scholarly journals ITALIAN GEOLOGY AND CLIMATE CHANGE IN THE DEEP PAST

2020 ◽  
Author(s):  
Hugh C. Jenkyns
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
World Wide ◽  
Sedimentary Rocks ◽  
Volcanic Eruptions ◽  
Black Shales ◽  
Geological Time ◽  
Anoxic Events ◽  
River Valleys ◽  
Water Character

Mesozoic sedimentary rocks, of both deep- and shallow-water character, are present throughout Italy and well exposed in mountains and river valleys. Detailed studies of these sections by Italian geologists, beginning in the nineteenth century and continuing to this day, have produced a high-resolution biostratigraphy that allows identification of increments of geological time of less than a million years. Early work relied largely on ammonites to define biostratigraphy but was applicable primarily to sediments of Jurassic age. Study of deep-marine pelagic limestones and shales of Cretaceous age were subsequently, in the twentieth century, investigated using planktonic microfossils, the size of a sand grain, and even smaller nannofossils of micron scale. Pioneering work on magnetostratigraphy and cyclostratigraphy, undertaken primarily on Cretaceous sediments cropping out in Marche-Umbria, added further refinement to the measuring of small intervals of time in rock. With this stratigraphic background, distinct lithological and chemical signals, discovered first in Italian sequences, could be recognized world-wide and proven to be of global significance. In particular, the involvement of carbon isotopes has underscored the utility of chemostratigraphy, not only as a further aid to correlation, but also as a testimonial to major environmental change. Most significant in this context are the Cretaceous oceanic anoxic events, whose sedimentary record was first documented from Italy. These events were characterized by the development of organic-rich black shales deposited in waters largely lacking in oxygen during times of extraordinarily high temperatures known as hyperthermals. Hyperthermals, likely driven by supply of carbon dioxide from large-scale volcanic eruptions, illustrate the environmental impact on a planet affected by extreme global warming.

The Earth Is (Still) Our Mother

2021 ◽  
pp. 115-125
Author(s):  
Chad S. Hamill
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
World Wide ◽  
Climate Science ◽  
Indigenous Communities ◽  
Ecological Knowledge ◽  
Small Islands ◽  
Adaptive Power ◽  
Circumpolar Arctic ◽  
European Colonialism

As many large-scale protests by Indigenous people have articulated, lands inhabited by Indigenous communities (such as desert margins, small islands, lakes and rivers, high-altitude zones, and the circumpolar Arctic) are particularly vulnerable to the dramatic shifts in climate currently underway. The delicate ecosystems upon which Indigenous communities rely are in flux, and the accelerating rate of climate change—outpacing the direst scientific projections—amounts to a crisis that is every bit as threatening as the legacy of European colonialism. Fortunately, for millennia Indigenous communities have cultivated an intimate awareness of their ecology and have remained, throughout the era of world-wide industrial devastation, adept at adapting to environmental change. This awareness and adaptive power has been discussed within the framework of Traditional Ecological Knowledge (TEK). Using traditional stories and songs in Indigenous communities as a touchstone, this chapter will explore three interrelated aspects of TEK: (1) its role in assisting Indigenous communities in adapting to the effects of climate change; (2) its potential to inform and influence Western-generated climate science; and (3) its promise as a unifying thread tying Indigenous communities together, strengthening global self-determination.

Attributing the global increase in permafrost temperatures to human induced climate change

2021 ◽  
Author(s):  
Lukas Gudmundsson ◽  
Josefine Kirchner ◽  
Anne Gädeke ◽  
Eleanor Burke ◽  
Boris K. Biskaborn ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Climate Models ◽  
Global Climate ◽  
Volcanic Eruptions ◽  
Global Climate Models ◽  
Anthropogenic Climate Change ◽  
Permafrost Degradation ◽  
Climate Feedbacks ◽  
Permafrost Temperature

