Direct Climate Change Research Articles

Analysis of trends of meteoclimatic characteristics at Enderby Land, East Antarctica based on land observations data and reanalysis

The article studies the presence and possible direction of climate change in Enderby Land, East Antarctica, where from 1963 to 1999, the only meteorological station of the WMO network operated at the Molodezhnaya research station (now the summer field base of the RAE), and now an automatic meteorological station has been installed. The trends in surface air temperature, wind speed and direction for the period from the mid-1960s to the present have been analyzed. As initial data, we used the results of ground-based observations at the Molodezhnaya station, as well as reanalysis datasets, which made it possible to complete the instrumental series and evaluate the dynamics of temperature and wind characteristics for the last decades. Monthly values of climatic parameters were used as initial values, but for wind characteristics presented as the V and U components of the speed vector, single values were taken, according to which the average monthly wind speeds and wind distributions in directions were estimated. From different reanalysis systems, by comparison with ground-based observations, series were selected that showed the greatest similarity in the dynamics of the climatic characteristics studied. Good agreement was found between the temperature series of observations at the Molodezhnaya meteorological station and the datasets UDEL_AirT, ERA5, and GISS. The correlation between the wind observation series is less strong; ERA5 reanalysis data shows the wind speed dynamics slightly better. According to the analysis of the long-term dynamics of average annual and monthly temperatures in the region of Enderby Land, the warming trend has not been statistically confirmed, however, a progressive increase in the number of months of the year with positive temperature dynamics has been noted. Based on the analysis of wind characteristics, it is shown that only an increase in average annual wind speeds of 0,1–0,3 m/s/10 years is statistically significant.

A Review of Climate Change Impact Studies on Harmful Algal Blooms

The occurrence of harmful algal blooms (HABs) in coastal and inland waters has a significant impact on societies. This complex biogeophysical phenomenon becomes further complicated due to the impact of climate change. This review summarizes the research performed in recent years in the direction of climate change on three lake parameters, viz. lake temperature, precipitation, runoff, and lake ice, which impacts the lake ecology and, in turn, impacts the HABs. The present paper also reviews the research work related to the relationship between climate change and HABs. The purpose of this study is to provide the researchers with the opportunity to understand the current research in the direction of climate change and HABs so they can contribute effectively to one of the most important phenomena that will severely impact water quality in the future warmer climate, in coastal as well as inland water bodies. Furthermore, this work aims to discuss how HABs will change in the future warmer climate.

Evaluating the sensitivity of robust water resource interventions to climate change scenarios

Water resource system planning is complicated by uncertainty on the magnitude and direction of climate change. Therefore, developments such as new infrastructure or changed management rules that would work acceptably well under a diverse set of future conditions (i.e., robust solutions) are preferred. Robust multi-objective optimisation can help identify advantageous system designs which include existing infrastructure plus a selected subset of new interventions. The method evaluates options using simulated water resource performance metrics statistically aggregated to summarise performance over the climate scenario ensemble. In most cases such ‘robustness metrics’ are sensitive to scenarios under which the system performs poorly and so results may be strongly influenced by a minority of unfavorable climate scenarios. Understanding the influence of specific climate scenarios on robust optimised decision alternatives can help better interpret their results. We propose an automated multi-criteria design-under-uncertainty sensitivity analysis formulation that uses multi-objective evolutionary algorithms to reveal robust and efficient designs under different samples of a climate scenario ensemble. The method is applied to a reservoir management problem in the Rufiji River basin, Tanzania, which involves the second largest dam in Africa. We find that solutions optimised for robustness under alternative groups of climate scenarios exhibit important differences. This becomes particularly decision-relevant if analysts and/or decision-makers have differing confidence levels in the relevance of certain climate scenarios. The proposed approach motivates continued research on how climate model credibility should inform climate scenario selection because it demonstrates the influence scenario selection has on recommendations arising from robust optimisation design processes.

