Time-adjusted global warming potentials for LCA and carbon footprints

Purpose

The common practice of summing greenhouse gas (GHG) emissions and applying global warming potentials (GWPs) to calculate CO₂ equivalents misrepresents the global warming effects of emissions that occur over a product or system??s life cycle at a particular time in the future. The two primary purposes of this work are to develop an approach to correct for this distortion that can (1) be feasibly implemented by life cycle assessment and carbon footprint practitioners and (2) results in units of CO₂ equivalent. Units of CO₂ equilavent allow for easy integration in current reporting and policy frameworks.

Methods

CO₂ equivalency is typically calculated using GWPs from the Intergovernmental Panel on Climate Change. GWPs are calculated by dividing a GHG??s global warming effect, as measured by cumulative radiative forcing, over a prescribed time horizon by the global warming effect of CO₂ over that same time horizon. Current methods distort the actual effect of GHG emissions at a particular time in the future by summing emissions released at different times and applying GWPs; modeling them as if they occur at the beginning of the analytical time horizon. The method proposed here develops time-adjusted warming potentials (TAWPs), which use the reference gas CO₂, and a reference time of zero. Thus, application of TAWPs results in units of CO₂ equivalent today.

Results and discussion

A GWP for a given GHG only requires that a practitioner select an analytical time horizon. The TAWP, however, contains an additional independent variable; the year in which an emission occurs. Thus, for each GHG and each analytical time horizon, TAWPs require a simple software tool (TAWPv1.0) or an equation to estimate their value. Application of 100-year TAWPs to a commercial building??s life cycle emissions showed a 30?% reduction in CO₂ equivalent compared to typical practice using 100-year GWPs. As the analytical time horizon is extended the effect of emissions timing is less pronounced. For example, at a 500-year analytical time horizon the difference is only 5?%.

Conclusions and recommendations

TAWPs are one of many alternatives to traditional accounting methods, and are envisioned to be used as one of multiple characterizations in carbon accounting or life cycle impact assessment methods to assist in interpretation of a study??s outcome.     

Land use impacts on biodiversity in LCA: a global approach

Purpose

Land use is a main driver of global biodiversity loss and its environmental relevance is widely recognized in research on life cycle assessment (LCA). The inherent spatial heterogeneity of biodiversity and its non-uniform response to land use requires a regionalized assessment, whereas many LCA applications with globally distributed value chains require a global scale. This paper presents a first approach to quantify land use impacts on biodiversity across different world regions and highlights uncertainties and research needs.

Methods

The study is based on the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) land use assessment framework and focuses on occupation impacts, quantified as a biodiversity damage potential (BDP). Species richness of different land use types was compared to a (semi-)natural regional reference situation to calculate relative changes in species richness. Data on multiple species groups were derived from a global quantitative literature review and national biodiversity monitoring data from Switzerland. Differences across land use types, biogeographic regions (i.e., biomes), species groups and data source were statistically analyzed. For a data subset from the biome (sub-)tropical moist broadleaf forest, different species-based biodiversity indicators were calculated and the results compared.

Results and discussion

An overall negative land use impact was found for all analyzed land use types, but results varied considerably. Different land use impacts across biogeographic regions and taxonomic groups explained some of the variability. The choice of indicator also strongly influenced the results. Relative species richness was less sensitive to land use than indicators that considered similarity of species of the reference and the land use situation. Possible sources of uncertainty, such as choice of indicators and taxonomic groups, land use classification and regionalization are critically discussed and further improvements are suggested. Data on land use impacts were very unevenly distributed across the globe and considerable knowledge gaps on cause–effect chains remain.

Conclusions

The presented approach allows for a first rough quantification of land use impact on biodiversity in LCA on a global scale. As biodiversity is inherently heterogeneous and data availability is limited, uncertainty of the results is considerable. The presented characterization factors for BDP can approximate land use impacts on biodiversity in LCA studies that are not intended to directly support decision-making on land management practices. For such studies, more detailed and site-dependent assessments are required. To assess overall land use impacts, transformation impacts should additionally be quantified. Therefore, more accurate and regionalized data on regeneration times of ecosystems are needed.     

A crustal scarcity indicator for long-term global elemental resource assessment in LCA

The International Journal of Life Cycle Assessment - How to assess impacts of mineral resources is much discussed in life cycle assessment (LCA). We see a need for, and a lack of, a mineral...     

