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Abrupt Climate Change and Extinction Events in Earth History
Abstract
Slowly changing boundary conditions can sometimes cause discontinuous responses in climate models and result in relatively
rapid transitions between different climate states. Such terrestrially induced abrupt climate transitions could have contributed
to biotic crises in earth history. Ancillary events associated with transitions could disperse unstable climate behavior over
a longer but still geologically brief interval and account for the stepwise nature of some extinction events. There is a growing
body of theoretical and empirical support for the concept of abrupt climate change, and a comparison of paleoclimate data
with the Phanerozoic extinction record indicates that climate and biotic transitions often coincide. However, more stratigraphic
information is needed to precisely assess phase relations between the two types of transitions. The climate-life comparison
also suggests that, if climate change is significantly contributing to biotic turnover, ecosystems may be more sensitive to
forcing during the early stages of evolution from an ice-free to a glaciated state. Our analysis suggests that a terrestrially
induced climate instability is a viable mechanism for causing rapid environmental change and biotic turnover in earth history,
but the relation is not so strong that other sources of variance can be excluded.
... Tipping points (TPs) in complex systems are often assumed to obey the normal form of a saddlenode bifurcation, which gives rise to universal early warning signals (EWS) due to critical slowing down (CSD) [1][2][3][4]. In particular, when proceeding towards the bifurcation, saddle and node approach each other and eventually collide and disappear, at which point the largest Jacobian eigenvalue of the linearization around the node crosses the imaginary axis. ...
Tipping points (TPs) are often described as low-dimensional bifurcations, and are associated with early warning signals (EWS) due to critical slowing down (CSD). CSD is an increase in amplitude and correlation of noise-induced fluctuations away from a reference attractor as the TP is approached. But for high-dimensional systems, it is not obvious which variables or observables would display the critical dynamics and carry CSD. Many variables may display no CSD, or show changes in variability not related to a TP. It is thus helpful to identify beforehand which observables are relevant for a given TP. Here we propose this may be achieved by knowledge of an unstable edge state that separates the reference from an alternative attractor that remains after the TP. This is because stochastic fluctuations away from the reference attractor are preferentially directed towards the edge state along a most likely path (the instanton). As the TP is approached the edge state and reference attractor typically become closer, and the fluctuations can evolve farther along the instanton. This can be exploited to find linear observables with substantial CSD, which we demonstrate using conceptual dynamical systems models and climate model simulations of a collapse of the Atlantic meridional overturning circulation.
... Again, the model predicts the same patterns as the total one (Supplementary Table 2) but with higher support. This is evident from the smaller credible intervals when comparing the models "without fossorial" vs. "with fossorial" (our total model) species across different habitats: Open (41% [35,44] vs. 41% [36,46]), Semi-Open (39% [36,41] vs. 39% [36,43]), and Closed (34% [29,37] vs. 36% [31,39]). These smaller credible intervals confirm the higher uncertainties of brightness prediction in fossorial species (Fig. 4). ...
While the ecological roles of colored integument have been extensively studied, what regulates global patterns of color variation remains poorly understood. Here, using a global dataset of 1249 squamates, we evaluate whether and how six key eco-environmental variables and their interactions shaped the evolutionary history of their coloration. We show that only habitat openness consistently associates with brightness evolution, with brighter integuments favored in open habitats, possibly for enhanced heat reflection. Furthermore, brightness evolution rates likely track δ¹⁸O (a temperature proxy) changes and increase during global aridification phases, such as those in the Miocene and Pliocene. This trend may be due to the establishment of an arid climate that promoted habitat openness shifts, ultimately inducing adaption to new niches. Our findings suggest that a single environmental variable is associated with color variation in the largest extant tetrapod order.
... In the field of climate science, the possibility of "abrupt climate change" and "critical points" was considered as early as the 1980s [31]. The notion that anthropogenic influence could also trigger sudden transitions in climate systems, slowly gained traction in the early 2000s [32,33]. ...
Visual models play a crucial role in both science and science communication. However, the distinction between mere analogies and mathematically sound graphical representations is not easy and can be misunderstood not only by laypeople but also within academic literature itself. Moreover, even when the graphical representation exactly corresponds to the mathematical model, its interpretation is often far from obvious. In this paper we discuss the "potential landscape" visualization commonly used for tipping points in the context of nonlinear dynamics and reveal potential pitfalls, in particular when distinguishing bifurcation induced tipping (B-tipping) from noise-induced tipping (N-tipping). We propose new visualization techniques for tipping dynamics, carefully distinguishing between B- and N-tipping as well as between single systems and ensembles of systems. Explicitly, we apply these visualizations both to molecular cell biology and to climate science in order to reveal the crucial differences in the interpretation of the visual models. We find that it is crucial to explicitly discuss the assumptions made within the visual model and to be aware of the risk of misinterpretation. Based on these findings, we propose as a next step to investigate individual mental models induced by these visualizations in the framework of empirical research.
