Tonnes Of Carbon Dioxide Equivalents Research Articles

Using Life Cycle Assessment to Evaluate Green and Grey Combined Sewer Overflow Control Strategies

SummaryDecentralized approaches to managing urban stormwater are gaining increased attention within the contexts of urban sustainability, climate change adaptation, and as a means of reducing combined sewer overflows (CSOs). This study applied a life cycle assessment (LCA) to comparing the environmental efficiency of three means of equivalently reducing CSOs to the Bronx River (Bronx, NY, USA). Strategy 1 featured decentralized green infrastructure technologies, while “grey” strategies 2 and 3 detained, and detained and treated, respectively, excess flows at the end of pipe. We estimated greenhouse gas emissions (in metric tons of carbon dioxide equivalents [t CO2‐eq]) over the construction, operation, and maintenance phases, including energy consumed at the wastewater treatment plant (WWTP), carbon sequestered, and shading provided by vegetation (in the case of the green approach) over a 50‐year analysis period. The study area comprised the entire drainage area contributing to New York State permitted CSO discharge points associated with the Hunts Point WWTP. The analysis was performed using a hybrid of process and economic input‐output (EIO) LCA methods. The decentralized green strategy outperformed the two grey strategies in terms of this set of environmental metrics. The net emissions of the green strategy over 50 years was 19,000 t CO2‐eq, whereas the grey strategies emitted 85,000 t CO2‐eq (detention) and 400,000 t CO2‐eq (detention and treatment). These results were significantly influenced by the emissions associated with the operation and maintenance activities required for strategies 2 and 3, and the carbon sequestered and shading provided by the vegetation in strategy 1, and suggest that watershed managers who seek to reduce CSOs and reduce carbon footprints would opt for the green approach.

Climate impact of international travel by Swedish residents

International travel is increasing rapidly, but emissions from this segment are not included in the Kyoto Protocol and seldom in national statistics. The aim of this paper is to estimate the volume of international travel by the Swedish population, and the emissions of greenhouse gas associated with that travel. Data used are from a national travel survey for 2006 including 27,000 telephone interviews. It is shown that international travel by the Swedish population amounted to 37billionpassenger-km, or 4100km per capita in 2006. This corresponds to 22.5% of total travel by Swedes, an increase from 16.6% in 1994. Emissions of greenhouse gases from international travel by the Swedish population in 2006 amounted to 8.5 million tons of carbon dioxide equivalents, of which 92% stems from air travel. This is approx. 11% of total Swedish emissions including international transport. It is concluded that a continued growth of international travel at current pace hardly may be reconciled with long-term climate targets.

The carbon footprint of Australian ambulance operations

To determine the greenhouse gas emissions associated with the energy consumption of Australian ambulance operations, and to identify the predominant energy sources that contribute to those emissions. A two-phase study of operational and financial data from a convenience sample of Australian ambulance operations to inventory their energy consumption and greenhouse gas emissions for 1 year. State- and territory-based ambulance systems serving 58% of Australia's population and performing 59% of Australia's ambulance responses provided data for the study. Emissions for the participating systems totalled 67 390 metric tons of carbon dioxide equivalents. For ground ambulance operations, emissions averaged 22 kg of carbon dioxide equivalents per ambulance response, 30 kg of carbon dioxide equivalents per patient transport and 3 kg of carbon dioxide equivalents per capita. Vehicle fuels accounted for 58% of the emissions from ground ambulance operations, with the remainder primarily attributable to electricity consumption. Emissions from air ambulance transport were nearly 200 times those for ground ambulance transport. On a national level, emissions from Australian ambulance operations are estimated to be between 110 000 and 120 000 tons of carbon dioxide equivalents each year. Vehicle fuels are the primary source of emissions for ground ambulance operations. Emissions from air ambulance transport are substantially higher than those for ground ambulance transport.

Whole-farm systems analysis of Australian dairy farm greenhouse gas emissions

The Australian dairy industry contributes ~1.6% of the nation’s greenhouse gas (GHG) emissions, emitting an estimated 9.3 million tonnes of carbon dioxide equivalents (CO2e) per annum. This study examined 41 contrasting Australian dairy farms for their GHG emissions using the Dairy Greenhouse Gas Abatement Strategies calculator, which incorporates Intergovernmental Panel on Climate Change and Australian inventory methodologies, algorithms and emission factors. Sources of GHG emissions included were pre-farm embedded emissions associated with key farm inputs (i.e. grains and concentrates, forages and fertilisers), CO2 emissions from electricity and fuel consumption, methane emissions from enteric fermentation and animal waste management, and nitrous oxide emissions from animal waste management and nitrogen fertilisers. The estimated mean (±s.d.) GHG emissions intensity was 1.04 ± 0.17 kg CO2 equivalents/kg of fat and protein-corrected milk (kg CO2e/kg FPCM). Enteric methane emissions were found to be approximately half of total farm emissions. Linear regression analysis showed that 95% of the variation in total farm GHG emissions could be explained by annual milk production. While the results of this study suggest that milk production alone could be a suitable surrogate for estimating GHG emissions for national inventory purposes, the GHG emissions intensity of milk production, on an individual farm basis, was shown to vary by over 100% (0.76–1.68 kg CO2e/kg FPCM). It is clear that using a single emissions factor, such as milk production alone, to estimate any given individual farm’s GHG emissions, has the potential to either substantially under- or overestimate individual farms’ GHG emissions.

