Anthropogenic-induced Climate Change Research Articles

Combined effects of precipitation anomalies and dams on streamwater-groundwater interaction in the Fen River basin, China

Both water management measures like damming and changes in precipitation as a result of anthropogenic induced climate change have exerted profound effects on the dynamics of streamwater-groundwater interaction (SGI). However, their compound effects on SGI have not been investigated so far. Taking the Fen River of China as an example, this study aims to examine the synergistic impacts of damming and precipitation anomalies on SGI dynamics. The sampling considered the seasonal and interannual variability of precipitation (May and September in 2019 representing a dry year; May and August in 2021 representing a wet year), and long-term daily observational data, including water levels and water discharge, were combined to elucidate the compound effects. Precipitation anomalies and damming exert significant individual and combined influences on SGI. Separately, dams and reservoirs reversed the SGI dynamics, significantly increasing the contributions of streamwater to groundwater from 0 to 29 % to 78 % in the dam-affected areas. Further, the groundwater discharge ratios behind the dam (about 60 %) were three times higher than those in front of the dam. Precipitation anomalies significantly amplified interannual variability in SGI patterns, and groundwater discharge ratios increased by 47 % during the dry period (2019) compared to flood period (2021). The combined influence of precipitation anomalies and dam regulation remarkably changed the lateral, vertical, and longitudinal water exchange dynamics. Precipitation anomalies affected the SGI dynamics at the whole watershed scale, whereas dam regulation regimes exhibited a stronger control at the local scale. The compound effects of dam regulation and precipitation anomalies can result in different SGI patterns under various climate scenarios. More attention should be paid to the interrelated feedback mechanisms between damming, extreme precipitation events, and their impact on the watershed-scale hydrological cycle.

The mechanisms and microstructures of passive atmospheric CO2 mineralisation with slag at ambient conditions

Removal of CO2 already in the Earth's atmosphere through CO2 mineralisation with alkaline waste materials such as steel slag is one approach to mitigate the effects of anthropogenically-induced climate change. However, the microstructures produced during passive carbonation of slag are not well known. Here we use Scanning Electron Microscopy imaging and chemical mapping, X-Ray diffraction and stable isotopes (δ13C and δ18O) to show that ingassed and hydroxylated atmospheric CO2 reacts with Ca leached from slag to precipitate calcite directly on the slag surface. Precipitated calcite crystal morphologies vary, ranging from bladed and acicular crystals to layered deposits of micron-scale equant crystals. The variable morphology and extent of calcite precipitation documented is linked to a combination of internal (i.e. microstructural properties of the slag itself) and external (environmental conditions) factors. This work shows that atmospheric CO2 can be drawn down and mineralised passively by the slag at ambient conditions as part of the slag valorisation and reutilisation process.

Acoustic propagation and ambient noise in a thawing Arctic

Over the past 50 years, the extent and volume of sea ice coverage in the Atlantic Ocean has been receding at a nearly linear rate due to anthropogenic induced climate change. It is expected that some time within the next 10 to 30 years, there will be an ice free summer. For periods beyond this time, the Arctic Ocean will change from mostly covered by multi-year ice to mostly covered by first year ice. In this talk, the impact of the changes in ice morphology (roughness and thickness) and ice extent will be examined from both an under-ice propagation modeling and an ambient noise modeling perspective. The first year ice is expected to have less loss, leading to better sound propagation. The reduced ice coverage will lead to more open water exposed surfaces for wind generated noise, and more open water for ice-free propagaiton of shipping induced anthropogenic sound. Both of these features will drive up the background level of sound in the Arctic Ocean. Regional differences in ice cover and expected wind and shipping noise will be addressed.

Ocean warming favours a northern Argyrosomus species over its southern congener, whereas preliminary metabolic evidence suggests that hybridization may promote their adaptation.

