scholarly journals Rapid climate change results in long-lasting spatial homogenization of phylogenetic diversity

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Bianca Saladin ◽  
Loïc Pellissier ◽  
Catherine H. Graham ◽  
Michael P. Nobis ◽  
Nicolas Salamin ◽  
...  
Keyword(s):  
Climate Change ◽  
Spatial Variability ◽  
Phylogenetic Diversity ◽  
Climate Changes ◽  
Northern Europe ◽  
Seed Plants ◽  
Climate Oscillations ◽  
The Past ◽  
Rapid Climate Change ◽  
Insight Into

Abstract Scientific understanding of biodiversity dynamics, resulting from past climate oscillations and projections of future changes in biodiversity, has advanced over the past decade. Little is known about how these responses, past or future, are spatially connected. Analyzing the spatial variability in biodiversity provides insight into how climate change affects the accumulation of diversity across space. Here, we evaluate the spatial variation of phylogenetic diversity of European seed plants among neighboring sites and assess the effects of past rapid climate changes during the Quaternary on these patterns. Our work shows a marked homogenization in phylogenetic diversity across Central and Northern Europe linked to high climate change velocity and large distances to refugia. Our results suggest that the future projected loss in evolutionary heritage may be even more dramatic, as homogenization in response to rapid climate change has occurred among sites across large landscapes, leaving a legacy that has lasted for millennia.

scholarly journals Late Holocene summer temperatures in the central Andes reconstructed from the sediments of high-elevation Laguna Chepical, Chile (32° S)

2013 ◽  
Vol 9 (3) ◽  
pp. 2277-2308
Author(s):  
R. de Jong ◽  
L. von Gunten ◽  
A. Maldonado ◽  
M. Grosjean
Keyword(s):  
Climate Change ◽  
South America ◽  
Temperature Reconstruction ◽  
High Elevation ◽  
Ice Age ◽  
Central Chile ◽  
Southern South America ◽  
Calibration Period ◽  
The Past ◽  
Insight Into

Abstract. High-resolution reconstructions of climate variability that cover the past millennia are necessary to improve the understanding of natural and anthropogenic climate change across the globe. Although numerous records are available for the mid- and high-latitudes of the Northern Hemisphere, global assessments are still compromised by the scarcity of data from the Southern Hemisphere. This is particularly the case for the tropical and subtropical areas. In addition, high elevation sites in the South American Andes may provide insight into the vertical structure of climate change in the mid-troposphere. This study presents a 3000 yr long austral summer (November to February) temperature reconstruction derived from the 210Pb and 14C dated organic sediments of Laguna Chepical (32°16' S/70°30' W, 3050 m a.s.l.), a high-elevation glacial lake in the subtropical Andes of central Chile. Scanning reflectance spectroscopy in the visible light range provided the spectral index R570/R630, which reflects the clay mineral content in lake sediments. For the calibration period (AD 1901–2006), the R570/R630 data were regressed against monthly meteorological reanalysis data, showing that this proxy was strongly and significantly correlated with mean summer (NDJF) temperatures (R3yr = −0.63, padj = 0.01). This calibration model was used to make a quantitative temperature reconstruction back to 1000 BC. The reconstruction (with a model error RMSEPboot of 0.33 °C) shows that the warmest decades of the past 3000 yr occurred during the calibration period. The 19th century (end of the Little Ice Age (LIA)) was cool. The prominent warmth reconstructed for the 18th century, which was also observed in other records from this area, seems systematic for subtropical and southern South America but remains difficult to explain. Except for this warm period, the LIA was generally characterized by cool summers. Back to AD 1400, the results from this study compare remarkably well to low altitude records from the Chilean Central Valley and Southern South America. However, the reconstruction from Laguna Chepical does not show a warm Medieval Climate Anomaly during the 12–13th century, which is consistent with records from tropical South America. The Chepical record also indicates substantial cooling prior to 800 BC. This coincides with well-known regional as well as global glacier advances which have been attributed to a grand solar minimum. This study thus provides insight into the climatic drivers and temperature patterns in a region for which currently very few data are available. It also shows that since ca AD 1400, long term temperature patterns were generally similar at low and high altitudes in central Chile.

