scholarly journals A theoretical basis for the equivalence between physical and economic climate metrics and implications for the choice of Global Warming Potential time horizon

2019 ◽  
Vol 158 (2) ◽  
pp. 107-124 ◽  
Author(s):  
Dharik S. Mallapragada ◽  
Bryan K. Mignone
Keyword(s):  
Global Warming ◽  
Discount Rate ◽  
Global Warming Potential ◽  
Theoretical Basis ◽  
Time Horizon ◽  
Ghg Emissions ◽  
Damage Potential ◽  
Theoretical Finding ◽  
Potential Gdp ◽  
The Impact

Abstract The global warming potential (GWP) is widely used in policy analysis, national greenhouse gas (GHG) accounting, and technology life cycle assessment (LCA) to compare the impact of non-CO2 GHG emissions to the impact of CO2 emissions. While the GWP is simple and versatile, different views about the appropriate choice of time horizon—and the factors that affect that choice—can impede decision-making. If the GWP is viewed as an approximation to a climate metric that more directly measures economic impact—the global damage potential (GDP)—then the time horizon may be viewed as a proxy for the discount rate. However, the validity of this equivalence rests on the theoretical basis used to equate the two metrics. In this paper, we develop a new theoretical basis for relating the GWP time horizon and the economic discount rate that avoids the most restrictive assumptions of prior studies, such as an assumed linear relationship between economic damages and temperature. We validate this approach with an extensive set of numerical experiments using an up-to-date climate emulator that represents state-dependent climate-carbon cycle feedbacks. The numerical results largely confirm the theoretical finding that, under certain reasonable assumptions, time horizons in the GWP of 100 years and 20 years are most consistent with discount rates of approximately 3% and 7% (or greater), respectively.

scholarly journals The impact on global warming potential of converting from disposable to reusable sharps containers in a large US hospital geographically distant from polymer and container manufacturer

2018 ◽  
Author(s):  
Brett McPherson ◽  
Mihray Sharip ◽  
Terry Grimmond
Keyword(s):  
Global Warming ◽  
Health System ◽  
Global Warming Potential ◽  
Ghg Emissions ◽  
Medical Waste ◽  
University Hospital ◽  
Waste Stream ◽  
Unit Process ◽  
Ghg Reduction ◽  
The Impact

Background. Sustainable purchasing can reduce greenhouse gas (GHG) emissions at healthcare facilities (HCF). A previous study found that converting from disposable to reusable sharps containers (DSC, RSC) reduced sharps waste stream GHG by 84% but, in finding transport distances impacted significantly on GHG outcomes, recommended further studies where transport distances are large. This case-study examines the impact on GHG of nation-wide transport distances when a large US health system converted from DSC to RSC. Methods. The study examined the alternate use of DSC and RSC at a large US university hospital where: the source of polymer was distant from the RSC manufacturing plant; both manufacturing plants were over 3,000 km from the HCF; and the RSC disposal plant was considerably further from the HCF than was the DSC disposal plant. Using a “cradle to grave” life cycle assessment (LCA) tool we calculated annual GHG emissions (CO2, CH4, N2O) in metric tonnes of carbon dioxide equivalents (MTCO2eq) to assess the impact on global warming potential (GWP) of each container system. Primary energy input data was used wherever possible and region-specific impact conversions used to calculate GWP of each activity over a 12-month period. Unit process GHG were collated into Manufacture, Transport, Washing, and Treatment & disposal. Emission totals were workload-normalized and analysed using CHI2 test with P ≤0.05 and rate ratios at 95% CL. Results. The hospital reduced its annual GWP by 168 MTCO2eq (-64.5%; p < 0.001), and annually eliminated 50.2 tonnes of plastic DSC and 8.1 tonnes of cardboard from the sharps waste stream. Of the plastic eliminated, 31.8 tonnes were diverted from landfill and 18.4 from incineration. Discussion. Unlike GHG reduction strategies dependent on changes in staff behaviour (waste segregation, recycling, turning off lights, car-pooling, etc), purchasing strategies can enable immediate, sustainable and institution-wide GHG reductions to be achieved. Medical waste containers contribute significantly to the supply chain carbon footprint and, although non-sharp medical waste volumes have decreased significantly with avid segregation, sharps wastes have increased, and can account for 50% of total medical waste volume. Thus converting from DSC to RSC can assist reduce the GWP footprint of the medical waste stream. This study confirmed that large transport distances between polymer manufacturer and container manufacturer; container manufacturer and user; and/or between user and processing facilities, can significantly impact the GWP of sharps containment systems. However, even with large transport distances, we found that a large university health system significantly reduced the GWP of their sharps waste stream by converting from DSC to RSC.

