Climate simulations for 1880–2003 with GISS modelE

We carry out climate simulations for 1880–2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880–2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A concept of flexibility

In the world of commerce, adaptability to change is a weapon for survival. In a world of shrinking material resources the capacity and inclination of the bulk commodity trading system to adapt to change and to adopt efficient patterns of trade will be vital. A concept of flexibility should be developed which treats adaptability not only as a quality but as a possible strategy or policy in the trading system.     

A versatile pump-sampler for live zooplankton

The sampler consists of a readily interchangeable nylon-mesh sleeve mounted on the suction of a submersible pump. The unit is compact and robust, with the mesh totally protected from external damage. Although designed primarily for use in the intakes and outfalls of power stations, this sampler and the variants described could find more general application. The incorporation of a submersible pump circumvents both the suction lift restriction and the problems associated with plankton travel through long lengths of hose that are inherent in previous designs. Less than 3% of the members of estuarine/inshore zooplankton so collected showed damage or had died within 48 hours of capture.     

Dynamic behaviour of a cable-stayed bridge

The dynamic response of a cable-stayed bridge to seismic, wind and simulated traffic loads is discussed. The analysis procedure which is used considers non-linear behaviour of the cables, caused by the variation in sag with tensile force, and non-linear behaviour of the bending members, caused by the interaction of axial and bending deformations. It is concluded that the non-linearity of the structure must be considered in determining the stiffness of the structure in the dead load deformed state. A linear dynamic analysis, however, starting from the dead load deformed state will give results within normally required design accuracy.     

Challenges to achieving greater and fairer stakeholder involvement in marine spatial planning as illustrated by the Lyme Bay scallop dredging closure

The statutory closure of 60 square miles of Lyme Bay to towed fishing gear in 2008 marked the culmination of nearly 20 years of discussions between conservationists and fishermen. Prior to the 2008 decision, voluntary, bottom-up led agreements resulted in inadequate protection of the bay's biological resources and significant erosion of social capital. Lyme Bay provides an excellent case study of the challenges likely to be posed by wider stakeholder involvement imposed under the new Marine Act. This paper examines a broad range of perspectives in relation to the Lyme Bay consultation and subsequent closure, via semi-structured interviews with 25 representatives of different interest groups in Lyme Bay. All respondents acknowledged significant flaws in the process leading to the Lyme Bay decision and felt the Marine Act was well placed to tackle many of these criticisms. However, while the Marine Act should provide a framework for resolving conflicts, it will not prevent them. Success will depend on collaboration between different marine interests, and also on the government acknowledging that outcomes are unlikely to favour everyone in the short-term and that top-down interventions are inevitable.     

Landscape-Scale Analysis of Interactions between Insect Defoliation and Forest Fire in Central Canada

Analysis of Ontario's historical records from 1941–1996 showed that spruce budworm, Choristoneura fumiferana (Clem.) caused whole tree mortality within 389×10³ km². This amounted to 9.2% of the annually cumulative area with moderate-severe defoliation. Large (>2 km²) fires were reported in approximately 65,000 km² and overlapped only 2.8% of the area of reported spruce budworm (SBW) caused tree mortality. Within the 417×10³ km² defoliated by SBW at least once in 1941–1996, the maximum total area recorded as defoliated in any year was over 20 times the maximal area burnt. In the 19,950 km² experiencing both wildfire and SBW defoliation, analysis of the spectra of time lags between the two disturbance types indicated that fires occurred 3–9 years after a SBW outbreak disproportionately often. This window of opportunity for wildfire varies geographically: it starts later after SBW outbreak and lasts longer in western than in eastern Ontario. In addition, 7.5% of the areas containing SBW killed trees were burnt in western compared to 4.8% in eastern Ontario. These geographical differences may result at least partly from slower decomposition of dead fuels in the drier climates of the western SBW belt compared to the eastern SBW belt. The implications for climatic change are discussed.     

A concept of flexibility

In the world of commerce, adaptability to change is a weapon for survival. In a world of shrinking material resources the capacity and inclination of the bulk commodity trading system to adapt to change and to adopt efficient patterns of trade will be vital. A concept of flexibility should be developed which treats adaptability not only as a quality but as a possible strategy or policy in the trading system.     

A model for assessing iceberg hazard

Natural Hazards - With the polar regions opening up to more marine activities but iceberg numbers more likely to increase than decline as a result of global warming, the risk from icebergs to...