MATLAB在GPS定位坐标系统模拟中的应用

针对在GPS定位坐标系统中进行精密计算的复杂性,通过使用MATLAB来处理协议天球坐标系的定义及转换问题,以此来确定GPS卫星星座在天球坐标系中的具体位置。通过使用MATLAB来模拟其原理及计算过程,可大幅度提高GPS定位坐标系统中的计算速度以及精度。     

Polar bear management,sport hunting and Inuit subsistence at Clyde River,Nunavut

This paper begins by reviewing the structure and evolution of polar bear (Ursus maritimus) management in Canada and in the Territory of Nunavut since the inception of the Agreement on the Conservation of Polar Bears in the 1970s. This is followed by the paper's main focus, the examination of the socio-economic and cultural importance of polar bears for Inuit and the success of the Agreement in supporting contemporary Inuit subsistence relations in Nunavut.     

Overview of the subsurface structural pattern of the Paris Basin (France): Insights from the reprocessing and interpretation of regional seismic lines

The study presents the methodology used by the French Geological Survey (BRGM) for the building, reprocessing and interpretation of selected regional seismic lines in the Paris intracratonic basin (France): the 14 constructed E-W and N-S regional transects represent a total of 2,516 km length, and are based on the merge of 240 seismic single profiles recorded by petroleum operators between 1971 and 1995. The regional lines have been selected to cross the main oil fields of the Paris Basin, as well as high potential areas for oil exploration. A first difficulty was to recover the raw data necessary to build-up the regional transects. The signal reprocessing, harmonization and merge of the single seismic lines, constituent of the regional transects, are then described; these operations represent the cornerstone of the study. We put the emphasis on the primary static corrections, as the targeted structures are commonly spatially associated with large seismic velocity variations in the upper Cretaceous chalk and Tertiary sedimentary cover.The interpreted regional transects definitely give complementary information to the existing studies, which generally lack seismic (and therefore structural) data: we give an overview of the main structural and geometrical features of the Paris Basin: inversion structures, major unconformities, as well as Permo-Carboniferous basins. We also describe the structural pattern, and show the close relationships between the faults geometry, the faults density, and the geological evolution of the Paris Basin: we distinguish (1) few large-scale polyphase faults, with a Variscan origin, representing the first order structural frame of the Paris Basin; (2) monophase normal faults, with strike-slip features, representing the subsurface prolongation of Cenozoic grabens cropping out in the neighbourhood; (3) deep normal faults, sealed by the base Calcareous Dogger sequence, related to the Permo-Liassic extensional tectonic regime. This large-scale view of the Paris Basin has highlighted several potential exploration targets.     

Testing and evaluation of strength and deformation behaviour of jointed rocks

The objective of the paper is to derive the strength and modulus properties of rockmass as a function of intact rock strength and joint factor. The joint factor reflects the combined effect of joint frequency, joint inclination and joint strength. A study for the strength and deformation characteristics of jointed rock is done by conducting standard laboratory tests on cylindrical specimens of plaster of Paris after introducing artificial joints. The specimens having one to four joints at different inclinations which vary from 0° to 90° were tested at different confining conditions. The test results were examined to understand the effect of joint frequency and joint inclination on the strength and deformation behaviour of rock mass. Empirical correlations were developed for prediction of the uniaxial compressive strength and elastic modulus of jointed rocks. Results are compared with the earlier work on jointed specimens covering a wide variety of rocks. So, knowing the intact rock properties and the joint factor, the jointed rock properties can be estimated. These relations can be used for developing an equivalent continuum model for rock mass for handling boundary value problems. A failure criterion as proposed by Ramamurthy (1993 Ramamurthy, T. 1993. “Strength and modulus response of anisotropic rocks”. In Comprehensive rock engineering, Edited by: Hudson, J.A. Vol. 1, 313–329. Oxford: Pergamon Press.  [Google Scholar]) has been validated from these experimental results.     

Swimming upstream: addressing fossil fuel supply under the UNFCCC

Reducing fossil fuel supply is necessary to meet the Paris Agreement goal to keep warming ‘well below 2°C’, yet the Agreement is silent on the topic of fossil fuels. This article outlines reasons why it is important that Parties to the Agreement find ways to more explicitly address the phasing out of fossil fuel production under the UNFCCC. It describes how countries aiming to keep fossil fuel supply in line with Paris goals could articulate and report their actions within the current architecture of the Agreement. It also outlines specific mechanisms of the Paris Agreement through which issues related to the curtailment of fossil fuel supply can be addressed. Mapping out a transition away from fossil fuels – and facilitating this transition under the auspices of the UNFCCC process – can enhance the ambition and effectiveness of national and international climate mitigation efforts.