Anthropogenic-induced climate change is having profound impacts on aquatic ecosystems, and the resilience of fish populations will be determined by their response to these impacts. The northern Namibian coast is an ocean warming hotspot, with temperatures rising faster than the global average. The rapid warming in Namibia has had considerable impacts on marine fauna, such as the southern extension of the distribution of Argyrosomus coronus from southern Angola into northern Namibian waters, where it now overlaps and hybridizes with the closely related Namibian species, A. inodorus. Understanding how these species (and their hybrids) perform at current and future temperatures is vital to optimize adaptive management for Argyrosomus species. Intermittent flow-through respirometry was used to quantify standard and maximum metabolic rates for Argyrosomus individuals across a range of temperatures. The modelled aerobic scope (AS) of A. inodorus was notably higher at cooler temperatures (12, 15, 18 and 21°C) compared with that of A. coronus, whereas the AS was similar at 24°C. Although only five hybrids were detected and three modelled, their AS was in the upper bounds of the models at 15, 18 and 24°C. These findings suggest that the warming conditions in northern Namibia may increasingly favour A. coronus and promote the poleward movement of the leading edge of their southern distribution. In contrast, the poor aerobic performance of both species at cold temperatures (12°C) suggests that the cold water associated with the permanent Lüderitz Upwelling Cell in the south may constrain both species to central Namibia. This is most concerning for A. inodorus because it may be subjected to a considerable coastal squeeze.

Shipping noise modelling in the thawing Arctic Ocean

One of the earliest and clearest signals of the impact of anthropogenic induced climate change has been the severe reduction in sea ice extent in the Arctic Ocean, particularly in the summer. Predictions of an ice free summer range from 2030 to 2050. The reduction of ice extent and thickness opens the possibility for greater shipping traffic through polar regions for international shipping (cutting the transit time from Europe to Asia), for mine and indegenous nations logistics support and for high north fishing. The increased number and presence of ships is a potential threat to the sensitive marine species that live in the arctic and have evolved in a region devoid of anthropogenic sounds. Effective management of the region requires an understanding of the potential increases in shipping noise levels and in their relative levels to natural backround sound, such as wind and ice noise. In this paper, we present a modelling study of 2013–2019 shipping noise and look to build a model to predict the shipping noise in 2030 based upon the combination of national forecast economic plans and ice modeling. Mapping the projected levels of shipping noise into excess noise (level above wind and/or background ice levels) provides a methodology for developing management decisions consistent with other noise measurement and mitigation projects. Comparison of models with passive observations of arctic soundscapes will be presented.

The stress and strain dependent response of THF hydrate

Large volumes of methane gas hydrate reside within fine-grained marine sediments on continental slopes within the Arctic region, where hydrate exists as fracture filling veins that may hinder normal consolidation processes during ongoing burial. Hydrate dissociation due to anthropogenic induced climate change, which is magnified in the Artic, may lead to significant weakening of the sediment triggering slope instabilities. However, the potential response of hydrate veins under axial loading is poorly understood. To gain better insights a series of uniaxial compression tests, under different stress and strain conditions, were conducted on cylindrical tetrahydrofuran (THF) hydrate specimens with different slenderness ratios. Results highlight the strain rate dependent behavior of the THF hydrate with compressive strength reducing with reducing strain rate. Specimens with high slenderness ratios under high strain rates failed predominantly from spontaneous brittle buckling of the specimen, while for low slenderness ratio specimens, at low strain rates, hydrate behavior is more ductile resulting in lower peak stresses but higher residual stresses. Hydrate under constant stresses exhibited extensive plastic deformation as axial stresses approached failure conditions, with low slenderness ratios showing extensive cracking and shear dislocations, while those high slenderness ratios experienced large out-of-plane deformations. The stress-strain response of the hydrate suggests that at shallow burial depths such as that on the Arctic continental slope where climate change will have the greatest impact, hydrate veins will inhibit sediment consolidation. However, at greater burial stresses the plastic deformation of the hydrate veins may not provide significant impediment to sediment consolidation. Further research is required to characterize the impact of the sediment matrix on hydrate behavior.

Community structure, species–habitat relationships, and conservation of amphibians in forested vernal pools in the Georgian Bay region of Ontario

Forested vernal pools serve an integral role in the recruitment of amphibians in glaciated northeastern North America. In south-central Ontario, vernal pools exist in relatively unimpacted forest networks, but the amphibian communities face uncertain challenges from anthropogenic-induced climate change. We surveyed amphibian larvae and collected measurements of habitat characteristics from vernal pools to collect baseline information on amphibian community structure and species–habitat relationships. Amphibian communities were influenced by hydroperiod length and canopy openness, and the relative abundances of early breeding amphibians were affected by changes in the structure of vegetation communities within pools. Our study suggests that, even across moderate ranges of breeding habitat characteristics, the structure of amphibian communities is dynamic. With anthropogenic-induced climate change leading to more drought-prone summers, the conservation of intact forests that support diverse wetland assemblages will be a necessary component of future legislation.

