Achievability of the Paris Agreement targets in the EU: demand-side reduction potentials in a carbon budget perspective

Limiting global warming to ‘well below’ 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase even further to 1.5°C is an integral part of the 2015 Paris Agreement. To achieve these aims, cumulative global carbon emissions after 2016 should not exceed 940 – 390?Gt of CO₂ (for the 2°C target) and 167 – ?48?Gt of CO₂ (for the 1.5°C target) by the end of the century. This paper analyses the EU’s cumulative carbon emissions in different models and scenarios (global models, EU-focused models and national carbon mitigation scenarios). Due to the higher reductions in energy use and carbon intensity of the end-use sectors in the national scenarios, we identify an additional mitigation potential of 26–37 Gt cumulative CO₂ emissions up to 2050 compared to what is currently included in global or EU scenarios. These additional reductions could help to both reduce the need for carbon dioxide removals and bring cumulative emissions in global and EU scenarios in line with a fairness-based domestic EU budget for a 2°C target, while still remaining way above the budget for 1.5°C.

Key policy insights

• Models used for policy advice such as global integrated assessment models or EU models fail to consider certain mitigation potential available at the level of sectors.

• Global and EU models assume significant levels of CO₂ emission reductions from carbon capture and storage to reach the 1.5°C target but also to reach the 2°C target.

• Global and EU model scenarios are not compatible with a fair domestic EU share in the global carbon budget either for 2°C or for 1.5°C.

• Integrating additional sectoral mitigation potential from detailed national models can help bring down cumulative emissions in global and EU models to a level comparable to a fairness-based domestic EU share compatible with the 2°C target, but not the 1.5°C aspiration.

     

Debris-flow simulations on Cheekye River, British Columbia

Cheekye River fan is the best-studied fan complex in Canada. The desire to develop portions of the fan with urban housing triggered a series of studies to estimate debris-flow risk to future residents. A recent study (Jakob and Friele 2010) provided debris-flow frequency-volume and frequency-discharge data, spanning 20-year to 10,000-year return periods that form the basis for modeling of debris flows on Cheekye River. The numerical computer model FLO-2D was chosen as a modelling tool to predict likely flow paths and to estimate debris-flow intensities for a spectrum of debris-flow return periods. The model is calibrated with the so-called Garbage Dump debris flow that occurred some 900  years ago. Field evidence suggests that the Garbage Dump debris flow has a viscous flow phase that deposited a steep-sided debris plug high in organics in centre fan, which then deflected a low-viscosity afterflow that travelled to Squamish River with slowly diminishing flow depths. The realization of a two-phase flow led to a modelling approach in which the debris-flow hydrograph was split into a high viscosity and low viscosity phase that were modelled in chronologic sequence as two separate and independent modelling runs. A perfect simulation of the Garbage Dump debris flow with modelling is not possible because the exact topography at the time of the event is, to some degree, speculative. However, runout distance, debris deposition and deposit thickness are well known and serve as a good basis for calibration. Predictive analyses using the calibrated model parameters suggest that, under existing conditions, debris flows exceeding a 50-year return period are likely to avulse onto the southern fan sector, thereby damaging existing development and infrastructure. Debris flows of several thousand years return period would inundate large portions of the fan, sever Highway 99, CN Rail, and the Squamish Valley road and would impact existing housing development on the fan. These observations suggest a need for debris-flow mitigation for existing and future development alike.     

Modeling the hydro-mechanical responses of strip and circular punch loadings on water-saturated collapsible geomaterials

A stabilized enhanced strain finite element procedure for poromechanics is fully integrated with an elasto-plastic cap model to simulate the hydro-mechanical interactions of fluid-infiltrating porous rocks with associative and non-associative plastic flow. We present a quantitative analysis on how macroscopic plastic volumetric response caused by pore collapse and grain rearrangement affects the seepage of pore fluid, and vice versa. Results of finite element simulations imply that the dissipation of excess pore pressure may significantly affect the stress path and thus alter the volumetric plastic responses.     

