Period Of Climate Warming Research Articles

Landscape evolution in the southern Transantarctic Mountains during the early Miocene (c. 20–17 Ma) and evidence for a highly dynamic East Antarctic Ice Sheet margin from the southernmost volcanoes in the world (87°S)

Observations of ice sheet stability in Antarctica in the past, during significantly warmer climatic periods than today, are hampered by a paucity of continental outcrops but they are essential if we are to test and more fully understand established concepts of ice sheet growth and decay and robustly predict Earth's future during rapid global warming. In this paper we use the unique terrestrial record preserved in the three most southerly volcanoes on Earth to reconstruct Antarctica's environmental landscape in the Transantarctic Mountains for three time slices (at 20.1, 19.31 and c. 17 Ma). We demonstrate that the East Antarctic Ice Sheet margin was highly dynamic and fluctuated greatly during the Early Miocene. The period included a much-reduced ice cover that left the southern Transantarctic Mountains virtually ice-free, although a few tidewater glaciers reached the shores of the Early Miocene Ross Sea (Sheridan Bluff; 20.1 Ma); and a substantially thicker, much more voluminous ice mass (represented by volcanism at Mount Early; 19.31 Ma). An intermediate stage of ice retreat is also indicated (at c. 17 Ma), when the East Antarctic Ice Sheet had again withdrawn to behind the Transantarctic Mountains. It is represented by a subglacial volcanic centre identified remotely by aerogeophysics and sampled only as glacial erratics. The associated ice cover at c. 17 Ma had a relatively low surface elevation but it was confluent with thin ice domes that covered the adjacent mountains. Although the ice margin probably did not extend down to the Ross Sea coast, several glaciers fed icebergs into the Ross Sea. The large ice sheet indicated by the Mount Early volcanic centre is the only known physical record of a significant glacial event that took place at 19.31 ± 0.32 Ma (‘Mount Early glacial’). The records examined at the other two volcanic sites correspond to eruptions during periods of substantially reduced ice in Antarctica, of which that at 20.1 ± 0.4 Ma is the most remarkable (‘Sheridan Bluff interglacial’). The causes of the extreme variations in ice sheet thickness and extent indicated are uncertain but they occurred during a period of rapidly fluctuating atmospheric CO2 compositions. Although Milankovitch astronomical forcing probably also played a significant part, the results suggest that the East Antarctic Ice Sheet was highly susceptible to comparatively slight changes in CO2 during the warm Early Miocene.

Spatial patterns in recent forest growth trends across the Czech Republic

ABSTRACT The radial growth of trees significantly contributes to climate change mitigation by sequestering carbon into woody biomass. Radial growth trends observed in European temperate forests during the recent period of climate warming vary between growth acceleration due to longer growing seasons and growth declines due to amplified drought stress. Assessing the spatial variation of growth trends is challenging due to the point relevance of available empirical data including forest inventories and tree-ring width chronologies. Here, we used a database of tree-ring width chronologies from 596 sites and spatial models to describe the growth trends of five tree species across the Czech Republic between 1990 and 2018. The resulting map highlights multiple sources of variation in growth trends including differences between species and prominent spatial gradients along elevation, latitude, and longitude. The knowledge of spatially explicit growth trends is essential for the adaptation of the forestry sector to ongoing climate change.

Structure and functioning of plankton communities оf the Rybinsky Reservoir under the conditions of climate change