<p>Permafrost temperatures are increasing at the global scale, resulting in permafrost degradation. Besides substantial impacts on Arctic and Alpine hydrology and the stability of landscapes and infrastructure, permafrost degradation can trigger a large-scale release of carbon to the atmosphere with possible global climate feedbacks. Although increasing global air temperature is unanimously linked to human emissions into the atmosphere, the attribution of observed permafrost warming to anthropogenic climate change has so far mostly relied on anecdotal evidence. Here we apply a climate change detection and attribution approach to long permafrost temperature records from 15 boreholes located in the northern Hemisphere and simulated soil temperatures obtained from global climate models contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6). We show that observed and simulated trends in permafrost temperature are only consistent if the effect of human emissions on the climate system is considered in the simulations. Moreover, the analysis also reveals that neither simulated pre-industrial climate variability nor the effects natural drivers of climate change (e.g. impacts of large volcanic eruptions) suffice to explain the observed trends. While these results are most significant for a global mean assessment, our analysis also reveals that simulated effects of anthropogenic climate change on permafrost temperature are also consistent with the observed record at the station scale. In summary, the quantitative combination of observed and simulated evidence supports the conclusion that anthropogenic climate change is the key driver of increasing permafrost temperatures with implications for carbon cycle-climate feedbacks at the planetary scale.</p>

scholarly journals Understanding Recent Stratospheric Climate Change

2009 ◽  
Vol 22 (8) ◽  
pp. 1934-1943 ◽  
Author(s):  
David W. J. Thompson ◽  
Susan Solomon
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Lower Stratosphere ◽  
Climate Model ◽  
Longwave Radiation ◽  
Volcanic Eruptions ◽  
Stratospheric Temperature ◽  
Ozone Trends ◽  
Global Mean

Abstract The long-term, global-mean cooling of the lower stratosphere stems from two downward steps in temperature, both of which are coincident with the cessation of transient warming after the volcanic eruptions of El Chichón and Mount Pinatubo. Previous attribution studies reveal that the long-term cooling is linked to ozone trends, and modeling studies driven by a range of known forcings suggest that the steps reflect the superposition of the long-term cooling with transient variability in upwelling longwave radiation from the troposphere. However, the long-term cooling of the lower stratosphere is evident at all latitudes despite the fact that chemical ozone losses are thought to be greatest at middle and polar latitudes. Further, the ozone concentrations used in such studies are based on either 1) smooth mathematical functions fit to sparsely sampled observations that are unavailable during postvolcanic periods or 2) calculations by a coupled chemistry–climate model. Here the authors provide observational analyses that yield new insight into three key aspects of recent stratospheric climate change. First, evidence is provided that shows the unusual steplike behavior of global-mean stratospheric temperatures is dependent not only upon the trend but also on the temporal variability in global-mean ozone immediately following volcanic eruptions. Second, the authors argue that the warming/cooling pattern in global-mean temperatures following major volcanic eruptions is consistent with the competing radiative and chemical effects of volcanic eruptions on stratospheric temperature and ozone. Third, it is revealed that the contrasting latitudinal structures of recent stratospheric temperature and ozone trends are consistent with large-scale increases in the stratospheric overturning Brewer–Dobson circulation.

Lead isotope abundance studies on mineral occurrences in the British Isles and their geological significance

1962 ◽  
Vol 254 (1042) ◽  
pp. 295-360 ◽  
Keyword(s):  
Great Britain ◽  
Excellent Agreement ◽  
Large Scale ◽  
Lead Isotope ◽  
Sedimentary Rocks ◽  
British Isles ◽  
Geological Time ◽  
North West ◽  
Basement Rocks ◽  
Metamorphic Basement