Environmental optima for an ecosystem engineer: a multidisciplinary trait-based approach

A complex interplay of biotic and abiotic factors underpins the distribution of species and operates across different levels of biological organization and life history stages. Understanding ecosystem engineer reproductive traits is critical for comprehending and managing the biodiversity-rich habitats they create. Little is known about how the reproduction of the reef-forming worm, Sabellaria alveolata, varies across environmental gradients. By integrating broad-scale environmental data with in-situ physiological data in the form of biochemical traits, we identified and ranked the drivers of intraspecific reproductive trait variability (ITV). ITV was highest in locations with variable environmental conditions, subjected to fluctuating temperature and hydrodynamic conditions. Our trait selection pointed to poleward sites being the most physiologically stressful, with low numbers of irregularly shaped eggs suggesting potentially reduced reproductive success. Centre-range individuals allocated the most energy to reproduction, with the highest number of intermediate-sized eggs, whilst equatorward sites were the least physiologically stressful, thus confirming the warm-adapted nature of our model organism. Variation in total egg diameter and relative fecundity were influenced by a combination of environmental conditions, which changed depending on the trait and sampling period. An integrated approach involving biochemical and reproductive traits is essential for understanding macro-scale patterns in the face of anthropogenic-induced climate change across environmental and latitudinal gradients.

Impact Assessment Analysis of Sea Level Rise in Denmark: A Case Study of Falster Island, Guldborgsund

Anthropogenically-induced climate change is expected to be the contributing cause of sea level rise and severe storm events in the immediate future. While Danish authorities have downscaled the future oscillation of sea level rise across Danish coast lines in order to empower the coastal municipalities, there is a need to project the local cascading effects on different sectors. Using geospatial analysis and climate change projection data, we developed a proposed workflow to analyze the impacts of sea level rise in the coastal municipalities of Guldborgsund, located in Southeastern Denmark as a case study. With current estimates of sea level rise and storm surge events, the island of Falster can expect to have up to 19% of its landmass inundated, with approximately 39% of the population experiencing sea level rise directly. Developing an analytical workflow can allow stakeholders to understand the extent of expected sea level rise and consider alternative methods of prevention at the national and local levels. The proposed approach along with the choice of data and open source tools can empower other communities at risk of sea level rise to plan their adaptation.

Thermal tolerance, safety margins and vulnerability of coastal species: Projected impact of climate change induced cold water variability in a temperate African region

Anthropogenic induced climate change is predicted to increase the thermal variability in coastal waters, which can have strong physiological effects on individuals and populations of marine ectotherms. The magnitude and direction of these thermal effects varies depending on species, life stage, biogeography, habitat and season. This study aimed to compare the thermal tolerance of a range of juvenile fish and adult macro-invertebrates from intertidal and estuarine habitats in a warm-temperate, thermally variable region on the south-east coast of South Africa. Seasonal variability in thermal tolerance was compared between species, taxonomic groups, biogeographical distribution and habitat affinity and related to existing and projected water temperature data to gauge the local vulnerability of each species. Critical thermal maximum (CTmax), critical thermal minimum (CTmin), thermal breadths and scopes, and the thermal safety margins of each species were quantified. The greatest differences in thermal tolerance patterns were based on taxonomy, with macro-invertebrates having broader thermal tolerance compared to fish, with the exception of the Cape sea urchin, in both summer and winter. Relatively narrow lower breadths in tolerance and safety margin values for transient juvenile sub-tropical and temperate fish species from the intertidal rocky low-shore habitat were observed in both summer and winter. This indicates that these fish species and the Cape sea urchin may be more vulnerable to projected increases in cold temperature (upwelling in summer) than warm temperature variability in this warm-temperate region if they are unable to seek thermal habitat refuge.

Safeguarding Cultural Heritage using novel technologies: The perspective from a UK volunteer-led site

Continuing anthropogenic induced climate change poses risks to Cultural Heritage (CH) across the world. In the UK, concerns about future flood risks, increased number of heatwaves and changes to freeze-thaw cycles are at the forefront for managers of CH assets. Importantly, in the UK, and unlike many European countries, cultural, natural and built heritage sites are often run by or with the help of groups of volunteers, whether that being at a national level working in partnership with organisations like Historic England or at a local level with small community trusts. Mellor Archaeological Trust is one such local charity which aims to preserve, maintain and protect the local CH assets for our community and future generations. Climate change and its impacts are, therefore, a big concern for the trust as it looks to plan for the future. After a successful pilot of the STORM service, Mellor was able to demonstrate how the use of inexpensive and novel technologies can help small and large volunteer-led organisations in protecting heritage whilst ensuring that correct procedures are followed. In this paper, we demonstrate the successful use of the STORM service from a UK perspective explaining the benefits and drawbacks and highlight how such services should be utilised by other organisations.

