A5059594920- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Plant Diversity and Evolution
- Geological and Geochemical Analysis
- Hydrocarbon exploration and reservoir analysis
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Evolution and Paleontology Studies
- Marine Biology and Ecology Research
- Plant responses to elevated CO2
- Geological formations and processes
- Species Distribution and Climate Change
- Biocrusts and Microbial Ecology
- Geological Studies and Exploration
- Plant and Fungal Species Descriptions
- Marine Ecology and Invasive Species
- Geological Modeling and Analysis
- Climate variability and models
- Fossil Insects in Amber
- Chemical synthesis and alkaloids
- Plant Parasitism and Resistance
- CO2 Sequestration and Geologic Interactions
- Scientific Computing and Data Management
- Marine and coastal ecosystems
- Plant Water Relations and Carbon Dynamics
Bolin Centre for Climate Research
2014-2024
Stockholm University
2014-2024
Swedish Museum of Natural History
2017-2024
Swedish Biodiversity Data Infrastructure
2023
Lafayette College
2021
University College Dublin
2011-2012
Trinity College Dublin
2011
Field Museum of Natural History
2006
Abstract The Miocene epoch (23.03–5.33 Ma) was a time interval of global warmth, relative to today. Continental configurations and mountain topography transitioned toward modern conditions, many flora fauna evolved into the same taxa that exist climate dynamic: long periods early late glaciation bracketed ∼2 Myr greenhouse interval—the Climatic Optimum (MCO). Floras, faunas, ice sheets, precipitation, p CO 2 , ocean atmospheric circulation mostly (but not ubiquitously) covaried with these...
The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO 2 ) over long short timescales, as well potential drivers of evolutionary transitions. However, reconstructing CO beyond direct measurements requires use paleoproxies herein lies challenge, proxies differ in their assumptions, degree understanding, even reconstructed values. In this study, we critically evaluated, categorized, integrated available to create a high-fidelity transparently...
The stomatal index (a measure of density) an extinct Australian Early Jurassic araucariacean conifer species, Allocladus helgei Jansson, is used to reconstruct the atmospheric carbon dioxide concentration (pCO2) in Jurassic. fossil leaves are preserved a single bed, palynologically dated late Pliensbachian (~ 185–183 Mya). Atmospheric pCO2 estimated from ratios between A. and indices three modern analogs (nearest living equivalent plants). CO2 range ~ 750–975 ppm was calibrated material,...
Abstract To improve future predictions of anthropogenic climate change, a better understanding the relationship between global temperature and atmospheric concentrations CO 2 ( p ), or sensitivity, is urgently required. Analyzing proxy data from change episodes in past necessary to achieve this goal, with certain geologic periods, such as Miocene climatic optimum (MCO), transient period warming temperatures up ~7°C higher than today, increasingly viewed good analogues under present emission...
Research Article| September 01, 2012 Deep-time evidence of a link between elevated CO2 concentrations and perturbations in the hydrological cycle via drop plant transpiration Margret Steinthorsdottir; Steinthorsdottir * 1School Biology Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland *Current address: Department Geological Sciences, Stockholm University, SE-106 91 Stockholm, Sweden; E-mail: margret.stein@gmail.com. Search for other works by this author on: GSW...
Abstract. A unique stratigraphic sequence of fossil leaves Eotrigonobalanus furcinervis (extinct trees the beech family, Fagaceae) from central Germany has been used to derive an atmospheric pCO2 record with multiple data points spanning late middle Eocene, two sampling levels which may be earliest Oligocene, and samples later in Oligocene. Using inverse relationship between density stomata pCO2, we show that decreased continuously reaching a relatively stable low value before end Eocene....
Reliable reconstructions of atmospheric carbon dioxide concentrations (pCO2) are required at higher resolution than currently available to help resolve the relationship between mass extinctions and changes in palaeo-pCO2 levels. Such needed: 1, a high temporal for constraining pre- post-extinction atmospheres; 2, sufficient spatial constrain potential inter-hemispheric differences. Here we estimate pCO2 based on fossil Lauraceae leaf cuticle specimens derived from three localities with...