Climate migration and the UK

This article discusses the relationship between climate change and migration in the context of the UK. After a brief overview of climate migration scholarship, it examines the framing of climate migration as a crisis in UK policy discourse, highlighting the disjuncture between policy and academic scholarship in this respect. Subsequently, it examines the reasons for this schism, exploring both the framing of climate migration within the UK media landscape and the securitisation of the topic within UK government policy. Finally, the article explores how the UK�s political landscape undergirds the political logic of climate finance, emphasising the role of British domestic politics in shaping the boundaries and direction of climate change as it manifests in governance. The article closes by exploring potential new directions in UK climate migration policy.

The last glacial termination in the Coyhaique sector of central Patagonia

Southern South America is the only continental landmass that intersects the core of the Southern Westerly Winds (SWW), and thus is important for studying their role as a driver/conduit for the initiation/propagation of climate signals since the last glaciation. Their interaction with the Southern Ocean (SO) affects global climate through its influence on high-latitude upwelling and biological productivity, deep-water convection sites and, consequently, ventilation of CO2 from the deep ocean. Variations in the SWW-SO coupled system have been postulated as fundamental drivers of climate change during glacial terminations and the current interglacial. Hence, deciphering the evolution of the SWW from sensitive locations in the southern middle latitudes is essential for understanding important climatic transitions during and since the Last Glacial Termination (T1). Terrestrial records from the central Patagonian Andes (CPA) (44°-49°S), however, show heterogeneities in the timing, rates, and direction of climate change during T1, impeding detailed assessment of its drivers at regional, hemispheric, and global scales. Here we present new data on glacier, vegetation, and fire-regime changes in the Coyhaique sector (45°34′S) of CPA to improve our understanding on the timing and structure of the T1, including the behavior of the SWW. Our results indicate glacial recession from the youngest Last Glacial Maximum moraines just before ∼17.9 ka and development of an ice-dammed proglacial lake during the early stages of T1. Drainage of the ice-dammed lake, triggered by renewed glacial recession, was near-synchronous with the onset of a gradual multi-millennial trend toward arboreal dominance that started at ∼16 ka east and west of the Andes at that latitude. We detect increased influence of the SWW at ∼45°S starting at ∼16.6 ka, relative to the first millennium of T1, that led to positive anomalies in precipitation between ∼16–14.4 and ∼12.8–11.5 ka, followed by negative anomalies between ∼11.5–9 ka. The synchronous spread of arboreal vegetation east and west of the CPA divide during T1, despite the trans-Andean precipitation contrasts, suggests an upward shift in the temperature-controlled Andean tree line, underscoring the role of deglacial warming as the critical driver for afforestation at regional scale.

Response of plant functional traits to climate change

Climate change has caused serious impacts on the ecosystem, including destroying the stability of the ecosystem and affecting the biodiversity of the ecosystem. Plant functional traits show good response and adaptation to environmental changes, and the change of plant functional traits will indicate climate change. It is a hot research topic to identify the mechanism of the effects of plant functional traits on climate change. By studying relevant references, this paper conducted in-depth studies on leaf functional traits, root traits and the relationship between leaf and root traits among plant functional traits. On this basis, the direction of climate change was further clarified by predicting the development trend of functional traits, and the relationship between plant functional traits and climate change was further discussed.

Impacts of Climate Change on Bread Wheat (Triticum aestivum L) Yield in Adet, North Western Ethiopia

Quantifying the extent and direction of climate change and its impacts is important on crop production as earth’s climate is undergoing changes. Thus the aim of this study was to assess the historical and future climate and its change impact on the yield of Tay and Senkegna bread wheat varieties in Adet, North Western Ethiopia. The observed daily climate data were obtained from National Meteorological Agency of Ethiopia, Bahir Dar branch for 33 years (1983 - 2015). Future climate data were from Climate Research Programme’s Fifth Coupled Model Intercomparison Project (CMIP5) database across 20 GCMs for RCP 8.5 emission scenarios in the time horizon of early-term (2010-2039), mid-century (2040-2069) and end-century (2070-2100). Soil data were obtained from Adet Agricultural Research Center. The onset, end dates, Length of Growing Period (LGP) and dry spell risk for the main rainy season were analyzed using first-order Markov model built in INSTAT tools version 3.36. Decision Support System for Agro-technology Transfer (DSSAT) crop model was employed during yield simulation. Onset of rainy seasons occurred before 1st decade of June was only 25% of the study years while it occurred before 2nd decade of June was 75% of the study years with coefficient of variation (CV) 5.3%. The end date of the rainy seasons occurred before 1st decade of November was 25% of the study years and occurred before 2nd decade of November was 75% of the study years with CV of 3.7%. Length of Growing Period (LGP) was ranged between 125-185 days with CV of 9%. The observed rainfall was decreased while both maximum and minimum temperatures were increased significantly (P<0.05). The projected maximum temperature is expected to increase by 1 to 4.69°C in 2030 to 2080. Furthermore, minimum temperature will increase by 0.93 to 4.73°C in 2030 to 2080. For Tay bread wheat variety, the grain yield is expected to increase by 0.5-1.3% in 2030 to 2050 but decreasing of 3% in 2080s. For Senkegna bread wheat variety, the yield is also increase by 1-2.3% in 2030 to 2080 relative to the baseline. However, days to anthesis and days to maturity of both wheat varieties will decline by 5-21% from the baseline.