Mapping carbon in tropical Australia: Estimates of carbon stocks and fluxes in the Northern Territory using the national carbon accounting toolbox

Summary The Northern Territory (NT) in Australia has been perceived by many as a frontier for future agricultural development that could serve as a future food bowl for Australia. However, such development is likely to require the conversion of large areas of relatively intact savanna forests, woodlands and grasslands into other land uses, resulting in the release of large amounts of greenhouse gases. With the evolution of international carbon markets, new livelihood opportunities are arising from the management of carbon in landscapes, to enhance sequestration as a means of combating climate change. In order for land owners and governments to realise these opportunities, it is necessary to gain a better understanding of the potential carbon stocks that can occur across different ecosystems throughout the NT. This article assesses the utility of the National Carbon Accounting Toolbox (NCAT) for estimating and mapping carbon stocks in the NT. The NCAT modelling estimates that the NT environments hold approximately 21.5 billion tonnes of carbon dioxide equivalents. The estimates of carbon vary from 5 to 235 tonnes of carbon per ha, decreasing from the north, where the highest estimates are for north-east Arnhem Land and the Tiwi Islands, to the arid lands of the south. They are thought to be the lowest in the Spinifex grasslands east of Alice Springs and west of Tennant Creek. Estimates of potential emissions from clearing and burning of native vegetation range from 27 to 439 tonnes of carbon dioxide per ha, depending on the initial vegetation type. The NCAT estimates are already being used for land-clearing assessments in the NT and demonstrate that Indigenous lands hold high levels of carbon. The performance of NCAT will depend strongly on the quality of the data on which predictions are based and the robustness of model parameterisation. We suggest that further work on soils, fire, grasslands, wetlands and woody debris is needed to improve the validity of the NCAT estimates for carbon in north Australian environments.

Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials

BackgroundAll sectors of the economy, including the health research sector, must reduce their carbon emissions. The UK National Institute for Health Research has recently prepared guidelines on how to minimize the carbon footprint of research. We compare the carbon emissions from two international clinical trials in order to identify where emissions reductions can be made.MethodsWe conducted a carbon audit of two clinical trials (the CRASH-1 and CRASH-2 trials), quantifying the carbon dioxide emissions produced over a one-year audit period. Carbon emissions arising from the coordination centre, freight delivery, trial-related travel and commuting were calculated and compared.ResultsThe total emissions in carbon dioxide equivalents during the one-year audit period were 181.3 tonnes for CRASH-1 and 108.2 tonnes for CRASH-2. In total, CRASH-1 emitted 924.6 tonnes of carbon dioxide equivalents compared with 508.5 tonnes for CRASH-2. The CRASH-1 trial recruited 10,008 patients over 5.1 years, corresponding to 92 kg of carbon dioxide per randomized patient. The CRASH-2 trial recruited 20,211 patients over 4.7 years, corresponding to 25 kg of carbon dioxide per randomized patient. The largest contributor to emissions in CRASH-1 was freight delivery of trial materials (86.0 tonnes, 48% of total emissions), whereas the largest contributor in CRASH-2 was energy use by the trial coordination centre (54.6 tonnes, 30% of total emissions).ConclusionsFaster patient recruitment in the CRASH-2 trial largely accounted for its greatly increased carbon efficiency in terms of emissions per randomized patient. Lighter trial materials and web-based data entry also contributed to the overall lower carbon emissions in CRASH-2 as compared to CRASH-1.Trial Registration NumbersCRASH-1: ISRCTN74459797CRASH-2: ISRCTN86750102

The Impact of Telemedicine on Greenhouse Gas Emissions at an Academic Health Science Center in Canada

This study estimates the reduction in greenhouse gas (GHG) emissions resulting from 840 telemedicine consultations completed in a 6-month time period. Our model considers GHG emissions for both vehicle and videoconferencing unit energy use. Cost avoidance factors are also discussed. Travel distances in kilometers were calculated for each appointment using postal code data and Google Maps™ Web-based map calculator tools. Including return travel, an estimated 757,234 km were avoided, resulting in a GHG emissions savings of 185,159 kg (185 metric tons) of carbon dioxide equivalents in vehicle emissions. Approximately 360,444 g of other air pollutant emissions was also avoided. The GHG emissions produced by energy consumption for videoconference units were estimated to be 42 kg of carbon dioxide equivalents emitted for this sample. The overall GHG emissions associated with videoconferencing unit energy is minor when compared with those avoided from vehicle use. In addition to improved patient-centered care and cost savings, environmental benefits provide additional incentives for the adoption of telemedicine services.

