scholarly journals Two-phased Mass Rarity and Extinction in Land Plants During the End-Triassic Climate Crisis

2021 ◽  
Vol 9 ◽  
Author(s):  
Sofie Lindström
Keyword(s):  
Sea Level ◽  
Large Scale ◽  
Rare Plants ◽  
Land Plants ◽  
Future Climate Change ◽  
Pollen Record ◽  
Coastal Lowland ◽  
Climate Crisis ◽  
The Impact ◽  
Rising Sea Level

Greenhouse gas emissions from large-scale volcanism in the Central Atlantic Magmatic Province is considered to have caused the end-Triassic mass extinction (201.5 million years ago), but the impact on land plants has been debated. Here, abundance changes in spores and pollen record the devastating effects this volcanic induced climate crisis had on coastal and near-coastal lowland mire vegetation around the European epicontinental sea and the European Tethys margin. Combined stress from rising air temperatures and changing climate at the onset of the crisis was exacerbated by a rapidly rising sea-level resulting in fragmentation and destruction of coastal and near-coastal lowland mire habitats, causing mass rarity and extinctions primarily in gymnosperm trees and shrubs adapted to these environments. The devastation of these habitats was further amplified by a subsequent sea-level fall leaving pioneering opportunists and herbaceous survivors to colonize disturbed areas in an environment stressed by increased wildfire activity and enhanced soil erosion. The pioneering flora was severely decimated in a second mass rarity phase and ultimately extirpated. The second mass rarity phase occurred just prior to and at the onset of a prominent negative excursion in δ13Corg. A subsequent sea-level rise appears to have restored some of the near-coastal mire habitats allowing some of plants to recover. The supraregional mass rarity during the end-Triassic crisis affected both previously dominant as well as rare plants and this resonates with ongoing and future climate change and attests to the vulnerability of coastal and lowland vegetation, especially rare plant species, to climatic and environmental disturbances, where rising sea-level threatens entire ecosystems.

scholarly journals Impact of climate change on groundwater point discharge: backflooding of karstic springs (Loiret, France)

2011 ◽  
Vol 8 (2) ◽  
pp. 2235-2262
Author(s):  
E. Joigneaux ◽  
P. Albéric ◽  
H. Pauwels ◽  
C. Pagé ◽  
L. Terray ◽  
...  
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Groundwater Quality ◽  
Atmospheric Circulation ◽  
Large Scale ◽  
Weather Type ◽  
Future Climate Change ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Large Scale Atmospheric Circulation

Abstract. Under certain hydrological conditions it is possible for spring flow in karst systems to be reversed. When this occurs, the resulting invasion by surface water, i.e. the backflooding, represents a serious threat to groundwater quality because the surface water could well be contaminated. Here we examine the possible impact of future climate change on the occurrences of backflooding in a specific karst system, having first established the occurrence of such events in the selected study area over the past 40 yr. It would appear that backflooding has been more frequent since the 1980s, and that it is apparently linked to river flow variability on the pluri-annual scale. The avenue that we adopt here for studying recent and future variations of these events is based on a downscaling algorithm relating large-scale atmospheric circulation to local precipitation spatial patterns. The large-scale atmospheric circulation is viewed as a set of quasi-stationary and recurrent states, called weather types, and its variability as the transition between them. Based on a set of climate model projections, simulated changes in weather-type occurrence for the end of the century suggests that backflooding events can be expected to decrease in 2075–2099. If such is the case, then the potential risk for groundwater quality in the area will be greatly reduced compared to the current situation. Finally, our results also show the potential interest of the weather-type based downscaling approach for examining the impact of climate change on hydrological systems.

Vulnerability of coastal areas to increased aquifer saturation due to climate change

2021 ◽  
Author(s):  
Alexandre Gauvain ◽  
Ronan Abhervé ◽  
Jean-Raynald de Dreuzy ◽  
Luc Aquilina ◽  
Frédéric Gresselin
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Large Scale ◽  
Regional Scale ◽  
Drainage System ◽  
Hydrological Regime ◽  
Coastal Areas ◽  
Western Coast ◽  
Study Sites ◽  
The Impact