Based on the data of complex environmental studies, which have been regularly carried out at six standard stations of the Rybinsk Reservoir since the middle of the 20th century, the orientation of changes in the elements of the reservoir ecosystem associated with global climatic events has been analyzed. During the period of climate warming, which began in 1977 and continues into the 21st century, the air temperature in the warm season increased by 0.9°C, the water temperature by 1.4°C, the average annual inflow by 7.5%, and the duration of the ice-free period by two weeks. An increase in electrical conductivity and color of water, a decrease in transparency were noted. With significant interannual variations in biological characteristics, in the XXI century, the number of bacterioplankton increased by 1.7 times, and bacterial production doubled. Chlorophyll content increased by 1.4 times and values 15 µg/L reflecting the eutrophic state of the reservoir began to be observed more often. In the biomass of phytoplankton, the proportion of small cell forms increased. The total abundance of phytoplankton increased due to the development of cyanobacteria, which form a long summer maximum in the seasonal dynamics of the community. The increase in water mineralization promoted the progressive spread of alien brackish-water algae. Biomass of zooplankton increased by 2.5 times. An increase in the abundance of crustaceans (Cladocerans, by 1.6 times; Copepods, by 1.9 times) caused a change in the structure of zooplankton and the formation of a strong late summer peak of biomass. The intensification of hydrobiological processes was clearly manifested after the abnormally hot 2010, the conditions of which not only stimulated the development of plankton communities, but also but also caused the formation of oxygen deficiency in the bottom layers. Warming has significantly transformed the ecosystem of the Rybinsk Reservoir, intensified eutrophication processes and worsened water quality. Changes in hydrometeorological characteristics have gone beyond the mild scenario of climate warming.

Anthropogenic activity in prehistory on the background of Holocene climate changes in the south-eastern Baltic region

Data on natural palaeoarchives combined with archaeological materials from prehistoric sites of the south-eastern Baltic provide a picture of ancient anthropogenic activity and main stages of evolution of local communities starting from the Mesolithic. Modern Analog Technique (MAT) method applied for the Kamyshovoe lake palynological data is used to reconstruct the seasonal temperature and precipitation trends and values during the Holocene. During the Mesolithic, climate conditions changed from those close to the late Glacial through a period of warmer and wetter climate with parameters close to the present day to conditions of climatic optimum, when temperature was several degrees higher that modern ones. These climate conditions existed during the first part of the Neolithic as well, while from about 5500 cal yr BP the climate changed towards colder temperatures and a shift in seasonal moisture content: summers became wetter and winters less snowy. For the Bronze Age, relative temperature stability along with significant precipitation fluctuations are reconstructed. Since the Iron Age, temperatures remain close to modern ones and several “wetter” episods are distinguished.

The influence of palaeo-fire activity on the dynamics of vegetation cover in the piedmont of Northern Altai for the past 16000 years

This work presents results of reconstructing dynamics of palaeo-fires in the piedmont of Northern Altai over the past 16185 cal. yr BP on the example of sediments of the Mokhovoe mire (Altai krai). 27 local fire episodes were identified based on macro-charcoal analysis and statistical processing in the CharAnalysis software package in R space. According these data, 7 periods of maximum pyrogenic activity were identified over the entire period of the Mokhovoe mire existed. The obtained data were compared with published paleoecological reconstructions for the Mokhovoe mire. To identify relationship between vegetation and fires, we carried out a correlation analysis between macro-charcoal and pollen data using the Pearson method in the PAST program. As a result, the possible influence of fires on the change of vegetation cover (post-fire successions) was revealed. The study also recorded high pyrogenic activity during warm and humid climatic periods when fir (Abies sibirica) dominated in the vegetation cover.

Cercospora beticola causes leaf and stem spots of New Zealand spinach (Tetragonia tetragonoides) in Brazil

New Zealand (NZ) spinach (Tetragonia tetragonoides) is an important leafy vegetable crop in Brazil and other countries. This plant is used as a substitute for common spinach because it is rustic and tolerant to tropical and subtropical environmental conditions. It is often affected by a leaf and stem spot disease, which increases in severity during the warm climatic periods. Cercospora tetragoniae has been reported as the cause of this disease, but this is based on an early description of a Cercospora-like species on this host in Argentina, first named Cercosporina tetragoniae but later recombined into Cercospora. In the present study, isolates of Cercospora-like fungi were obtained from NZ spinach and beetroot plants in Brazil, and a multigene molecular study including the act, cal, gapdh, his3, ITS, and tef1-α regions was carried out to identify the causative pathogen. Additionally, morphological and cross inoculation studies were conducted with isolates obtained from diseased plants. The pathogen was confirmed as Cercospora beticola, a common and harmful pathogen of beetroot (Beta vulgaris). Cross-inoculations of isolates obtained from NZ spinach and beetroot showed that the isolates are infective to both hosts. This increases knowledge of epidemiology and management of this important disease. Several attempts to re-collect samples from the type locality in Argentina failed. NZ spinach is no longer grown at La Plata (Argentina), the type locality of C. tetragoniae. Therefore, the task of re-collecting the pathogen is still pending, for epitype designation and for a full clarification of the taxonomic status of C. tetragoniae. The possibility of the pathogen being seed-transmitted has been assessed, and evidence obtained justifies further assessment of this aspect.