Key policy insights

• The international commitment to limit global average temperature increases to ‘well below 2°C’ provides a strong rationale for Parties to the Paris Agreement and the UNFCCC to pursue a phase-down in fossil fuel production, not just consumption.

• Several countries have already made commitments to address fossil fuel supply, by agreeing to phase down coal or oil exploration and production.

• Integrating these commitments into the UNFCCC process would link them to global climate goals, and ensure they form part of a broader global effort to transition away from fossil fuels.

• The Paris Agreement provides a number of new opportunities for Parties to address fossil fuel production.

     

美国退出《巴黎协定》对全球温室气体排放的影响

现有研究表明美国退出《巴黎协定》将会在2025年导致其国内排放增加约1.2 Gt CO₂-eq,然而美国退出《巴黎协定》对全球气候治理的影响不仅限于此,还包括资金效应、政治效应,以及惯性效应等对全球排放的间接和长期影响。本文通过构建体现不同效应的全球温室气体排放情景,分析了美国退出《巴黎协定》后对全球温室气体排放可能造成的不同影响。结果表明,美国退出《巴黎协定》的自身效应、资金效应、对伞形国家的政治效应和对发展中国家的政治效应,将分别导致全球2030年的年温室气体净排放量(扣除碳汇吸收量后的温室气体排放量)上升2.0、1.0、1.0和1.9 Gt CO₂-eq,并导致全球2015—2100年的累计排放量分别上升246.9、145.3、102.0和270.2 Gt CO₂-eq。为防止美国退出《巴黎协定》的不利影响进一步扩大,中国应积极引领全球气候治理制度的建设与发展,与各国紧密合作全面平衡地推进《巴黎协定》的落实和实施。     

公平实现《巴黎协定》目标的碳减排贡献分担研究综述

各国目前的国家自主贡献与实现《巴黎协定》温控目标的要求仍有较大的差距,各国进一步强化其自主贡献力度亟需公平的碳减排贡献分担作为目标参考。本文系统梳理了碳减排分配涉及的公平原则及其4个主要维度,即排放责任、经济能力、人均主义和国家主义,评述了依据不同维度或维度组合制定的分配方案的研究进展和存在的问题,并将该领域错综复杂的分歧矛盾分为3个层次,即公平原则维度的选择、分配机制的设计以及具体参数设置。研究发现,目前旨在指导各国提高自主贡献力度的公平分配研究在全面性、一致性和客观性方面仍有缺陷,特别是基于多元文献分析以及综合分配模型的综合分配研究不能全面客观地反映发展中国家对公平的关切。为此,本文针对性地提出了未来碳减排贡献分担综合研究的需求和方向,即需要系统阐述发展中国家视角的公平分配方案并构建一个全面、平衡、客观的综合碳减排贡献分担模型,以提升中国在这一问题上的话语权,在公平实现《巴黎协定》目标的进程中更好地发挥贡献者和引领者的作用。     

Alignment between nationally determined contributions and the sustainable development goals for West Africa

The UN Sustainable Development Goals (SDGs) and the 2015 Paris Agreement are two of the most important policy frameworks of the twenty-first century. However, the alignment of national commitments linked to them has not yet been analysed for West African states. Such analyses are vital to avoid perverse outcomes if states assess targets and develop SDG implementation plans, and Nationally Determined Contributions (NDC) under the Paris Agreement, without integrated planning and cross-sectoral alignment. This article provides a situation analysis guided by the following questions: (a) Which priority sectors are mentioned in relation to adaptation and mitigation in West African NDCs? (b) Are the NDCs of West African states well aligned with the SDGs? (c) What are the co-benefits of NDCs in contributing towards the SDGs? and (d) How are West African states planning to finance actions in their NDCs? The study uses iterative content analysis to explore key themes for adaptation and mitigation within NDCs of 11 West African states and their alignment to selected SDGs. A national multi-stakeholder workshop was held in Ghana to examine the co-benefits of the NDCs in contributing towards the SDGs and their implementation challenges. Results show that agriculture and energy are priority sectors where NDCs have pledged significant commitments. The analysis displays good alignment between mitigation and adaptation actions proposed in NDCs and the SDGs. These represent opportunities that can be harnessed through integration into national sectoral policies. However, cross-sectoral discussions in Ghana identify significant challenges relating to institutional capacity, a lack of coordination among institutions and agencies, and insufficient resources in moving towards integrated implementation of national planning priorities to address successfully both NDC priorities and the SDGs.

