In-Use Stocks of Iron in the State of Connecticut, USA

A “bottom-up” study was conducted for in-use stocks of iron in the State of Connecticut for the base year of 2000. The study covers 145 product types in the four major categories of transportation, buildings, equipment, and infrastructure. The method of calculation, as well as the allocation of iron in different use categories is discussed. The total result of 9,300 kg of iron per capita is slightly higher than that from a previous study for the city of New Haven, but below the results of national top-down analyses. Possible reasons for these discrepancies are considered. A sensitivity analysis and an error rating were applied to the calculations to examine uncertainties

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

The 2020 report of The Lancet Countdown on health and climate change: responding to converging crises

The Lancet Countdown is an international collaboration, established to provide an independent, global monitoring system dedicated to tracking the emerging health profile of the changing climate. The 2020 report presents 43 indicators across five sections: climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; economics and finance; and public and political engagement. This report represents the findings and consensus of the 35 leading academic institutions and UN agencies that make up the Lancet Countdown, and draws on the expertise of climate scientists, geographers, and engineers; of energy, food, and transport experts; and of economists, social and political scientists, data scientists, public health professionals, and doctors

Life cycle assessment in support of sustainable transportation

In our rapidly urbanizing world, sustainable transportation presents a major challenge. Transportation decisions have considerable direct impacts on urban society, both positive and negative, for example through changes in transit times and economic productivity, urban connectivity, tailpipe emissions and attendant air quality concerns, traffic accidents, and noise pollution. Much research has been dedicated to quantifying these direct impacts for various transportation modes. Transportation planning decisions also result in a variety of indirect environmental and human health impacts, a portion of which can accrue outside of the transit service area and so outside of the local decision-making process. Integrated modeling of direct and indirect impacts over the life cycle of different transportation modes provides decision support that is more comprehensive and less prone to triggering unintended consequences than a sole focus on direct tailpipe emissions. The recent work of Chester et al (2013) in this journal makes important contributions to this research by examining the environmental implications of introducing bus rapid transit and light rail in Los Angeles using life cycle assessment (LCA). Transport in the LA region is dominated by automobile trips, and the authors show that potential shifts to either bus or train modes would reduce energy use and emissions of criteria air pollutants, on an average passenger mile travelled basis. This work compares not just the use of each vehicle, but also upstream impacts from its manufacturing and maintenance, as well as the construction and maintenance of the entire infrastructure required for each mode. Previous work by the lead author (Chester and Horvath 2009), has shown that these non-operational sources and largely non-local can dominate life cycle impacts from transportation, again on an average (or attributional) basis, for example increasing rail-related GHG emissions by >150% over just operational emissions. While average results are valuable in comparing transport modes generally, they are less representative of local planning decisions, where the focus is on understanding the consequences of new infrastructure and how it might affect traffic, community impacts, and environmental aspects going forward. Chester et al (2013) also present their results using consequential LCA, which provides more detailed insights about the marginal effects of the specific rapid bus and light rail lines under study. The trade-offs between the additional resources required to install the public transit infrastructure (the ‘resource debt’) and the environmental advantages during the operation of these modes can be considered explicitly in terms of environmental impact payback periods, which vary with the type of environmental impact being considered. For example, bus rapid transit incurs a relatively small carbon debt associated with the GHG emissions of manufacturing new buses and installing transit infrastructure and pays this debt off almost immediately, while it takes half a century for the light rail line to pay off the ‘smog debt’ of its required infrastructure. This payback period approach, ubiquitous in life cycle costing, has been useful for communicating the magnitude of unintended environmental consequences from other resource and land management decisions, e.g., the release of soil carbon from land conversion to bioenergy crops (Fargione et al 2008), and will likely grow in prevalence as consequential LCA is used for decision support. The locations of projected emissions is just as important to decision-making as their magnitudes, as policy-making bodies seek to understand effects in their jurisdictions; however, life cycle impact assessment methods typically aggregate results by impact category rather than by source or sink location. Chester et al (2013) address this issue by providing both local (within Los Angeles) and total emissions results, with accompanying local-only payback periods. Much more challenging is the geographic mapping of impacts that these emissions will cause, given the many point and mobile sources of air pollutants over the entire transportation life cycle. Integration of LCA with high-resolution data sets is an active area of model development (Mutel and Hellweg 2009) and will provide site- and population-specific information for impacts ranging from water quality to biodiversity to human respiratory health. Another complex challenge in modeling environmental impacts of transportation (and cities in general) is the long run, interdependent relationship between transportation technologies and urban form. LCA modeling has tended to assume a fixed pattern of settlements and demand for mobility and then examined changes to a particular technology or practice within the transportation system, such as electric or hybrid vehicles or improved pavement materials. New transit options or other travel demand management strategies might induce mode switching or reduced trips, but the overall pattern of where people live and work is generally assumed in these models to be constant in the short run. In contrast, the automobile has been influencing land-use patterns for a century, and it is the resulting geographic structure that determines the baseline need for transportation, and thus drives the use of material and energy resources used in transportation systems (Kunstler 1994). We have seen that cities with high population densities tend to have lower tailpipe emissions from transportation (Kennedy et al 2009). Recent studies have modeled how changes in urban land-use or zoning changes the geographic structure of transportation demand and then used LCA to determine the environmental benefits of such policies. For example, Mashayekh et al (2012) summarized travel demand reductions projected from several studies of compact, smart growth, and brownfield in-fill development strategies to find benefits ranging up to 75% reductions in life cycle GHG and air pollutant emissions. A related study in Toronto on life cycle energy use and GHG emissions for high- and low-density development strategies found a ~60% difference in GHG emissions, largely due to transportation (Norman et al 2006). System dynamics and agent-based models may complement LCA in capturing long-term effects of transportation strategies as they are inherently dynamic (Stepp et al 2009), and can internalize spatially resolved decisions about where to settle and work (Waddell 2002). Transportation planning decisions have both direct and indirect, spatially distributed, often long-term effects on our health and our environment. The accompanying work by Chester et al (2013) provides a well-documented case study that highlights the potential of LCA as a rich source of decision support. References Chester M, Pincetl S, Elizabeth Z, Eisenstein W and Matute J 2013 Infrastructure and automobile shifts: positioning transit to reduce life-cycle environmental impacts for urban sustainability goals Environ. Res. Lett. 8 015041 Chester M V and Horvath A 2009 Environmental assessment of passenger transportation should include infrastructure and supply chains Environ. Res. Lett. 4 024008 Fargione J, Hill J, Tilman D, Polasky S and Hawthorne P 2008 Land clearing and the biofuel carbon debt Science 319 1235–8 Kennedy C, Steinberger J, Gasson B, Hansen Y, Hillman T, Havránek M, Pataki D, Phdungsilp A, Ramaswami A and Mendez G V 2009 Greenhouse gas emissions from global cities Environ. Sci. Technol. 43 7297–302 Kunstler J H 1994 Geography of Nowhere: The Rise and Decline of America’s Man-Made Landscape (New York: Free Press) Mashayekh Y, Jaramillo P, Samaras C, Hendrickson C T, Blackhurst M, MacLean H L and Matthews H S 2012 Potentials for sustainable transportation in cities to alleviate climate change impacts Environ. Sci. Technol. 46 2529–37 Mutel C L and Hellweg S 2009 Regionalized life cycle assessment: computational methodology and application to inventory databases Environ. Sci. Technol. 43 5797–803 Norman J, MacLean H L and Kennedy C A 2006 Comparing high and low residential density: life-cycle analysis of energy use and greenhouse gas emissions J. Urban Plann. Dev. 132 10–21 Stepp M D, Winebrake J J, Hawker J S and Skerlos S J 2009 Greenhouse gas mitigation policies and the transportation sector: the role of feedback effects on policy effectiveness Energy Policy 37 2774–87 Waddell P 2002 UrbanSim: modeling urban development for land use, transportation, and environmental planning J. Am. Plann. Assoc. 68 297–31