Lead isotope abundances are reported for ninety-eight galena specimens from Great Britain and Ireland. The analyses were made with a solid-source mass spectrometer. Comparison analyses show excellent agreement with results from other laboratories using solid-source techniques, but differences of 1 to 5% may occur for individual abundances when comparison is made with laboratories utilizing the lead tetramethyl vapour technique. The model chosen for calculation of ages from the isotopic composition is that of Holmes and Houtermans, using the published values of Patterson for the isotopic comparison of primeval lead in iron meteorites and modern lead in ocean sediments. This model permits calculation of the parameters uranium-238/lead-204 and thorium-232/uranium-238 in the source of the ores, which may exhibit small regional differences. The Holmes-Houtermans model ages of three suites of galenas from south-west England, northern England and southern Norway give excellent agreement with published values of the absolute ages of genetically associated igneous rocks. Other models used for interpreting lead isotope abundances do not generally give such satisfactory agreement. The significance of the isotope data from Great Britain and Ireland is discussed regionally in terms of the age of mineralization as well as the possible correlation and origin of different deposits. Of the ninety-eight leads investigated, eighty-six are assumed to be normal and to obey the conditions of the Holmes-Houtermans model. The remaining twelve are B -type leads, as defined by Houtermans, i.e. the model ages are demonstrably older than the true age of mineralization. The main criteria for recognizing normal leads are, first, the close regional grouping of isotope abundances and, secondly, that the model age does not exceed the age of the enclosing sedimentary rocks on the basis of the most recently published geological time-scales of the fossiliferous strata. Detailed consideration of normal leads suggests the existence of six periods of mineralization in the British Isles, ranging in age from Lower Palaeozoic to Upper Mesozoic. The two most important and clearly defined groups are associated with the Caledonian and Hercynian orogenies, respectively. There is, as yet, no isotopic evidence for Tertiary mineralization in the British Isles. A discussion of the causes of normal lead isotope abundances indicates that the latter could be the result of large-scale crustal homogenization processes in continental geosynclinal-orogenic belts. However, there is not enough critical evidence to identify definitely the source of normal lead ores with either crust or mantle. B -type leads probably arise by comparatively localized remobilization and regeneration of lead from metamorphic basement complexes with high lead/uranium ratios, or low radiogenic lead content. The source of such leads frequently appears to be somewhat heterogeneous and ore solutions may not have the opportunity for extensive mixing before the site of deposition is reached. However, B -type leads in some cases give an approximation to the true age of the basement rocks from which they are derived. Processes of this type probably account for the 5-type leads in the north-west and central highlands of Scotland and in County Galway, western Ireland, where the occurrences are situated in metamorphic basement rocks. No cases have been definitely recognized within the British Isles in which lead has a negative, or anomalously young, model age ( J -type leads). The results presented in this paper do not support the view of Russell and co-workers that most vein-type deposits which have traversed sedimentary rocks exhibit J -type anomalies—a consequence of their suggestion that B -type leads, as defined by Houtermans, should be regarded as normal leads.

scholarly journals A well-timed shift from local to global agreements accelerates climate change mitigation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vadim A. Karatayev ◽  
Vítor V. Vasconcelos ◽  
Anne-Sophie Lafuite ◽  
Simon A. Levin ◽  
Chris T. Bauch ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Change Mitigation ◽  
Large Scale ◽  
World Wide ◽  
Building Blocks ◽  
Global Scale ◽  
Climate Mitigation ◽  
Limited Efficacy ◽  
Policy Shift ◽  
Change Mitigation

AbstractRecent attempts at cooperating on climate change mitigation highlight the limited efficacy of large-scale negotiations, when commitment to mitigation is costly and initially rare. Deepening existing voluntary mitigation pledges could require more stringent, legally-binding agreements that currently remain untenable at the global scale. Building-blocks approaches promise greater success by localizing agreements to regions or few-nation summits, but risk slowing mitigation adoption globally. Here, we show that a well-timed policy shift from local to global legally-binding agreements can dramatically accelerate mitigation compared to using only local, only global, or both agreement types simultaneously. This highlights the scale-specific roles of mitigation incentives: local agreements promote and sustain mitigation commitments in early-adopting groups, after which global agreements rapidly draw in late-adopting groups. We conclude that focusing negotiations on local legally-binding agreements and, as these become common, a renewed pursuit of stringent, legally-binding world-wide agreements could best overcome many current challenges facing climate mitigation.

Constructing paleoclimate networks from annually laminated lake sediments – the VARDA database

2020 ◽  
Author(s):  
Arne Ramisch ◽  
Alexander Brauser ◽  
Mario Dorn ◽  
Cecile Blanchet ◽  
Brian Brademann ◽  
...  
Keyword(s):  
Climate Change ◽  
Lake Sediments ◽  
Large Scale ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Volcanic Eruptions ◽  
Scale Model ◽  
Graph Database ◽  
Varve Thickness ◽  
Novel Approach

