Modelling the impact of climate change on Pacific skipjack tuna population and fisheries

IPCC-type climate models have produced simulations of the oceanic environment that can be used to drive models of upper trophic levels to explore the impact of climate change on marine resources. We use the Spatial Ecosystem And Population Dynamics Model (SEAPODYM) to investigate the potential impact of Climate change under IPCC A2 scenario on Pacific skipjack tuna (Katsuwonus pelamis). IPCC-type models are still coarse in resolution and can produce significant anomalies, e.g., in water temperature. These limitations have direct and strong effects when modeling the dynamics of marine species. Therefore, parameter estimation experiments based on assimilation of historical fishing data are necessary to calibrate the model to these conditions before exploring the future scenarios. A new simulation based on corrected temperature fields of the A2 simulation from one climate model (IPSL-CM4) is presented. The corrected fields led to a new parameterization close to the one achieved with more realistic environment from an ocean reanalysis and satellite-derived primary production. Projected changes in skipjack population under simple fishing effort scenarios are presented. The skipjack catch and biomass is predicted to slightly increase in the Western Central Pacific Ocean until 2050 then the biomass stabilizes and starts to decrease after 2060 while the catch reaches a plateau. Both feeding and spawning habitat become progressively more favourable in the eastern Pacific Ocean and also extend to higher latitudes, while the western equatorial warm pool is predicted to become less favorable for skipjack spawning.     

Impact of climate change on the hydrogeology of two basins in northern France

This study presents an analysis of climate-change impacts on the water resources of two basins located in northern France, by integrating four sources of uncertainty: climate modelling, hydrological modelling, downscaling methods, and emission scenarios. The analysis focused on the evolution of the water budget, the river discharges and piezometric heads. Seven hydrological models were used, from lumped rainfall-discharge to distributed hydrogeological models, and led to quite different estimates of the water-balance components. One of the hydrological models, CLSM, was found to be unable to simulate the increased water stress and was, thus, considered as an outlier even though it gave fair results for the present day compared to observations. Although there were large differences in the results between the models, there was a marked tendency towards a decrease of the water resource in the rivers and aquifers (on average in 2050 about ?14 % and ?2.5 m, respectively), associated with global warming and a reduction in annual precipitation (on average in 2050 +2.1 K and ?3 %, respectively). The uncertainty associated to climate models was shown to clearly dominate, while the three others were about the same order of magnitude and 3–4 times lower. In terms of impact, the results found in this work are rather different from those obtained in a previous study, even though two of the hydrological models and one of the climate models were used in both studies. This emphasizes the need for a survey of the climatic-change impact on the water resource.     

Globalization,Pacific Islands,and the paradox of resilience

On April 2nd, 2007 a 12 m tsunami struck Simbo, a relatively remote island in Western Province, Solomon Islands. Although Simbo's population continues to depend on their own food production and small-scale governance regimes regulate access to resources, the island's way of life over the last century has increasingly been affected by processes associated with globalization. In this context of a rapidly globalizing world, this article examines the island's resilience and vulnerability to the tsunami and the adaptive capacities that enabled the response and recovery. The tsunami completely destroyed two villages and damaged fringing coral reefs, but casualties were low and social–ecological rebound relatively brisk. By combining social science methods (household surveys, focus group and ethnographic interviews) and underwater reef surveys we identify a number of countervailing challenges and opportunities presented by globalization that both nurture and suppress the island's resilience to high amplitude, low-frequency disturbances like tsunamis. Analysis suggests that certain adaptive capacities that sustain general system resilience come at the cost of more vulnerability to low-probability hazards. We discuss how communities undergoing increasingly complex processes of change must negotiate these kinds of trade-offs as they manage resilience at multiple spatial and temporal scales. Understanding the shifting dynamics of resilience may be critical for Pacific Island communities who seek to leverage globalization in their favor as they adapt to current social–ecological change and prepare for future large-scale ecological disturbances.     

The public perception of carbon dioxide capture and storage in the UK: results from focus groups and a survey

Abstract

A series of meetings of two ‘Citizen Panels’ were held to explore public perceptions of off-shore carbon dioxide (CO₂) capture and storage (CCS). In addition, a face-to-face survey of 212 randomly selected individuals was conducted. We found that, on first hearing about CCS in the absence of any information on its purpose, the majority of people either do not have an opinion at all or have a somewhat negative perspective. However, when (even limited) information is provided on the role of CO₂ storage in reducing CO₂ emissions to the atmosphere, opinion shifts towards expressing slight support for the concept.

Support depends, however, upon concern about human-caused climate change, plus recognition of the need for major reductions in CO₂ emissions. It also depends upon CCS being seen as just one part of a wider strategy for achieving significant cuts in CO₂ emissions. A portfolio including renewable energy technologies, energy efficiency, and lifestyle change to reduce demand was generally favoured. CCS can be part of such a portfolio, but wind, wave, tidal, solar and energy efficiency were preferred. It was felt that uncertainties concerning the potential risks of CCS had to be better addressed and reduced; in particular the risks of accidents and leakage (including the potential environmental, ecosystem and human health impacts which might result from leakage).     

