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1.
The geologic storage (GS) of carbon dioxide (CO2) is emerging as an important tool for managing carbon. While this Journal recently published an excellent review of GS technology (Bruant, R. G.; Guswa, A. J.; Celia, M. A.; Peters, C. A. Environ. Sci. Technol. 2002, 36, 240A-245A), few studies have explored the regulatory environment for GS or have compared it with current underground injection experience. We review the risks and regulatory history of deep underground injection on the U.S. mainland and surrounding continental shelf. Our treatment is selective, focusing on the technical and regulatory aspects that are most likely to be important in assessing and managing the risks of GS. We also describe current underground injection activities and explore how these are now regulated.  相似文献   

2.
Carbon capture and sequestration (CCS) has the potential to enable deep reductions in global carbon dioxide (CO2) emissions, however this promise can only be fulfilled with large-scale deployment. For this to happen, CCS must be successfully embedded into a larger legal and regulatory context, and any potential risks must be effectively managed. We developed a list of outstanding research and technical questions driven by the demands of the regulatory and legal systems for the geologic sequestration (GS) component of CCS. We then looked at case studies that bound uncertainty within two of the research themes that emerge. These case studies, on surface leakage from abandoned wells and groundwater quality impacts from metals mobilization, illustrate how research can inform decision makers on issues of policy, regulatory need, and legal considerations. A central challenge is to ensure that the research program supports development of general regulatory and legal frameworks, and also the development of geological, geophysical, geochemical, and modeling methods necessary for effective GS site monitoring and verification (M&V) protocols, as well as mitigation and remediation plans. If large-scale deployment of GS is to occur in a manner that adequately protects human and ecological health and does not discourage private investment, strengthening the scientific underpinnings of regulatory and legal decision-making is crucial.  相似文献   

3.
This analysis uses linear programming modeling of the U.S. refining sector to estimate total annual energy consumption and CO(2) emissions in 2025, for four projected U.S. crude oil slates. The baseline is similar to the current U.S. crude slate; the other three contain larger proportions of higher density, higher sulfur crudes than the current or any previous U.S. crude slates. The latter cases reflect aggressive assumptions regarding the volumes of Canadian crudes in the U.S. crude slate in 2025. The analysis projects U.S. refinery energy use 3.7%-6.3% (≈ 0.13-0.22 quads/year) higher and refinery CO(2) emissions 5.4%-9.3% (≈ 0.014-0.024 gigatons/year) higher in the study cases than in the baseline. Refining heavier crude slates would require significant investments in new refinery processing capability, especially coking and hydrotreating units. These findings differ substantially from a recent estimate asserting that processing heavy oil or bitumen blends could increase industry CO(2) emissions by 1.6-3.7 gigatons/year.  相似文献   

4.
Employing life cycle greenhouse gas (GHG) emissions as a key performance metric in energy and environmental policy may underestimate actual climate change impacts. Emissions released early in the life cycle cause greater cumulative radiative forcing (CRF) over the next decades than later emissions. Some indicate that ignoring emissions timing in traditional biofuel GHG accounting overestimates the effectiveness of policies supporting corn ethanol by 10-90% due to early land use change (LUC) induced GHGs. We use an IPCC climate model to (1) estimate absolute CRF from U.S. corn ethanol and (2) quantify an emissions timing factor (ETF), which is masked in the traditional GHG accounting. In contrast to earlier analyses, ETF is only 2% (5%) over 100 (50) years of impacts. Emissions uncertainty itself (LUC, fuel production period) is 1-2 orders of magnitude higher, which dwarfs the timing effect. From a GHG accounting perspective, emissions timing adds little to our understanding of the climate impacts of biofuels. However, policy makers should recognize that ETF could significantly decrease corn ethanol's probability of meeting the 20% GHG reduction target in the 2007 Energy Independence and Security Act. The added uncertainty of potentially employing more complex emissions metrics is yet to be quantified.  相似文献   