... waste) into the earth and atmosphere (Erdoğan et al. 2019;Kurniawan et al. 2021). The simple reason is that if growth is generated costing the natural environment quality in the long run, it can become a sign of environmental instability (Crowley and North 1988). Suppose such a situation continues to prevail over a more extended period. ...
Since fossil fuel consumption drives environmental degradation, existing studies highlight the role of clean energy development in climate change mitigation. The emerging economies can mitigate climate change and also achieve sustainable development if they focus on innovation-led renewable energy development. In this context, this study is motivated to analyze the impact of domestic and overseas innovations (i.e., resident and non-resident) on renewable energy generation for 16 emerging market economies by employing balanced panel data from 1996 to 2019. This study incorporates financial development, regulatory quality, and real economic growth as crucial control variables in renewable energy generation function. The long-run results of the PMG-ARDL estimation technique show the positive (negative) impact of domestic (overseas) innovation on renewable energy generation, while regulatory quality, financial development, and economic growth promote it. Our results are robust across FGLS, Driscoll–Kraay standard error, and dynamic GMM estimation techniques. The policy implications are also discussed.
We study the effect of phase-separating diffusive dynamics on the mean time to extinction (MTE) in several reaction-diffusion models with slow reactions. We consider a continuum theory similar to model AB, and a simple model where individual particles on two sites undergo on-site reactions and hopping between the sites. In the slow-reaction limit, we project the models’ dynamics onto suitable one-dimensional reaction coordinates, which allows the derivation of quasi-equilibrium effective free energies. For weak noise, this enables characterisation of the MTE. This time can be enhanced or suppressed by the addition of phase separation, compared with homogeneous reference cases. We discuss how Allee effects can be affected by phase separation, including situations where the tendency to phase-separate renders an otherwise stable population unstable.
In this chapter, we deal with the change from the exception to the rule in biological systems, both by the action of nature and by the changes that occur due to human action. We talk about the origin of life on planet Earth, the first organisms that colonized primitive environments and changed the atmosphere, giving rise to new forms of life, the appearance of eukaryotic, multicellular organisms, and the different forms of reproduction. We focus on events and changes that were initially considered teratological and that are familiar to our current vision. We also mention adaptations, plasticity, and different phenotypes that became advantages and allowed organisms to continue living in different environments. On the other hand, we point to global processes that affect humans and that in many cases are caused by humans. We discuss examples of diseases that turn into pandemics, the processes of environmental pollution, and accelerated climate change. Finally, we will discuss the changes in scientific ideas, which are closely linked to the social context at each moment in human history, the changes in the different fields of study and within society itself.
In this chapter, we look at the other side, the cases where the rules have become exceptions. The factors responsible for these changes are diverse. Let us consider, for example, those changes produced by nature itself, where certain characters, behaviors, and even interactions that were previously very common became rare or even disappeared; changes associated with climatic relics, relict species, up to major extinction events. Let us also think of the changes that humans have made in nature that are responsible for certain rules becoming exceptions, the effects of artificial selection, deforestation, species introduced into environments that are not natural, and of course the climate change in which we are major participants, to name just a few examples. Additionally, the changes from rules to exceptions can result from changes in scientific interpretations, such as biases in study approaches, biases in the choice of model species for research, and their general extrapolation of results without, in many cases, the necessary precautions, in addition to the biases in interpretations associated with the use of certain current equipment and methodologies.
Natural climate changes have been responsible for new rearrangements of global biodiversity over geological time. The Anthropogenic Climate Change (ACC), over the last 100 years, has as its main cause the human contribution to the increase in greenhouse gas emissions. The ACC has sharply challenged the adaptive capacity of species. In the Amazon Forest, due to the peculiarity of the hot and humid climate, many species present high climatic vulnerability, mainly due to their narrow climatic niches. Amazonian mammals are one of the groups that have shown great changes in their distributions in the face of ACC. Due to the critical ecological roles of mammals in tropical forests, drastic reductions in their populations could have serious consequences for Amazonian ecosystems. In this chapter, we describe anthropogenic climate change and its impacts on ecosystems and biodiversity in general, emphasizing the Amazon mammals. We detail how land-use changes in the Amazon have contributed to climate change and how climate change has affected the Amazon. To assess the impact of ACC on mammals, we analyzed 43 studies carried out on the subject in the last 15 years. The effects of ACC, together with the effects of deforestation, mainly affect the ability to access new areas with favorable climatic conditions and the dispersal capacity of mammal species in the Amazon Region.