The valuation step within LCA

Some basic principles required for the development of a valuation procedure in life cycle assessment are described. International human rights conventions and international environmental laws and conventions are analyzed for the usefulness in obtaining general principles for the valuation step of life cycle assessment. The human right to the enjoyment of the highest attainable standard of physical and mental health, the conventions of the Earth Summit in Rio 1992, the Montreal Protocol on Substances that Deplete the Ozone Layer 1987, and other treaties and conventions are shown to be a suitable basis for the valuation.     

The valuation step within LCA

International human rights conventions and international environmental laws and conventions have been used to deduce criteria for a valuation procedure for life cycle assessment. The valuation procedure relates to the impact oriented assessment of the Centrum voor Milieukunde in Leiden (CML). The panel method is suitable for comparison LCAs of two systems, or optimization LCAs. The method consists of four steps. Step one is the normalization of the results of the impact assessment. In step two, a panel of experts values the results by three qualitative criteria (time, space, hazard). In step three, a ranking diagram technique is used for a formalized priority setting and a preliminary identification of the product causing the most environmental burdens. Step four includes a sensitivity analysis and a plausibility check based on an energy and waste analysis. Discrepancies between the plausibility check and step three may cause a reevaluation of parts of the valuation, impact assessment, inventory table or goal definition of the LCA.     

Migration and health in Canada: health in the global village

Background:

Immigration has been and remains an important force shaping Canadian demography and identity. Health characteristics associated with the movement of large numbers of people have current and future implications for migrants, health practitioners and health systems. We aimed to identify demographics and health status data for migrant populations in Canada.

Methods:

We systematically searched Ovid MEDLINE (1996–2009) and other relevant web-based databases to examine immigrant selection processes, demographic statistics, health status from population studies and health service implications associated with migration to Canada. Studies and data were selected based on relevance, use of recent data and quality.

Results:

Currently, immigration represents two-thirds of Canada’s population growth, and immigrants make up more than 20% of the nation’s population. Both of these metrics are expected to increase. In general, newly arriving immigrants are healthier than the Canadian population, but over time there is a decline in this healthy immigrant effect. Immigrants and children born to new immigrants represent growing cohorts; in some metropolitan regions of Canada, they represent the majority of the patient population. Access to health services and health conditions of some migrant populations differ from patterns among Canadian-born patients, and these disparities have implications for preventive care and provision of health services.

Interpretation:

Because the health characteristics of some migrant populations vary according to their origin and experience, improved understanding of the scope and nature of the immigration process will help practitioners who will be increasingly involved in the care of immigrant populations, including prevention, early detection of disease and treatment.Migration is an important component of globalization. International migration is estimated at 200 million people,¹ and the volume of migration continues to increase. Between 1990 and 2005, global migrants increased by some 33 million people, with the largest growth observed in the developed world. The movement of populations of this size has important implications for health practitioners, health systems² and the health of individuals.^3,4Health status is associated with quality of life and use of formal and informal health services.⁵ Overall, immigrants appear to be healthier than the Canadian-born population, by virtue of being capable, both physically and mentally, of successfully moving themselves, and often their families, from one country to another.⁶ However, over time, this healthy immigrant effect is lost.⁷Health status is not equivalent across all subgroups of immigrants. Certain migrant populations experience a higher risk of infectious diseases, cancer, diabetes and heart disease, which has clinical implications for those providing care to migrant communities.⁶ The health of migrants is a product of environmental, economic, genetic and socio-cultural factors related to when people migrated to Canada, where and how they lived in their original home country, and how and why they migrated. Their health is also influenced by postmigration factors involving integration into their new place of residence, employment, education and poverty, as well as the accessibility and responsiveness of health practitioners and responsiveness of the Canadian health care system to immigrants’ health needs.⁸Migration medicine is complicated by the use of similar terms, such as immigrant, refugee or migrant, for what are, in reality, different populations. This article will use standard Canadian immigration terminology. To help primary care practitioners interpret the clinical preventive recommendations of the Canadian Collaboration for Immigrant and Refugee Health, we aimed to identify demographics, health status reports, access to health care and health system implications of migrant populations in Canada.     

Evolvement of uniformity and volatility in the stressed global financial village

Background

In the current era of strong worldwide market couplings the global financial village became highly prone to systemic collapses, events that can rapidly sweep throughout the entire village.