<p>Reconstructing global patterns of past climate change requires large-scale networks of paleoclimatic archives. Generating paleoclimatic networks relies on precise synchronization of individual records with robust age control. The detailed age constrains of continuous varved lake sediments and the good preservation of isochrones from supra-regional extreme events make these records ideal for constructing large scale continental paleoclimatic networks. Yet, a global synthesis of varved lake archives is missing.</p><p>Here we present the VARved sediments DAtabase 1.0 (VARDA 1.0), the first global data compilation for varve chronologies and associated palaeoclimatic proxy records. VARDA 1.0 uses a connected data model provided by a state-of-the-art graph database, enabling custom generations of synchronized paleoclimatic networks. We report on compilation strategies for the identification of varved lakes and assimilation of high-resolution chronologies. Existing chronologies have been re-assessed and harmonized using a novel approach that infers information on sedimentation rates enclosed in varve thickness records. This information provides detailed information on the priors required for Bayesian age-depth modelling and strongly improves these results. Additionally, a synthesis of tephra layers from volcanic eruptions provides supra-regional isochrones for synchronizing even distant varved lake records. The current version (VARDA 1.0) comprises 261 datasets from 95 varved lake archives, including chronological information from <sup>14</sup>C dating and varve thickness measurements, but also palaeoclimatological proxy data. We further explore potential applications of such networks in paleoclimatic studies, such as identifying leads and lags of regional climate change, large-scale model-data comparisons or differentiated proxy responses between archives. The VARDA graph-database and user interface can be accessed online at https://varve.gfz-potsdam.de.</p>

scholarly journals The effect of climate change damages on agriculture, forestry and fisheries in ASEAN countries

2021 ◽  
Vol 905 (1) ◽  
pp. 012120
Author(s):  
R M Indriawati ◽  
D Prasetyani
Keyword(s):  
Climate Change ◽  
Environmental Sustainability ◽  
Large Scale ◽  
Volcanic Eruptions ◽  
Progressive Increase ◽  
Household Waste ◽  
Vision 2020 ◽  
Agricultural Insurance ◽  
Impact Of Climate Change ◽  
The Impact

Abstract Countries in ASEAN region have a significant potential for the impact of climate change disruption and disasters such as El Nino, La Nina, earthquakes, tsunamis, volcanic eruptions, hurricanes, floods, tropical storms, landslides, and CO2 emissions. The ASEAN Secretariat recorded a progressive increase in CO2 emission levels of around 61% from 2014 to 2025, more than 90% of transboundary haze from the expansion of large-scale commercial plantations, accumulation of plastic waste and household waste that cannot be properly recycled. The contribution of agriculture, forestry and fisheries is also relatively varied. Geographical conditions, policy orientations of each government, structure of production inputs including human resource competence and technology are thought to determine the adverse effects of climate change on the agriculture, forestry, and fisheries sectors. This study focuses on the impact of climate change on the agriculture, fisheries, and forestry sectors in the ASEAN region. The analytical framework is adapted to the ASEAN Vision 2020 and ASEAN Vision 2021. In addition, a deeper analysis of several climate change impact control instruments such as polluter pays, agricultural insurance, agri-environment climate schemes and payments for environmental services will also be studied. These instruments are directed to achieve environmental sustainability in the ASEAN region.

scholarly journals On the Role of Volcanism in Dansgaard-Oeschger Cycles

2020 ◽  
Author(s):  
Johannes Lohmann ◽  
Anders Svensson
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Abrupt Climate Change ◽  
Last Glacial Period ◽  
Large Volcanic Eruptions ◽  
The Last Glacial

Abstract. A significant influence of major volcanic eruptions on regime shifts and long-term climate variability has been suggested previously. But a statistical assessment of this has been hampered by inaccurate synchronization of large volcanic eruptions to changes in past climate. Here, this is achieved by combining a new record of bipolar volcanism from Greenland and Antarctic ice cores with records of abrupt climate change derived from the same ice cores. We show that at > 99 % confidence bipolar volcanic eruptions occurred more frequently than expected by chance just before the onset of Dansgaard-Oeschger events, the most prominent large-scale abrupt climate changes of the last glacial period. Out of 20 climate change events in the 12–60 ka period, 5 (7) occur within 20 (50) years after a bipolar eruption. Thus, such large eruptions may act as short-term triggers for large-scale abrupt climate change, and may explain part of the variability of Dansgaard-Oeschger cycles.

Large-scale mapping of the catenas vegetation in Subarctic tundra

1995 ◽  
pp. 3-21
Author(s):  
S. S. Kholod
Keyword(s):  
Spatial Distribution ◽  
Vegetation Cover ◽  
Large Scale ◽  
Block Diagram ◽  
Abiotic Factors ◽  
Ecological Factors ◽  
Spatial Arrangement ◽  
Geological Time ◽  
Ecological Barriers ◽  
Functional Zones

