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31.
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.

  相似文献   
32.
Carbonaceous matter (CM) from ca. 3.5 Ga hydrothermal black cherts of the Pilbara Craton of Western Australia and the Barberton Greenstone Belt of South Africa yielded transmission electron microscopy (TEM) images that are suggestive of microbial remains and possible remnants of microbial cell walls. These are compared to a potential modern analogue, the hyperthermophilic Methanocaldococcus jannaschii, derived from an active seafloor hydrothermal environment and cultured under similar conditions. A striking resemblance to the early Archaean forms was evident in wall structure and thermal degradation mode. Cell disintegration of the cultures occurred at 100 °C marking the limits of life. Complete disintegration, deformation and shrinkage occurred at 132 °C. A multidisciplinary approach to the characterisation of the CM was undertaken using organic petrology, TEM coupled with electron dispersive spectral analysis (EDS), high resolution TEM (HRTEM) to determine molecular ordering, and elemental and carbon isotope geochemistry. Reflectance measurements of the CM to determine thermal stress yielded a range of values corresponding to several populations, and pointing to different sources and processes. The δ13C values of Dresser Formation CM (−36.5 to −32.1‰) are negatively correlated with TOC (0.13–0.75%) and positively correlated with C/N ratio (134–569), which is interpreted to reflect the relative abundance of high Ro/oxidised/recycled CM and preferential loss of 12C and N during thermal maturation. TEM observations, inferred carbon isotopic heterogeneity and isotope fractionations of −27 to −32‰ are consistent with the activity of chemosynthetic microbes in a seafloor hydrothermal system where rapid silicification at relatively low temperature preserved the CM.  相似文献   
33.
Kilometer-scale lenses of quartz-rich metasedimentary rocks crop out in a discontinuous belt along the southern margin of the Menderes Massif, Turkey, and preserve evidence for high-pressure–low-temperature (HP–LT) metamorphism related to subduction of a continental margin during Alpine orogeny. Kyanite schist, quartzite, and quartz veins contain kyanite + phengite + Mg-chlorite, and the veins also contain magnesiocarpholite. A deformed carbonate metaconglomerate juxtaposed with the quartzite-dominated unit does not contain HP index minerals, and likely represents the tectonized boundary of the siliceous rocks with adjacent marble. The HP–LT rocks (10–12 kbar, 470–570 °C) record different pressure conditions than the adjacent, apparently lower pressure Menderes metasedimentary sequence. Despite this difference there is disagreement as to whether these HP–LT rocks are part of the Menderes sequence or are related to the tectonically overlying Cycladic blueschist unit. If the former, the entire southern Menderes Massif experienced HP–LT metamorphism but the evidence has been obliterated from most rocks; if the latter, rocks recording different metamorphic-kinematic conditions experienced different tectonic histories and were tectonically juxtaposed during thrusting. Based on observations and data in this study, the second model better accounts for the differences in PT-deformation histories of the southern Menderes Massif rocks, and suggests that the HP–LT rocks are not part of the Menderes cover sequence.  相似文献   
34.
Recent settlers of many marine benthic invertebrates are cryptic, which exposes them to a suite of animals that differs from those they may experience as adults, potentially resulting in interactions causing mortality and/or reducing growth. Previous field experiments have indicated that such is the case with small juvenile green sea urchins Strongylocentrotus droebachiensis but which taxa are responsible for the mortality and reduced growth was not determined. A laboratory study was conducted to examine the effects of small macro‐benthic invertebrates, specifically chitons, scaleworms and larger juvenile conspecifics, as well as the full suite of cobble‐dwelling organisms, on the mortality, growth and behaviour of small (<3 mm) juvenile sea urchins. The likelihood of survival of small juvenile sea urchins was lower in the presence of larger juvenile sea urchins or with the full suite of cobble‐dwelling organisms than in the absence of animals. The small juvenile sea urchins survived and grew the best when they were with chitons and scaleworms. The behaviour of small sea urchins with the full suite of cobble‐dwelling organisms was more cryptic than the behaviour of urchins with scaleworms. This study indicates that interactions with the suite of small organisms living amongst cobbles can affect survival, growth and behaviour of small juvenile sea urchins, and that larger juvenile sea urchins can be a source of mortality for smaller conspecifics.  相似文献   
35.
36.
The biogeochemistry of the following elements Al, Fe, Sibio, POC, PNtot, Cabio, Sorg, P and Mn has been studied within waters of the Cretan Sea in March and September 1994, as part of the PELAGOS project. Particulate aluminosilicate concentrations, exemplified by Al, are very low (<1 μgl−1) especially in the upper waters. Higher concentrations occur below 200 m, especially at depths of 200 m and 500–700 m in the central and eastern areas, and are thought to result from sediment injections from the shelf edge and slope. The results for Sibio, Cabio, P and Sorg show much higher concentrations within the photic waters. Temporal and spatial high concentrations in these waters closely relate to the existence of cyclonic eddies on the east and west sides of the sea, while low concentrations are associated with an intervening anticyclonic eddy. However in September, discharge of Black Sea Water in the west sufficiently suppresses the thermocline to prevent upwelled water from reaching the surface and hence these substances are prevented from forming.Particulate Fe (expressed as Feexcess) concentrations show much higher concentrations relative to Al in September, and are thought to result from additional atmospheric inputs. The low particulate Mn concentrations in the upper water compared with deeper waters are considered to be a product of photoinhibition of MnOx precipitation from Mn(II).An attempt has been made to assess input/output budgets of Al, Ca, Fe and Mn through the Antikithira and Kassos Straits. Much of the outflows leave through the Kassos Strait and, except for Ca, net outflows through the Antikithira Straits are negligible.  相似文献   
37.