Urbanization effects on surface air temperature trends in Thailand during 1970-2019

Continued urban expansion undergone in the last decades has converted many weather stations in Thailand into suburban and urban setting. Based on homogenized data during 1970-2019, therefore, this study examines urbanization effects on mean surface air temperature (Tmean) trends in Thailand. Analysis shows that urban-type stations register the strongest warming trends while rural-type stations exhibit the smallest trends. Across Thailand, annual urban-warming contribution exhibits a wide range (< 5% to 77%), probably manifesting the Urban Heat Island (UHI) differences from city to city resulting from the varied urban characteristics and climatic background. Country-wide average urban warming contribution shows a significant increasing trend of 0.15 <sup>o</sup>C per decade, accounting for 40.5% of the overall warming. This evidence indicates that urban expansion has great influence on surface warming, and the urban-warming bias contributes large fraction of rising temperature trends in Thailand. The increasing trend of annual Tmean for Thailand as a whole after adjusting urban-warming bias is brought down to the same rate as the annual global mean temperature trend, reflecting a national baseline signal driven by large-scale anthropogenic-induced climate change. Our results provide a scientific reference for policy makers and urban planners to mitigate substantial fraction of the UHI warming.

The Need of Species Distribution Models Metadata: Using Species Distribution Model to Address Decision Making on Climate Change

Anthropogenic-induced climate change has already altered the conditions to which species have adapted locally, and consequently, shifts of occurrence areas have been previously reported (Chen et al. 2011). Anticipating the results of climate change is urgent, and using these results efficiently to guide decision-making can help to build strategies to protect species from those changes. Therefore, our objective is to propose the use of climate change impact assessments, obtained through species distribution models (SDMs), to guide decision making. The emphasis will be on data that could help determine the potentially vulnerable species and the priority areas, which could act as climate refuges, as well as wildlife corridors. SDMs are based on species occurrence points, available mainly from biological collections and observations (Franklin 2010). When combined with geospatially explicit layers of abiotic or biotic data (e. g. temperature, precipitation, land use), which defines the ecological requirements of species under study, it can generate species distribution models. These models are projected in the form of maps indicating areas where the species can find the most suitable habitats and, therefore, where one can most likely find them. To support public policies decision, the generation of robust and reliable model is an important factor. A minimum number of six occurrence points is a mandatory requirement, with non-overlapping area as a filter criteria. Unfortunatelly, in Brasil, as well as in Latin America in general, this type of data is scarce. Thus, with SDMs, four types of decision making information data regarding priority species and areas could be obtained (Fig. 1). Size of potential occurrence areas: species that have a small area of occurrence are potentially vulnerable, since they present endemism, usually living in restricted environmental conditions. In this case, any small change in environmental conditions can result in the extinction of the impacted species. Thus, this region needs to be protected. Difference between current and future area: species presenting the most significant reduction in potential areas should be prioritized by decision-makers. This measurement could be used as an indication of vulnerability. Even species that have no predicted area reduction or an increase could be prioritized in management programs due to its role in the complex interaction networks of ecosystem services, such as pollinators, seed dispersers or disease control. These species could be more resilient to network interaction changes due climate, and possibly are better able to provide their services in the extreme unfavorable climate scenarios. Areas that maintain higher species diversity in future scenarios: their protection could be prioritized in restoration and conservation programs. Especially in cases involving multiple species, those areas could be considered as climate refuges by decision-makers. Additionally, for the reconstruction and use of SDM published in peer-reviewed journals, it is necessary that all pieces of information about models, its generation, ensemble methods, data cleaning and data quality criteria applied should be available. The availability of the four above mentioned types of information can help on decision-making strategies aiming the protection of priority species and areas. In conclusion, SDMs present essential information about the present and future impacts of projected climate change and their derived data could be preserved using a standard controlled vocabulary.