Temporal and spatial comparisons of ocean quahog (Arctica islandica) growth and lifespan on the mid-Atlantic continental shelf during inshore transgressions of their range from the Neoglacial through the twentieth century

Arctica islandica provide long-term records of climate change on the U.S. northeast continental shelf transgressing and regressing across the shelf numerous times synchronously with cold and warm climatic periods. The availability of A. islandica in the death assemblage over a wide geographic and temporal range makes this species well suited for documenting both spatial and temporal influences of climate change in the Mid-Atlantic through the correlation of growth rates in response to changing water conditions. This study focuses on comparing regional growth of subfossil ocean quahogs obtained offshore of the Delmarva Peninsula (Delmarva), and living during the cold periods since the Holocene Climate Optimum, with living A. islandica from offshore New Jersey, offshore Long Island, and Georges Bank. These populations exhibited different growth rates, with subfossil individuals from Delmarva death assemblages, representing previous Holocene cold periods, having growth rates as greater than or equal the growth rates of living individuals. Moreover, the growth rates for subfossil A. islandica from Delmarva that were alive from 1740 to 1940 were more rapid than contemporaneous individuals of the same age alive today. Higher growth rates for A. islandica from off Delmarva suggest that conditions supported near maximum growth during the cold periods after the Holocene Climate Optimum, possibly due to increased food supply in water shallower than that inhabited today. Unlike many bivalves, evidence for range recession of A. islandica as bottom water temperatures warm is found first in juvenile abundance, suggesting that recruitment ceases long before the population's demise: range recession in this species is a 100+ year process determined by the survivorship of the oldest and largest individuals. This study is the largest spatial and temporal growth comparison of A. islandica ever recorded and the first record of the process by which this species' inshore range regresses as temperatures rise.

Ammonium “nutrient capacitor” model for δ15N signatures associated with marine anoxic events

Abstract Geochemical records of ancient periods of warm climate can be useful to help understand the looming effects of modern anthropogenic warming, including changes to biogeochemical nutrient cycles. Stable nitrogen isotope compositions of marine sediments archive the balance of processes in the global nitrogen cycle. However, the unusual isotopic signals of Mesozoic oceanic anoxic events (OAEs) remain enigmatic, thus hindering our understanding of nitrogen cycle processes and dynamics under conditions of ocean deoxygenation. Here, we present an ammonium “nutrient capacitor” model of the water-column nitrogen cycle to explain the anomalously negative isotopic compositions seen in Mesozoic OAE sediments. Our model applies isotopic inferences derived from high-resolution records of Lake Kivu sediments to show how periodic chemocline overturning of redox-stratified water columns during Mesozoic OAEs may have delivered ammonium to the photic zone in excess of primary producer requirements. Smoothed, stochastic sampling of the changing fluxes within the nitrogen cycle across these events can simulate OAE nitrogen isotope records.

Gradually increasing precipitation since 20 ka as evidenced by loess dolomite abundance in the Ili Basin, Central Asia

The mechanisms and processes of precipitation change during warm climatic periods, such as the Holocene, may provide critical insights into future regional precipitation trends in the arid and semiarid Central Asian core in the context of potential global warming. Previous studies have reconstructed different effective moisture changes during the warm Holocene epoch, i.e., a long-term wetting trend vs. a long-term drying trend. A potential reason for these conflicting results is that the reconstructed effective moisture proxies may involve effects from both temperature and precipitation, which can differ in different contexts. A pure precipitation proxy, which could be used to disentangle the interference of temperature, is important to solving this conflict. Here, we present two precipitation records based on the dolomite abundance in loess sections, which is nearly independent of temperature change, in the Ili Basin. These records span the past 20 ka and are constrained by high-resolution chronologies based on quartz optically stimulated luminescence. Our records indicate gradually increasing precipitation since 20 ka. This precipitation change is then assessed in the context of the Northern Hemisphere high-latitude ice volume, migration of the mid-latitude westerlies, and penetration of the Asian monsoon. We conclude that (1) the precipitation change is generally consistent with the reported effective moisture change since 20 ka in the study area; (2) increasing precipitation from the Last Glacial Maximum to the early Holocene was mainly controlled by the decreasing Northern Hemisphere high-latitude ice volume; and (3) further increases in precipitation during the Holocene were possibly related to the southward migration of the mid-latitude westerlies and penetration of the Asian monsoon. Our precipitation records also reconcile the common disconnection using the driving mechanism of precipitation to interpret the geological effective moisture changes in Central Asia.

