The Nationally Determined Contributions (NDCs) submitted under the Paris Agreement propose a country’s contribution to global mitigation efforts and domestic adaptation initiatives. This paper provides a systematic analysis of NDCs submitted by South Asian nations, in order to assess how far their commitments might deliver meaningful contributions to the global 2°C target and to sustainable broad-based adaptation benefits. Though agriculture-related emissions are prominent in emission profiles of South Asian countries, their emission reduction commitments are less likely to include agriculture, partly because of a concern over food security. We find that income-enhancing mitigation technologies that do not jeopardize food security may significantly augment the region’s mitigation potential. In the case of adaptation, analysis shows that the greatest effort will be directed towards protecting the cornerstones of the ‘green revolution’ for ensuring food security. Development of efficient and climate-resilient agricultural value chains and integrated farming bodies will be important to ensuring adaptation investment. Potentially useful models of landscape level climate resilience actions and ecosystem-based adaptation are also presented, along with estimates of the aggregate costs of agricultural adaptation. Countries in the region propose different mixes of domestic and foreign, and public and private, adaptation finance to meet the substantial gaps.
Key policy insights
Though substantial potential for mitigation of agricultural emissions exists in South Asia, governments in the region do not commit to agricultural emissions reductions in their NDCs.
Large-scale adoption of income-enhancing technologies is the key to realizing agricultural mitigation potential in South Asia, whilst maintaining food security.
Increasing resilience and profitability through structural changes, value chain interventions, and landscape-level actions may provide strong options to build adaptive capacity and enhance food security.
Both private finance (autonomous adaptation) and international financial transfers will be required to close the substantial adaptation finance gap
The Campi Flegrei (Campanian Region, Italy) experienced two cataclysmic caldera-forming eruptions which produced the Campanian
Ignimbrite (39 ka, CI) and the Neapolitan Yellow Tuff (15 ka, NYT). We studied the minor eruptions before both these large
events to understand magma chamber evolution leading towards such catastrophic eruptions. Major, trace element, and Sr and
Nd isotope compositions of pre-Campanian Ignimbrite and pre-Neapolitan Yellow Tuff products define distinct geochemical groups,
which are here interpreted as distinct magma batches. These batches do not show any transitional trend towards the CI and
NYT eruptions. The CI and NYT systems are decoupled geochemically and isotopically. At least one of the pre-CI and one of
the pre-NYT erupted magma batches qualifies as mixing endmembers for the large CI and NYT eruptions, and thus, must have been
stored in reservoirs for some time to remain available for the CI and NYT eruptions. The least evolved, isotopically distinct
magma compositions that are typical of the last phases of the NYT and CI eruptions did not occur before caldera-forming events.
Based on the new data, we propose the following scenario: Multiple magma chambers with distinct compositions existed below
the Campi Flegrei before the CI and NYT eruptions and remained generally separated for some time unless new magma was recharged.
In each case, one of the residing magma reservoirs was recharged by a new large-volume magma input of intermediate composition
from a deeper differentiating magma reservoir. This may have triggered the coalescence of the previously separated reservoirs
into one large chamber which fed the cataclysmic caldera-forming eruption. Large magma chambers in the Campi Flegrei may therefore
be ephemeral features, interrupted by periods of evolution in individual, separated magma reservoirs. 相似文献
Abstract— We present a purely physical model for the calculation of depth‐ and size‐dependent production rates of cosmogenic nuclides by galactic cosmic‐ray (GCR) particles. besides the spectra of primary and secondary particles and the excitation functions of the underlying nuclear reactions, the model is based on only one free parameter—the integral number of gcr particles in the meteoroid orbits. We derived this value from analysis of radionuclide data in Knyahinya. We also show that the mean GCR proton spectrum in the meteoroid orbits has been constant over about the last 10 Ma. For the major target elements in stony meteoroids, we present depth‐ and size‐dependent production rates for 10Be, 14C, 26Al, 36Cl, and 53Mn as well as for the rare gas isotopes 3He, 20Ne, 21Ne, 22Ne, 36Ar, and 38Ar. The new data differ from semi‐empirical estimates by up to a factor of 4 but agree within ~20% with results obtained by earlier parametric or physical approaches. The depth and size dependence of the shielding parameter 22Ne/21Ne and the correlations 26Al vs.10Be, 26Al vs.53Mn, 10Be/21Ne vs.22Ne/21Ne, and 36Ar vs.36Cl for deciphering preatmospheric sizes, shielding depths, terrestrial residence times, and exposure histories are also discussed. 相似文献
This paper examines disposal of metals and the origin, characteristics, and distribution of sedimentary organic matter (SOM) in a Mediterranean karstic estuary in the north-eastern Adriatic. This environment offers a real-time, small model system for studies of geochemical processes in microtidal Mediterranean estuaries that are infilling with sediments and classified as river-dominated disequilibrium estuaries. The results have shown that the longitudinal distribution of heavy metals in sediments follows the sedimentation dynamics and deposition pattern of river-borne, clay mineral particles. The highest concentration of metals was found in the restricted upper part of the estuary, characterized by rapid deposition of clay particles and terrestrial sedimentary organic matter, and decreases toward the open sea. The vertical distribution of metals in sediment cores depends on the prevailing pH and Eh conditions. Significant increases of the concentrations of metals in the uppermost strata are the result of recent anthropogenic inputs. The share of the terrestrial component in SOM, estimated by N/Corg atomic ratios and δ13C values, decreases with distance from the river mouth. The small vertical variation in δ13C values of SOM indicates that a fast sedimentation rate overrides the diagenetically determined decomposition. The results obtained indicate that river-borne inorganic particles, natural terrigenous organic material, and anthropogenic metal loads are trapped in sediments of the estuarine system. Under the prevailing conditions, there is negligible transport towards the open sea. 相似文献
