scholarly journals The role of glacier dynamics and threshold definition in the characterisation of future streamflow droughts in glacierised catchments

2017 ◽  
Author(s):  
Marit Van Tiel ◽  
Adriaan J. Teuling ◽  
Niko Wanders ◽  
Marc J. P. Vis ◽  
Kerstin Stahl ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Scales ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Glacier Area ◽  
Short Term ◽  
Drought Characteristics ◽  
Wide Range ◽  
Glacier Dynamics ◽  
The Future

Abstract. Glaciers are essential hydrological reservoirs, storing and releasing water at various time scales. Short-term variability in glacier melt is one of the causes of streamflow droughts, defined as below normal water availabilities. Streamflow droughts in glacierised catchments have a wide range of interlinked causing factors related to precipitation and temperature on short and long time scales. Climate change affects glacier storage capacity, with resulting consequences for discharge regimes and drought. Future projections of streamflow drought in glacierised basins can, however, strongly depend on the modelling strategies and analysis approaches applied. Here, we examine the effect of different approaches, concerning the glacier modelling and the drought threshold, on the characterisation of streamflow droughts in glacierised catchments. Streamflow is simulated with the HBV-light model for two case study catchments, the Nigardsbreen catchment in Norway and the Wolverine catchment in Alaska, and two future climate change scenarios (RCP4.5 and RCP8.5). Two types of glacier modelling are applied, a constant and dynamical glacier area conceptualisation. Streamflow droughts are identified with the variable threshold level method and their characteristics are compared between two periods, a historical (1975–2004) and future (2071–2100) period. Two existing threshold approaches to define future droughts are employed, (1) the threshold from the historical period and (2) a transient threshold approach, whereby the threshold adapts every year in the future to the changing regimes. Results show that drought characteristics differ among the combinations of glacier area modelling and thresholds. The historical threshold combined with a dynamical glacier area projects extreme increases in drought severity in the future, caused by the regime shift due to a reduction in glacier area. The historical threshold combined with a constant glacier area results in a drastic decrease of the number of droughts. The drought characteristics between future and historic periods are more similar when the transient threshold is used, for both glacier dynamics conceptualisations. With the transient threshold causing factors of future droughts, can be analysed. This study revealed the different effects of methodological choices on future streamflow drought projections and it highlights how the options can be used to analyse different aspects of future droughts: the transient threshold for analysing future drought processes, the historical threshold to assess changes between periods, the constant glacier area to analyse the effect of short term climate variability on droughts and the dynamical glacier area to model realistic future discharges under climate change.

scholarly journals The role of glacier changes and threshold definition in the characterisation of future streamflow droughts in glacierised catchments

2018 ◽  
Vol 22 (1) ◽  
pp. 463-485 ◽  
Author(s):  
Marit Van Tiel ◽  
Adriaan J. Teuling ◽  
Niko Wanders ◽  
Marc J. P. Vis ◽  
Kerstin Stahl ◽  
...  
Keyword(s):  
Climate Change ◽  
Future Climate Change ◽  
Drought Severity ◽  
Historical Period ◽  
Climate Change Scenarios ◽  
Glacier Area ◽  
Short Term ◽  
Drought Characteristics ◽  
Wide Range ◽  
The Future

