The role of technology for achieving climate policy objectives: overview of the EMF 27 study on global technology and climate policy strategies

This article presents the synthesis of results from the Stanford Energy Modeling Forum Study 27, an inter-comparison of 18 energy-economy and integrated assessment models. The study investigated the importance of individual mitigation options such as energy intensity improvements, carbon capture and storage (CCS), nuclear power, solar and wind power and bioenergy for climate mitigation. Limiting the atmospheric greenhouse gas concentration to 450 or 550 ppm CO₂ equivalent by 2100 would require a decarbonization of the global energy system in the 21^st century. Robust characteristics of the energy transformation are increased energy intensity improvements and the electrification of energy end use coupled with a fast decarbonization of the electricity sector. Non-electric energy end use is hardest to decarbonize, particularly in the transport sector. Technology is a key element of climate mitigation. Versatile technologies such as CCS and bioenergy are found to be most important, due in part to their combined ability to produce negative emissions. The importance of individual low-carbon electricity technologies is more limited due to the many alternatives in the sector. The scale of the energy transformation is larger for the 450 ppm than for the 550 ppm CO₂e target. As a result, the achievability and the costs of the 450 ppm target are more sensitive to variations in technology availability.     

The value of technology and of its evolution towards a low carbon economy

This paper assesses the economic value associated with the development of various low-carbon technologies in the context of climate stabilization. We analyze the impact of restrictions on the development of specific mitigation technologies, comparing three integrated assessment models used in the RECIPE comparison exercise. Our results indicate that the diversification of the carbon mitigation portfolio is an important determinant of the feasibility of climate policy. Foregoing specific low carbon technologies raises the cost of achieving the climate policy, though at different rates. CCS and renewables are shown to have the highest value, given their flexibility and wide coverage. The costs associated with technology failure are shown to be related to the role that each technology plays in the stabilization scenario, but also to the expectations about their technological progress. In particular, the costs of restriction of mature technologies can be partly compensated by more innovation and technological advancement.     

Environmental policy and regulation for oil exploration and shipping activities in the Barents Sea

The Barents Sea has one of the highest levels of biological production of all the world's oceans, and holds some of the largest fish stocks and concentrations of seabirds. Environmental conditions in the area make it particularly vulnerable to damage from human activities. Given the vulnerability of this ecosystem to the effects of human activity, and the fact that physical factors (e.g. reduced visibility, ice) increase risks due to oil exploitation and shipping activities, environmental authorities will work towards more stringent discharge limits and higher standards for emergency preparedness for both oil exploitation and shipping in the Barents Sea. The Norwegian Pollution Control Authority gives priority to preventive measures that can lower the probability of accidents and particular emphasis will be given to conditions attached to production licences and controls on activities in areas that have not yet been opened for petroleum activities. Within the Arctic Environmental Protection Strategy (the Rovaniemi-process), Norway has proposed that efforts should be made to improve the protection of Arctic marine areas, and further that a working group including representatives of all the Arctic countries should assess various legal instruments and possible measures, and make recommendations for action. Currently, no special international requirements apply to ships sailing in ice-infested waters, and the recommendations from the working group will therefore be of great importance in protecting the area from damage from shipping.     

Transit times of water under steady stormflow conditions in the Gårdsjön G1 catchment

In this paper we report on a series of replicated tracer experiments with deuterium conducted under controlled, steady stormflow conditions at the Gårdsjön G1 catchment in south‐western Sweden. In five different years, these experiments were carried out in a subcatchment of G1. Deuterium was applied as a narrow pulse so that distributions of water transit times could be directly inferred from the observed tracer breakthrough curves. Significantly different transit times of water were observed under similar experimental conditions. Coefficients of variation for estimated mean transit times were greater than 60%, which can be understood as a measure of the interannual variability for this type of experiments. Implications for water transit times under more natural flow conditions as wells as for future experimentation are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Bacterial community succession in response to dissolved organic matter released from live jellyfish

Jellyfish blooms have increased worldwide, and the outbreaks of jellyfish population not only affect the food web structures via voracious predation but also play an important role in the dynamics of nutrients and oxygen in planktonic food webs. However, it remains unclear whether specific carbon compounds released through jellyfish metabolic processes have the potential to shape bacterial community composition. Therefore, in this study, we aimed to investigate the compositional succession of the bacterioplankton community in response to the dissolved organic matter (DOM) released by the live Scyphomedusae Cyanea lamarckii and Chrysaora hysoscella collected from Helgoland Roads of the North Sea. The bacterial community was significantly stimulated by the DOM released form live jellyfish and different dominant phylotypes were observed for these two Scyphomedusae species. Furthermore, the bacterial community structures in the different DOM sources, jellyfish-incubated media, Kabeltonne seawater, and artificial seawater (DOM-free) were significantly different, as revealed by automated ribosomal intergenic spacer analysis fingerprints. Catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) revealed a rapid species-specific shift in bacterial community composition. Gammaproteobacteria dominated the community instead of the Bacteroidetes community for C. lamarckii, whereas Gammaproteobacteria and Bacteroidetes dominated the community for C. hysoscella. The significant differences in the bacterial community composition and succession indicate that the components of the DOM released by jellyfish might differ with jellyfish species.     

Tjörnes fracture zone. New and old seismic evidences for the link between the North Iceland rift zone and the Mid-Atlantic ridge

The Tjörnes facture zone (TFZ) connects the EW extension of the Mid-Atlantic ridge north of Iceland to the extension of the North volcanic zone (NVZ) of Iceland. Earthquakes up to magnitude 7 (Ms) can occur in TFZ, volcanic eruptions have been observed and large crustal deformations are expected in similar way as have been observed in the NVZ. Most of the zone is below ocean, which limits the historical information and geological observations. For studying the dynamics of the zone we must rely on interpretation and modelling based on seismic observations, especially on microearthquake observations for the last 10 years. In this paper we demonstrate how microearthquakes can be applied to map the details of the plate boundary, and how this information can be applied to find epicenters and fault planes of large historical earthquakes, also how seismic information can be applied in dynamic modelling and to infer spatial and temporal interplay in activity, and to enhance hazard assessment.     

Arsenic remobilization from sediments contaminated with mine tailings near the Adak mine in Västerbotten district (northern Sweden)

Weathering of mine tailings have resulted in high As concentrations in water (up to 2900 μg l^− 1) and sediment (up to 900 mg kg^− 1) samples around the Adak mine. Notably, As occurs as As(III) species (15–85%) in the oxic surface and ground water samples, which is not common. Time-series based sediment incubations were set up in the laboratory with contaminated sediments to study the microbial processes involved in transformation and remobilization of As across the sediment–water interface. The microcosm experiments indicate that microorganisms are capable of surviving in As-rich sediments and reduce As(V) to As(III). A decrease in total As concentration in sediments is coupled to an increase in As(III) concentration in the aqueous media. In contrast, the controls (treated with HgCl₂ and formaldehyde) did not show growth, and As(V) concentrations increased steadily in the sediments and aqueous medium. The results imply that active metabolism is necessary for As(V) reduction. These microorganisms possess reduction mechanisms that are not necessarily coupled to respiration, but most likely impart resistance to As toxicity.