scholarly journals Probability Assessment of Slope Instability in Seasonally Cold Regions under Climate Change

2021 ◽  
Author(s):  
Yulong Zhu ◽  
Tatsuya Ishikawa ◽  
Tomohito J. Yamada ◽  
Srikrishnan Siva Subramanian
Keyword(s):  
Climate Change ◽  
Slope Stability ◽  
Water Content ◽  
Air Temperature ◽  
Climate Changes ◽  
Slope Instability ◽  
Climate Factors ◽  
Cold Regions ◽  
The Past ◽  
Assessment Approach

Abstract This paper proposes an effective approach for evaluating the influences of climate change on slope stability in seasonally cold regions. Firstly, to semi-quantitatively assess the effects of climate changes on the uncertainty of climate factors, this study analyzes the trend of the two main climate factors (precipitation and air temperature) by the regression analysis using the meteorological monitoring data of the past 120 years in different scales (e.g., world, country (Japan), and city (Sapporo)), and the meteorological simulation data obtained by downscaling the outputs of three different regional atmospheric models (RAMs) with lateral boundary conditions from three different general circulation models (GCMs). Next, to discuss the effects of different climate factors (air temperature, precipitation, etc.) and to determine the key climate factors on the slope instability, an assessment approach for evaluating the effects of climate changes on slope instability is proposed through the water content simulation and slope stability analysis using a 2-dimensional (2D) finite element method (FEM) homogeneous conceptual slope model with considering freeze-thaw action. Finally, to check the effectiveness of the above assessment approach, assessment of instability of an actual highway embankment slope with the local layer geometry is done by applying the past and predicted future climate data. The results indicate that affected by global warming, the air temperature rise in some cold cities is more serious. The predicted future weather will affect the shape of the normal density curve (NDC) of the distribution of slope failures in one year. The climate changes (especially the increase in precipitation) in the future will increase the infiltration during the Spring season. It will lengthen the time that the highway slope is in an unstable state due to high volumetric water content, thereby enhancing the instability of the slopes and threatening more slopes in the future.

scholarly journals Climate Change Disclosure: An Empirical Study On The Oil & Gas Companies Listed on Toronto Stock Exchange (TSX)

2021 ◽  
Author(s):  
Amirus Salat
Keyword(s):  
Climate Change ◽  
Climate Changes ◽  
Stock Exchange ◽  
Environmental Accounting ◽  
Point Of View ◽  
Toronto Stock Exchange ◽  
Current State ◽  
Oil Gas ◽  
The Relationship ◽  
Insight Into

This research investigates the current state of disclosure on the climate change issues of the oil & gas companies listed on the Toronto Stock Exchange (TSX). Using a sample of 58 companies, I conduct a content analysis of their publicly available documents and develop a disclosure index. The study demonstrates that there is a significant association between the level of disclosure of climate change issues (disclosures index) and the board of director’s effectiveness (measured by Board Shareholder Confidence Index) for Canadian oil & gas companies. This study also explores the association between firms’ value and the level of climate change disclosure. The empirical evidence indicates that the investors take the extent of disclosures on climate changes into considerations when they assess the market value of the firms. This study contributes to environmental accounting literature because it examines the relationship between climate change disclosures and corporate governance. From a practical point of view, the outcome of this analysis will help Canadian Securities Administrator (CSA) to have insight into climate change disclosures practices and provides a frame of references for developing related disclosures requirement.

Global climate changes during the most recent two millennia

2020 ◽  
Author(s):  
Sarah S. Eggleston ◽  
Oliver Bothe ◽  
Nerilie Abram ◽  
Bronwen Konecky ◽  
Hans Linderholm ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Changes ◽  
Climate Models ◽  
Global Climate ◽  
Climate Science ◽  
High Temporal Resolution ◽  
Past Climate ◽  
Global Climate Changes ◽  
The Past ◽  
Earth’S Climate

