Climate-driven change in Himalayan Rhododendron phenology

Phenology – the seasonal timing of life-history events – is a critical dimension of natural history. It is also one of the earliest and most noticeable traits by which organisms respond to climate change. However, these responses are complex, and only beginning to be understood, especially in the montane and alpine environments that are among the ecosystems most vulnerable to climate change. Drawing from diverse data sets and employing multiple methodologies, I examined how climate affects phenology in Himalayan Rhododendron spp. Comprehensively monitoring flowering phenology over gradients of season and elevation on Mt. Yulong, China – home to a diverse assemblage of Rhododendron spp. that is ecologically and culturally salient – I showed that the species have an elaborate sequenced progression of flowering over season and elevation. Both phenology and the responses to annual temperatures directly impact reproductive success, making this progression vulnerable to the effects of future climate change. A community phylogeny suggests this flowering progression experiences constraints from shared evolutionary history and morphology: the last flowering day of each species shows phylogenetic signal, and is associated with flower size and fruit size. This pattern may be driven by the limited time for fruit development before the onset of cold temperatures in autumn, underscoring the asymmetric pressures on phenology at seasonal extremes. To gain a longer-term perspective, I contextualized Rhododendron phenological progressions within a 125 year proxy record of phenology based on herbarium collections, demonstrating that although increased annual temperatures are associated with earlier flowering, increased fall temperatures are associated with delayed flowering. These contrasting effects have resulted in opposing changes in flowering time, even during rapid recent anthropogenic warming. Finally, interviews with Mt. Yulong villagers revealed a rich knowledge base, with local understandings of changes in and drivers of Rhododendron phenology paralleling the results from ecological studies. In combination, these studies reveal the complexity of phenological responses to climate change. The multiple methodologies allowed a deeper exploration than simple ‘earlier spring’ models of phenological response. Each illuminated distinct details, while agreement among diverse data sources increased confidence in both the methodologies and the conclusions

Autonomous adaptation to climate-driven change in marine biodiversity in a global marine hotspot

While governments and natural resource managers grapple with how to respond to climatic changes, many marine-dependent individuals, organisations and user-groups in fast-changing regions of the world are already adjusting their behaviour to accommodate these. However, we have little information on the nature of these autonomous adaptations that are being initiated by resource user-groups. The east coast of Tasmania, Australia, is one of the world’s fastest warming marine regions with extensive climate-driven changes in biodiversity already observed. We present and compare examples of autonomous adaptations from marine users of the region to provide insights into factors that may have constrained or facilitated the available range of autonomous adaptation options and discuss potential interactions with governmental planned adaptations. We aim to support effective adaptation by identifying the suite of changes that marine users are making largely without government or management intervention, i.e. autonomous adaptations, to better understand these and their potential interactions with formal adaptation strategies. © 2019, Royal Swedish Academy of Sciences

Climate-driven change in the North Atlantic and Arctic Ocean can greatly reduce the circulation of the North Sea

We demonstrate for the first time a direct oceanic link between climate‐driven change in the North Atlantic and Arctic oceans and the circulation of the northwest European shelf‐seas. Downscaled scenarios show a shutdown of the exchange between the Atlantic and the North Sea, and a substantial decrease in the circulation of the North Sea in the second half of the 21st Century. The northern North Sea inflow decreases from 1.2‐1.3Sv (1Sv=106 m3s‐1) to 0.0‐0.6Sv with Atlantic water largely bypassing the North Sea. This is traced to changes in oceanic haline stratification and gyre structure, and to a newly identified circulation‐salinity feedback. The scenario presented here is of a novel potential future state for the North Sea, with wide‐ranging environmental management and societal impacts. Specifically, the sea would become more estuarine and susceptible to anthropogenic influence with an enhanced risk of coastal eutrophication

Temporal controls on silicic acid utilisation along the West Antarctic Peninsula

The impact of climatic change along the Antarctica Peninsula has been widely debated in light of atmospheric/oceanic warming and increases in glacial melt over the past half century. Particular concern exists over the impact of these changes on marine ecosystems, not only on primary producers but also on higher trophic levels. Here we present a record detailing the historical controls on the biogeochemical cycling of silicic acid [Si(OH)4] on the west Antarctica Peninsula margin, a region in which the modern phytoplankton environment is constrained by seasonal sea-ice. We demonstrate that Si(OH)4 cycling through the Holocene alternates between being primarily regulated by sea-ice or glacial discharge from the surrounding grounded ice-sheet. With further climate-driven change and melting forecast for the 21st Century, our findings document the potential for biogeochemical cycling and multi-trophic interactions along the peninsula to be increasingly regulated by glacial discharge, altering food-web interactions