Abstract. Glaciers are essential hydrological reservoirs, storing and releasing water at various timescales. Short-term variability in glacier melt is one of the causes of streamflow droughts, here defined as deficiencies from the flow regime. Streamflow droughts in glacierised catchments have a wide range of interlinked causing factors related to precipitation and temperature on short and long timescales. Climate change affects glacier storage capacity, with resulting consequences for discharge regimes and streamflow drought. Future projections of streamflow drought in glacierised basins can, however, strongly depend on the modelling strategies and analysis approaches applied. Here, we examine the effect of different approaches, concerning the glacier modelling and the drought threshold, on the characterisation of streamflow droughts in glacierised catchments. Streamflow is simulated with the Hydrologiska Byråns Vattenbalansavdelning (HBV-light) model for two case study catchments, the Nigardsbreen catchment in Norway and the Wolverine catchment in Alaska, and two future climate change scenarios (RCP4.5 and RCP8.5). Two types of glacier modelling are applied, a constant and dynamic glacier area conceptualisation. Streamflow droughts are identified with the variable threshold level method and their characteristics are compared between two periods, a historical (1975–2004) and future (2071–2100) period. Two existing threshold approaches to define future droughts are employed: (1) the threshold from the historical period; (2) a transient threshold approach, whereby the threshold adapts every year in the future to the changing regimes. Results show that drought characteristics differ among the combinations of glacier area modelling and thresholds. The historical threshold combined with a dynamic glacier area projects extreme increases in drought severity in the future, caused by the regime shift due to a reduction in glacier area. The historical threshold combined with a constant glacier area results in a drastic decrease of the number of droughts. The drought characteristics between future and historical periods are more similar when the transient threshold is used, for both glacier area conceptualisations. With the transient threshold, factors causing future droughts can be analysed. This study revealed the different effects of methodological choices on future streamflow drought projections and it highlights how the options can be used to analyse different aspects of future droughts: the transient threshold for analysing future drought processes, the historical threshold to assess changes between periods, the constant glacier area to analyse the effect of short-term climate variability on droughts and the dynamic glacier area to model more realistic future discharges under climate change.

scholarly journals Climate Change Can Drive a Significant Loss of Suitable Habitat for Polylepis quadrijuga, a Treeline Species in the Sky Islands of the Northern Andes

2021 ◽  
Vol 9 ◽  
Author(s):  
Lina Caballero-Villalobos ◽  
Francisco Fajardo-Gutiérrez ◽  
Mariasole Calbi ◽  
Gustavo A. Silva-Arias
Keyword(s):  
Climate Change ◽  
Species Distribution ◽  
Ex Situ ◽  
Future Climate Change ◽  
Suitable Habitat ◽  
Climate Change Scenarios ◽  
Sky Islands ◽  
Future Projections ◽  
Wide Range ◽  
The Future

It is predicted that climate change will strongly affect plant distributions in high elevation “sky islands” of tropical Andes. Polylepis forests are a dominant element of the treeline throughout the Andes Cordillera in South America. However, little is known about the climatic factors underlying the current distribution of Polylepis trees and the possible effect of global climate change. The species Polylepis quadrijuga is endemic to the Colombian Eastern Cordillera, where it plays a fundamental ecological role in high-altitude páramo-forest ecotones. We sought to evaluate the potential distribution of P. quadrijuga under future climate change scenarios using ensemble modeling approaches. We conducted a comprehensive assessment of future climatic projections deriving from 12 different general circulation models (GCMs), four Representative Concentration Pathways (R) emissions scenarios, and two different time frames (2041–2060 and 2061–2080). Additionally, based on the future projections, we evaluate the effectiveness of the National System of Protected Natural Areas of Colombia (SINAP) and Páramo Complexes of Colombia (PCC) in protecting P. quadrijuga woodlands. Here, we compiled a comprehensive set of observations of P. quadrijuga and study them in connection with climatic and topographic variables to identify environmental predictors of the species distribution, possible habitat differentiation throughout the geographic distribution of the species, and predict the effect of different climate change scenarios on the future distribution of P. quadrijuga. Our results predict a dramatic loss of suitable habitat due to climate change on this key tropical Andean treeline species. The ensemble Habitat Suitability Modeling (HSM) shows differences in suitable scores among north and south regions of the species distribution consistent with differences in topographic features throughout the available habitat of P. quadrijuga. Future projections of the HSM predicted the Páramo complex “Sumapaz-Cruz Verde” as a major area for the long-term conservation of P. quadrijuga because it provides a wide range of suitable habitats for the different evaluated climate change scenarios. We provide the first set of priority areas to perform both in situ and ex situ conservation efforts based on suitable habitat projections.