Markov chain modeling of the global technological lifetime of copper

Markov chain modeling is applied to the global anthropogenic copper cycle for the year 2000. The lifetime of copper varies from product to product and region to region, as well as through time. Assumptions of average lifetimes are therefore subject to a high degree of uncertainty. A large state transition table is created that encompasses the life-cycle stages of copper (mining, smelting, refining, fabrication, use, waste management, scrap, and final disposal), five end-uses (buildings, transportation, consumer products, electrical equipment, and machinery) in eight world regions, including trade at every stage. The system requires closure by mass balance, so all possible routes of copper trade and recycling are considered. Transitions between each pair of states are calculated using previous material flow analysis data. The main result is that an atom of copper is used 1.9 times by human society before it enters final disposal. Scaling by the lifetime of copper in each life-cycle stage in each region gives a total average technological lifetime of copper of 60 years. A sensitivity analysis is applied to the model in order to test the robustness of the results. Several scenarios are also considered: increasing the recycling rate in each region to 70%, applying European or North American in-use lifetimes to all regions, and increasing the share of the world copper cathode and scrap markets taken in by Asia to 50%. Several limitations of the Markov chain approach are discussed, as are the further research opportunities it affords.Copper Lifetimes Markov chain modeling Recycling Global cycle In-use stock

Long-term trends of electric efficiencies in electricity generation in developing countries

This analysis provides time-series data on electric efficiencies for 138 countries and regions, covering all fossil fuels for the period 1971-2005, with an emphasis on non-Organization for Economic Cooperation and Development (OECD) countries. Fossil fuel consumption for electricity generation in non-OECD countries now exceeds that in the OECD. The historical performance of the top five non-OECD consumers of each fossil fuel for which reliable data are available is presented and discussed. For each fuel, the countries that lead the world in efficiency are used for benchmarks; bringing the rest of the world up to these standards would result in energy savings of 26EJ (equivalent to 5% of global energy consumption) and CO2 emissions reduction of 2.1Pg (equivalent to 8% of global CO2 emissions). Coal showed the largest potential margin of improvement for both energy and CO2, with possible savings equivalent to 3% of current global energy consumption and 5% of global CO2 emissions. The gap in electric efficiency between OECD and non-OECD countries over the past 35 years has widened for coal-fired generation, stayed relatively constant for natural gas, but has shrunk for petroleum. The results show the very gradual nature of overall efficiency improvements and the significant differences among regions and countries.Electric efficiency Power generation Carbon dioxide emissions