Detection of anthropogenic climate change using a fingerprint method

A fingerprint method for detecting anthropogenic climate change is applied to new simulations with a coupled ocean-atmosphere general circulation model (CGCM) forced by increasing concentrations of greenhouse gases and aerosols covering the years 1880 to 2050. In addition to the anthropogenic climate change signal, the space-time structure of the natural climate variability for near-surface temperatures is estimated from instrumental data over the last 134 years and two 1000 year simulations with CGCMs. The estimates are compared with paleoclimate data over 570 years. The space-time information on both the signal and the noise is used to maximize the signal-to-noise ratio of a detection variable obtained by applying an optimal filter (fingerprint) to the observed data. The inclusion of aerosols slows the predicted future warming. The probability that the observed increase in near-surface temperatures in recent decades is of natural origin is estimated to be less than 5%. However, this number is dependent on the estimated natural variability level, which is still subject to some uncertainty.

Assessing continental-scale risks for generalist and specialist pollinating bee species under climate change

Increased risks of extinction to populations of animals and plants under changing climate have now been demonstrated for many taxa. This study assesses the extinction risks to species within an important genus of pollinating bees (Colletes: Apidae) by estimating the expected changes in the area and isolation of suitable habitat under predicted climatic condition for 2050. Suitable habitat was defined on the basis of the presence of known forage plants as well as climatic suitability. To investigate whether ecological specialisation was linked to extinction risk we compared three species which were generalist pollen foragers on several plant families with three species which specialised on pollen from a single plant species. Both specialist and generalist species showed an increased risk of extinction with shifting climate, and this was particularly high for the most specialised species (Colletes anchusae and C. wolfi). The forage generalist C. impunctatus, which is associated with Boreo-Alpine environments, is potentially threatened through significant reduction in available climatic niche space. Including the distribution of the principal or sole pollen forage plant, when modelling the distribution of monolectic or narrowly oligolectic species, did not improve the predictive accuracy of our models as the plant species were considerably more widespread than the specialised bees associated with them.

Implications of climate change for diseases, crop yields and food security

Accelerated climate change affects components of complex biological interactions differentially, often causing changes that are difficult to predict. Crop yield and quality are affected by climate change directly, and indirectly, through diseases that themselves will change but remain important. These effects are difficult to dissect and model as their mechanistic bases are generally poorly understood. Nevertheless, a combination of integrated modelling from different disciplines and multi-factorial experimentation will advance our understanding and prioritisation of the challenges. Food security brings in additional socio-economic, geographical and political factors. Enhancing resilience to the effects of climate change is important for all these systems and functional diversity is one of the most effective targets for improved sustainability.

Climate change scenarios for precipitation extremes in Portugal

Precipitation indices are commonly used as climate change indicators. Considering four Climate Variability and Predictability-recommended indices, this study assesses possible changes in their spatial patterns over Portugal under future climatic conditions. Precipitation data from the regional climate model Consortium for Small-Scale Modelling–Climate version of the Local Model (CCLM) ensemble simulations with ECHAM5/MPI-OM1 boundary conditions are used for this purpose. For recent–past, medians and probability density functions of the CCLM-based indices are validated against station-based and gridded observational dataset from ENSEMBLES-based (gridded daily precipitation data provided by the European Climate Assessment & Dataset project) indices. It is demonstrated that the model is able to realistically reproduce not only precipitation but also the corresponding extreme indices. Climate change projections for 2071–2100 (A1B and B1 SRES scenarios) reveal significant decreases in total precipitation, particularly in autumn over northwestern and southern Portugal, though changes exhibit distinct local and seasonal patterns and are typically stronger for A1B than for B1. The increase in winter precipitation over northeastern Portugal in A1B is the most important exception to the overall drying trend. Contributions of extreme precipitation events to total precipitation are also expected to increase, mainly in winter and spring over northeastern Portugal. Strong projected increases in the dry spell lengths in autumn and spring are also noteworthy, giving evidence for an extension of the dry season from summer to spring and autumn. Although no coupling analysis is undertaken, these changes are qualitatively related to modifications in the large-scale circulation over the Euro-Atlantic area, more specifically to shifts in the position of the Azores High and associated changes in the large-scale pressure gradient over the area.

