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Purpose — In 2007, the issues of global and climate change in particular, have become major issues in the social psyche. With the United Nations declaring 2008 the "International Year of Planet Earth", this; paper aims to look at four recent reports and comments on how the reports aim to deal with the climate and global change challenges ahead. Design/methodology/approach — After a brief introduction to the subject, this paper looks at each of the four reports in turn. It describes the methodology of each report and then discusses its relative strengths and weaknesses. This is followed by a conclusion on the reports as a whole and where policy makers can make improvements. Findings — All four reports are well structured and they have certainly raised the profile and illustrated the importance of global and climate change. However, there are a number of ways each could and should be improved in future updates. Practical implications — This paper aims to bring the reports to a wider audience and make recommendations on improvements to future reports on these important global issues. Originality/value — The paper evaluates four recent reports on the important social issues of global, change and climate change. By comparing and contrasting the reports, the paper gives an overview 01 what some of the larger policy makers are doing to tackle global and climate change. The paper also makes recommendations for improvements to the reports. [ABSTRACT FROM AUTHOR]

The relative importance of the processes responsible for the annual cycle in the upper-ocean heat content in the Peru Current, in the southeastern tropical Pacific, was diagnosed from an oceanic analysis dataset. It was found that the annual cycle of heat content is forced mainly by insolation. However, the ocean dynamical processes play an important role in producing different regional budget characteristics. In a band 500 km from the coast of Peru, the annual heat content changes in this region are relatively large and can be approximated as sea surface temperature (SST) changes in a fixed-depth mixed layer. The annual cycle of the albedo associated with low-level clouds enhances the annual cycle in insolation, which explains the relatively strong annual cycle of heat content. These clouds, to a large extent, act as a feedback to SST, but a small additional forcing, which is proposed to be cold air advection in this paper, is needed to explain the fact that the maximum cloudiness leads the lowest SST by around a month. Ocean dynamics is important closer to the coast, where upwelling acts partly as damping of the heat content changes and forces it to peak earlier than farther offshore. In a band farther to the southwest, locally wind-forced thermocline motions, which become shallower (deeper) in the warm (cool) season, partially cancel the effect of net surface heat fluxes, whose annual cycle is comparable to that in the region previously mentioned, producing a relatively small annual cycle of heat content. The local forcing appears to be associated with the annual meridional displacements of the South Pacific anticyclone. The annual cycle in SST is also relatively small, which is probably due to the changes in the temperature of the water entrained into the mixed layer associated with the thermocline motions, but also to a mixed layer deeper than that closer to the coast. [ABSTRACT FROM AUTHOR]

The natural resources of the Okavango Delta, a large wetland in semi-arid Botswana, form the basis of livelihoods of the local population and support economically important high-end tourism. The hydro-ecological system is dynamic at various time scales, responding to climate variability, and both flood and drought conditions have in the past put pressure on the system's users. Human-induced climate change can potentially exacerbate the effects of existing climate variability. In this paper, we present simulated future hydro-ecological conditions in the Okavango Delta generated by a step-wise modelling procedure. The outputs of three different global climate models are used to drive a suite of hydrological models. Lastly, a rule-based dynamic model relates hydroperiod conditions to vegetation assemblages. The simulated future conditions vary from much drier to much wetter than those recorded in the past. Models indicate that climatic change would result in change in both extent and distribution of the major ecotopes of the Okavango Delta. Importantly, the different ecotopes will be affected to varying degrees. The projected changes will have consequences for the wildlife-based management of the system. They will affect, for example, available grazing and migration/movement patterns of large herbivores, as well as fish. Such consequences can have rapid up-trophic level effects, ultimately leading to potentially substantial impacts on the economy. The main conclusion to be drawn is that management planning and land-use systems should be as flexible as possible. [ABSTRACT FROM AUTHOR]

Simple equations are developed to express regional climate changes for the twenty-first century and associated uncertainty in terms of the global temperature change (GTC) without a dependence on the underlying emission pathways. The equations are applied to regional temperature and precipitation changes over different regions of the world, and relevant parameters are calculated using the latest multimodel ensemble of global climate change simulations. Examples are also shown of how to use the equations to develop probability density functions (PDFs) of regional climate change based on PDFs of GTC. The main advantage of these equations is that they can be used to estimate regional changes from GTC obtained either from simple and intermediate complexity models or from target CO2 stabilization concentrations. [ABSTRACT FROM AUTHOR]