<p>The past two thousand years is a key interval for climate science because this period encompasses both the era of human-induced global warming and a much longer interval when changes in Earth's climate were governed principally by natural drivers. This earlier 'pre-industrial' period is particularly important for two reasons. Firstly, we now have a growing number of well-dated, climate sensitive proxy data with high temporal resolution that spans the full period. Secondly, the pre-industrial climate provides context for present-day climate change, sets real-world targets against which to evaluate the performance of climate models, and allows us to address other questions of Earth sciences that cannot be answered using only a century and a half of observational data. </p><p>Here, we first provide several perspectives on the concept of a 'pre-industrial climate'. Then, we highlight the activities of the PAGES 2k Network, an international collaborative effort focused on global climate change during the past two thousand years. We highlight those aspects of pre-industrial conditions (including both past climate changes and past climate drivers) that are not yet well constrained, and suggest potential areas for research during this period that would be relevant to the evolution of Earth's future climate.</p>

Central European vegetation and climate dynamics during the past 130 ka at Füramoos, SW Germany

2020 ◽  
Author(s):  
Oliver Kern ◽  
Frederik Allstädt ◽  
Andreas Koutsodendris ◽  
Bertil Mächtle ◽  
Gerd Schukraft ◽  
...  
Keyword(s):  
Climate Change ◽  
Boreal Forests ◽  
Pollen Record ◽  
Short Term ◽  
Central European ◽  
The Past ◽  
The Alps ◽  
Mis 5E ◽  
Insight Into ◽  
The Last Glacial

<p>To better understand the response of Central European vegetation to rapid climate change during the late Quaternary, we have revisited the Füramoos peat bog in southwestern Germany. Located between two moraine ridges of Rissian age and comprising a near-complete sedimentary sequence from late Marine Isotope Stage (MIS) 6 to 1, this peat bog represents the longest continuous pollen record from the last glacial-interglacial cycle north of the Alps. The Füramoos site has been in the focus of several palynological studies in the past, showing that it presents an excellent archive to study the impact of Dansgaard-Oeschger (D-O) events on the Central European ecosystems (e.g., Müller et al., 2003). However, these previous studies were only of limited temporal resolution, which has yet precluded detailed insight into the ecosystem response to short-term climate change. We present a new, highly resolved pollen record (temporal resolution: 80–200 yrs) and XRF core scanning data from Füramoos spanning the past ~130 ka based on two new drill cores that consist of peat and lake sediments (Kern et al., 2019).</p><p>Our results show that closed temperate forests thrived at Füramoos during full interglacials characterized by <em>Alnus</em>, <em>Corylus</em>, <em>Quercus</em>, and <em>Ulmus</em>. The major difference between the past two interglacials is that <em>Fagus</em> dominates during MIS 1 whereas it is mostly absent during MIS 5e. During MIS 5, the vegetation evolved from closed temperate (MIS 5e) to boreal forests (dominated by <em>Betula</em>, <em>Picea</em>, and <em>Pinus</em>; MIS 5d–5a). The youngest part of the last interglacial (MIS 5d–5a) is marked by six distinct forests contractions (decreases in arboreal pollen by ~30–50%) before the establishment of a steppe vegetation that prevailed throughout the Last Glacial (MIS 2–4). In addition, seven transient increases in tree-pollen percentages document the expansion of boreal forests during MIS 2–4; they are associated with synchronous increases of Si, Ti, K and Fe contents as evidenced in XRF data.</p><p>We attribute the forest contractions during MIS 5d–5a to the cooling events C19–C24 known from marine records in the North Atlantic and terrestrial records from southern Europe. Moreover, the forest expansions during MIS 2–4 are associated with warm and moist conditions occurring during D-O events 7–12, and 14. In contrast, D-O events 13 and 15–19 don’t leave an imprint on the vegetation although their presence is clearly documented in the XRF data. Our findings emphasize that the sediments from Füramoos are exceptionally well suited to reconstruct ecosystem dynamics in Central Europe yielding unprecedented insight into the vegetation response to short-term climatic forcing north of the Alps during the past 130 kyrs.</p><p> </p><p>Müller, U.C., Pross, J., Bibus, E., 2003. Vegetation response to rapid climate change in Central Europe during the past 140,000 yr based on evidence from the Füramoos pollen record. <em>Quaternary Research</em> 59, 235–245.</p><p>Kern, O.A., Koutsodendris, A., Mächtle, B., et al., 2019. X-ray fluorescence core scanning yields reliable semiquantitative data on the elemental composition of peat and organic-rich lake sediments. <em>Science of the Total Environment</em> 697, 134110.</p>