5.
ABSTRACT: Functional foods are intended to help consumers manage or reduce disease risks or support the structure or function of the body. In the U.S.A., the term functional food is an intellectual concept that has not been defined in either statute or regulation. Functional foods are treated as conventional foods for purposes of determination of safety and, as such, are subject to the same regulatory approval process. Interest in and demand for more information concerning the health promoting properties of foods and dietary supplements has steadily increased. However, inequities in the regulatory process including the differing treatment of efficacy claims for dietary supplements and functional foods, confusion between structure/function, health claims, and qualified health claims, and the constraints of severely limited resources have all had an impact on the delivery of accurate information to consumers. Although their efforts are coordinated, different agencies view efficacy claims differently, employing different standards for levels of scientific evidence, and different processes for evaluation. A third-party review process that could provide a consistent and sound scientific basis to the evaluation of the evidence would be desirable. Recent proposals by the U.S. Food and Drug Administration concerning qualified health claims may help consumers get more of the information they need and enable them to make informed decisions.  相似文献   

6.
The quality of drinking water in the United States has continued to improve over the past 40 years. The formation of the U.S. Environmental Protection Agency (USEPA) in 1971, the passage of the initial Safe Drinking Water Act (SDWA, PL 93-523) in 1974, and the passage of the 1996 SDWA Amendments (PL 104-208) represent significant progress in drinking water quality. While the widespread adoption of filtration and disinfection in the early 1900s virtually eliminated waterborne typhoid fever, some residual risks still remained 40 years ago. These national regulatory developments compelled USEPA and the drinking water community to address these remaining risks in drinking water and optimize risk reduction for the public.  相似文献   

7.
To understand the long-term energy and climate implications of different implementation strategies for carbon capture and storage (CCS) in the US coal-fired electricity fleet, we integrate three analytical elements: scenario projection of energy supply systems, temporally explicit life cycle modeling, and time-dependent calculation of radiative forcing. Assuming continued large-scale use of coal for electricity generation, we find that aggressive implementation of CCS could reduce cumulative greenhouse gas emissions (CO(2), CH(4), and N(2)O) from the US coal-fired power fleet through 2100 by 37-58%. Cumulative radiative forcing through 2100 would be reduced by only 24-46%, due to the front-loaded time profile of the emissions and the long atmospheric residence time of CO(2). The efficiency of energy conversion and carbon capture technologies strongly affects the amount of primary energy used but has little effect on greenhouse gas emissions or radiative forcing. Delaying implementation of CCS deployment significantly increases long-term radiative forcing. This study highlights the time-dynamic nature of potential climate benefits and energy costs of different CCS deployment pathways and identifies opportunities and constraints of successful CCS implementation.  相似文献   

8.
Many U.S. states conduct greenhouse gas (GHG) inventories to inform their climate change planning efforts. These inventories usually follow a production-based method adapted from the Intergovernmental Panel on Climate Change. States could also take a consumption-based perspective, however, and estimate all emissions released to support consumption in their state, regardless of where the emissions occur. In what may be the first such comprehensive inventory conducted for a U.S. state, we find that consumption-based emissions for Oregon are 47% higher than those released in-state. This finding implies that Oregon's contribution to global greenhouse gas emissions (carbon footprint) is considerably higher than traditional production-based methods would suggest. Furthermore, the consumption-based inventory helps highlight the role of goods and services (and associated purchasing behaviors) more so than do production-based methods. Accordingly, a consumption-based perspective opens new opportunities for many states and their local government partners to reduce GHG emissions, such as initiatives to advance lower-carbon public sector or household consumption, that are well within their sphere of influence. State and local governments should consider conducting consumption-based GHG inventories and adopting consumption-based emission reductions targets in order to broaden the reach and effectiveness of state and local actions in reducing global GHG emissions. Consumption-based frameworks should be viewed as a complement to, but not a substitute for, production-based (in-state) GHG emissions inventories and targets.  相似文献   