scholarly journals The impact on global warming potential of converting from disposable to reusable sharps containers in a large US hospital geographically distant from polymer and container manufacturer

2018 ◽  
Author(s):  
Brett McPherson ◽  
Mihray Sharip ◽  
Terry Grimmond
Keyword(s):  
Global Warming ◽  
Health System ◽  
Global Warming Potential ◽  
Ghg Emissions ◽  
Medical Waste ◽  
University Hospital ◽  
Waste Stream ◽  
Unit Process ◽  
Ghg Reduction ◽  
The Impact

Background. Sustainable purchasing can reduce greenhouse gas (GHG) emissions at healthcare facilities (HCF). A previous study found that converting from disposable to reusable sharps containers (DSC, RSC) reduced sharps waste stream GHG by 84% but, in finding transport distances impacted significantly on GHG outcomes, recommended further studies where transport distances are large. This case-study examines the impact on GHG of nation-wide transport distances when a large US health system converted from DSC to RSC. Methods. The study examined the alternate use of DSC and RSC at a large US university hospital where: the source of polymer was distant from the RSC manufacturing plant; both manufacturing plants were over 3,000 km from the HCF; and the RSC disposal plant was considerably further from the HCF than was the DSC disposal plant. Using a “cradle to grave” life cycle assessment (LCA) tool we calculated annual GHG emissions (CO2, CH4, N2O) in metric tonnes of carbon dioxide equivalents (MTCO2eq) to assess the impact on global warming potential (GWP) of each container system. Primary energy input data was used wherever possible and region-specific impact conversions used to calculate GWP of each activity over a 12-month period. Unit process GHG were collated into Manufacture, Transport, Washing, and Treatment & disposal. Emission totals were workload-normalized and analysed using CHI2 test with P ≤0.05 and rate ratios at 95% CL. Results. The hospital reduced its annual GWP by 168 MTCO2eq (-64.5%; p < 0.001), and annually eliminated 50.2 tonnes of plastic DSC and 8.1 tonnes of cardboard from the sharps waste stream. Of the plastic eliminated, 31.8 tonnes were diverted from landfill and 18.4 from incineration. Discussion. Unlike GHG reduction strategies dependent on changes in staff behaviour (waste segregation, recycling, turning off lights, car-pooling, etc), purchasing strategies can enable immediate, sustainable and institution-wide GHG reductions to be achieved. Medical waste containers contribute significantly to the supply chain carbon footprint and, although non-sharp medical waste volumes have decreased significantly with avid segregation, sharps wastes have increased, and can account for 50% of total medical waste volume. Thus converting from DSC to RSC can assist reduce the GWP footprint of the medical waste stream. This study confirmed that large transport distances between polymer manufacturer and container manufacturer; container manufacturer and user; and/or between user and processing facilities, can significantly impact the GWP of sharps containment systems. However, even with large transport distances, we found that a large university health system significantly reduced the GWP of their sharps waste stream by converting from DSC to RSC.

scholarly journals The impact on global warming potential of converting from disposable to reusable sharps containers in a large US hospital geographically distant from polymer and container manufacturer

2018 ◽  
Author(s):  
Brett McPherson ◽  
Mihray Sharip ◽  
Terry Grimmond
Keyword(s):  
Global Warming ◽  
Health System ◽  
Global Warming Potential ◽  
Ghg Emissions ◽  
Medical Waste ◽  
University Hospital ◽  
Waste Stream ◽  
Unit Process ◽  
Ghg Reduction ◽  
The Impact