Perceptions of climate change among Grade 11 learners in the Tshwane Metropolitan Municipality, South Africa

Of all the environmental problems facing humankind today, anthropogenic-induced climate change is regarded as one of the most damaging in its potential repercussions. For this reason, the perceptions of climate change among high-school learners, who represent future decision-makers and stand as a proxy for the next generation, are of importance. This study was designed so as to gain insight into the nature of perceptions and associated determinants among Grade 11 learners in the Tshwane metropolitan municipal area. Specifically, it probed dynamics between the content in the formal curriculum (Curriculum and Assessment Policy Statement or CAPS) and learners’ exposure to electronic media, their peers and parents (their arenas of social interaction) in forming these perceptions. The study involved a qualitative analysis of 68 questionnaires completed by learners from two high schools. Findings include misconceptions regarding climate change among learners, as they conflate climate change and the greenhouse effect. The learners’ perceptions seem to be shaped by the cumulative outcomes of dynamics between different arenas of exposure and influence (formal education, peers, parents and the media). It is argued that learners’ perceptions about climate change fostered in formal education should also be understood in the context of their potential exposure to: (1) alarmist framings of climate change in the media; (2) conceptual disagreements in the climate change research community; and (3) the influence of peers and parents. Rather than avoiding the dynamics from contesting and diverging ‘arenas of exposure’, future climate change education planning should accommodate and align contending views that might influence the learning process. Keywords: Climate change, school curriculum, learner perceptions, media, peers

Assessment of Hydrologic Alterations in Elbe and Rhine Rivers, Germany

In light of recent anthropogenic-induced climate change, a burning question at present is how these changes influence the water regime of rivers, which are of vital importance for humans as well as for biota. In this study, we investigate the changes in the hydrologic regime of two major German rivers, Elbe and Rhine, after the middle of the 20th century. Here, we use the widely adopted Range of Variability Approach (RVA) method on daily streamflow data from five (Elbe) and seven (Rhine) hydrological stations to determine the variability and spatial pattern of hydrologic alterations. We discuss the potential effect of climate change on the water regime of these two rivers, as well as other potential causes. For both rivers, we find that some hydrologic parameters are highly altered, especially the number of reversals, indicating higher variability. The highest impact is found at Ems hydrological station on Rhine River. The order of affected hydrological stations follows mostly the downstream course of both rivers. Our study indicates that the hydrological behavior of Elbe and Rhine Rivers has altered since the middle of the 20th century, a probable consequence of climate change. These hydrologic alterations can lead to undesirable ecological effects on local biota.

Social–ecological challenges in the Yellow River basin (China): a review

The human–environment relationship within the Yellow River basin has a long history, because favorable environmental circumstances allowed the early emergence of societies along the river banks, and hence, the Yellow River basin was the birthplace of ancient Chinese civilization. On the other hand, the Yellow River is “China’s sorrow” due to the constant occurrences of flooding events throughout history. In recent decades, the Yellow River basin is facing a spectacular economic boom, but mainly achieved at the expenses of the environment by over-exploiting the natural resources provided within the basin, which causes various challenges on ecology and society. Water scarcity, pollution, and ecosystem degradation accompanied with biodiversity decline have been further aggravated by anthropogenic-induced climate change. To address the pressing socio-ecological challenges, various conservation and management plans and strategies have been issued, often consulted by international bodies. This article is a comprehensive overview of the current state and recent developments that have occurred in the Yellow River basin and presents and discusses current and pressing socio-ecological challenges. Additionally, we address different policy and management instruments that have been launched to ensure a long-term sustainable development within the basin.

Environmental controls on the distribution and diversity of lentic Chironomidae (Insecta: Diptera) across an altitudinal gradient in tropical South America.