One of the most difficult tasks in large-scale vegetation mapping is the clarification of mechanisms of the internal integration of vegetation cover territorial units. Traditional way of searching such mechanisms is the study of ecological factors controlling the space heterogeneity of vegetation cover. In essence, this is autecological analysis of vegetation. We propose another way of searching the mechanisms of territorial integration of vegetation. It is connected with intracoenotic interrelation, in particular, with the changing role of edificator synusium in a community along the altitudinal gradient. This way of searching is illustrated in the model-plot in subarctic tundra of Central Chukotka. Our further suggestion concerns the way of depicting these mechanisms on large-scale vegetation map. As a model object we chose the catena, that is the landscape formation including all geomorphjc positions of a slope, joint by the process of moving the material down the slope. The process of peneplanation of a mountain system for a long geological time favours to the levelling the lower (accumulative) parts of slopes. The colonization of these parts of the slope by the vegetation variants, corresponding to the lowest part of catena is the result of peneplanation. Vegetation of this part of catena makes a certain biogeocoenotic work which is the levelling of the small infralandscape limits and of the boundaries in vegetation cover. This process we name as the continualization on catena. In this process the variants of vegetation in the lower part of catena are being broken into separate synusiums. This is the process of decumbation of layers described by V. B. Sochava. Up to the slope the edificator power of the shrub synusiums sharply decreases. Moss and herb synusium have "to seek" the habitats similar to those under the shrub canopy. The competition between the synusium arises resulting in arrangement of a certain spatial assemblage of vegetation cover elements. In such assemblage the position of each element is determined by both biotic (interrelation with other coenotic elements) and abiotic (presence of appropriate habitats) factors. Taking into account the biogeocoenotic character of the process of continualization on catena we name such spatial assemblage an exolutionary-biogeocoenotic series. The space within each evolutionary-biogeocoenotic series is divided by ecological barriers into some functional zones. In each of the such zones the struggle between synusiums has its individual expression and direction. In the start zone of catena (extensive pediment) the interrelations of synusiums and layers control the mutual spatial arrangement of these elements at the largest extent. Here, as a rule, there predominate edificator synusiums of low and dwarfshrubs. In the first order limit zone (the bend of pediment to the above part of the slope) one-species herb and moss synusiums, oftenly substituting each other in similar habitats, get prevalence. In the zone of active colonization of slope (denudation slope) the coenotic factor has the least role in the spatial distribution of the vegetation cover elements. In particular, phytocoenotic interactions take place only within separate microcoenoses of herbs, mosses and lichens. In the zone of the attenuation of continualization process (the upper most parts of slope, crests) phytocoenotic interactions are almost absent and the spatial distribution of vegetation cover elements depends exclusively on the abiotic factors. The principal scheme of the distribution of vegetation cover elements and the disposition of functional zones on catena are shown on block-diagram (fig. 1).

The large-scale vegetation maps of the western coast of Peter the Great Bay (Far East, the Sea of Japan)

2000 ◽  
pp. 50-61 ◽  
Author(s):  
S. V. Osipov ◽  
V. P. Verkholat
Keyword(s):  
Vegetation Cover ◽  
Large Scale ◽  
Far East ◽  
Peter The Great Bay ◽  
The Sea Of Japan ◽  
Western Coast ◽  
Spatial Unit ◽  
Peter The Great ◽  
Great Bay ◽  
River Valleys

Two territories on the western coast of Peter the Great Bay were mapped in the large scale. The geobotanical mapping means revealing and displaying the essential regularities of vegetation cover. Both the spatial and temporal regularities of vegetation under natural and anthropogenic influences are well pronounced in the territory under consideration. The concept of the vegetation spatial unit (vegetation complexes) was applied as a basis for mapping. The maps and their legend were worked out as a system of vegetation combination types (vegetation combination is a spatial unit of the supracoenotic level). Such categories, as vegetation of tops and slopes, lowlands and river valleys, sea coasts reflect maximal contrasts in vegetation cover, so they are the highest level divisions of the map legend. Types of succession series and stages of series are developed for construction of the second and third levels of the legend. Communities, similar in ecotope, total species composition, saplings and some other characteristics, are referred to one type of series. 5 types of series have been distinguished: dry, fresh, moist, very moist, wet. The main factor of dynamics in considered territory is fire and the series are mainly pyrogeneous. Series are presented as sequences of vegetation stages. The vegetation stages for tops and slopes are: closed low forest — open low woodland — shrub thicket with saplings — meadow with saplings, for lowlands and river valleys they are: open low woodland — thicket of saplings — meadow or mire with saplings.

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