Morphometric Analysis of a Trapdoor Spider (Araneae, Idiopidae) across Different Brazilian Biomes Reveals the Geographic Variation of Spiders from the Caatinga Biome

Widespread species are exposed to different environmental drivers and can consequently present variations in body shape and/or size. Trapdoor spiders of the genus Idiops are generally associated with a sedentary lifestyle and limited dispersion. However, the species Idiops pirassununguensis has a wide distribution, occurring in a diverse range of distinct environmental conditions, with their presence recorded in the Amazon, Caatinga, and Cerrado Brazilian biomes. We investigated how their morphological variation is structured regarding the biomes in which they occur through a morphometric analysis of the linear measurements and morphogeometric shapes of 64 specimens. Combining different methods proved to be a valuable approach to understanding how the spider’s morphology varies in different environments. The results were congruent and complementary, indicating intraspecific geographic variation, with the Caatinga specimens being distinct from their biome conspecifics. In Caatinga, a biome with periods of severe drought and warm climate, I. pirassununguensis specimens were found to be smaller, in addition to having narrower and elongated sternums and shorter legs. The morphological structuring herein is consistent with the results found comparing animals from Caatinga and other Brazilian biomes. Despite differences in their non-sexual structures, the specimens share a set of diagnostic sexual characteristics for the species, allowing all individuals to be classified as belonging to the same species.

Understanding the characteristics of loess strata and quaternary climate changes in Luochuan, Shaanxi Province, China, through core analysis

Abstract Profile sampling, which causes missing or overlapping horizons, has been generally used while studying loess stratigraphy and paleoclimate. Conversely, drill sampling of thick loess can provide a relatively complete and actual record of the Quaternary climate and environmental changes. Here, paleomagnetic chronological analysis and particle size and magnetic susceptibility analyses were performed to accurately reveal the loess stratigraphy characteristics of Luochuan loess tableland in Fu County, Shaanxi Province, China. The FX core revealed that the Quaternary loess layer was 167.03 m thick and consisted of 33 layers of developed loess/paleosol sequences and 37 loess/paleosol assemblages. The paleosol horizons indicated relatively warm and humid climatic period, while loess/sand reflected cold and arid climate. Since 2.6 Ma, the climate of the region has undergone 37 warm and cold cycles trending toward an increasingly dry and cold climate. During this time, 10 paleoclimate cycles occurred during 2.6–1.6 Ma, 15 climate cycles occurred during 1.6–0.8 Ma, and 12 loess–paleosol cycles have occurred from 0.8 Ma to the present day. Our study provides a basis for accurately and comprehensively interpreting the paleoclimate and paleoenvironment during loess deposition formation.

Environmental regulation and corporate employment revisited: New quasi-natural experimental evidence from China's new environmental protection law

This paper investigates how environmental regulation affects corporate hiring decisions. Using the enactment of China's New Environmental Protection Law in 2015 as an exogenously regulatory shock, we run a difference-in-differences regression to identify causality. The results show that stricter environmental regulation significantly reduces corporate employment by approximately 5.1% on average. This negative effect is stronger for firms with greater liquidity constraints, worse environmental performance, higher labor intensity, more severe labor market frictions, and regions under stricter law enforcement. In addition, the mechanism tests reveal that stricter environmental regulation conduces to higher environmental risks, less debt financing, and higher liquidity constraints, which is consistent with the financial constraints channel. Overall, the government should take the employment destruction effect of environmental regulation seriously, especially during periods of climate warming and the coronavirus disease pandemic.

