to globally acceptable levels of resource use, based on the concept of safe operating space. It is shown that the European Union currently uses one-third more cropland than globally available on a per capita basis and that with constant consumption levels it would exceed its fair share of acceptable resource use in 2030. As the use of global forests to meet renewable energy targets is becoming a concern, an approach to account for sustainable levels of timber flows is also proposed, based on the use of net annual increment, exemplified with preliminary data for Switzerland. Altogether, our approach would integrate the concept of sustainable consumption into national resource management plans; offering a conceptual basis and concrete reference values for informed policy making and urging countries to monitor and adjust their levels of resource consumption in a comprehensive way, respectful of the limits of sustainable supply.