The European storm Kyrill in January 2007: synoptic evolution, meteorological impacts and some considerations with respect to climate change

The synoptic evolution and some meteorological impacts of the European winter storm Kyrill that swept across Western, Central, and Eastern Europe between 17 and 19 January 2007 are investigated. The intensity and large storm damage associated with Kyrill is explained based on synoptic and mesoscale environmental storm features, as well as on comparisons to previous storms. Kyrill appeared on weather maps over the US state of Arkansas about four days before it hit Europe. It underwent an explosive intensification over the Western North Atlantic Ocean while crossing a very intense zonal polar jet stream. A superposition of several favourable meteorological conditions west of the British Isles caused a further deepening of the storm when it started to affect Western Europe. Evidence is provided that a favourable alignment of three polar jet streaks and a dry air intrusion over the occlusion and cold fronts were causal factors in maintaining Kyrill's low pressure very far into Eastern Europe. Kyrill, like many other strong European winter storms, was embedded in a pre-existing, anomalously wide, north-south mean sea-level pressure (MSLP) gradient field. In addition to the range of gusts that might be expected from the synoptic-scale pressure field, mesoscale features associated with convective overturning at the cold front are suggested as the likely causes for the extremely damaging peak gusts observed at many lowland stations during the passage of Kyrill's cold front. Compared to other storms, Kyrill was by far not the most intense system in terms of core pressure and circulation anomaly. However, the system moved into a pre-existing strong MSLP gradient located over Central Europe which extended into Eastern Europe. This fact is considered determinant for the anomalously large area affected by Kyrill. Additionally, considerations of windiness in climate change simulations using two state-of-the-art regional climate models driven by ECHAM5 indicate that not only Central, but also Eastern Central Europe may be affected by higher surface wind speeds at the end of the 21st century. These changes are partially associated with the increased pressure gradient over Europe which is identified in the ECHAM5 simulations. Thus, with respect to the area affected, as well as to the synoptic and mesoscale storm features, it is proposed that Kyrill may serve as an interesting study case to assess future storm impacts.

Tackling regional climate change by leaf albedo bio-geoengineering

The likelihood that continuing greenhouse-gas emissions will lead to an unmanageable degree of climate change [1] has stimulated the search for planetary-scale technological solutions for reducing global warming [2] (“geoengineering”), typically characterized by the necessity for costly new infrastructures and industries [3]. We suggest that the existing global infrastructure associated with arable agriculture can help, given that crop plants exert an important influence over the climatic energy budget 4 and 5 because of differences in their albedo (solar reflectivity) compared to soils and to natural vegetation [6]. Specifically, we propose a “bio-geoengineering” approach to mitigate surface warming, in which crop varieties having specific leaf glossiness and/or canopy morphological traits are specifically chosen to maximize solar reflectivity. We quantify this by modifying the canopy albedo of vegetation in prescribed cropland areas in a global-climate model, and thereby estimate the near-term potential for bio-geoengineering to be a summertime cooling of more than 1°C throughout much of central North America and midlatitude Eurasia, equivalent to seasonally offsetting approximately one-fifth of regional warming due to doubling of atmospheric CO2[7]. Ultimately, genetic modification of plant leaf waxes or canopy structure could achieve greater temperature reductions, although better characterization of existing intraspecies variability is needed first.

Centennial-scale climate change in Ireland during the Holocene

We examine mid- to late Holocene centennial-scale climate variability in Ireland using proxy data from peatlands, lakes and a speleothem. A high degree of between-record variability is apparent in the proxy data and significant chronological uncertainties are present. However, tephra layers provide a robust tool for correlation and improve the chronological precision of the records. Although we can find no statistically significant coherence in the dataset as a whole, a selection of high-quality peatland water table reconstructions co-vary more than would be expected by chance alone. A locally weighted regression model with bootstrapping can be used to construct a ‘best-estimate’ palaeoclimatic reconstruction from these datasets. Visual comparison and cross-wavelet analysis of peatland water table compilations from Ireland and Northern Britain show that there are some periods of coherence between these records. Some terrestrial palaeoclimatic changes in Ireland appear to coincide with changes in the North Atlantic thermohaline circulation and solar activity. However, these relationships are inconsistent and may be obscured by chronological uncertainties. We conclude by suggesting an agenda for future Holocene climate research in Ireland.