Background. Sustainable purchasing can reduce greenhouse gas (GHG) emissions at healthcare facilities (HCF). A previous study found that converting from disposable to reusable sharps containers (DSC, RSC) reduced sharps waste stream GHG by 84% but, in finding transport distances impacted significantly on GHG outcomes, recommended further studies where transport distances are large. This case-study examines the impact on GHG of nation-wide transport distances when a large US health system converted from DSC to RSC. Methods. The study examined the alternate use of DSC and RSC at a large US university hospital where: the source of polymer was distant from the RSC manufacturing plant; both manufacturing plants were over 3,000 km from the HCF; and the RSC disposal plant was considerably further from the HCF than was the DSC disposal plant. Using a “cradle to grave” life cycle assessment (LCA) tool we calculated annual GHG emissions (CO2, CH4, N2O) in metric tonnes of carbon dioxide equivalents (MTCO2eq) to assess the impact on global warming potential (GWP) of each container system. Primary energy input data was used wherever possible and region-specific impact conversions used to calculate GWP of each activity over a 12-month period. Unit process GHG were collated into Manufacture, Transport, Washing, and Treatment & disposal. Emission totals were workload-normalized and analysed using CHI2 test with P ≤0.05 and rate ratios at 95% CL. Results. The hospital reduced its annual GWP by 168 MTCO2eq (-64.5%; p < 0.001), and annually eliminated 50.2 tonnes of plastic DSC and 8.1 tonnes of cardboard from the sharps waste stream. Of the plastic eliminated, 31.8 tonnes were diverted from landfill and 18.4 from incineration. Discussion. Unlike GHG reduction strategies dependent on changes in staff behaviour (waste segregation, recycling, turning off lights, car-pooling, etc), purchasing strategies can enable immediate, sustainable and institution-wide GHG reductions to be achieved. Medical waste containers contribute significantly to the supply chain carbon footprint and, although non-sharp medical waste volumes have decreased significantly with avid segregation, sharps wastes have increased, and can account for 50% of total medical waste volume. Thus converting from DSC to RSC can assist reduce the GWP footprint of the medical waste stream. This study confirmed that large transport distances between polymer manufacturer and container manufacturer; container manufacturer and user; and/or between user and processing facilities, can significantly impact the GWP of sharps containment systems. However, even with large transport distances, we found that a large university health system significantly reduced the GWP of their sharps waste stream by converting from DSC to RSC.

scholarly journals Only the instantaneous global warming potential is consistent with honest and responsible greenhouse gas accounting

2018 ◽  
Author(s):  
Peter Nightingale
Keyword(s):  
Global Warming ◽  
Natural Gas ◽  
Greenhouse Gas ◽  
Global Warming Potential ◽  
Time Horizon ◽  
Energy Production ◽  
Term Effect ◽  
Near Term ◽  
Bridge Fuel ◽  
The Impact

Abstract. This paper presents a simple model to describe the impact on global warming of methane (natural gas) when used for energy production. The model is used to estimate the near-term effect of energy policies based on natural gas as a bridge fuel. The results make it clear that the commonly employed global warming potential of methane with a 100-year time horizon has the following problems: 1: it produces misleading results; 2: is inconsistent with meaningful tracking of greenhouse gas emissions; and 3: is incompatible with the precautionary principle.

scholarly journals Predicting the global warming potential of agro-ecosystems

2007 ◽  
Vol 4 (2) ◽  
pp. 1059-1092 ◽  
Author(s):  
S. Lehuger ◽  
B. Gabrielle ◽  
E. Larmanou ◽  
P. Laville ◽  
P. Cellier ◽  
...  
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Cropping Systems ◽  
C Sequestration ◽  
N2o Emissions ◽  
Data Sets ◽  
Management Scenarios ◽  
Global Warming Impact ◽  
Sequestration Potential ◽  
The Impact