A sensitivity-based analysis for managing storage capacity of a small agricultural reservoir under drying climate

Reservoirs have played a vital role in sustaining agricultural production and human livelihood with changing environments and demands. While expanding the storage capacity of a reservoir is deemed a robust structural adaptation that improves water allocation, few studies have discussed the sensitivity of this approach to climatic stresses. In this study, we investigated the effectiveness of building and upsizing reservoirs on addressing water scarcity under climate change in a simple reservoir system in South Korea. We employed a sensitivity-based framework that combines a stochastic system analysis and climate projections, and assessed the response of mean water scarcity to climatic stresses. Results showed that building or upsizing a reservoir made system performance more responsive to climatic stresses. Although additional reservoir capacity can help reducing water scarcity, the effectiveness of such an approach is expected to diminish rapidly when climate becomes drier. If existing climate changes towards drier conditions, performance achieved through additional storage capacity decreases more rapidly, resulting in lager performance loss than before making structural measures. This study suggests that the direction of climate change and operational upgrades should be considered to reduce potential shortcomings associated with the structural adaptation strategies for a simple reservoir system.

Improving the interpretability of climate landscape metrics: An ecological risk analysis of Japan's Marine Protected Areas.

Conservation efforts strive to protect significant swaths of terrestrial, freshwater and marine ecosystems from a range of threats. As climate change becomes an increasing concern, these efforts must take into account how resilient-protected spaces will be in the face of future drivers of change such as warming temperatures. Climate landscape metrics, which signal the spatial magnitude and direction of climate change, support a convenient initial assessment of potential threats to and opportunities within ecosystems to inform conservation and policy efforts where biological data are not available. However, inference of risk from purely physical climatic changes is difficult unless set in a meaningful ecological context. Here, we aim to establish this context using historical climatic variability, as a proxy for local adaptation by resident biota, to identify areas where current local climate conditions will remain extant and future regional climate analogues will emerge. This information is then related to the processes governing species' climate-driven range edge dynamics, differentiating changes in local climate conditions as promoters of species range contractions from those in neighbouring locations facilitating range expansions. We applied this approach to assess the future climatic stability and connectivity of Japanese waters and its network of marine protected areas (MPAs). We find 88% of Japanese waters transitioning to climates outside their historical variability bounds by 2035, resulting in large reductions in the amount of available climatic space potentially promoting widespread range contractions and expansions. Areas of high connectivity, where shifting climates converge, are present along sections of the coast facilitated by the strong latitudinal gradient of the Japanese archipelago and its ocean current system. While these areas overlap significantly with areas currently under significant anthropogenic pressures, they also include much of the MPA network that may provide stepping-stone protection for species that must shift their distribution because of climate change.

Persistence in a Two-Dimensional Moving-Habitat Model.