A simple equilibrial model for the growth and maintenance of Phanerozoic global marine taxonomie diversity can be constructed from considerations of the behavior of origination and extinction rates with respect to diversity. An initial postulate that total rate of diversification is proportional to number of taxa extant leads to an exponential model for early phases of diversification. This model appears to describe adequately the “explosive” diversification of known metazoan orders across the Precambrian-Cambrian Boundary, suggesting that no special event, other than the initial appearance of Metazoa, is necessary to explain this phenomenon. As numbers of taxa increase, the rate of diversification should become “diversity dependent.” Ecological factors should cause the per taxon rate of origination to decline and the per taxon rate of extinction to increase. If these relationships are modeled as simple linear functions, a logistic description of the behavior of taxonomie diversity through time results. This model appears remarkably consistent with the known pattern of Phanerozoic marine ordinal diversity as a whole. Analysis of observed rates of ordinal origination also indicates these are to a large extent diversity dependent; however, diversity dependence is not immediately evident in rates of ordinal extinction. Possible explanations for this pattern are derived from considerations of the size of higher taxa and from simulations of their diversification. These suggest that both the standing diversity and the pattern of origination of orders may adequately reflect the behavior of species diversity through time; however, correspondence between rates of ordinal and species extinction may deteriorate with progressive loss of information resulting from incomplete sampling of the fossil record.
It follows from the analysis of observation data that the secular variation of the mean temperature of the Earth can be explained by the variation of short-wave radiation, arriving at the surface of the Earth. In connection with this, the influence of long-term changes of radiation, caused by variations of atmospheric transparency on the thermal regime is being studied. Taking into account the influence of changes of planetary albedo of the Earth under the development of glaciations on the thermal regime, it is found that comparatively small variations of atmospheric transparency could be sufficient for the development of quaternary glaciations. DOI: 10.1111/j.2153-3490.1969.tb00466.x
The classic loess deposits of China have been intensively studied in recent years, especially from the standpoint of paleoclimate. A sequence up to 200 m thick of interlayered loesses and paleosols has been firmly established dating back to 2.4 Ma. The stratigraphy, magnetostratigraphy, petrography, chemistry and fossil content of the layers and their close correlation with results from deep-sea cores permit reconstruction of varying paleoenvironments and paleoclimates. -from Editor
Diversity and faunal turnover of North American land mammals are calibrated against the magnetic polarity time scale for million-year intervals for the latest Eocene through late Oligocene. A major, gradual Late Eocene decline in diversity, caused mostly by an extended period of extinction of archaic forms, seems to be related to the worldwide crisis known as the “Terminal Eocene Event.” Along with other evidence of gradual changes in deep-sea microfossils, this evidence argues against a catastrophic explanation for late Eocene extinctions.
Faunal stability characterized the rest of the Oligocene except for a wave of extinctions in the mid-Oligocene (Chadronian-Orellan boundary, about 32.4 ma). This mid-Oligocene event is sudden and severe, occurring in less than 200,000 yr, based on estimates from sedimentation rates calibrated from magnetic polarity interval boundaries. The mid-Oligocene event is found in many paleoclimatic records, but not in all of them. It may be related to the completion of the Circum-Antarctic Current and to increased mid-Oligocene glaciation.
Examines the evolution of the low-level flow over the Arabian Sea during the onset of the summer monsoon. A detailed examination of the onset vortex that forms over the Arabian Sea just prior to the commencement of heavy rains over central India is carried out. Of major interest is a finding that the kinetic energy of the zonal flow over the central Arabian Sea increases by an order, of magnitude 1 week prior to the commencement of monsoon rain over central India. -from Authors Department of Meteorology, Florida State University, Tallahassee 32306, USA.
V28-239 core from cruise 28 of R / V Vema preserves a detailed oxygen-isotope and paleomagnetic record for all of the Pleistocene Epoch. The entire 21-m-long core has been analyzed at 5-cm intervals. Glacial stage 22, above the Jaramillo magnetic event, may represent the first major Northern Hemisphere continental glaciation of middle Pleistocene character. Prior to this, higher frequency glacial events extend to near the level of the Olduvai magnetic event. Glacial events of less regular frequency extend to the bottom of the core, which represents late Pliocene time. Fluctuations in carbonate dissolution intensity occur throughout the core with a similar frequency to the oxygen-isotope fluctuations.
The central Cordilleran region has been an ecotone between forest and woodland-scrub vegetation since the middle Eocene. Responding to spreading drought and increasing topographic diversity, many near-modern Cordilleran species were present in both vegetation zones by the late Eocene. Following the elimination of most exotics of eastern affinity during the middle Oligocene, Cordilleran endemic woody species and endemic genera have dominated the forests and woodlands and have changed but little since then. Cordilleran taxa spread into the western Great Basin largely after 14 m.y. ago as climate became drier, summer rains were reduced, and eastern exotic taxa were eliminated. In the late Miocene (5-7 m.y.) some Cordilleran taxa were restricted eastward as summer rains decreased further. Elevation of the southern Rocky Mountain region 1500-3000 m following the later Miocene, together with the global trend to cooler climate, restricted many frost-senstive taxa to the Madrean region farther south. The Great Basin differentiated from the southern Rocky Mountain flora as a double rainshadow developed as the Sierra Nevada-Peninsula Ranges and the Wasatch-Colorado Plateau were elevated in the late Neogene and Quaternary. During this period species in a few herbaceous and perennial groups, such as Astragalus, Eriogonum, and Penstemon, proliferated as new adaptive zones became available at both low and high elevations. The surviving Cordilleran flora in both its Great Basin and southern Rocky Mountain sectors is impoverished, its taxa having adapted to the present more severe continental climate.