Abstract. Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHG) contributing to the global warming potential (GWP) of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires a capacity to predict the net exchanges of these gases in an integrated manner, as related to environmental conditions and crop management. Here, we used two year-round data sets from two intensively-monitored cropping systems in northern France to test the ability of the biophysical crop model CERES-EGC to simulate GHG exchanges at the plot-scale. The experiments involved maize and rapeseed crops on a loam and rendzina soils, respectively. The model was subsequently extrapolated to predict CO2 and N2O fluxes over an entire crop rotation. Indirect emissions (IE) arising from the production of agricultural inputs and from cropping operations were also added to the final GWP. One experimental site (involving a wheat-maize-barley rotation on a loamy soil) was a net source of GHG with a GWP of 350 kg CO2-C eq ha−1 yr−1, of which 75% were due to IE and 25% to direct N2O emissions. The other site (involving an oilseed rape-wheat-barley rotation on a rendzina) was a net sink of GHG for –250 kg CO2-C eq ha−1 yr−1, mainly due to a higher predicted C sequestration potential and C return from crops. Such modelling approach makes it possible to test various agronomic management scenarios, in order to design productive agro-ecosystems with low global warming impact.

scholarly journals Environmental Payback of Renovation Strategies in a Northern Climate—the Impact of Nuclear Power and Fossil Fuels in the Electricity Supply

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 80 ◽  
Author(s):  
Ricardo Ramírez-Villegas ◽  
Ola Eriksson ◽  
Thomas Olofsson
Keyword(s):  
European Union ◽  
Energy Efficiency ◽  
Global Warming ◽  
Life Cycle ◽  
Radioactive Waste ◽  
Global Warming Potential ◽  
Nuclear Power ◽  
Fossil Fuels ◽  
The European Union ◽  
The Impact

The aim of this study is to assess how the use of fossil and nuclear power in different renovation scenarios affects the environmental impacts of a multi-family dwelling in Sweden, and how changes in the electricity production with different energy carriers affect the environmental impact. In line with the Paris Agreement, the European Union has set an agenda to reduce greenhouse gas emissions by means of energy efficiency in buildings. It is estimated that by the year 2050, 80% of Europe’s population will be living in buildings that already exist. This means it is important for the European Union to renovate buildings to improve energy efficiency. In this study, eight renovation scenarios, using six different Northern European electricity mixes, were analyzed using the standard of the European Committee for Standardization for life cycle assessment of buildings. This study covers all life cycle steps from cradle to grave. The renovation scenarios include combinations of photovoltaics, geothermal heat pumps, heat recovery ventilation, and improvement of the building envelope. The results show that while in some electricity mixes a reduction in the global warming potential can be achieved, it can be at the expense of an increase in radioactive waste production, and, in mixes with a high share of fossil fuels, the global warming potential of the scenarios increases with time, compared with that of the original building. It also shows that in most electricity mixes, scenarios that reduce the active heat demand of the building end up in reducing both the global warming potential and radioactive waste, making them less sensitive to changes in the energy system.

scholarly journals Comparison of physically- and economically-based CO<sub>2</sub>-equivalences for methane

2012 ◽  
Vol 3 (1) ◽  
pp. 1-29 ◽  
Author(s):  
O. Boucher
Keyword(s):  
Global Warming ◽  
Cost Function ◽  
Ad Hoc ◽  
Natural Increase ◽  
Climate Mitigation ◽  
Damage Cost ◽  
Damage Potential ◽  
Pulse Emission ◽  
Physically Based ◽  
Potential Gdp

Abstract. There is a controversy on the role methane (and other short-lived species) should play in climate mitigation policies and no consensus on what an optimal methane CO2-equivalence should be. We revisit this question by discussing the relative merits of physically-based (i.e. Global Warming Potential or GWP and Global Temperature change Potential or GTP) and socio-economically-based climate metrics. To this effect we use a simplified Global Damage Potential (GDP) that was introduced by earlier authors and investigate the uncertainties in the methane CO2-equivalence that arise from physical and socio-economic factors. The median value of the methane GDP comes out very close to the widely used methane 100-year GWP because of various compensating effects. However there is a large spread in possible methane CO2-equivalences (1–99% interval: 10.0–42.5; 5–95% interval: 12.5–38.0) that is essentially due to the choice in some socio-economic parameters (i.e. the damage cost function and the discount rate). The methane 100-year GTP falls outside these ranges. It is legitimate to increase the methane CO2-equivalence in the future as global warming unfolds. While changes in biogeochemical cycles and radiative efficiencies cause some small changes to physically-based metrics, a systematic increase in the methane CO2-equivalence can only be achieved by some ad-hoc shortening of the time horizon. In contrast using a convex damage cost function provides a natural increase in the methane CO2-equivalence for the socio-economically-based metrics. We also show that a methane CO2-equivalence based on a pulse emission is sufficient to inform multi-year climate policies and emissions reductions as long as there is some degree of visibility on CO2 prices and CO2-equivalences.