Sedimentary rocks of the Palaeoproterozoic Calvert and Isa Superbasins are exposed across a large area of northern Australia. Despite the extent of the exposures there is little to indicate the nature of the basin margins as most outcrop boundaries are structurally or erosionally defined, or the margins, where preserved, are concealed beneath younger basins. The Murphy Inlier, which forms the boundary between the Mt Isa and McArthur Basins, is unique in that on its southern flanks a basin‐margin succession is well‐preserved as the Fickling Group. A detailed sequence‐stratigraphic analysis of outcrop sections and well logs, supplemented by seismic reflection profiles and SHRIMP U–Pb zircon ages, shows that all seven supersequences of the Isa Superbasin and one supersequence from the older Calvert Superbasin are represented in the Fickling Group. Through this high‐resolution sequence‐stratigraphic framework, it is possible to accurately correlate chronostratigraphically equivalent strata from the McNamara Group on the central Lawn Hill Platform to the Fickling Group on the southern Murphy Inlier. Each supersequence thins substantially from the McNamara Group (~11 km thick) to the Fickling Group (<1 km thick). The combined effects of truncation and onlap of sequences over the Murphy Inlier basement high are responsible for the thinning. Major time breaks of up to 25 million years occur between supersequences in the Fickling Group. Erosional hiatuses are often manifested at the base of supersequences as conglomerate beds composed of silicified detritus from older strata. Sequences in the Fickling Group were generally deposited in a proximal basin‐margin setting, while sequences in the McNamara Group were deposited in distal basin depocentres. The proximal depositional setting of Fickling Group sequences reduces the number of thick carbonaceous shale and siltstone intervals, which often host Zn–Pb–Ag and Cu deposits in the McNamara Group. Many host sequences from the McNamara Group are also absent in the Fickling Group due to truncation and onlap pinchout. Consequently, the economic potential of Palaeoproterozoic strata on the southern Murphy Inlier is less than equivalent strata from the central Lawn Hill Platform. Despite this, potential does exist for future discoveries of economic mineral deposits in the Mt Les Siltstone and Walford Dolomite units of the Fickling Group.  相似文献   
38.
39.
Following wildfires, the probability of flooding and debris flows increase, posing risks to human lives, downstream communities, infrastructure, and ecosystems. In southern California (USA), the Rowe, Countryman, and Storey (RCS) 1949 methodology is an empirical method that is used to rapidly estimate post-fire peak streamflow. We re-evaluated the accuracy of RCS for 33 watersheds under current conditions. Pre-fire peak streamflow prediction performance was low, where the average R2 was 0.29 and average RMSE was 1.10 cms/km2 for the 2- and 10-year recurrence interval events, respectively. Post-fire, RCS performance was also low, with an average R2 of 0.26 and RMSE of 15.77 cms/km2 for the 2- and 10-year events. We demonstrated that RCS overgeneralizes watershed processes and does not adequately represent the spatial and temporal variability in systems affected by wildfire and extreme weather events and often underpredicted peak streamflow without sediment bulking factors. A novel application of machine learning was used to identify critical watershed characteristics including local physiography, land cover, geology, slope, aspect, rainfall intensity, and soil burn severity, resulting in two random forest models with 45 and five parameters (RF-45 and RF-5, respectively) to predict post-fire peak streamflow. RF-45 and RF-5 performed better than the RCS method; however, they demonstrated the importance and reliance on data availability. The important parameters identified by the machine learning techniques were used to create a three-dimensional polynomial function to calculate post-fire peak streamflow in small catchments in southern California during the first year after fire (R2 = 0.82; RMSE = 6.59 cms/km2) which can be used as an interim tool by post-fire risk assessment teams. We conclude that a significant increase in data collection of high temporal and spatial resolution rainfall intensity, streamflow, and sediment loading in channels will help to guide future model development to quantify post-fire flood risk.  相似文献   
40.
The low‐temperature form of CuFe2S3, cubanite, has been identified in the CI chondrite and NASA Stardust mission collections. The presence of this mineral constrains the maximum temperature to 210 °C since the time of its formation. However, until now, the conditions under which cubanite forms were less well constrained. In order to refine the history of the time‐varying, low‐temperature fluids which existed on the CI‐chondrite parent body and Comet 81P/Wild 2 (Wild 2), we synthesized cubanite. The experimental synthesis of this mineral was achieved, for the first time, under low‐temperature aqueous conditions relevant to the CI‐chondrite parent body. Using a variant of in situ hydrothermal recrystallization, cubanite formed in aqueous experiments starting with temperatures of 150 and 200 °C, pH approximately 9, and oxygen fugacities corresponding to the iron‐magnetite buffer. The composition and structure of the cubanite were determined using electron microprobe and transmission electron microscopy techniques, respectively. The combined compositional, crystallographic, and experimental data allow us to place limits on the conditions under which the formation of cubanite is feasible, which in turn constrains the nature of the fluid phase on the CI‐chondrite parent body and Wild 2 when cubanite was forming.  相似文献   
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