Environmental changes are forcing many species to track suitable conditions or face extinction. In this study, we use a two-dimensional integrodifference equation to analyze whether a population can track a habitat that is moving due to climate change. We model habitat as a simple rectangle. Our model quickly leads to an eigenvalue problem that determines whether the population persists or declines. After surveying techniques to solve the eigenvalue problem, we highlight three findings that impact conservation efforts such as reserve design and species risk assessment. First, while other models focus on habitat length (parallel to the direction of habitat movement), we show that ignoring habitat width (perpendicular to habitat movement) can lead to overestimates of persistence. Dispersal barriers and hostile landscapes that constrain habitat width greatly decrease the population's ability to track its habitat. Second, for some long-distance dispersal kernels, increasing habitat length improves persistence without limit; for other kernels, increasing length is of limited help and has diminishing returns. Third, it is not always best to orient the long side of the habitat in the direction of climate change. Evidence suggests that the kurtosis of the dispersal kernel determines whether it is best to have a long, wide, or square habitat. In particular, populations with platykurtic dispersal benefit more from a wide habitat, while those with leptokurtic dispersal benefit more from a long habitat. We apply our model to the Rocky Mountain Apollo butterfly (Parnassius smintheus).

Twenty‐five years of change in southern African passerine diversity: nonclimatic factors of change

We analysed more than 25 years of change in passerine bird distribution in South Africa, Swaziland and Lesotho, to show that species distributions can be influenced by processes that are at least in part independent of the local strength and direction of climate change: land use and ecological succession. We used occupancy models that separate species' detection from species' occupancy probability, fitted to citizen science data from both phases of the Southern African Bird Atlas Project (1987-1996 and 2007-2013). Temporal trends in species' occupancy probability were interpreted in terms of local extinction/colonization, and temporal trends in detection probability were interpreted in terms of change in abundance. We found for the first time at this scale that, as predicted in the context of bush encroachment, closed-savannah specialists increased where open-savannah specialists decreased. In addition, the trend in the abundance of species a priori thought to be favoured by agricultural conversion was negatively correlated with human population density, which is in line with hypotheses explaining the decline in farmland birds in the Northern Hemisphere. In addition to climate, vegetation cover and the intensity and time since agricultural conversion constitute important predictors of biodiversity changes in the region. Their inclusion will improve the reliability of predictive models of species distribution.

How does contemporary climate versus climate change velocity affect endemic plant species richness in China?

Climate change is considered a top threat to biodiversity, but the relative roles of contemporary climate versus the rate of climate change in determining spatial patterns of biodiversity are far from clear. China has a very diverse flora and harbors a high percentage of endemic species, but the mechanisms underlying spatial patterns of plant endemism are poorly understood. This study explores the geographical patterns of a representative sample of 555 endemic seed plant species at the scale of 0.5° latitude × 0.5° longitude. Ordinary least squares and spatial autoregressive models were compared to assess the relationship between richness of endemics and the rate of climate change in the past century, as well as a group of contemporary climate variables. In China, a high level of endemism was associated with high elevation and low rate of climate change. However, contemporary climate had a stronger impact than climate change velocity in the past century on endemic species richness patterns. Specifically, mean annual precipitation and annual range of temperature were important contemporary climatic factors. The rate of change of annual mean temperature, but not that of annual precipitation, also significantly contributed to the spatial pattern of plant endemic species richness. We found no significant relationship between topographic variation and endemic species richness, while temperature variability at multiple time scales was strongly correlated with the species richness pattern. Future work should consider the direction of climate change and incorporate higher-resolution data.

Provision of usable projections of future water availability for southeastern Australia: The South Eastern Australian Climate Initiative

Projections of future water availability are required by water managers and policy makers in order to take action to mitigate some of the potentially negative impacts of climate change on water supplies in the urban, agricultural and environmental sectors. However, in order to do this, these projections must have some level of confidence associated with them, and even if this is the case, the research community must make the data and/or information available in a format that is directly usable by water managers and policy makers. This paper presents results from a water availability study recently carried out across southeastern Australia as part of the South Eastern Australian Climate Initiative. More importantly, it shows how the results of this study have been used in defining a range of plausible future streamflow scenarios to be used by water resource managers in the state of Victoria in updating its water supply-demand strategies for the next 50 years. Climate change projections for this region were summarised by creating “dry”, “wet” and “median” future runoff scenarios for 2030 and 2060 based on the second driest, second wettest and median global climate model (GCM) results. These results were then averaged across 27 catchments covering the state of Victoria. We contend that in areas such as the state of Victoria where there is near-unanimous agreement among GCMs as to the direction of climate change impacts on rainfall, along with theoretical understanding consistent with changes in large scale circulation in a warmer world, projected changes in water availability can be used by water resource planners to assist them in better planning for future changes in supply.