Iron isotope fractionation during proton- and ligand-promoted dissolution of primary phyllosilicates

We studied stable iron isotope fractionation during dissolution of a biotite and chlorite enriched mineral fraction from granite by HCl and 5 mM oxalic acid in a pH range of 4-5.9. Batch experiments covered a time period from 2 h to 100 days and were performed at initial potassium concentrations of 0, 0.5, and 5 mM to induce different levels of biotite exfoliation. All experiments were kept anoxic to investigate solely the dissolution step without the influence of oxidation and precipitation of secondary Fe oxyhydroxides. Oxalic acid increased the release of Fe by a factor of ∼15 compared with the HCl experiments. Addition of 0.5 mM K to initial solutions in proton-promoted dissolution decreased the release of Fe by 30-65% depending on the dissolution stage. In ligand-controlled dissolution, K reduced the Fe release only to a minor extent. All solutions of the early dissolution stages were enriched in light Fe isotopes by up to −1.4‰ in δ⁵⁶Fe compared with the isotopic composition of biotite and chlorite mineral separates, which we explained by a kinetic isotope effect. In proton-promoted dissolution, early released fractions of K-enriched experiments were significantly lighter (−0.7‰ to −0.9‰) than in the initially K-free experiments. The evolution of Fe isotope ratios in solution was modeled by a linear combination of kinetic isotope effects during two independent dissolution processes attacking different crystallographic sites. In ligand-controlled dissolution, K did not influence the kinetic isotope effect and the Fe isotope composition in solution in the late dissolution stages remained slightly lighter than the bulk composition of the biotite/chlorite enriched mineral fraction. This study demonstrates that the initial Fe weathering flux should be enriched in light Fe isotopes and that Fe isotope data in combination with dissolution kinetics and stoichiometry provide new insights into dissolution mechanisms.     

Statistical and hydrodynamic models for the operational forecasting of floods in the Venice Lagoon

The risk of flooding in Venice has increased strongly since the beginning of the century. To reduce the damage to the city and the negative impact on the activities in the lagoon, an accurate flood warning system is necessary. This system will also be fundamental during the construction and for the efficient operation of storm surge barriers covering the three existing inlets of the lagoon. In this context new operational statistical and hydrodynamic models have been developed. Forecast winds and pressure fields which constitute basic information for the warning system have been obtained through an ad hoc Limited Area Meteorological model. It has been demonstrated that, provided that this information is available on an operational basis, the implementation of a flood warning system for Venice using the models developed is feasible. The statistical model, which is based on a multiple regression technique, extends the forecasting range of the model presently in operation at the Centro Previsioni e Segnalazioni Maree del Comune di Venezia, from 3 hrs up to 24 hrs, and presents good accuracy (estimated mean absolute errors smaller than 10 cm) for short-term forecasts up to 9 hrs. The hydrodynamic model includes all the physical processes important for the simulation of water levels and currents in coastal and marine environments. The model set-up adopted covers the entire Adriatic Sea, with a grid spacing of 6 km. Special attention has been given to the positioning of the open boundary and to the correct reproduction of the main free oscillation of the Adriatic, which is responsible for the possible recurrence of flooding after the main storm has passed. The inclusion of this model in a flood warning system is mainly intended for long-term forecasts (> 24 hrs), and can typically be used to forecast up to 3–4 days ahead, with an estimated mean absolute error smaller than 20 cm.     

Long-term landscape development of the Coloradofjella plateau, central Spitsbergen, Svalbard

The development and age of the present geomorphology and superficial material of the Coloradofjella plateau, Spitsbergen, have been investigated through field surveying and laboratory sediment analyses. The focus was specifically on the role of glacial erosion and periglacial processes. The summit plain is deeply incised with large V-shaped valleys. Extensive networks of ice wedge polygons indicate that the fine-grained regolith is at least a few metres thick. An abundance of coarse-grained gabbroid erratics, clearly derived from sources further to the east, are distributed over parts of the summit plain. A vertical-walled dolerite dyke protruding up to 4 m above the adjacent surface shows no sign of glacial erosion. Our findings confirm that the present bedrock geomorphology and regolith in the summit plain survived at least the Late Weichselian glaciation. This is best explained by the ice sheet having been cold-based throughout its existence on the summit plain. Cold-based conditions imply that permafrost survived the last glacial cover. Based on the geomorphic evidence and estimates of Late Cenozoic erosion, we suggest that the present summit plains roughly represent the remains of a preglacial surface.     

Geodemographics as a tool for targeting neighbourhoods in public health campaigns

Geodemographics offers the prospects of integrating, modelling and mapping health care needs and other health indicators that are useful for targeting neighbourhoods in public health campaigns. Yet reports about this application domain has to date been sporadic. The purpose of this paper is to examine the potential of a bespoke geodemographic system for neighbourhood targeting in an inner city public health authority, Southwark Primary Care Trust, London. This system, the London Output Area Classification (LOAC), is compared to six other geodemographic systems from both governmental and commercial sources. The paper proposes two new indicators for assessing the performance of geodemographic systems for neighbourhood targeting based on local hospital demand data. The paper also analyses and discusses the utility of age- and sex standardisation of geodemographic profiles of health care demand.     