Flood basalt volcanism has been implicated in several episodes of mass extinctions and environmental degradation the geological past, including at Triassic–Jurassic (Tr–J) transition, through global warming caused by massive outgassing carbon dioxide. However, patterns biodiversity loss observed are complicated sometimes difficult to reconcile with effects alone. Recently, attention turned additional volcanic products as potential aggravating factors, particular sulphur dioxide (SO2). SO2...
The reorganisation of Earth's climate system from the Oligocene to Miocene was influenced by complex interactions between Tethyan tectonics, orbital parameters, oceanographic changes, and carbon cycle feedbacks, with modelling indicating that pCO2 an important factor. Oscillating episodes change during Oligocene–Miocene transition (OMT) have however been difficult reconcile existing records. Here we present a new record OMT into early Miocene, reconstructed using stomatal proxy method...
Abstract Reducing the uncertainty in predictions of future climate change is one today’s greatest scientific challenges, with many significant problems unsolved, including relationship between pCO2 and global temperature. To better constrain these forecasts, it meaningful to study past time intervals warmth, such as Eocene (56.0–33.9 Ma), serving climatic analogues for future. Here we reconstructed using stomatal densities a large fossil Lauraceae (laurel) leaf database from ten sites across...
The Last Termination (19 000–11 000 a BP ) with its rapid and distinct climate shifts provides perfect laboratory to study the nature regional impact of variability. sedimentary succession from ancient lake at Hässeldala Port in southern Sweden Lateglacial/early Holocene stratigraphy (>14.1–9.5 cal. ka is one few chronologically well‐constrained, multi‐proxy sites Europe that capture variety local climatic environmental signals. Here we present Hässeldala's records (lithology,...
Abstract: Bennettites are an abundant and frequently well‐preserved component of many Mesozoic fossil floras, often playing important ecological role in flood plain vegetation communities. During a recent study focusing on stomatal indices Triassic–Jurassic plants, it became evident that the leaf fragments two bennettite genera Anomozamites Schimper (1870) emend. Harris (1969) Pterophyllum Brongniart (1825) display significant overlap shape as well cuticular characters. Owing to preference...
The Ginkgoales, including the 'living fossil' Ginkgo biloba, are an important group for stomata-based palaeo-pCO2 reconstructions, with long evolutionary lineages and extensive, abundant fossil record. stomatal proxy can improve our understanding of exact relationship between pCO2 temperatures – Earth's climate sensitivity: a key measure global warming by pCO2. However, records from future analogues in past, such as mid-Miocene Climatic Optimum, seemingly underestimate models cannot simulate...
The end-Triassic event (ETE), a short global interval occurring at the end of Triassic Period (~201.5 Ma), was characterized by climate change, environmental upheaval, as well widespread extinctions in both marine and terrestrial realms. It associated with extensive perturbations carbon cycle, principally caused volcanic emplacement Central Atlantic Magmatic Province relation to break-up Pangea. correlated change atmospheric CO2 concentrations (pCO2) can be reconstructed stomatal proxy,...
During a study of macroflora from the Astartekloft locality in Jameson Land, East Greenland, endophytic insect ovipositions (egg traces) belonging to ichnogenus Paleoovoidus were recorded for first time ginkgoalean (Ginkgoites, Sphenobaiera, and Baiera) fossil leaves across Triassic-Jurassic (Tr-J) transition (ca. 200 Ma). The may have been produced by insects order Odonata (dragonflies damselflies) are relatively more abundant before than after Tr-J transition, possibly reflecting changes...
The Triassic-Jurassic boundary (TJB) coincides with major disruption to the carbon cycle and global warming as Central Atlantic Magmatic Province developed. This resulted in both marine terrestrial extinctions, plants thought experience thermal stress temperatures atmospheric CO_2 levels rose. As plant compression fossils typically only preserve external morphological features, it has not been possible reconstruct paleophysiology order elucidate mechanisms underlying extinction. Here we...