Climate, ticks and disease

2021 ◽  
Keyword(s):  
Climate Change ◽  
Spatial Distribution ◽  
Disease Ecology ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Expert Opinions ◽  
The World ◽  
Host Pathogen ◽  
The Future ◽  
Impacts Of Climate Change

Abstract This book is a collection of 77 expert opinions arranged in three sections. Section 1 on "Climate" sets the scene, including predictions of future climate change, how climate change affects ecosystems, and how to model projections of the spatial distribution of ticks and tick-borne infections under different climate change scenarios. Section 2 on "Ticks" focuses on ticks (although tick-borne pathogens creep in) and whether or not changes in climate affect the tick biosphere, from physiology to ecology. Section 3 on "Disease" focuses on the tick-host-pathogen biosphere, ranging from the triangle of tick-host-pathogen molecular interactions to disease ecology in various regions and ecosystems of the world. Each of these three sections ends with a synopsis that aims to give a brief overview of all the expert opinions within the section. The book concludes with Section 4 (Final Synopsis and Future Predictions). This synopsis attempts to summarize evidence provided by the experts of tangible impacts of climate change on ticks and tick-borne infections. In constructing their expert opinions, contributors give their views on what the future might hold. The final synopsis provides a snapshot of their expert thoughts on the future.

scholarly journals Projected Future Temporal Trends of Two Different Urban Heat Islands in Athens (Greece) under Three Climate Change Scenarios: A Statistical Approach

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 637 ◽  
Author(s):  
Tim van der Schriek ◽  
Konstantinos V. Varotsos ◽  
Christos Giannakopoulos ◽  
Dimitra Founda
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Air Temperature ◽  
Temporal Trends ◽  
Temperature Data ◽  
Rural Site ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
The Future ◽  
The Impact

This is the first study to look at future temporal urban heath island (UHI) trends of Athens (Greece) under different UHI intensity regimes. Historical changes in the Athens UHI, spanning 1971–2016, were assessed by contrasting two air temperature records from stable meteorological stations in contrasting urban and rural settings. Subsequently, we used a five-member regional climate model (RCM) sub-ensemble from EURO-CORDEX with a horizontal resolution of 0.11° (~12 × 12 km) to simulate air temperature data, spanning the period 1976–2100, for the two station sites. Three future emissions scenarios (RCP2.6, RCP4.5, and RCP8.5) were implanted in the simulations after 2005 covering the period 2006–2100. Two 20-year historical reference periods (1976–1995 and 1996–2015) were selected with contrasting UHI regimes; the second period had a stronger intensity. The daily maximum and minimum air temperature data (Tmax and Tmin) for the two reference periods were perturbed to two future periods, 2046–2065 and 2076–2095, under the three RCPs, by applying the empirical quantile mapping (eqm) bias-adjusting method. This novel approach allows us to assess future temperature developments in Athens under two UHI intensity regimes that are mainly forced by differences in air pollution and heat input. We found that the future frequency of days with Tmax > 37 °C in Athens was only different from rural background values under the intense UHI regime. Thus, the impact of heatwaves on the urban environment of Athens is dependent on UHI intensity. There is a large increase in the future frequency of nights with Tmin > 26 °C in Athens under all UHI regimes and climate scenarios; these events remain comparatively rare at the rural site. This large urban amplification of the frequency of extremely hot nights is likely caused by air pollution. Consequently, local mitigation policies aimed at decreasing urban atmospheric pollution are expected to be highly effective in reducing urban temperatures and extreme heat events in Athens under future climate change scenarios. Such policies directly have multiple benefits, including reduced electricity (energy) needs, improved living quality and strong health advantages (heat- and pollution-related illness/deaths).