In this study, a penalized maximal F test (PMFT) is proposed for detecting undocumented mean shifts that are not accompanied by any sudden change in the linear trend of time series. PMFT aims to even out the uneven distribution of false alarm rate and detection power of the corresponding unpenalized maximal F test that is based on a common-trend two-phase regression model (TPR3). The performance of PMFT is compared with that of TPR3 using Monte Carlo simulations and real climate data series. It is shown that, due to the effect of unequal sample sizes, the false alarm rate of TPR3 has a W-shaped distribution, with much higher than specified values for points near the ends of the series and lower values for points between either of the ends and the middle of the series. Consequently, for a mean shift of certain magnitude, TPR3 would detect it with a lower-than-specified level of confidence and hence more easily when it occurs near the ends of the series than somewhere between either of the ends and the middle of the series; it would mistakenly declare many more changepoints near the ends of a homogeneous series. These undesirable features of TPR3 are diminished in PMFT by using an empirical penalty function to take into account the relative position of each point being tested. As a result, PMFT has a notably higher power of detection; its false alarm rate and effective level of confidence are very close to the nominal level, basically evenly distributed across all possible candidate changepoints. The improvement in hit rate can be more than 10% for detecting small shifts (Δ ≤ σ, where σ is the noise standard deviation). [ABSTRACT FROM AUTHOR]

Climate models used to produce global warming scenarios exhibit widely diverging responses of the thermohaline circulation (THC). To investigate the mechanisms responsible for this variability, a regional Atlantic Ocean model driven with forcing diagnosed from two coupled greenhouse gas simulations has been employed. One of the coupled models (MPI) shows an almost constant THC, the other (GFDL) shows a declining THC in the twenty-first century. The THC evolution in the regional model corresponds rather closely to that of the respective coupled simulation, that is, it remains constant when driven with the forcing from the MPI model, and declines when driven with the GFDL forcing. These findings indicate that a detailed representation of ocean processes in the region covered by the Atlantic model may not be critical for the simulation of the overall THC changes in a global warming scenario, and specifically that the coupled model’s rather coarse representation of water mass formation processes in the subpolar North Atlantic is unlikely to be the primary cause for the large differences in the THC evolution. Sensitivity experiments have confirmed that a main parameter governing the THC response to global warming is the density of the intermediate waters in the Greenland–Iceland–Norwegian Seas, which in turn influences the density of the North Atlantic Deep Water, whereas changes in the air–sea heat and freshwater fluxes over the subpolar North Atlantic are only of moderate importance, and mainly influence the interannual–decadal variability of THC. Finally, as a consequence of changing surface fluxes, the Labrador Sea convection ceases by about 2030 under both forcings (i.e., even in a situation where the overall THC is stable) indicating that the eventual breakdown of the convection is likely but need not coincide with substantial THC changes. [ABSTRACT FROM AUTHOR]

This article examines why Africa's climate change burden is greater than other countries, despite Africa's least contribution to global warming. The critical challenge in terms of climate change in Africa is the way that multiple stressors, such as the spread of AIDS, the effects of economic globalization, the privatization of resources, and conflict, converge with climate change. It is where several stressors reinforce each other that societies become vulnerable, and impacts of climate change can be particularly severe.

To identify the effect of climate change on selected plant species representative of the main vegetation types in the Faroe Islands. Due to a possible weakening of the North Atlantic Current, it is difficult to predict whether the climate in the Faroe Islands will be warmer or colder as a result of global warming. Therefore, two scenarios are proposed. The first scenario assumes an increase in summer and winter temperature of 2 °C, and the second a decrease in summer and winter temperature of 2 °C. Temperate, low alpine and alpine areas in the northern and central part of the Faroe Islands. The responses of 12 different plant species in the Faroe Islands were tested against measured soil temperature, expressed as Tmin, Tmax, snow cover and growing degree days (GDD), using generalised linear modelling (GLM). The tolerance to changes in winter soil temperature (0.3–0.8 °C) was found to be lower than the tolerance to changing summer soil temperature (0.7–1.0 °C), and in both cases lower than the predicted climate changes. The species most affected by a warming scenario are those that are found with a limited distribution restricted to the uppermost parts of the mountains, especially Salix herbacea, Racomitrium fasciculare, and Bistorta vivipara. For other species, the effect will mainly be a general upward migration. The most vulnerable species are those with a low tolerance, especially Calluna vulgaris, and also Empetrum nigrum, and Nardus stricta. If the climate in the Faroe Islands should become colder, the most vulnerable species are those at low altitudes. A significantly lower temperature would be expected to produce a serious reduction in the extent of Vaccinium myrtillus and Galium saxatilis. Species like Empetrum nigrum, Nardus stricta, and Calluna vulgaris may also be vulnerable. In any case, these species can be expected to migrate downwards. [ABSTRACT FROM AUTHOR]