Enhancing the value of adaptation reporting as a driver for action: lessons from the UK

ABSTRACT

As increasing evidence shows that the risks of climate change are mounting, there is a call for further climate action (both reducing global emissions, and adaptation to better manage the risks of climate change). To promote and enable adaptation, governments have introduced, or are considering introducing, reporting on climate risks and efforts being taken to address those risks. This paper reports on an analysis of the first two rounds of such reports submitted under the UK Climate Change Act (2008) Adaptation Reporting Power. It highlights benefits and challenges for reporting authorities and policymakers receiving the reports that could also inform other countries considering such reporting. For reporting authorities, benefits arise from the reporting process and resulting reports. These benefits include elevating climate risks and adaptation to the corporate level and with stakeholders, alongside facilitating alignment and integration of actions within existing risk management and governance structures. For policymakers, reporting provides enhanced understanding of climate risks and actions from a bottom-up perspective that can be integrated into national-level assessments and adaptation planning processes. The identified challenges are those related to capacity and process. These include limited risk and adaptation assessment capacities; relevance of climate change risks and adaptation in the context of other urgent risks and actions; reporting process effectiveness and robustness; and the provision of effective and sufficiently comprehensive support, including feedback.

Key policy insights

• Effective adaptation reporting needs to be designed and delivered so as to enhance the value of the reporting process and resulting reports both for those reporting and those receiving the reports, as well as from the broader policy perspective.

• Providing a positive and supportive reporting environment is critical to encourage participation and facilitating contiuous learning and improvement, while also facilitating delivery of policy-relevant adaptation reports.

• Contributions of adaptation reporting can be enhanced by an inclusive reporting requirement involving a broader organizational mix that enables more effective risk management and reporting that reflects associated (inter)dependencies and consistency with the more comprehensive post-2015 resilience agenda (Paris Agreement, Sendai Framework for DRR and UN Agenda 2030 SDGs).

     

The High-Resolution Coronal Imager (Hi-C)

The High-Resolution Coronal Imager (Hi-C) was flown on a NASA sounding rocket on 11 July 2012. The goal of the Hi-C mission was to obtain high-resolution (≈?0.3?–?0.4′′), high-cadence (≈?5 seconds) images of a solar active region to investigate the dynamics of solar coronal structures at small spatial scales. The instrument consists of a normal-incidence telescope with the optics coated with multilayers to reflect a narrow wavelength range around 19.3 nm (including the Fe xii 19.5-nm spectral line) and a 4096×4096 camera with a plate scale of 0.1′′?pixel^?1. The target of the Hi-C rocket flight was Active Region 11520. Hi-C obtained 37 full-frame images and 86 partial-frame images during the rocket flight. Analysis of the Hi-C data indicates the corona is structured on scales smaller than currently resolved by existing satellite missions.     

The dynamics of eccentric accretion discs in superhump systems

We have applied an eccentric accretion disc theory in simplified form to the case of an accretion disc in a binary system, where the disc contains the 3:1 Lindblad resonance. This is relevant to the case of superhumps in SU Ursae Majoris cataclysmic variables and other systems, where it is thought that this resonance leads to growth of eccentricity and a modulation in the light curve due to the interaction of a precessing eccentric disc with tidal stresses. A single differential equation is formulated which describes the propagation, resonant excitation and viscous damping of eccentricity. The theory is first worked out in the simple case of a narrow ring and leads to the conclusion that the eccentricity distribution is locally suppressed by the presence of the resonance, creating a dip in the eccentricity at the resonant radius. Application of this theory to the superhump case confirms this conclusion and produces a more accurate expression for the precession rate of the disc than has been previously accomplished with simple dynamical estimates.     

Axtell,a new CV3 chondrite find from Texas

Abstract— We describe a previously unreported meteorite found in Axtell, Texas, in 1943. Based on the mineralogical composition and texture of its matrix and the sizes and abundance of chondrules, we classify it as a CV3 carbonaceous chondrite. The dominant opaque phase in the chondrules is magnetite, and that in refractory inclusions is Ni-rich NiFe metal (awaruite). Axtell, therefore, belongs to the oxidized subgroup of CV3 chondrites, although unlike Allende it escaped strong sulfidation. The meteorite bears a strong textural resemblance to Allende, and its chondrule population and matrix appear to be quite similar to those of Allende, but its refractory inclusions, thermoluminescence properties, and cosmogenic ⁶⁰Co abundances are not. Our data are consistent with a terrestrial age for Axtell of ～100 years and a metamorphic grade slightly lower than that of Allende.     

Radial velocity variations of the pulsating subdwarf B star PG 1605+072

We present an analysis of high-speed spectroscopy of the pulsating subdwarf B star PG 1605+072. Periodic radial motions are detected at frequencies similar to those reported for photometric variations in the star, with amplitudes of up to 6 km s⁻¹. Differences between relative strengths for given frequency peaks for our velocity data and previously measured photometry are probably a result of shifting of power between modes over time. Small differences in the detected frequencies may also indicate mode-shifting. We report the detection of line-shape variations using the moments of the cross-correlation function profiles. It may be possible to use the moments to identify the pulsation modes of the star.