The anisotropy of magnetic susceptibility (AMS) and rock magnetic properties were measured on specimens from a basalt plate that was cut from a vertical section of a basalt column from Hrepphólar, Iceland. Macroscopic structures are clearly distinguishable in the plate, including banding inferred to represent viscous fingering parallel to the vertical axis of the column. Rock magnetic experiments indicate that the dominant ferromagnetic (sensu lato) mineral is titanomagnetite, Fe3?xTixO4, with a Ti-composition of x?=?~0.6. Magnetic properties are related to the position within the plate and reveal a dominant volume fraction of single domain titanomagnetite in the center of the basalt column, with multidomain titanomagnetite away from the center. The AMS determined by low-field measurements shows an inconclusive relationship with the visual structures, which arises from variation of the grain size (i.e., single domain versus multidomain) across the column. In contrast, the AMS measured with a high-field torsion magnetometer avoids the complication of magnetic domain state, as is demonstrated in this contribution, and additionally allows for the separation of ferrimagnetic from paramagnetic sub-fabrics. Both sub-fabrics display a clear relationship with the macroscopic structures and support the hypothesis that vertical flow of melt took place during development of the Hrepphólar columnar basalt. Maximum susceptibility axes of the ferrimagnetic sub-fabric are grouped near the vertical axis of the column. The paramagnetic sub-fabric varies systematically across the column in coincidence with internal structure. The shape of the magnetic susceptibility ellipsoid varies across the basalt column, showing an increasingly prolate fabric toward its center. 相似文献
AbstractWe studied geoid validation using ship-borne global navigation satellite systems (GNSS) on the Baltic Sea. We obtained geoid heights by combining GNSS–inertial measurement unit observations, tide gauge data, and a physical sea model. We used two different geoid models available for the area. The ship route was divided into lines and the lines were processed separately. The GNSS results were reduced to the sea surface using attitude and draft parameters available from the vessel during the campaign. For these lines, the residual errors between ellipsoidal height versus geoid height and absolute dynamic topography varied between 0 and 15?cm, grand mean being 2?cm. The mean standard deviations of the original time series were approximately 11?cm and reduced to below 5?cm for the time series filtered with 10?min moving average. We showed that it is possible to recover geoid heights from the GNSS observations at sea and validate existing geoid models in a well-controlled area. 相似文献
Population growth, urban sprawl and a high degree of car dependency as well as slowly rising petrol prices contribute towards increasing challenges for everyday urban mobility in Muscat, Oman. Until now, only a few empirical studies have dealt with urban mobility in Oman. Therefore, this article draws mainly on our own empirical findings to answer the following questions: What do daily and weekly mobility patterns look like in Muscat? How do these practices differ depending on the social position of the household, i.e. their nationality, income and education? Which interdependent effects can be discerned between everyday mobility practices and the fragmented and segregated urban structures? Since our research questions focus on the interrelations between urban structures and individual mobility, we chose a mixed‐methods approach including methods derived both from social and spatial research. This article in particular draws on our quantitative survey covering 850 households and extensive mappings of three selected case study areas and secondary data analysis. 相似文献
The South Iceland Seismic Zone (SISZ) was loaded to failure in June 2000, resulting in two M6.6 earthquakes. The SISZ is an E–W‐trending zone with an overall sinistral movement. Numerical models indicate that, when the SISZ is loaded to failure, there are stress concentrations at its ends: tensile in the north‐east and south‐west quadrants, and compressive in the north‐west and south‐east quadrants. These model predictions fit well with observations. Geodetic measurements indicate considerable compression, uplift and associated intense seismicity in recent years in the volcanoes of Hengill and Eyjafjallajokull, located in the quadrants of compression, whereas there have been unusually frequent eruptions in the past decades in the Hekla Volcano, located in one of the quadrants of extension. The models predict that following the large June 2000 earthquakes, stress relaxation within the SISZ should lead to stopping of the intense seismicity and deformation in the volcanoes of Hengill and Eyjafjallajokull, again in agreement with observations. However, when similar episodes of deformation and seismicity start again, particularly in the Hengill Volcano, a large earthquake would be expected within several years in the SISZ. The numerical models, and the deformation and seismic data, indicate that monitoring of ‘soft’ inclusions such as volcanoes (many with magma chambers) in the vicinity of a seismic zone may serve as precursors to large earthquakes. 相似文献
Ir abundance anomalies, platinum-group elements (PGE) enrichment and increased concentrations of meteoritic (Ni, Fe, Co) and nonmeteoritic (Sb, As, Zn and Cu) elements were found in the Palaeocene–Eocene (P/E) boundary interval in a flysch sequence from the Western Tethys (Goriška Brda section, W. Slovenia). This records one of the most important calcareous deep benthic extinctions in the history of the Earth. Although the observed geochemical patterns could indicate complex sources for these metals, such as weathering of the continental and oceanic crust, volcanic processes, as well as diagenetic mobilization and redistribution, we cannot preclude the highly speculative possibility that the observed Ir abundances may also indicate extraterrestrial contamination. 相似文献