<p>Like in other relatively flat coastal areas, flooding by aquifer overflow is a recurring problem on the western coast of Normandy (France). Threats are expected to be enhanced by the rise of the sea level and to have critical consequences on the future development and management of the territory. The delineation of the increased saturation areas is a required step to assess the impact of climate change locally. Preliminary models showed that vulnerability does not result only from the sea side but also from the continental side through the modifications of the hydrological regime.</p><p>We investigate the processes controlling these coastal flooding phenomena by using hydrogeological models calibrated at large scale with an innovative method reproducing the hydrographic network. Reference study sites selected for their proven sensitivity to flooding have been used to validate the methodology and determine the influence of the different geomorphological configurations frequently encountered along the coastal line.</p><p>Hydrogeological models show that the rise of the sea level induces an irregular increase in coastal aquifer saturations extending up to several kilometers inland. Back-littoral channels traditionally used as a large-scale drainage system against high tides limits the propagation of aquifer saturation upstream, provided that channels are not dominantly under maritime influence. High seepage fed by increased recharge occurring in climatic extremes may extend the vulnerable areas and further limit the effectiveness of the drainage system. Local configurations are investigated to categorize the influence of the local geological and geomorphological structures and upscale it at the regional scale.</p>

scholarly journals Understanding Future Water Challenges in a Highly Regulated Indian River Basin—Modelling the Impact of Climate Change on the Hydrology of the Upper Narmada

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1762 ◽  
Author(s):  
Nathan Rickards ◽  
Thomas Thomas ◽  
Alexandra Kaelin ◽  
Helen Houghton-Carr ◽  
Sharad K. Jain ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Basin ◽  
Large Scale ◽  
Monsoon Season ◽  
Future Climate Change ◽  
Impact Of Climate Change ◽  
Global Circulation Models ◽  
The Impact ◽  
Availability Assessment

The Narmada river basin is a highly regulated catchment in central India, supporting a population of over 16 million people. In such extensively modified hydrological systems, the influence of anthropogenic alterations is often underrepresented or excluded entirely by large-scale hydrological models. The Global Water Availability Assessment (GWAVA) model is applied to the Upper Narmada, with all major dams, water abstractions and irrigation command areas included, which allows for the development of a holistic methodology for the assessment of water resources in the basin. The model is driven with 17 Global Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to assess the impact of climate change on water resources in the basin for the period 2031–2060. The study finds that the hydrological regime within the basin is likely to intensify over the next half-century as a result of future climate change, causing long-term increases in monsoon season flow across the Upper Narmada. Climate is expected to have little impact on dry season flows, in comparison to water demand intensification over the same period, which may lead to increased water stress in parts of the basin.

scholarly journals Large-Scale Mode Impacts on the Sea Level over the Red Sea and Gulf of Aden

2019 ◽  
Vol 11 (19) ◽  
pp. 2224 ◽  
Author(s):  
Kamal A. Alawad ◽  
Abdullah M. Al-Subhi ◽  
Mohammed A. Alsaafani ◽  
Turki M. Alraddadi ◽  
Monica Ionita ◽  
...  
Keyword(s):  
Sea Level ◽  
Red Sea ◽  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Southern Oscillation ◽  
Positive Phase ◽  
El Nino Southern Oscillation ◽  
Gulf Of Aden ◽  
The Impact

Falling between seasonal cycle variability and the impact of local drivers, the sea level in the Red Sea and Gulf of Aden has been given less consideration, especially with large-scale modes. With multiple decades of satellite altimetry observations combined with good spatial resolution, the time has come for diagnosis of the impact of large-scale modes on the sea level in those important semi-enclosed basins. While the annual cycle of sea level appeared as a dominant cycle using spectral analysis, the semi-annual one was also found, although much weaker. The first empirical orthogonal function mode explained, on average, about 65% of the total variance throughout the seasons, while their principal components clearly captured the strong La Niña event (1999–2001) in all seasons. The sea level showed a strong positive relation with positive phase El Niño Southern Oscillation in all seasons and a strong negative relation with East Atlantic/West Russia during winter and spring over the study period (1993–2017). We show that the unusually stronger easterly winds that are displaced north of the equator generate an upwelling area near the Sumatra coast and they drive both warm surface and deep-water masses toward the West Indian Ocean and Arabian Sea, rising sea level over the Red Sea and Gulf of Aden. This process could explain the increase of sea level in the basin during the positive phase of El Niño Southern Oscillation events.

scholarly journals Impact of climate change on groundwater point discharge: backflooding of karstic springs (Loiret, France)