9.
Abstract

The U.S. Dietary Supplement Health and Education Act (DSHEA) established the regulatory framework for dietary supplements as foods through the Food and Drug Administration (FDA). DSHEA outlined the legal definition, labeling requirements, and process for adverse event reporting for dietary supplements. FDA also issued formal guidance on current Good Manufacturing Practice to ensure that processes for preparation, packaging, labeling, and storage of supplements and ingredients are documented and meet specifications to ensure purity, composition, and strength. However, efficacy of dietary supplements is not required under U.S. law. Despite regulations to improve the marketplace, many challenges remain; as a result, the quality and safety of products available can be highly variable, especially for botanical and herbal products. The ability of regulators to successfully carry out their mission is hampered by the sheer number of products and manufacturing facilities and a lack of analytical methods for all ingredients and products in the marketplace, this is especially difficult for herbal and botanical dietary supplements. Safety issues continue to exist such as adulteration and contamination, especially with specific product types (i.e. body building, sexual enhancement). Thus, a need remains for continued efforts and improved techniques to assess the quality of dietary supplements, especially with regard to purity, bioavailability, and safety. This review will highlight the existing American regulatory framework for dietary supplements and will describe the remaining regulatory barriers to ensuring that safe and high-quality dietary supplements are offered in the marketplace.  相似文献   

10.
Injection of CO(2) into geological structures is a key technology for sequestering CO(2) emissions captured from the combustion of fossil fuels. Current projects inject volumes on the order of megatonnes per year. However, injection volumes must be increased by several orders of magnitude for material reductions in ambient concentrations. A number of questions surrounding safety and security of injection have been raised about the large scale deployment of geological CO(2) sequestration. They are site specific and require an effective monitoring strategy to mitigate risks of concern to stakeholders. This paper presents a model-based framework for monitoring design that can provide a quantitative understanding of the trade-offs between operational decisions of cost, footprint size, and uncertainty in monitoring strategies. Potential risks and challenges of monitoring large scale CO(2) injection are discussed, and research areas needed to address uncertainties are identified. Lack of clear guidance surrounding monitoring has contributed to hampering the development of policies to promote the deployment of large scale sequestration projects. Modeling provides an understanding of site specific processes and allows insights into the complexity of these systems, facilitating the calibration of an appropriate plan to manage risk. An integrated policy for risk-based monitoring design, prior to large scale deployment of sequestration will ensure safe and secure storage through an understanding of the real risks associated with large scale injection.  相似文献   

11.
Chinese stakeholders (131) from 68 key institutions in 27 provinces were consulted in spring 2009 in an online survey of their perceptions of the barriers and opportunities in financing large-scale carbon dioxide capture and storage (CCS) demonstration projects in China. The online survey was supplemented by 31 follow-up face-to-face interviews. The National Development and Reform Commission (NDRC) was widely perceived as the most important institution in authorizing the first commercial-scale CCS demonstration project and authorization was viewed as more similar to that for a power project than a chemicals project. There were disagreements, however, on the appropriate size for a demonstration plant, the type of capture, and the type of storage. Most stakeholders believed that the international image of the Chinese Government could benefit from demonstrating commercial CCS and that such a project could also create advantages for Chinese companies investing in CCS technologies. In more detailed interviews with 16 financial officials, we found striking disagreements over the perceived risks of demonstrating CCS. The rate of return seen as appropriate for financing demonstration projects was split between stakeholders from development banks (who supported a rate of 5-8%) and those from commercial banks (12-20%). The divergence on rate alone could result in as much as a 40% difference in the cost of CO(2) abatement and 56% higher levelized cost of electricity based on a hypothetical case study of a typical 600-MW new build ultrasupercritical pulverized coal-fired (USCPC) power plant. To finance the extra operational costs, there were sharp divisions over which institutions should bear the brunt of financing although, overall, more than half of the support was expected to come from foreign and Chinese governments.  相似文献   