Climate and interrelated tree regeneration drivers in mixed temperate–boreal forests

Forest compositional shifts in response to climate change are likely to be initially detectable in the understory tree regeneration layer near species range limits. Because many factors in addition to climate, such as seedbed and soil characteristics, overstory composition, and interactions with other understory biota, drive tree regeneration trends, a thorough understanding of the relative importance of all variables as well as their interrelationships is needed. The range limits of several widespread temperate and boreal tree species overlap in the upper Great Lakes region, USA, thus facilitating an observational study over relatively short regional climate gradients. We used redundancy analysis and variation partitioning to quantify the unique, shared, and total explanatory power of four sets of explanatory variables. The results showed that all four variable sets (climate 9.5 %, understory environment 13.7 %, overstory composition 26.3 %, and understory biota 13.8 %) were significantly associated with tree regeneration compositional variation in mixed temperate–boreal forests. Partitioning also revealed high confounded or shared explanatory power, but also that each set contributed significant unique explanatory power not shared with other sets. Spatial patterning in regeneration composition was strongly related to broad scale environmental patterns, while the large majority of unexplained variation did not have a detectable spatial structure, suggesting factors with local scale variability. Future forest shifts across the landscape will depend not only on the rate and direction of climate change but also on how the strengths and interrelationships among other explanatory variables, such as overstory composition and understory biota, shift with a changing climate.

Policy implications of uncertainty

I want to begin by discussing three uncertainties: the first uncertainty is about what science says and means, and how conclusive we can all be about it. This is, of course, especially the case in relation to climate change, and the frustrating thing, I suspect, for most people engaged directly in

Modeling climate change uncertainties in water resources management models

The impact of climate change on hydrologic design and management of hydrosystems could be one of the important challenges faced by future practicing hydrologists and water resources managers. Many water resources managers currently rely on the historical hydrological data and adaptive real-time operations without consideration of the impact of climate change on major inputs influencing the behavior of hydrologic systems and the operating rules. Issues such as risk, reliability and robustness of water resources systems under different climate change scenarios were addressed in the past. However, water resources management with the decision maker’s preferences attached to climate change has never been dealt with. This short paper discusses issues related to impacts of climate change on water resources management and application of a soft-computing approach, fuzzy set theory, for climate-sensitive management of hydrosystems. A real-life case study example is presented to illustrate the applicability of a soft-computing approach for handling the decision maker’s preferences in accepting or rejecting the magnitude and direction of climate change.

The geography of climate change: implications for conservation biogeography

AbstractAim Climate change poses significant threats to biodiversity, including impacts on species distributions, abundance and ecological interactions. At a landscape scale, these impacts, and biotic responses such as adaptation and migration, will be mediated by spatial heterogeneity in climate and climate change. We examine several aspects of the geography of climate change and their significance for biodiversity conservation.Location California and Nevada, USA.Methods Using current climate surfaces (PRISM) and two scenarios of future climate (A1b, 2070–2099, warmer‐drier and warmer‐wetter), we mapped disappearing, declining, expanding and novel climates, and the velocity and direction of climate change in California and Nevada. We also examined fine‐scale spatial heterogeneity in protected areas of the San Francisco Bay Area in relation to reserve size, topographic complexity and distance from the ocean.Results Under the two climate change scenarios, current climates across most of California and Nevada will shrink greatly in extent, and the climates of the highest peaks will disappear from this region. Expanding and novel climates are projected for the Central Valley. Current temperature isoclines are projected to move up to 4.9 km year−1in flatter regions, but substantially slower in mountainous areas because of steep local topoclimate gradients. In the San Francisco Bay Area, climate diversity within currently protected areas increases with reserve size and proximity to the ocean (the latter because of strong coastal climate gradients). However, by 2100 of almost 500 protected areas (&gt;100 ha), only eight of the largest are projected to experience temperatures within their currently observed range. Topoclimate variability will further increase the range of conditions experienced and needs to be incorporated in future analyses.Main Conclusions Spatial heterogeneity in climate, from mesoclimate to topoclimate scales, represents an important spatial buffer in response to climate change, and merits increased attention in conservation planning.