Methodology/Principal Findings

We present a new methodology to assess and quantify inter-market relations. The approach is based on the correlations between the market index, the index volatility, the market Index Cohesive Force and the meta-correlations (correlations between the intra-correlations.) We investigated the relations between six important world markets—U.S., U.K., Germany, Japan, China and India—from January 2000 until December 2010. We found that while the developed “western” markets (U.S., U.K., Germany) are highly correlated, the interdependencies between these markets and the developing “eastern” markets (India and China) are volatile and with noticeable maxima at times of global world events. The Japanese market switches “identity”—it switches between periods of high meta-correlations with the “western” markets and periods when it behaves more similarly to the “eastern” markets.

Conclusions/Significance

The methodological framework presented here provides a way to quantify the evolvement of interdependencies in the global market, evaluate a world financial network and quantify changes in the world inter market relations. Such changes can be used as precursors to the agitation of the global financial village. Hence, the new approach can help to develop a sensitive “financial seismograph” to detect early signs of global financial crises so they can be treated before they develop into worldwide events.     

UNEP-SETAC guideline on global land use impact assessment on biodiversity and ecosystem services in LCA

Purpose

As a consequence of the multi-functionality of land, the impact assessment of land use in Life Cycle Impact Assessment requires the modelling of several impact pathways covering biodiversity and ecosystem services. To provide consistency amongst these separate impact pathways, general principles for their modelling are provided in this paper. These are refinements to the principles that have already been proposed in publications by the UNEP-SETAC Life Cycle Initiative. In particular, this paper addresses the calculation of land use interventions and land use impacts, the issue of impact reversibility, the spatial and temporal distribution of such impacts and the assessment of absolute or relative ecosystem quality changes. Based on this, we propose a guideline to build methods for land use impact assessment in Life Cycle Assessment (LCA).

Results

Recommendations are given for the development of new characterization models and for which a series of key elements should explicitly be stated, such as the modelled land use impact pathways, the land use/cover typology covered, the level of biogeographical differentiation used for the characterization factors, the reference land use situation used and if relative or absolute quality changes are used to calculate land use impacts. Moreover, for an application of the characterisation factors (CFs) in an LCA study, data collection should be transparent with respect to the data input required from the land use inventory and the regeneration times. Indications on how generic CFs can be used for the background system as well as how spatial-based CFs can be calculated for the foreground system in a specific LCA study and how land use change is to be allocated should be detailed. Finally, it becomes necessary to justify the modelling period for which land use impacts of land transformation and occupation are calculated and how uncertainty is accounted for.

Discussion

The presented guideline is based on a number of assumptions: Discrete land use types are sufficient for an assessment of land use impacts; ecosystem quality remains constant over time of occupation; time and area of occupation are substitutable; transformation time is negligible; regeneration is linear and independent from land use history and landscape configuration; biodiversity and multiple ecosystem services are independent; the ecological impact is linearly increasing with the intervention; and there is no interaction between land use and other drivers such as climate change. These assumptions might influence the results of land use Life Cycle Impact Assessment and need to be critically reflected.

Conclusions and recommendations

In this and the other papers of the special issue, we presented the principles and recommendations for the calculation of land use impacts on biodiversity and ecosystem services on a global scale. In the framework of LCA, they are mainly used for the assessment of land use impacts in the background system. The main areas for further development are the link to regional ecological models running in the foreground system, relative weighting of the ecosystem services midpoints and indirect land use.     

Regional LCA in a global perspective. A basis for spatially differentiated environmental life cycle assessment

Background, aim and scope  

In the context of environmental life cycle assessment (LCA), life cycle impact assessment (LCIA) is one of the central issues with respect to modelling and methodological data collection. The thesis described in this paper focusses on the assessment of toxicity-related impacts, and on the collection of normalisation data. A view on the complementary roles of LCA toxicity assessment on the one hand and human and environmental risk assessment (HERA) on the other is presented, and the global, spatially differentiated LCA toxicity assessment model GLOBOX for the assessment of organics and metals is described. Normalisation factors for the year 2000 are calculated on a global as well as on a European level.     

Transportation in LCA

The purpose of this paper is to investigate whether transport and logistics substantially contribute to the environmental interventions and impacts identified in LCAs. Four LCAs, encompassing very different products in different countries, were screened for the relative contribution of transport to the overall environmental interventions and impacts. Aside from this, the contribution of transport within individual life cycle phases was investigated. In none of the LCAs did transport contribute to less than 5% of the energy related interventions or impacts, whereas contributions with more than ten percent occurred regularly, especially in events involving NO_x related impact. The importance of transport strongly depends on the kind of product studied. It seems to be especially important for agricultural products. With respect to individual phases of the life cycle, the study indicates that special attention is required for the transport of raw materials, for use phase of electronics and for the disposal phase of recyclable products.