Climate Change and Social Change in a Himachal Village

This article looks at a particular Gaddi community living in high-altitude settlements in Chamba District, in western Himachal Pradesh. It focuses on local interpretations and discourses around changes in climate and examines the impacts on local practices and routines. Offering a different perspective to broad-brush depictions of the climate crisis, it seeks to “bring back to earth” and humanize larger statistical analyses. I show how it can be hard to disentangle climate-driven change from wider socio-economic drivers of change because they are so interwoven in local discourse. Drawing on Ingold’s dwelling perspective and his conception of “taskscapes,” this account shows how changes in seasonal patterns are integrated into people’s routines and practices and a “new normal” seasonality or temporality emerges. In this process, the primary local benchmark for Chobia’s inhabitants is their new road, carrying the weight of local narratives about climate change as well as moral evaluations about changes in human character, for which Lord Shiva is the ultimate arbiter. It is through the prism of local reflection about the new road that a dynamic co-creation of climate and human society becomes evident

Assessing Future Flood Risk and Developing Integrated Flood Risk Management Strategies: A Case Study from the UK Climate Change Risk Assessment

As Earth’s climate changes, individual nations must develop adaptation plans to respond to increasing or new climate risks. This study focuses on changing flood risk in England, UK, and examines the policy framework and actions that underpin England’s adaptation from a flood risk management (FRM) perspective. Specifically, the flood risk projections that fed into the UK’s Climate Change Risk Assessment were analysed alongside newly developed FRM adaptation portfolios that modified the flood risk projections to identify the potential of different measures to reduce Expected Annual Damages (EAD). The key findings indicate that: the range of EAD for all flood sources combined is projected to increase by 18–160% by the 2080s depending on the climate change, population growth and adaptation assumptions applied; adopting an enhanced adaptation approach presents an opportunity to manage much of the climate driven change in flood risk, particularly from river flooding; EAD from coastal flood risk shows the greatest increase relative to present day; and surface water flooding will become an increasingly more significant source of flood risk. Interpretation of the results in the context of the policy framework shows how greater coordination and integration of risk managers and interventions is required to improve adaptation planning

Individual and population dietary specialization decline in fin whales during a period of ecosystem shift

Abstract This study sought to estimate the effect of an anthropogenic and climate-driven change in prey availability on the degree of individual and population specialization of a large marine predator, the fin whale (Balaenoptera physalus). We examined skin biopsies from 99 fin whales sampled in the St. Lawrence Estuary (Canada) over a nine year period (1998–2006) during which environmental change was documented. We analyzed stable isotope ratios in skin and fatty acid signatures in blubber samples of whales, as well as in seven potential prey species, and diet was quantitatively assessed using Bayesian isotopic models. An abrupt change in fin whale dietary niche coincided with a decrease in biomass of their predominant prey, Arctic krill (Thysanoessa spp.). This dietary niche widening toward generalist diets occurred in nearly 60% of sampled individuals. The fin whale population, typically composed of specialists of either krill or lipid-rich pelagic fishes, shifted toward one composed either of krill specialists or true generalists feeding on various zooplankton and fish prey. This change likely reduced intraspecific competition. In the context of the current “Atlantification” of northern water masses, our findings emphasize the importance of considering individual-specific foraging tactics and not only population or group average responses when assessing population resilience or when implementing conservation measures

Climate change and variability, energy and disaster management: produced risks without produced solutions: rethinking the approach

Accelerated climate change and increasing climate variability is the single largest threat to the international goals of sustainable development, the Millennium Development Goals (MDGs) and disaster risk reduction. Global discourses recognise the need for effective and sustainable responses tso produced climate risks. The risk types likely to occur are known, but only in broad terms - their scale, severity, longevity and frequency are not known. The challenge for policymakers is developing an effective framework within which sustainable responses can be formulated. To address the problems of produced risks a comprehensive approach to risk management is necessary. The mechanisms within the climate change, sustainable development and disaster risk reduction discourses are not sufficiently effective or integrated to respond to this challenge. Fundamental reform to current modes of risk reduction is needed, but this can only be achieved through a shift in the dominant perspective on formulating sustainable responses. This requires a shift to an enabling policy framework that encourages bottom-up resilient responses. Resilience is argued as a tool for policy development that can enhance adaptive capacity to current climate risks and shape energy policy to respond to mitigate future climate risks