Phylogeny and biogeography of the mite harvestmen (Arachnida : Opiliones : Cyphophthalmi) of Queensland, Australia, with a description of six new species from the rainforests of the Wet Tropics

2015 ◽  
Vol 29 (1) ◽  
pp. 37 ◽  
Author(s):  
Sarah L. Boyer ◽  
Caitlin M. Baker ◽  
Zachary R. Popkin-Hall ◽  
Domokos I. Laukó ◽  
Hannah A. Wiesner ◽  
...  
Keyword(s):  
Climate Change ◽  
New Species ◽  
Molecular Data ◽  
Historical Biogeography ◽  
Phylogenetic Study ◽  
The Past ◽  
Wet Tropics ◽  
Morphological And Molecular Data ◽  
Insight Into

The Wet Tropics of Queensland, Australia, represent the largest remaining fragment of vast rainforests that once covered the entire continent. Over the past few decades the Wet Tropics bioregion has received much attention from biologists interested in the effect of climate change on diversity and distribution of rainforest animals. However, most such studies have focused on vertebrates, and despite considerable interest in the biota of the area, the diversity of many of Wet Tropics invertebrate taxa remains poorly known. Here we describe six new species of mite harvestman from the area, identified using a combination of morphological and molecular data. Our study represents the first detailed phylogenetic study of the genus Austropurcellia, and provides insight into the historical biogeography of these dispersal-limited arachnids.

scholarly journals Climate Change Disclosure: An Empirical Study On The Oil & Gas Companies Listed on Toronto Stock Exchange (TSX)

2021 ◽  
Author(s):  
Amirus Salat
Keyword(s):  
Climate Change ◽  
Climate Changes ◽  
Stock Exchange ◽  
Environmental Accounting ◽  
Point Of View ◽  
Toronto Stock Exchange ◽  
Current State ◽  
Oil Gas ◽  
The Relationship ◽  
Insight Into

This research investigates the current state of disclosure on the climate change issues of the oil & gas companies listed on the Toronto Stock Exchange (TSX). Using a sample of 58 companies, I conduct a content analysis of their publicly available documents and develop a disclosure index. The study demonstrates that there is a significant association between the level of disclosure of climate change issues (disclosures index) and the board of director’s effectiveness (measured by Board Shareholder Confidence Index) for Canadian oil & gas companies. This study also explores the association between firms’ value and the level of climate change disclosure. The empirical evidence indicates that the investors take the extent of disclosures on climate changes into considerations when they assess the market value of the firms. This study contributes to environmental accounting literature because it examines the relationship between climate change disclosures and corporate governance. From a practical point of view, the outcome of this analysis will help Canadian Securities Administrator (CSA) to have insight into climate change disclosures practices and provides a frame of references for developing related disclosures requirement.

scholarly journals Scenario-based impacts of land use and climate changes on the hydrology of a lowland rainforest catchment in Ghana, West Africa

2017 ◽  
Author(s):  
Michael S. Aduah ◽  
Graham P. W. Jewitt ◽  
Michele L. W. Toucher
Keyword(s):  
Climate Change ◽  
Land Use ◽  
West Africa ◽  
Spatial Variability ◽  
Climate Changes ◽  
Land Use Changes ◽  
Control Period ◽  
Mitigation Strategies ◽  
Climate Change Scenarios ◽  
Land Use Scenarios