Pleistocene gaps in the areas of birds of Eastern Siberia and their filling in the modern period of climate warming

Based on long-term studies (1968-2022), materials are presented on the change in the areas of birds in Eastern Siberia, caused by pronounced climate warming in the second half of the 20th - early 21st centuries. During the period of the last strong Pleistocene cooling, this territory was characterized by mountain-valley icing. As a result, the common areas of many bird species were torn apart. Subsequently, in isolated groups, evolution followed different paths, which led to the emergence of new closely related species. At present, due to the strong warming of the climate in Eastern Siberia (1.9°/100 years on average) and the change in the area boundaries of many bird species, the former gaps in their areas are being filled. For many bird species, secondary contact has been recorded with the formation of vast transitional zones in which their areas overlap to some extent. So far, there are relatively few of them, but the general trend towards overlapping areas of a number of bird species can be seen quite clearly. Among the species with area gaps without further speciation, shorebirds sharply predominate. However, among the species whose area gap ended in speciation, their number is significantly reduced. The current period of sharp climate warming and a significant change in the areas of birds in Eastern Siberia is characterized by a sharp increase in their biodiversity. However, it is combined with the low population density of many species, especially those new to the ecosystems of the region. Such a situation requires increased attention to the existing structure of the bird population and its dynamics, since it is observed extremely rarely - the shortest duration of the known centuries-old climate cycle is about 2000 years.

Microscopical palynology: Birch woodland expansion and species hybridisation coincide with periods of climate warming during the Holocene epoch in Iceland.

Introgressive hybridisation between arctic dwarf birch (Betula nana) and European downy birch (B.pubescens) is relatively common in natural woodlands in Iceland. As dwarf birch is a diploid species and downy tree birch a tetraploid species, their hybrids are triploid. In the introgression process, triploid hybrids, which are partially fertile, can backcross with the parental species, producing progenies comprising introgressed diploid, triploid and tetraploid plants. Triploid plants produce both normal triporate pollen (with three pores) and abnormal, aborted pollen, due to dysfunctional meiosis. The type of pollen abnormality that can be detected and quantified is non-triporate pollen (with four or more pores in the pollen wall). We therefore used the presence of non-triporate pollen as a marker to trace birch hybridisation in the past. In the current study we examined fossil pollen in samples from Holocene sediments from three locations: Grímsnes (SW), Eyjafjördur (N) and Thistilsfjördur (NE Iceland). All three peat monoliths had the starting age of 10.3cal. ka BP. Ages were calibrated based on known tephra layers and by radiocarbon dating. The size of Betula pollen grains was measured, and the species proportions calculated from size. Non-triporate grains were detected in samples from all three locations and throughout the Holocene, but with different frequencies. The peaks of intense hybridisation followed birch woodland expansion in two major periods of the Holocene, both coinciding with a warming of climate. The first period occurred in the Early Holocene, around 9.5-7cal. ka BP, when the climate warmed rapidly after deglaciation. The second period occurred around 5-3.5cal. ka BP, well within the mid-Holocene Northern Hemisphere warming. A new wave of birch hybridisation appears to have started in the last few decades as the climate has warmed. Birch woodlands are likely to become more widespread. Introgressed shrub birch is likely to be more competitive over dwarf birch.

Controlling of the Late Palaeozoic glaciation on reef evolution: A case study of a late Kasimovian coral reef in southern Guizhou, South China

A late Kasimovian (Pennsylvanian) coral reef is reported in the Yanbanzhai (YBZ) area, southern Guizhou Province, South China. The YBZ coral reef, with a thickness of approximately 5.5 m and a lateral exposure of nearly 50 m, is primarily composed of the colonial rugose coral Fomichevella. The fusulinids collected from the reef indicates a late Kasimovian age. Five microfacies types have been identified, including coated bioclastic grainstone, coral (Fomichevella) framestone, bioclastic wackestone, bioclastic grainstone, and peloidal grainstone. The vertical evolution of the microfacies in the YBZ coral reef indicates major sedimentary environmental changes associated with relative sea‐level changes. The growth of the reef‐builder Fomichevella was controlled by the transgression and regression. Deep water promoted the upward expansion of Fomichevella, while shallow water inhibited its growth. Published records of atmospheric pCO2 estimation and sea‐surface temperatures, combined with geochemical proxies, confirm a warm climatic period during the late Kasimovian. This is an interglacial period conducive to the growth of the coral reef. Sea‐level and climate changes associated with the Late Palaeozoic ice age (LPIA) are interpreted as significant controls of the development of the YBZ coral reef. This research of the YBZ coral reef in South China provides practical palaeobiological evidence for global sea‐level rising during the late Kasimovian period caused by the high‐latitude Gondwana delaciation.