Petrographic investigation of shatter cone melt films recovered from MEMIN impact experiments in sandstone and iSALE modeling of their formation boundary conditions

Shatter cones are diagnostic for the recognition of meteorite impact craters. They are unambiguously identifiable in the field and the only macroscopic shock deformation feature. However, the physical boundary conditions and exact formation mechanism(s) are still a subject of debate. Melt films found on shatter cone surfaces may allow the constraint of pressure–temperature conditions during or immediately after their formation. Within the framework of the MEMIN research group, we recovered 24 shatter cone fragments from the ejecta of hypervelocity impact experiments. Here, we focus on silicate melt films (now quenched to glass) found on shatter cone surfaces formed in experiments with 20–80 cm sized sandstone targets, impacted by aluminum and iron meteorite projectiles of 5 and 12 mm diameter at velocities of 7.0 and 4.6 km s⁻¹, respectively. The recovered shatter cone fragments vary in size from 1.2 to 9.3 mm. They show slightly curved, striated surfaces, and conical geometries with apical angles of 36°–52°. The fragments were recovered from experiments with peak pressures ranging from 46 to 86 GPa, and emanated from a zone within 0.38 crater radii. Based on iSale modeling and petrographic investigations, the shatter coned material experienced low bulk shock pressures of 0.5–5 GPa, whereas deformation shows a steep increase toward the shatter cone surface leading to localized melting of the rock, resulting in both vesicular as well as polished melt textures visible under the SEM. Subjacent to the melt films are zones of fragmentation and brittle shear, indicating movement away from the shatter cone apex of the rock that surrounds the cone. Smearing and extension of the melt film indicates subsequent movement in opposite direction to the comminuted and brecciated shear zone. We believe the documented shear textures and the adjacent smooth melt films can be related to frictional melting, whereas the overlying highly vesiculated melt layer could indicate rapid pressure release. From the observation of melting and mixing of quartz, phyllosilicates, and rutile in this overlying texture, we infer high, but very localized postshock temperatures exceeding 2000 °C. The melted upper part of the shatter cone surface cross-cuts the fragmented lower section, and is accompanied by PDFs developed in quartz parallel to the {112} plane. Based on the overprinting textures and documented shock effects, we hypothesize shatter cones start to form during shock loading and remain an active fracture surface until pressure release during unloading and infer that shatter cone surfaces are mixed mode I/II fracture surfaces.     

Hazard assessment of the Tidal Inlet landslide and potential subsequent tsunami, Glacier Bay National Park, Alaska

An unstable rock slump, estimated at 5 to 10 × 10⁶ m³, lies perched above the northern shore of Tidal Inlet in Glacier Bay National Park, Alaska. This landslide mass has the potential to rapidly move into Tidal Inlet and generate large, long-period-impulse tsunami waves. Field and photographic examination revealed that the landslide moved between 1892 and 1919 after the retreat of the Little Ice Age glaciers from Tidal Inlet in 1890. Global positioning system measurements over a 2-year period show that the perched mass is presently moving at 3–4 cm annually indicating the landslide remains unstable. Numerical simulations of landslide-generated waves suggest that in the western arm of Glacier Bay, wave amplitudes would be greatest near the mouth of Tidal Inlet and slightly decrease with water depth according to Green’s law. As a function of time, wave amplitude would be greatest within approximately 40 min of the landslide entering water, with significant wave activity continuing for potentially several hours.     

Oblique aggradation: a novel explanation for sinuosity of low‐energy streams in peat‐filled valley systems

Low‐energy streams in peatlands often have a high sinuosity. However, it is unknown how this sinuous planform formed, since lateral migration of the channel is hindered by relatively erosion‐resistant banks. We present a conceptual model of Holocene morphodynamic evolution of a stream in a peat‐filled valley, based on a palaeohydrological reconstruction. Coring, ground‐penetrating radar (GPR) data, and ¹⁴C and OSL dating were used for the reconstruction. We found that the stream planform is partly inherited from the Late‐Glacial topography, reflecting stream morphology prior to peat growth in the valley. Most importantly, we show that aggrading streams in a peat‐filled valley combine vertical aggradation with lateral displacement caused by attraction to the sandy valley sides, which are more erodible than the co‐evally aggrading valley‐fill. Owing to this oblique aggradation in combination with floodplain widening, the stream becomes stretched out as channel reaches may alternately aggrade along opposed valley sides, resulting in increased sinuosity over time. Hence, highly sinuous planforms can form in peat‐filled valleys without the traditional morphodynamics of alluvial bed lateral migration. Improved understanding of the evolution of streams provides inspiration for stream restoration. Copyright © 2016 John Wiley & Sons, Ltd.