Human geographies of climate change: landscape, temporality and lay knowledges.

In this paper we bring together work on landscape, temporality and lay knowledges to propose new ways of understanding climate change. A focus on the familiar landscapes of everyday life offers an opportunity to examine how climate change could be researched as a relational phenomenon, understood on a local level, with distinctive spatialities and temporalities. Climate change can be observed in relation to landscape but also felt, sensed, apprehended emotionally as part of the fabric of everyday life in which acceptance, denial, resignation and action co-exist as personal and social responses to the local manifestations of a global problem.

Conspicuous redemption? Reflections on the promises and perils of the 'celebritization' of climate change

With rising public awareness of climate change, celebrities have become an increasingly important community of non nation-state ‘actors’ influencing discourse and action, thereby comprising an emergent climate science–policy–celebrity complex. Some feel that these amplified and prominent voices contribute to greater public understanding of climate change science, as well as potentially catalyze climate policy cooperation. However, critics posit that increased involvement from the entertainment industry has not served to influence substantive long-term advancements in these arenas; rather, it has instead reduced the politics of climate change to the domain of fashion and fad, devoid of political and public saliency. Through tracking media coverage in Australia, Canada, the United States, and United Kingdom, we map out the terrain of a ‘Politicized Celebrity System’ in attempts to cut through dualistic characterizations of celebrity involvement in politics. We develop a classification system of the various types of climate change celebrity activities, and situate movements in contemporary consumer- and spectacle-driven carbon-based society. Through these analyses, we place dynamic and contested interactions in a spatially and temporally-sensitive ‘Cultural Circuits of Climate Change Celebrities’ model. In so doing, first we explore how these newly ‘authorized’ speakers and ‘experts’ might open up spaces in the public sphere and the science/policy nexus through ‘celebritization’ effects. Second, we examine how the celebrity as the ‘heroic individual’ seeking ‘conspicuous redemption’ may focus climate change actions through individualist frames. Overall, this paper explores potential promises, pitfalls and contradictions of this increasingly entrenched set of ‘agents’ in the cultural politics of climate change. Thus, as a form of climate change action, we consider whether it is more effective to ‘plant’ celebrities instead of trees.

Deriving a sea surface temperature record suitable for climate change research from the along-track scanning radiometers

We describe the approach to be adopted for a major new initiative to derive a homogeneous record of sea surface temperature for 1991–2007 from the observations of the series of three along-track scanning radiometers (ATSRs). This initiative is called (A)RC: (Advanced) ATSR Re-analysis for Climate. The main objectives are to reduce regional biases in retrieved sea surface temperature (SST) to less than 0.1 K for all global oceans, while creating a very homogenous record that is stable in time to within 0.05 K decade−1, with maximum independence of the record from existing analyses of SST used in climate change research. If these stringent targets are achieved, this record will enable significantly improved estimates of surface temperature trends and variability of sufficient quality to advance questions of climate change attribution, climate sensitivity and historical reconstruction of surface temperature changes. The approach includes development of new, consistent estimators for SST for each of the ATSRs, and detailed analysis of overlap periods. Novel aspects of the approach include generation of multiple versions of the record using alternative channel sets and cloud detection techniques, to assess for the first time the effect of such choices. There will be extensive effort in quality control, validation and analysis of the impact on climate SST data sets. Evidence for the plausibility of the 0.1 K target for systematic error is reviewed, as is the need for alternative cloud screening methods in this context.