To predict the response of aquatic ecosystems to future global climate change, data on the ecology and distribution of keystone groups in freshwater ecosystems are needed. In contrast to mid- and high-latitude zones, such data are scarce across tropical South America (Neotropics). We present the distribution and diversity of chironomid species using surface sediments of 59 lakes from the Andes to the Amazon (0.1-17°S and 64-78°W) within the Neotropics. We assess the spatial variation in community assemblages and identify the key variables influencing the distributional patterns. The relationships between environmental variables (pH, conductivity, depth, and sediment organic content), climatic data, and chironomid assemblages were assessed using multivariate statistics (detrended correspondence analysis and canonical correspondence analysis). Climatic parameters (temperature and precipitation) were most significant in describing the variance in chironomid assemblages. Temperature and precipitation are both predicted to change under future climate change scenarios in the tropical Andes. Our findings suggest taxa of Orthocladiinae, which show a preference to cold high-elevation oligotrophic lakes, will likely see range contraction under future anthropogenic-induced climate change. Taxa abundant in areas of high precipitation, such as Micropsectra and Phaenopsectra, will likely become restricted to the inner tropical Andes, as the outer tropical Andes become drier. The sensitivity of chironomids to climate parameters makes them important bio-indicators of regional climate change in the Neotropics. Furthermore, the distribution of chironomid taxa presented here is a vital first step toward providing urgently needed autecological data for interpreting fossil chironomid records of past ecological and climate change from the tropical Andes.

A tree-ring perspective on temporal changes in the frequency and intensity of hydroclimatic extremes in the territory of the Czech Republic since 761 AD

Abstract. It is generally accepted that anthropogenic-induced climate change may affect the frequency and intensity of hydrological extremes, together with a variety of subsequent impacts on ecosystems and human society. Proxy records that are absolutely dated and annually resolved are indispensable to a better understanding of temporal changes in the occurrence of floods and droughts. This contribution presents a new data set of 3194 oak (Quercus spp.) ring width samples from living trees and historical timbers, collected across the Czech Republic. A composite tree-ring width (TRW) chronology is developed that best captures the high-frequency extremes over the past 1250 years. The temporal distribution of negative and positive extremes is regular with no indication of clustering. The highest number of negative extremes was found in the 19th century, while positive extremes were most frequent in the 12th century. The lowest number of negative and positive extremes occurred in the 18th and 13th centuries respectively. Negative and positive TRW extremes were compared with the instrumental measurements back to 1805 AD, with documentary-based temperature and precipitation reconstructions from 1804 to 1500, and with documentary evidence before 1500 AD. Negative TRW extremes coincided with above-average March–May and June–August temperature means and below-average precipitation totals. Positive extremes coincided with higher summer precipitation, while temperatures were mostly normal. Mean sea level pressure (SLP) over the European/North Atlantic sector suggested drought for the negative oak TRW extremes, whereas the positive extremes corresponded to wetter conditions overall. More consistent patterns of synoptic SLP were found for negative rather than for positive extremes. Reasons for the possible offset between the oak-based hydroclimatic extremes and their counterparts from meteorological observations and documentary evidence may be manifold and emphasize the need for multi-proxy approaches.

Review of documented beak and feather disease virus cases in wild Cape parrots in South Africa during the last 20 years

Worldwide, there is concern about the increased prevalence of infectious diseases and their effects on biodiversity. Increasing changes in the environment, particularly changes in climatic conditions as a consequence of anthropogenic-induced climate change, are some of the factors driving this increased disease prevalence. Vertebrate taxa that appear to be most affected by these diseases are amphibians and birds, though this may be a consequence of research effort. Beak and feather disease virus (BFDV) affecting psittacine bird species is the disease of concern here. Data on BFDV incidence in wild, endangered Cape parrots (Poicephalus robustus) were collected opportunistically from 1992 to 2014. Data show that the disease is prevalent naturally in the wild during extreme climatic events, including drought. This stresses the birds, which may result in the expression of pathological symptoms. Juveniles in particular appear to succumb during times of drought. This has conservation implications with the impacts of extreme climatic events associated with anthropogenic-induced climate change.

Implications of reduced turbidity current and landslide activity for the Initial Eocene Thermal Maximum – evidence from two distal, deep-water sites

Previous studies propose that submarine landslides and turbidity currents may become more likely due to future rapid global warming. Determining whether global warming increases likelihood assists in assessment of landslide-triggered tsunami hazards and risk to seafloor structures. Other studies propose that landslides helped to trigger past rapid climate change due to sudden release of gas hydrates. Two deep-water turbidite records show prolonged hiatuses in turbidity current activity during the Initial Eocene Thermal Maximum (IETM) at ∼55 Ma. The IETM represents a possible proxy for future anthropogenically-induced climate change. It is likely that our records mainly represent large and fast moving disintegrative submarine landslides. Statistical analysis of long term (>2.3 Myr) records shows that turbidity current frequency significantly decreased after the IETM. Our results indicate that rapid climate change does not necessarily cause increased turbidity current activity, and do not provide evidence for landslides as a primary trigger for the IETM.