2011 ◽  
Vol 15 (8) ◽  
pp. 2459-2470 ◽  
Author(s):  
E. Joigneaux ◽  
P. Albéric ◽  
H. Pauwels ◽  
C. Pagé ◽  
L. Terray ◽  
...  
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Groundwater Quality ◽  
Atmospheric Circulation ◽  
Large Scale ◽  
Weather Type ◽  
Future Climate Change ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Large Scale Atmospheric Circulation

Abstract. Under certain hydrological conditions it is possible for spring flow in karst systems to be reversed. When this occurs, the resulting invasion by surface water, i.e. the backflooding, represents a serious threat to groundwater quality because the surface water could well be contaminated. Here we examine the possible impact of future climate change on the occurrences of backflooding in a specific karst system, having first established the occurrence of such events in the selected study area over the past 40 years. It would appear that backflooding has been more frequent since the 1980s, and that it is apparently linked to river flow variability on the pluri-annual scale. The avenue that we adopt here for studying recent and future variations of these events is based on a downscaling algorithm relating large-scale atmospheric circulation to local precipitation spatial patterns. The large-scale atmospheric circulation is viewed as a set of quasi-stationary and recurrent states, called weather types, and its variability as the transition between them. Based on a set of climate model projections, simulated changes in weather-type occurrence for the end of the century suggests that backflooding events can be expected to decrease in 2075–2099. If such is the case, then the potential risk for groundwater quality in the area will be greatly reduced compared to the current situation. Finally, our results also show the potential interest of the weather-type based downscaling approach for examining the impact of climate change on hydrological systems.

What happened in 1953? The Big Flood in the Netherlands in retrospect

2005 ◽  
Vol 363 (1831) ◽  
pp. 1271-1291 ◽  
Author(s):  
Herman Gerritsen
Keyword(s):  
The Netherlands ◽  
Sea Level ◽  
Large Scale ◽  
Land Reclamation ◽  
Spring Tide ◽  
Water Levels ◽  
The North ◽  
Human Stress ◽  
The Uk ◽  
The Impact

During the weekend of Saturday 31 January to Sunday 1 February 1953, a storm tide raged across the northwest European shelf and flooded the low-lying coastal areas of the countries around the North Sea. The peak high waters occurred during the night and the storm surprised many people in their sleep. The resulting disaster in terms of loss of life and damage to infrastructure was enormous. In the Netherlands, 1836 people fell victim to the flood; in the UK and Belgium, the casualities were 307 and 22, respectively. The large number of fatalities in the Netherlands was related to the fact that much of the affected area is below sea-level. This paper focuses on the case of the Netherlands. It discusses the history of land reclamation, and the fact that living in low-lying areas protected by dykes, often below sea-level, is an accepted fact of life in the Netherlands. The historical approach to dyke maintenance is then outlined, and the state of the dykes in the early twentieth century and after the war is discussed. The characteristics of the storm and the flood are discussed, along with people's experiences of the first hours and days following the flood. The impact of this human stress has often been lasting—many survivors continue to live with daily memories of the flood. Attention is given to the large-scale rescue and relief efforts, the closure of the dykes during the following nine months and the concept of the Delta Plan, designed to prevent such a large-scale disaster ever happening again. Although the 1953 storm was indeed a low probability event leading to very high storm-induced water-levels, and occurred in combination with spring tide, several arguments are presented that explain why this flood turned into a disaster of such a large scale. Equally, the question is raised whether the disaster could have been prevented. The paper concludes by noting the importance of awareness and preparedness in order to prevent a future storm threat of this scale turning into a disaster of the scope of the Big Flood of 1953.

scholarly journals Assessing population exposure to coastal flooding due to sea level rise

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mathew E. Hauer ◽  
Dean Hardy ◽  
Scott A. Kulp ◽  
Valerie Mueller ◽  
David J. Wrathall ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Future Climate Change ◽  
Population Exposure ◽  
Temporal Heterogeneity ◽  
Annual Probability ◽  
Spatial And Temporal Heterogeneity ◽  
Differential Exposure ◽  
Spatio Temporal ◽  
The Impact