Abstract. This study analysed the separate and the combined impacts of climate and land use changes on hydrology on the Bonsa catchment in Ghana, West Africa, using the ACRU hydrological model. The study used five RCP8.5 climate change scenarios (wet, 25th percentile, 75th percentile, dry and a multi-model median of nine GCMs) from the CMIP5 AR5 models for near (2020–2039) and far (2060–2079) future time slices. Change factors were used to downscale the GCM scenarios to the local scale, using observed climate data for the control period of 1990 to 2009. The land use of 1991 and 2011 were used as the baseline and current land use as well as three future land use scenarios (BAU, EG, EGR) for two time slices (2030 and 2070) were used. The study showed that under all separate climate change scenarios, overall flows reduced, but under combined climate and land use changes, streamflows increased. Under the combined scenarios, streamflow responses due to the different future land use scenarios were not substantially different. Also, land use is the dominant controlling factor in streamflow changes in the Bonsa catchment under a dry climate change, but under a wet climate change, climate controls streamflow changes. The spatial variability of catchment streamflow changes under combined land use and climate changes were greater than the spatial variability of streamflow changes under climate change. The range of plausible future streamflows changes derived in this study provides natural resources and environmental managers of the Bonsa catchment, the first ever and the most current information to develop suitable adaptation and mitigation strategies, to prepare adequately for climate and land use changes.

scholarly journals Late Holocene summer temperatures in the central Andes reconstructed from the sediments of high-elevation Laguna Chepical, Chile (32° S)

2013 ◽  
Vol 9 (4) ◽  
pp. 1921-1932 ◽  
Author(s):  
R. de Jong ◽  
L. von Gunten ◽  
A. Maldonado ◽  
M. Grosjean
Keyword(s):  
Climate Change ◽  
South America ◽  
Temperature Reconstruction ◽  
High Elevation ◽  
Ice Age ◽  
Central Chile ◽  
Southern South America ◽  
Calibration Period ◽  
The Past ◽  
Insight Into

Abstract. High-resolution reconstructions of climate variability that cover the past millennia are necessary to improve the understanding of natural and anthropogenic climate change across the globe. Although numerous records are available for the mid- and high-latitudes of the Northern Hemisphere, global assessments are still compromised by the scarcity of data from the Southern Hemisphere. This is particularly the case for the tropical and subtropical areas. In addition, high elevation sites in the South American Andes may provide insight into the vertical structure of climate change in the mid-troposphere. This study presents a 3000 yr-long austral summer (November to February) temperature reconstruction derived from the 210Pb- and 14C-dated organic sediments of Laguna Chepical (32°16' S, 70°30' W, 3050 m a.s.l.), a high-elevation glacial lake in the subtropical Andes of central Chile. Scanning reflectance spectroscopy in the visible light range provided the spectral index R570/R630, which reflects the clay mineral content in lake sediments. For the calibration period (AD 1901–2006), the R570/R630 data were regressed against monthly meteorological reanalysis data, showing that this proxy was strongly and significantly correlated with mean summer (NDJF) temperatures (R3 yr = −0.63, padj = 0.01). This calibration model was used to make a quantitative temperature reconstruction back to 1000 BC. The reconstruction (with a model error RMSEPboot of 0.33 °C) shows that the warmest decades of the past 3000 yr occurred during the calibration period. The 19th century (end of the Little Ice Age (LIA)) was cool. The prominent warmth reconstructed for the 18th century, which was also observed in other records from this area, seems systematic for subtropical and southern South America but remains difficult to explain. Except for this warm period, the LIA was generally characterized by cool summers. Back to AD 1400, the results from this study compare remarkably well to low altitude records from the Chilean Central Valley and southern South America. However, the reconstruction from Laguna Chepical does not show a warm Medieval Climate Anomaly during the 12–13th century, which is consistent with records from tropical South America. The Chepical record also indicates substantial cooling prior to 800 BC. This coincides with well-known regional as well as global glacier advances which have been attributed to a grand solar minimum. This study thus provides insight into the climatic drivers and temperature patterns in a region for which currently very few data are available. It also shows that since ca. AD 1400, long-term temperature patterns were generally similar at low and high altitudes in central Chile.

Alone, Together

2022 ◽  
pp. 77-95
Keyword(s):  
Climate Change ◽  
International Cooperation ◽  
International Community ◽  
The Past ◽  
The World ◽  
Cooperative Institutions ◽  
Insight Into

This chapter provides insight into the contemporary problems plaguing the international community, including climate change and terrorism, and examines how international cooperation has worked to combat issues in the past. The chapter will highlight the criticality of cooperative institutions and organizations within the international community and how those organizations may stand up to the rising tide of nationalism around the world.

Sign in / Sign up

Export Citation Format

Share Document