12.
The purpose of this work was to investigate incentives and barriers to fuel ethanol production from biomass in the U.S. during the past decade (2000-2010). In particular, we examine the results of policies and economic conditions during this period by way of cellulosic ethanol activity in four selected states with the potential to produce different types of feedstocks (i.e., sugar, starch, and cellulosic crops) for ethanol production (Florida, California, Hawaii, and Iowa). Two of the four states, Iowa and California, currently have commercial ethanol production facilities in operation using corn feedstocks. While several companies have proposed commercial scale facilities in Florida and Hawaii, none are operating to date. Federal and state policies and incentives, potential for feedstock production and conversion to ethanol and associated potential environmental impacts, and environmental regulatory conditions among the states were investigated. Additionally, an analysis of proposed and operational ethanol production facilities provided evidence that a combination of these policies and incentives along with the ability to address environmental issues and regulatory environment and positive economic conditions all impact ethanol production. The 2000-2010 decade saw the rise of the promise of cellulosic ethanol. Federal and state policies were enacted to increase ethanol production. Since the initial push for development, expansion of cellulosic ethanol production has not happened as quickly as predicted. Government and private funding supported the development of ethanol production facilities, which peaked and then declined by the end of the decade. Although there are technical issues that remain to be solved to more efficiently convert cellulosic material to ethanol while reducing environmental impacts, the largest barriers to increasing ethanol production appear to be related to government policies, economics, and logistical issues. The numerous federal and state policies do not effectively give investors confidence to commit to the construction and long-term operation of facilities under current economic conditions. Additional changes in policy and breakthroughs in technology and logistics will be required to address these hurdles to increases in ethanol production in the U.S. in the next decade.  相似文献   

13.
While carbon capture and storage (CCS) is considered to be critical to achieving long-term climate-protection goals, public concerns about the CCS practice could pose significant obstacles to its deployment. This study reports findings from the first state-wide survey of public perceptions of CCS in a coal-intensive state, with an analysis of which factors predict early attitudes toward CCS. Nearly three-quarters of an Indiana sample (N = 1001) agree that storing carbon underground is a good approach to protecting the environment, despite 80% of the sample being unaware of CCS prior to participation in the two-wave survey. The majority of respondents do not hold strong opinions about CCS technology. Multivariate analyses indicate that support for CCS is predicted by a belief that humankind contributes to climate change, a preference for increased use of renewable energy, and egalitarian and individualistic worldviews, while opposition to CCS is predicted by self-identified political conservatism and by selective attitudes regarding energy and climate change. Knowledge about early impressions of CCS can help inform near-term technology decisions at state regulatory agencies, utilities, and pipeline companies, but follow-up surveys are necessary to assess how public sentiments evolve in response to image-building efforts with different positions on coal and CCS.  相似文献   

14.
Aqueous U(VI) reduction by hydrogen sulfide was investigated by batch experiments and speciation modeling; product analysis by transmission electron microscopy (TEM) was also performed. The molar ratio of U(VI) reduced to sulfide consumed, and the TEM result suggested that the reaction stoichiometry could be best represented by UO2(2+) + HS- = UO2+ S* + H+. At pH 6.89 and total carbonate concentration ([CO32-]T) of 4.0 mM, the reaction took place according to the following kinetics: -d[U(VI)]/dt = 0.0103[U(VI)][S2-]T0.54 where [U(VI)] is the concentration of hexavalent uranium, and [S2-]T is the total concentration of sulfide. The kinetics of U(VI) reduction was found to be largely controlled by [CO32-]T (examined from 0.0 to 30.0 mM) and pH (examined from 6.37 to 9.06). The reduction was almost completely inhibited with the following [CO32-]T and pH combinations: [(> or = 15.0 mM, pH 6.89); (> or = 4.0 mM, pH 8.01); and (> or = 2.0 mM, pH 9.06)]. By comparing the experimental results with the calculated speciation of U(VI), it was found that there was a strong correlation between the measured initial reaction rates and the calculated total concentrations of uranium-hydroxyl species; we, therefore, concluded that uranium-hydroxyl species were the ones being reduced by sulfide, not the dominant U-carbonate species present in many carbonate-containing systems.  相似文献   

15.
Achieving food security in the face of climate change is a major challenge for humanity in the 21st century but comprehensive analyses of climate change impacts, including global market feedbacks are still lacking. In the context of uneven impacts of climate change across regions interconnected through trade, climate change impact and adaptation policies in one region need to be assessed in a global framework. Focusing on four Eastern Asian countries and using a global integrated modeling framework we show that i) once imports are considered, the overall climate change impact on the amount of food available could be of opposite sign to the direct domestic impacts and ii) production and trade adjustments following price signals could reduce the spread of climate change impacts on food availability. We then investigated how pressure on the food system in Eastern Asia could be mitigated by a consumer support policy. We found that the costs of adaptation policies to 2050 varied greatly across climate projections. The costs of consumer support policies would also be lower if only implemented in one region but market price leakage could exacerbate pressure on food systems in other regions. We conclude that climate adaptation should no longer be viewed only as a geographically isolated local problem.  相似文献   