The national dialogue on behaviour change in UK climate policy: some observations on responsibility, agency and political dimensions

This chapter explores the politics around the role of agency in the UK climate change debate. Government interventions on the demand side of consumption have increasingly involved attempts to obtain greater traction with the values, attitudes and beliefs of citizens in relation to climate change and also in terms of influencing consumer behaviour at an individual level. With figures showing that approximately 40% of the UK’s carbon emissions are attributable to household and transport behaviour, policy initiatives have progressively focused on the facilitation of “sustainable behaviours”. Evidence suggests however, that mobilisation of pro-environmental attitudes in addressing the perceived “value-action gap” has so far had limited success. Research in this field suggests that there is a more significant and nuanced “gap” between context and behaviour; a relationship that perhaps provides a more adroit reflection of reasons why people do not necessarily react in the way that policy-makers anticipate. Tracing the development of the UK Government’s behaviour change agenda over the last decade, we posit that a core reason for the limitations of this programme relates to an excessively narrow focus on the individual. This has served to obscure some of the wider political and economic aspects of the debate in favour of a more simplified discussion. The second part of the chapter reports findings from a series of focus groups exploring some of the wider political views that people hold around household energy habits, purchase and use of domestic appliances, and transport behaviour-and discusses these insights in relation to the literature on the agenda’s apparent limitations. The chapter concludes by considering whether the aims of the Big Society approach (recently established by the UK’s Coalition Government) hold the potential to engage more directly with some of these issues or whether they merely constitute a “repackaging” of the individualism agenda.

Private climate change reporting: a discourse of risk and opportunity

Purpose – This paper aims to explore the nature of the emerging discourse of private climate change reporting, which takes place in one-on-one meetings between institutional investors and their investee companies. Design/methodology/approach – Semi-structured interviews were conducted with representatives from 20 UK investment institutions to derive data which was then coded and analysed, in order to derive a picture of the emerging discourse of private climate change reporting, using an interpretive methodological approach, in addition to explorative analysis using NVivo software. Findings – The authors find that private climate change reporting is dominated by a discourse of risk and risk management. This emerging risk discourse derives from institutional investors' belief that climate change represents a material risk, that it is the most salient sustainability issue, and that their clients require them to manage climate change-related risk within their portfolio investment. It is found that institutional investors are using the private reporting process to compensate for the acknowledged inadequacies of public climate change reporting. Contrary to evidence indicating corporate capture of public sustainability reporting, these findings suggest that the emerging private climate change reporting discourse is being captured by the institutional investment community. There is also evidence of an emerging discourse of opportunity in private climate change reporting as the institutional investors are increasingly aware of a range of ways in which climate change presents material opportunities for their investee companies to exploit. Lastly, the authors find an absence of any ethical discourse, such that private climate change reporting reinforces rather than challenges the “business case” status quo. Originality/value – Although there is a wealth of sustainability reporting research, there is no academic research on private climate change reporting. This paper attempts to fill this gap by providing rich interview evidence regarding the nature of the emerging private climate change reporting discourse.

Anticipatory objects and uncertain imminence: cattle grids, landscape and the presencing of climate change on the Lizard Peninsula, UK

In this paper we show how a seemingly unremarkable object – a cattle grid – has come to presence climate change in partial and contingent ways on the Lizard Peninsula, Cornwall, UK. We identify the cattle grid as an ‘anticipatory object’ through which conservation organisations seek to manage the future and adapt to climate change, but which at the same time presences that unthought-of future for others in the landscape. We explore the ways in which the cattle grid acts to presence something that is not only absent – climate change – but has uncertain imminence. We investigate the ways in which the cattle grid make climate relevant as an embodied and experiential process, a physical and intellectual artefact, and the means to imagine climate and the ways it might change. Drawing upon interpretative approaches informed by theorisations of materiality, presence and absence to understand climate change as a social phenomenon, we go beyond a consideration of this ordinary object defined by its function to consider how the object is experienced, the processes and practices through which people relate to it, and the ways in which social meaning accumulates around it. The empirical basis for this argument is provided by in-depth interviews with local representatives of Natural England, residents and farmers.