Mid-Holocene climate change in Europe: a data-model comparison

Abstract. We present here a comparison between the outputs of 25 General Circulation Models run for the mid-Holocene period (6 ka BP) with a set of palaeoclimate reconstructions based on over 400 fossil pollen sequences distributed across the European continent. Three climate parameters were available (moisture availability, temperature of the coldest month and growing degree days), which were grouped together using cluster analysis to provide regions of homogenous climate change. Each model was then investigated to see if it reproduced 1) similar patterns of change and 2) the correct location of these regions. A fuzzy logic distance was used to compare the output of the model with the data, which allowed uncertainties from both the model and data to be taken into account. The models were compared by the magnitude and direction of climate change within the region as well as the spatial pattern of these changes. The majority of the models are grouped together, suggesting that they are becoming more consistent. A test against a set of zero anomalies (no climate change) shows that, although the models are unable to reproduce the exact patterns of change, they all produce the correct signs of change observed for the mid-Holocene.

Urban Water Management vs. Climate Change: Impacts on Cold Region Waste Water Inflows

Failure to account for non-climatic changes to water systems, such as design and operation, within climate change impact assessments leads to misconceptions because these activities buffer the human built enviroment from bio-physical impacts. Urban drainage in cold regions, which is dominated by snowmelt, is especially vulnerable to climate change and is investigated in this paper within the context of future rehabilitation of the sewer network. The objectives are to illustrate the relative response of urban drainage to changes in both the pipe network and climate and demonstrate the use of response surfaces for climate change studies. An incremental climate scenario approach is used to generate two sensitivity analyses for waste water inflows to the Lycksele waste water treatment plant in north-central Sweden. Air temperature and precipitation data (1984–1993) are altered incrementally between –5 and +15 °C and –10 and +40% respectively. These data are then used to drive a hydrological transformation model to obtain estimates of sewer infiltration from groundwater. The results are presented as winter and spring response surfaces – these are graphical representations of a response matrix where each point relates to a single model run. Climate scenario envelopes which summarise a series of GCM runs (ACACIA; Carter, 2002, pers. comm.) are overlaid to indicate the range of plausible waste water inflows. Estimates of natural multi-decadal variability are also included. The first sensitivity analysis assumes no change to the drainage system while the second simulates sewer renovation in which the system is fully separated and sewer infiltration is reduced. The main conclusions are that innovations in drainage network technology have a greater potential to alter waste water inflows than climate change and that, while the direction of climate change is fairly certain, there is great uncertainty surrounding magnitude of those changes and their impacts.

Sediment supply and climate change: implications for basin stratigraphy

The rate of sediment supply from erosional catchment to depositional basin depends primarily upon climate, relief, catchment slope and lithology. It varies in both time and space. Spatial changes in erosion rates due to variations in lithology are illustrated by contrasting rates of drainage divide migration away from faults of known ages. Time variations in relative sediment supply are extremely complex and vary widely according to the direction and magnitude of climate change. In many parts of the Great Basin and south‐western USA, glacial maximum climates were characterized by higher effective moisture and the altitudinal downward spread of woods and forests. Sparse data from alluvial fans indicate reduced sediment supply, despite the increased runoff evident from higher lake levels. The situation in Mediterranean areas is less clear, with rival climatic scenarios for vegetation ecotypes predicting contrasting runoff. In order to test these latter we run Cumulative Seasonal Erosion Potential [CSEP] experiments for present‐day and a variety of full‐glacial Mediterranean candidate climates. The results indicate the likelihood of enhanced sediment supply and runoff compared to the present day during full‐glacial times for a cool wet winter climate and a reduction in sediment supply and runoff for a full‐glacial cool dry winter climate. We then explore the consequences of such phase differences in sediment supply, and sea and lake levels for the stratigraphy of sedimentary basins. Highstands and lowstands of sea or lake may be accompanied by greater or lesser sediment and water supply, as determined by the regional climate and the direction of climatic change. Thus marine lowstands are not necessarily periods of great transfer of coarse clastic sediments to shelves and deep water basinal environments. Unsteady sediment supply has greatest implications for alluvial systems, in particular the effect that changing relative supplies of water and sediment have upon river and fan channel incision.