16.
The climate change impacts of U.S. petroleum-based fuels consumption have contributed to the development of legislation supporting the introduction of low carbon alternatives, such as biofuels. However, the potential greenhouse gas (GHG) emissions reductions estimated for these policies using life cycle assessment methods are predominantly based on deterministic approaches that do not account for any uncertainty in outcomes. This may lead to unreliable and expensive decision making. In this study, the uncertainty in life cycle GHG emissions associated with petroleum-based fuels consumed in the U.S. is determined using a process-based framework and statistical modeling methods. Probability distributions fitted to available data were used to represent uncertain parameters in the life cycle model. Where data were not readily available, a partial least-squares (PLS) regression model based on existing data was developed. This was used in conjunction with probability mixture models to select appropriate distributions for specific life cycle stages. Finally, a Monte Carlo simulation was performed to generate sample output distributions. As an example of results from using these methods, the uncertainty range in life cycle GHG emissions from gasoline was shown to be 13%-higher than the typical 10% minimum emissions reductions targets specified by low carbon fuel policies.  相似文献   

17.
18.
Dietary supplements, including those containing botanical ingredients and botanical‐derived compounds, have been marketed to consumers globally for many decades. However, the legislative framework for such products remains inconsistent across jurisdictions internationally. This study aims to compare the regulatory framework of botanical food supplements in the EU, USA, Canada, Australia, New Zealand, India, Japan, and China. The study also aims to investigate and describe safety assessment criteria for botanical food supplements where they are present in the above said jurisdictions, and attempts to analyze whether these criteria are suitable for addressing the toxicological risks associated with the use of botanical food supplement products, based on the evaluation of reported adverse effects related to botanical food supplement use as examples. Finally, this study discusses some future issues that need further attention, such as the consideration of less than lifetime exposures, potential for misidentification, and adulteration of botanical supplements by pharmacologically active substances. It is concluded that the regulatory approaches towards botanical food supplements differ significantly across jurisdictions. In addition, national authorities are increasingly considering having more regulatory oversight for such products. Further consideration of the actual impact of adverse events arising from botanical food supplement usage will be helpful in guiding such decisions.  相似文献   

19.
The unprecedented uncertainty associated with engineered nanomaterials greatly expands the need for research regarding their potential environmental consequences. However, decision-makers such as regulatory agencies, product developers, or other nanotechnology stakeholders may not find the results of such research directly informative of decisions intended to mitigate environmental risks. To help interpret research findings and prioritize new research needs, there is an acute need for structured decision-analytic aids that are operable in a context of extraordinary uncertainty. Whereas existing stochastic decision-analytic techniques explore uncertainty only in decision-maker preference information, this paper extends model uncertainty to technology performance. As an illustrative example, the framework is applied to the case of single-wall carbon nanotubes. Four different synthesis processes (arc, high pressure carbon monoxide, chemical vapor deposition, and laser) are compared based on five salient performance criteria. A probabilistic rank ordering of preferred processes is determined using outranking normalization and a linear-weighted sum for different weighting scenarios including completely unknown weights and four fixed-weight sets representing hypothetical stakeholder views. No single process pathway dominates under all weight scenarios, but it is likely that some inferior process technologies could be identified as low priorities for further research.  相似文献   

20.
Large numbers of infants and young children suffer from the short- and long-term health effects of poor breastfeeding and complementary feeding practices. Strategies to improve the availability of and access to low-cost fortified complementary foods can play an important corresponding role to that of behavior change in improving nutritional status of young children. However, the nutritional quality of complementary foods used in publicly funded programs is not always optimal, and such programs are costly and reach only a tiny fraction of those who could benefit. To broadly reach the target population, such foods need to be commercially available at affordable prices and promoted in a way that generates demand for their purchase. A sensible long-term policy for the promotion of low-cost fortified complementary foods calls for attention to their nutritional formulations and cost, the economics of production, and the legislative, regulatory, and competitive framework in which marketing occurs. This paper provides information on how to improve the nutritional formulations of fortified complementary foods and outlines the necessary conditions for a market approach to their production and promotion.  相似文献   

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