AbstractThe exposure of populations to sea-level rise (SLR) is a leading indicator assessing the impact of future climate change on coastal regions. SLR exposes coastal populations to a spectrum of impacts with broad spatial and temporal heterogeneity, but exposure assessments often narrowly define the spatial zone of flooding. Here we show how choice of zone results in differential exposure estimates across space and time. Further, we apply a spatio-temporal flood-modeling approach that integrates across these spatial zones to assess the annual probability of population exposure. We apply our model to the coastal United States to demonstrate a more robust assessment of population exposure to flooding from SLR in any given year. Our results suggest that more explicit decisions regarding spatial zone (and associated temporal implication) will improve adaptation planning and policies by indicating the relative chance and magnitude of coastal populations to be affected by future SLR.

scholarly journals RISING SEA LEVEL: LEGAL CONSEQUENCES ON THE SHIFTING OF COASTAL STATE BASELINE

2019 ◽  
Vol 3 (2) ◽  
pp. 142-160
Author(s):  
Ratu Gita Narnina W ◽  
Arie Afriansyah
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Sea Water ◽  
Intergovernmental Panel ◽  
Assessment Report ◽  
Coastal State ◽  
Change Climate ◽  
New Phenomena ◽  
The Impact ◽  
Rising Sea Level

AbstractBaseline is a line drawn from the coastal configuration features, which is very important because the drawing of a baseline allows a coastal State to claim its own maritime zone as measured from said line. However, this concept of baseline currently faced new phenomena called the sea-level rise caused by the climate change. Climate change is caused by the accumulation of greenhouse gas emissions in the atmosphere and causing the earth's surface temperature and sea surface temperatures to increase causing the melting of ice and glaciers. Based on survey data Fifth Assessment Report conducted by the Intergovernmental Panel on Climate Change (IPCC), it is said that in 2100 the rise of sea water will reach 0.52m to 0.98m. In this regard, the rise of seawater brings a legal implication of the possibility in a shift of the baseline due to the inundation of the coastline used as a place to draw the baseline itself, resulting in the possibility of States losing juridical claims in its maritime zone. Coastal States must now begin to have awareness regarding the impacts caused by rising sea level in order to anticipate and reduce the impact of rising sea level. Keywords: Baseline, Climate Change, Maritime Zone, Rising-Sea Level.   AbstrakGaris pangkal merupakan garis yang ditarik dari fitur-fitur konfigurasi pantai yang sangat penting karena penarikan garis pangkal memungkinkan suatu negara untuk mengklaim zona maritim miliknya, diukur dari garis tersebut. Akan tetapi, garis pangkal ini kini menghadapi kendala yaitu fenomena kenaikan air laut yang disebabkan oleh perubahan iklim. Perubahan iklim disebabkan karena menumpuknya gas emisi rumah kaca dan menyebabkan suhu permukaan bumi dan suhu permukaan air laut meningkat sehingga menyebabkan mencairnya es dan gletser di bumi. Dari kejadian tersebut lahirlah fenomena yang dinamakan kenaikan air laut. Berdasarkan data dari survei yang dilakukan oleh Intergovernmental Panel on Climate Change (IPCC) dalam Fifth Assessment Report, dikatakan bahwa pada tahun 2100 kenaikan air laut akan mencapai 0,52m hingga 0,98m. Dalam hal ini, kenaikan air laut akan membawa implikasi hukum terkait kemungkinan adanya pergeseran pada garis pangkal dikarenakan tergenangnya wilayah garis pantai yang digunakan sebagai tempat untuk menarik garis pangkal, sehingga besar kemungkinan terjadinya hilangnya klaim yuridis pada zona maritim tertentu. Negara-negara pantai sekarang sudah harus menyadari dampak yang disebabkan oleh kenaikan air laut ini sehingga kemudian dapat mengantisipasi dampak dari kenaikan air laut. Kata Kunci: Garis Pangkal, Kenaikan Air Laut, Perubahan Iklim, Zona Maritim.

scholarly journals Assessing the Impacts of Rising Sea Level on Coastal Morpho-Dynamics with Automated High-Frequency Shoreline Mapping Using Multi-Sensor Optical Satellites

2021 ◽  
Vol 13 (18) ◽  
pp. 3587
Author(s):  
Naheem Adebisi ◽  
Abdul-Lateef Balogun ◽  
Masoud Mahdianpari ◽  
Teh Hee Min
Keyword(s):  
Sea Level ◽  
High Frequency ◽  
Tide Gauge ◽  
Anthropogenic Activities ◽  
Sandy Beaches ◽  
Google Earth ◽  
Data Sampling ◽  
Shoreline Displacement ◽  
The Impact ◽  
Rising Sea Level