Greenhouse gas emissions in Chicago: Emissions inventories and reduction strategies for Chicago and its metropolitan region

A greenhouse gas emissions inventory was conducted for Chicago and its metropolitan region for the years 2000 and 2005. Emissions of carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride totaled 34.7 million metric tons of carbon dioxide equivalents (MMTCO 2e) in Chicago in 2000 with 91% of emissions attributable to the indirect emissions associated with electricity consumption, the direct emissions of natural gas use, and the direct emissions of the transportation sector. A portfolio of 33 potential emissions reduction strategies was analyzed that, implemented together, could meet Chicago's target of reducing greenhouse gas emissions to 25% below 1990 levels by 2020. The largest potential for reduction is found in the areas with the largest emissions—energy use in buildings and transport. Compared to its metropolitan region, Chicago is found to have existing transportation efficiencies on a per household basis that can be an example for other communities.

Ideology with evidence: global warming, maps and ethics

calculated the energy costs of food production and transportation arising in two hypothetical populations, in which one has a 3.5% prevalence of obesity (reflecting UK in 1970) and the other of 40% (UK in 2010). The authors claim an increase in greenhouse gas emissions of between 0.4 and 1.0 Giga tonnes of carbon dioxide equivalents that was readily translated for environmentally nao ¨ve readers by The Sun— ‘FATTIES CAUSE GLOBAL WARMING’ as a front page headline. It would be tempting to suggest that air companies should levy an additional carbon tax on obese passengers but the underlying message is the need to reduce the population distribution of energy consumption downwards—something for which we all need to take responsibility—rather than target those at the top end of the distribution. Powles provides a commentary that highlights the need for considering what we eat as an integral part of policy on climate change but notes the reluctance of affluent Western politicians and the public to consider a halving of their meat consumption in order to move towards ‘contraction and convergence’ policies

Greenhouse gas emission reduction and environmental quality improvement from implementation of aerobic waste treatment systems in swine farms

Trading of greenhouse gas (GHG) emission reductions is an attractive approach to help producers implement cleaner treatment technologies to replace current anaerobic lagoons. Our objectives were to estimate greenhouse gas (GHG) emission reductions from implementation of aerobic technology in USA swine farms. Emission reductions were calculated using the approved United Nations framework convention on climate change (UNFCCC) methodology in conjunction with monitoring information collected during full-scale demonstration of the new treatment system in a 4360-head swine operation in North Carolina (USA). Emission sources for the project and baseline manure management system were methane (CH4) emissions from the decomposition of manure under anaerobic conditions and nitrous oxide (N2O) emissions during storage and handling of manure in the manure management system. Emission reductions resulted from the difference between total project and baseline emissions. The project activity included an on-farm wastewater treatment system consisting of liquid-solid separation, treatment of the separated liquid using aerobic biological N removal, chemical disinfection and soluble P removal using lime. The project activity was completed with a centralized facility that used aerobic composting to process the separated solids. Replacement of the lagoon technology with the cleaner aerobic technology reduced GHG emissions 96.9%, from 4972 tonnes of carbon dioxide equivalents (CO2-eq) to 153 tonnes CO2-eq/year. Total net emission reductions by the project activity in the 4360-head finishing operation were 4776.6 tonnes CO2-eq per year or 1.10 tonnes CO2-eq/head per year. The dollar value from implementation of this project in this swine farm was US$19,106/year using current Chicago Climate Exchange trading values of US$4/t CO2. This translates into a direct economic benefit to the producer of US$1.75 per finished pig. Thus, GHG emission reductions and credits can help compensate for the higher installation cost of cleaner aerobic technologies and facilitate producer adoption of environmentally superior technologies to replace current anaerobic lagoons in the USA.

A Spatial Analysis of Residential Greenhouse Gas Emissions in the Toronto Census Metropolitan Area

Residential greenhouse gas (GHG) emissions in the Toronto Census Metropolitan Area are spatially analyzed to determine the impact of urban form on emission‐causing activities. The key finding is that over the entire region, emissions from private auto use are on par with those from fuel use for building heating. Once beyond the transit‐intensive central core, private auto emissions surpass the emissions from building operations. Variation in total auto‐ and building‐related emissions is quite significant between census tracts, ranging from 3.1 to 13.1 tonnes of carbon dioxide equivalents per year. Of all tracts, the top ten in terms of GHG emission are located in the lower‐density suburbs, and their high emissions were largely due to private auto use.