Correlation of Global Warming Potential and Atmospheric Life Times of Halocarbons

2009 ◽  
Author(s):  
Suman Kumar Sharma
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Large Scale ◽  
Life Form ◽  
Warming Trend ◽  
Economic Consequences ◽  
Empirical Relations ◽  
Food Shortages ◽  
Important Challenge ◽  
The Impact

Sustainability of life form on the earth is a major concern of every nation, which stems from the continued global warming trend, which has become a major policy, political, and economic issue. Global warming is the most important challenge thrown by the human activities largely due to rapid pace of industrialization in the twenty first century. The impact is likely to extend to next few centuries and unless controlled there would be irrevocable damage to the life form on this planet. Human made halocarbons have a high global warming potential, and some still have the potential to cause damage to the ozone layer as well if released to the atmosphere. The implications of global warming have far-reaching effects beyond the imagination of common person. Rise in global temperature, rise in sea level, food shortages, large scale spread of diseases & infections, catastrophic economic consequences and colossal loss of bio-diversity are some of the major implications of global warming trend. Although many methods are in vogue for comparison of impact of global warming of different compounds, yet the concept of Global warming potential with reference to Carbon dioxide is the simplest one and is widely used. An endeavor has been made in this paper to correlate and develop empirical relations of global warming potential and atmospheric lifetimes of Halocarbons. A new parameter Glife has been evolved for this purpose.

scholarly journals Global Warming Potential of Biomass-to-Ethanol: Review and Sensitivity Analysis through a Case Study

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2535 ◽  
Author(s):  
Rui Pacheco ◽  
Carla Silva
Keyword(s):  
Global Warming ◽  
Environmental Sustainability ◽  
Global Warming Potential ◽  
Intergovernmental Panel ◽  
Methodological Choices ◽  
The Usa ◽  
Electricity Mix ◽  
Ch4 And N2o ◽  
The Impact ◽  
Biomass To Ethanol

In Europe, ethanol is blended with gasoline fuel in 5 or 10% volume (E5 or E10). In USA the blend is 15% in volume (E15) and there are also pumps that provide E85. In Brazil, the conventional gasoline is E27 and there are pumps that offer E100, due to the growing market of flex fuel vehicles. Bioethanol production is usually by means of biological conversion of several biomass feedstocks (first generation sugar cane in Brazil, corn in the USA, sugar beet in Europe, or second-generation bagasse of sugarcane or lignocellulosic materials from crop wastes). The environmental sustainability of the bioethanol is usually measured by the global warming potential metric (GWP in CO2eq), 100 years time horizon. Reviewed values could range from 0.31 to 5.55 gCO2eq/LETOH. A biomass-to-ethanol industrial scenario was used to evaluate the impact of methodological choices on CO2eq: conventional versus dynamic Life Cycle Assessment; different impact assessment methods (TRACI, IPCC, ILCD, IMPACT, EDIP, and CML); electricity mix of the geographical region/country for different factory locations; differences in CO2eq factor for CH4 and N2O due to updates in Intergovernmental Panel on Climate Change (IPCC) reports (5 reports so far), different factory operational lifetimes and future improved productivities. Results showed that the electricity mix (factory location) and land use are the factors that have the greatest effect (up to 800% deviation). The use of the CO2 equivalency factors stated in different IPCC reports has the least influence (less than 3%). The consideration of the biogenic emissions (uptake at agricultural stage and release at the fermentation stage) and different allocation methods is also influential, and each can make values vary by 250%.

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