Detecting future changes of short-term rainfall characteristics in the mountainous regions of Slovakia

2021 ◽  
Author(s):  
Gabriel Földes ◽  
Marija Mihaela Labat ◽  
Silvia Kohnová ◽  
Miroslav Kandera
Keyword(s):  
Climate Change ◽  
Climate Change Impacts ◽  
Kendall Test ◽  
Future Climate Change ◽  
Short Term ◽  
Rainfall Characteristics ◽  
Mountainous Regions ◽  
Community Land Model ◽  
The Future ◽  
The Usa

<p>The study focuses on future changes in short-term rainfall characteristics. The analysis was performed for the mountainous regions in the northern part of Slovakia at 10 selected climatological stations. The rainfall data are simulated by Community Land Model Scenario which represents the future climate change.  The Community Land Model Scenario is a multidisciplinary project between scientists and several working groups mainly in the USA. The model includes impacts of changes in vegetation on the climate. The scenario has semi- pessimistic characteristics with a predicted global temperature increase by 2.9°C by the 2100. The analysis was performed for five rainfall durations (60, 120, 180, 240 and 1440 minutes) for the historical (1961-2020) and for the future (2071-2100) periods.  The detection of the future changes in short-term rainfall characteristics was made by several methods; for the seasonal changes the Burn´s vector was used, for the trend testing the data the Mann-Kendall test was applied. Results provide information how climate change impacts the short-term rainfall intensities in the mountainous regions of Slovakia.</p>

The City Pack - the co-production of an urban climate service providing local summaries of a city's future climate 

2021 ◽  
Author(s):  
Elizabeth Fuller ◽  
Claire Scannell ◽  
Victoria Ramsey ◽  
Rebecca Parfitt ◽  
Nicola Golding
Keyword(s):  
Climate Change ◽  
Urban Climate ◽  
City Council ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Climate Services ◽  
The Future ◽  
Climate Service ◽  
The City

<p>In 2018, the UN estimated that around 55% of the world’s population currently live within urban areas, with this value projected to rise to 60% by 2030 (United Nations, 2018). High levels of urbanisation, coupled with an increasing trend in extreme weather under future climate change scenarios, combine to create significant challenges to increasing urban resilience for the future (Masson et al., 2020).</p><p>Urban climate services provide tools to support decision making at a range of scales across the city, from day-to-day operations to informing urban design over longer timescales (Grimmond et al., 2015). Whilst urban climate services may be developed at a range of scales (Grimmond et al., 2020), this presentation looks at a prototype climate service which provides long-term climate change projections at the city-specific scale. The ‘City Pack’ was developed through a process of co-production, in which project development aims to move away from a one-way push of scientific information, to a two-way collaborative process of knowledge construction and sharing (Vincent et al., 2019).</p><p>This ‘City Pack’ service was co-developed by the Met Office and Bristol City Council following an assessment of the Council’s climate information needs. The City Pack comprises of three non-technical factsheets which explain how the climate of Bristol has changed and will continue to change into the 21<sup>st</sup> Century based on the UKCP climate projections. The City Pack’s primary aims are to raise awareness of how a cities climate may change in the future and to inform the development of city resilience whilst also providing a tool to be used by city stakeholders to raise awareness of climate change across the council. The audience for the City Pack therefore includes city officials, city planners and the general public. The Bristol City Pack has since provided an evidence base for the Bristol City Council Climate Change Risk Assessment and informed Bristol’s Climate Strategy. In addition, the City Pack has been used to engage with the council’s wider stakeholders and also as a communication and training tool. As such, whilst the co-production of a climate service may be time and resource intensive, the process may also be rewarded with the production of a highly tailored and user-relevant tool.</p><p>Following the success of the prototype ‘City Pack’ service for Bristol City Council, the Met Office are continuing to produce City Packs for additional cities across the UK, and also in China. The project is seeking to ascertain if services which are co-produced with and bespoke to one set of stakeholders, may provide an equally valuable service for other cities and if so, how can we make these services scalable.</p>

scholarly journals Prediction of the Suitable Area of the Chinese White Pines (Pinus subsect. Strobus) under Climate Changes and Implications for Their Conservation