Key policy insights

• Positive alignments between West African NDCs and SDGs present opportunities for mutual benefits that can advance national development via a more climate resilient pathway.

• NDCs of West African states can provide mutual benefits across the water–energy–food nexus, such as through climate-smart agriculture and low carbon energy technologies.

• Ghanaian multi-sectoral insights show the need to empower national coordinating bodies to overcome misalignments across different sectors.

     

The impact of the US retreat from the Paris Agreement: Kyoto revisited?

The United States’ decision to withdraw from the Paris Agreement (pending possible re-engagement under different terms) may have significant ramifications for international climate policy, but the implications of this decision remain contested. This commentary illustrates how comparative analysis of US participation in multilateral environmental agreements can inform predictions and future assessments of the decision. We compare and contrast US non-participation in the Kyoto Protocol and the Paris Agreement, focusing on four key areas that may condition the influence of US treaty decisions on international climate policy: (i) global momentum on climate change mitigation; (ii) the possibility of US non-participation giving rise to alternative forms of international collaboration on climate policy; (iii) the timing and circumstances of the US decision to exit; and (iv) the influence of treaty design on countries’ incentives to participate and comply. We find that differences across the two treaties relating to the first three factors are more likely to reduce the negative ramifications of US withdrawal from the Paris Agreement compared to the Kyoto Protocol. However, the increased urgency of deep decarbonization renders US non-participation a major concern despite its declining share of global emissions. Moreover, key design features of the Paris Agreement suggest that other countries may react to the US decision by scaling back their levels of ambition and compliance, even if they remain in the Agreement.

Key policy insights

• Increasing global momentum on mitigation since 1997 means that US withdrawal from the Paris Agreement is potentially less damaging than its non-participation in the Kyoto Protocol

• Despite the declining US share of global emissions, greater urgency of deep decarbonization means that the non-participation of a major player, such as the US, remains problematic for global cooperation and achieving the Paris Agreement’s goals

• Differences in the design of the Kyoto Protocol and Paris Agreement suggest that US non-participation is more likely to prompt reluctant countries to stay within the Paris framework but reduce levels of ambition and compliance, rather than exit the Agreement altogether

     

Governance of bioenergy with carbon capture and storage (BECCS): accounting,rewarding, and the Paris agreement

Studies show that the ‘well below 2°C’ target from the Paris Agreement will be hard to meet without large negative emissions from mid-century onwards, which means removing CO₂ from the atmosphere and storing the carbon dioxide in biomass, soil, suitable geological formations, deep ocean sediments, or chemically bound to certain minerals. Biomass energy combined with Carbon Capture and Storage (BECCS) is the negative emission technology (NET) given most attention in a number of integrated assessment model studies and in the latest IPCC reports. However, less attention has been given to governance aspects of NETs. This study aims to identify pragmatic ways forward for BECCS, through synthesizing the literature relevant to accounting and rewarding BECCS, and its relation to the Paris Agreement. BECCS is divided into its two elements: biomass and CCS. Calculating net negative emissions requires accounting for sustainability and resource use related to biomass energy production, processing and use, and interactions with the global carbon cycle. Accounting for the CCS element of BECCS foremost relates to the carbon dioxide capture rate and safe underground storage. Rewarding BECCS as a NET depends on the efficiency of biomass production, transport and processing for energy use, global carbon cycle feedbacks, and safe storage of carbon dioxide, which together determine net carbon dioxide removal from the atmosphere. Sustainable biomass production is essential, especially with regard to trade-offs with competing land use. Negative emissions have an added value compared to avoided emissions, which should be reflected in the price of negative emission ‘credits’, but must be discounted due to global carbon cycle feedbacks. BECCS development will depend on linkages to carbon trading mechanisms and biomass trading.

Key policy insights

• A standardized framework for sustainable biomass should be adopted.

• Countries should agree on a standardized framework for accounting and rewarding BECCS and other negative emission technologies.

• Early government support is indispensable to enable BECCS development, scale-up and business engagement.

• BECCS projects should be designed to maximize learning across various applications and across other NETs.

• BECCS development should be aligned with modalities of the Paris Agreement and market mechanisms.