Rising sea level is generally assumed and widely reported to be the significant driver of coastal erosion of most low-lying sandy beaches globally. However, there is limited data-driven evidence of this relationship due to the challenges in quantifying shoreline dynamics at the same temporal scale as sea-level records. Using a Google Earth Engine (GEE)-enabled Python toolkit, this study conducted shoreline dynamic analysis using high-frequency data sampling to analyze the impact of sea-level rise on the Malaysian coastline between 1993 and 2019. Instantaneous shorelines were extracted from a test site on Teluk Nipah Island and 21 tide gauge sites from the combined Landsat 5–8 and Sentinel 2 images using an automated shoreline-detection method, which was based on supervised image classification and sub-pixel border segmentation. The results indicated that rising sea level is contributing to shoreline erosion in the study area, but is not the only driver of shoreline displacement. The impacts of high population density, anthropogenic activities, and longshore sediment transportation on shoreline displacement were observed in some of the beaches. The conclusions of this study highlight that the synergistic use of multi-sensor remote-sensing data improves temporal resolution of shoreline detection, removes short-term variability, and reduces uncertainties in satellite-derived shoreline analysis compared to the low-frequency sampling approach.

Projections and uncertainties of sandy beach loss due to sea level rise at the European scale

2020 ◽  
Author(s):  
Panagiotis Athanasiou ◽  
Ap van Dongeren ◽  
Alessio Giardino ◽  
Michalis Vousdoukas ◽  
Roshanka Ranasinghe ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Sea Level Rise ◽  
Sea Level ◽  
Input Data ◽  
Large Scale ◽  
Satellite Images ◽  
Sandy Beaches ◽  
Land Loss ◽  
Shoreline Retreat ◽  
The Impact

<p>Climate change driven sea level rise (SLR) is expected to rise with even higher rates during the second half of the present century. This will exacerbate shoreline retreat of sandy coasts, which comprise one third of the global coastline. Sandy coasts have high touristic and ecological value while they are the first level of defense against storms, protecting valuable infrastructures and buildings. Therefore, in recent years, large scale risk assessments are considered useful tools for the guidance of policy makers to identify high risk hotspots.  Reliable input data at this scale are required in order to make useful estimations. Among others, crucial data to assess the impact of SLR on shoreline retreat are the detection of different coastal types and, in particular, of sandy erodible beaches, and the nearshore slope, which is usually assumed to be uniform.</p><p>The important issue of input data uncertainty and spatial variation and consequent impact on predictions has been so far ignored in most large-scale studies. Estimates of shoreline retreat are however very sensitive to the variation in these inputs. Here we quantify SLR driven potential shoreline retreat and consequent land loss in Europe during the 21st century by employing different combinations of geophysical datasets for (a) the location of sandy beaches and (b) their nearshore slopes. For the estimation of the shoreline retreat, the Bruun Rule is used, which offers a suitable approach for a first approximation of erosion impacts at large scales. Sea level rise projections associated with the moderate-emission- mitigation-policy (RCP4.5) and the high-end, business-as-usual scenario (RCP8.5) are used as boundary conditions. The location of sandy beaches is determined from two different datasets. One is based on manual visual estimation from satellite images and the other on automatic detection from satellite images using machine learning techniques. For nearshore slopes we apply the commonly used constant slope assumption of 1:100 and a newly produced global dataset which captures the spatial variation of coastal slopes.</p><p>With this approach, we create four different combinations for each SLR scenario, for which we estimate and compare land loss at EU, country and NUTS3 regional level. We find that the land loss estimations for each combination can differ significantly, especially at the regional and local level. At the European or country level, even though differences in total land loss projections can be significant, they can be concealed by the spatial aggregation of the results. Using data-based spatially-varying nearshore slope data, a European averaged median shoreline retreat of 97 m (54 m) is projected under RCP 8.5 (4.5) by year 2100, relative to the baseline year 2010. This retreat would translate to 2,500 km2 (1,400 km2) of land loss. A variance-based global sensitivity analysis indicates that the uncertainty associated with the choice of geophysical datasets can contribute up to 45% (26%) of the variance in land loss projections for Europe by 2050 (2100).</p>

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