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 996
Author(s):  
Lele Lin ◽  
Jian He ◽  
Lei Xie ◽  
Guofa Cui
Keyword(s):  
Climate Change ◽  
Current Distribution ◽  
Future Climate ◽  
Ex Situ ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
White Pine ◽  
Chinese White ◽  
The Future ◽  
Pine Species

White pines (Pinus subsect. Strobus) play important roles in forest ecosystems in the Northern Hemisphere. Species of this group are narrowly distributed or endangered in China. In this study, we used a species distribution model (SDM) to project and predict the distribution patterns of the 12 species of Chinese white pine under a variety of paleoclimatic and future climate change scenarios based on 39 high-resolution environmental variables and 1459 distribution records. We also computed the centroid shift, range expansion/contraction, and suitability change of the current distribution area to assess the potential risk to each species in the future. The modeling results revealed that the suitable habitat of each species is consistent with but slightly larger than its actual distribution range and that temperature, precipitation, and UV radiation are important determining factors for the distribution of different white pine species. The results indicate that the Last Glacial Maximum (LGM) greatly affected the current distribution of the Chinese white pine species. Additionally, it was predicted that under the future climate change scenarios, there will be a reduction in the area of habitats suitable for P. armandii, P. morrisonicola, and P. mastersiana. Furthermore, some of the current distribution sites of P. armandii, P. kwangtungensis, P. mastersiana, P. morrisonicola, P. sibirica, and P. wallichiana were predicted to become more unsuitable under these scenarios. These results indicate that some Chinese white pine species, such as P. armandii, P. morrisonicola, and P. mastersiana, may have a very high risk of population shrinkage in the future. Overall, this study provided relevant data for the long-term conservation (both in situ and ex situ) and sustainable management of Chinese white pine species.

Methods and uncertainties in bioclimatic envelope modelling under climate change

2006 ◽  
Vol 30 (6) ◽  
pp. 751-777 ◽  
Author(s):  
Risto K. Heikkinen ◽  
Miska Luoto ◽  
Miguel B. Araújo ◽  
Raimo Virkkala ◽  
Wilfried Thuiller ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Climatic Factors ◽  
Future Climate Change ◽  
Future Research ◽  
Climate Change Scenarios ◽  
Distribution Models ◽  
Wide Range ◽  
Bioclimatic Modelling ◽  
Bioclimatic Envelope

Potential impacts of projected climate change on biodiversity are often assessed using single-species bioclimatic ‘envelope’models. Such models are a special case of species distribution models in which the current geographical distribution of species is related to climatic variables so to enable projections of distributions under future climate change scenarios. This work reviews a number of critical methodological issues that may lead to uncertainty in predictions from bioclimatic modelling. Particular attention is paid to recent developments of bioclimatic modelling that address some of these issues as well as to the topics where more progress needs to be made. Developing and applying bioclimatic models in a informative way requires good understanding of a wide range of methodologies, including the choice of modelling technique, model validation, collinearity, autocorrelation, biased sampling of explanatory variables, scaling and impacts of non-climatic factors. A key challenge for future research is integrating factors such as land cover, direct CO2 effects, biotic interactions and dispersal mechanisms into species-climate models. We conclude that, although bioclimatic envelope models have a number of important advantages, they need to be applied only when users of models have a thorough understanding of their limitations and uncertainties.

scholarly journals Evaluation of Climate Change Impacts on the Potential Distribution of Styrax sumatrana in North Sumatra, Indonesia

2021 ◽  
Vol 13 (2) ◽  
pp. 462
Author(s):  
Muhammad Hadi Saputra ◽  
Han Soo Lee
Keyword(s):  
Climate Change ◽  
Future Climate ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Future Climate Change ◽  
Slope Aspect ◽  
Climate Change Scenarios ◽  
The Future ◽  
Suitable Area ◽  
North Sumatra

This study aims to assess the impact of climate change on the distribution of Styrax sumatrana in North Sumatra by applying the maximum entropy (MaxEnt) model with biophysical factors (elevation, slope, aspect, and soil), climatic factors (19 bioclimate data sets for 2050 and 2070), and anthropogenic factors (land use land cover (LULC) changes in 2050 and 2070). The future climate data retrieved and used are the output of four climate models from Coupled Model Intercomparison Project Phase 5 (CMIP5), namely, the CCSM4, CNRM-CM5, MIROC5, and MRI-CGCM3 models, under the Representative Concentration Pathways (RCPs) 4.5 and 8.5 scenarios. The MaxEnt modelling results showed the importance of the mean temperature of the coldest quarter and the LULC variables. Styrax sumatrana rely on environmental conditions with air temperatures ranging from 13 to 19 °C. The potentially suitable land types for Styrax sumatrana are shrubs, gardens, and forests. The future predictions show that the suitable habitat for Styrax sumatrana is predicted to decrease to 3.87% in 2050 and to 3.54% in 2070 under the RCP4.5 scenario. Under the RCP8.5 scenario, the suitable area is predicted to decrease to 3.04% in 2050 and to 1.36% in 2070, respectively. The degradation of the suitable area is mainly due to increasing temperature and deforestation in future predictions. The modelling results illustrate that the suitable habitats of Styrax sumatrana are likely to be reduced under future climate change scenarios or lost in 2070 under the RCP8.5 scenario. The potential future extinction of this species should alert authorities to formulate conservation strategies. Results also demonstrated key variables that should be used for formulating ex situ conservation strategies.

scholarly journals Response of the Carbon Budget of Global Forest Ecosystems to Future Climate Change

2020 ◽  
Author(s):  
Hongfei Xie ◽  
JUNFANG ZHAO ◽  
Jianyong Ma ◽  
Weixiong Yan
Keyword(s):  
Climate Change ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Carbon Budget ◽  
Forest Ecosystems ◽  
Carbon Sink ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
The Future

Abstract Background At present, global warming is an indisputable fact, and more and more attention has been paid to the impacts of climate warming on global ecological environments. Forests play increasing significant roles in regulating global carbon balance and mitigating climate change. Therefore, to understand the response mechanisms of the carbon budget of global forest ecosystems to future climate change, an improved version of the FORest ecosystem Carbon budget model for CHiNa (FORCCHN) and future Representative Concentration Pathway (RCP) scenario RCP4.5 and RCP8.5 were applied in this study.Results The global forest ecosystems will play a major role in the carbon sink under the future two climate change scenarios. In particular, the average carbon budget (namely the Net Ecosystem Productivity, NEP) of global forest ecosystems under RCP4.5 scenario was estimated to be 0.017 kg(C)·m− 2·yr− 1 from 2006 to 2100. The future carbon sink areas of global forest ecosystems will increase significantly. Under RCP4.5 and RCP8.5 climate scenarios, the carbon sink areas of global forest ecosystems during 2026–2100 would be significantly higher than those in 2006–2025, with increases of 83.16–87.26% and 23.53–29.70%, respectively. The impacts of future climate change on NEP of global forest ecosystems will significantly vary between different regions. The NEP of forests will be enhanced in the northern hemisphere and significantly weakened in the southern hemisphere under the future two climate change scenarios. The carbon sink regions of global forests will be mainly distributed in the middle and high latitudes of the northern hemisphere. In particular, the forests'NEP in northeastern and central Asia, northern Europe and western North America will increase by 40%~80%. However, the NEP of forests will decrease by 20%~40% in the most regions of the southern hemisphere. In northern South America and central Africa, the forests' NEP will be reduced by more than 40%.Conclusions The global forest ecosystems will play a major role in the carbon sink under the future two climate change scenarios. However, the NEP of forests will be enhanced in the northern hemisphere and significantly weakened in the southern hemisphere. In the future, in some areas of southern hemisphere, where the forests' NEP was predicted to be reduced, some measures for improving forest carbon sink, such as strengthening forest tending, enforcing prohibiting deforestation laws and scientific forest management, and so on, should be implemented to ensure immediate mitigation and adaptation to climate change.

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