Climate Change Influences Brain Size in Humans

Brain size evolution in hominins constitutes a crucial evolutionary trend, yet the underlying mechanisms behind those changes are not well understood. Here, climate change is considered as an environmental factor using multiple paleoclimate records testing temperature, humidity, and precipitation against changes to brain size in 298 Homo specimens over the past fifty thousand years. Across regional and global paleoclimate records, brain size in Homo averaged significantly lower during periods of climate warming as compared to cooler periods. Geological epochs displayed similar patterns, with Holocene warming periods comprising significantly smaller brained individuals as compared to those living during glacial periods at the end of the Late Pleistocene. Testing spatiotemporal patterns, the adaptive response appears to have started roughly fifteen thousand years ago and may persist into modern times. To a smaller degree, humidity and precipitation levels were also predictive of brain size, with arid periods associated with greater brain size in Homo. The findings suggest an adaptive response to climate change in human brain size that is driven by natural selection in response to environmental stress.

Origin of the Cryogenian iron formations: Climatic fluctuation coupling with local hydrothermal iron input

The brief resurgence of iron formation deposition during the Neoproterozoic Era appears to have been closely associated with the glaciation deposits. However, the genesis of these Cryogenian iron formations (CIFs) remains unclear. Here, we present Fe isotopic compositions and rare earth element (REE) contents for four Fulu iron formation (IF) lithostratigraphic sequences in the Sanjiang area, South China. The Fulu IF strata are in conformable contact with the underlying Chang’an glacial succession. However, owing to lack of glacial deposits evidence, they are interpreted to have formed in non-glacial conditions, probably during a warm period Sturtian glaciation. Because of the shrinking ice cover over the ocean surface, more oxidants have been transferred from the atmosphere to the ocean during this Sturtian warm period, leading to reconstruction of a redox-stratified ocean. Local hydrothermal vent systems provided dissolved Fe(II) to form the IFs, as inferred from the δ56Fe values and Eu anomalies of the Fulu IFs. Our results allow us to propose a new genetic model for the origin of CIFs; whereby partial Fe(II) oxidation caused the precipitation of Fe(III) oxide and enabled the deposition of CIFs. This occurred under redox-stratified conditions over an extended warm climatic period in combination with iron sourced from local hydrothermal activities during Cryogenian glaciations.

Quantification of Asian Dust Source Variabilities in Silt and Clay Fractions since 10 Ma by Parallel Factor (PARAFAC) Endmember Modeling at IODP Site U1425 in the Japan Sea

Abstract Japan sea sediments consist of various detrital materials of eolian and riverine origin. Understanding the provenance of eolian dust is vital for reconstructing the variability of wind patterns and monsoons in the past. New and complete eolian accumulation rates from Taklimakan, Gobi, and Ordos are reconstructed at Integrated Ocean Drilling Program (IODP) Site U1425 in the Japan Sea using parallel factor (PARAFAC) endmember modeling. Our results show that Taklimakan dust is dominated by the silt fraction, while Gobi dust is dominated by the clay fraction, and they are controlled by the relative contributions of different pathways of dust transport, such as the westerly winds and East Asian winter monsoon (EAWM). Clay-size dust from Gobi increased during three periods, late Miocene global cooling (LMGC), intensification of Northern Hemisphere Glaciation (iNHG), and mid-Pleistocene Transition (MPT), which reflected increased EAWM winds associated with global cooling and glaciation. Taklimakan became the major dust contributor to the Japan Sea sediments during the warmer climate periods in the latest Miocene to early Pliocene and the Late Pleistocene, where westerly wind activity dominated eolian transport. Dust from Ordos increased greatly 0.95-0.85 Ma due to enhanced Asian aridification since 2 Ma in Northwest China. Detrital flux from Japanese islands suggests that the East Asian summer monsoon (EASM) was stronger 9.6-8 Ma and weakened from 8 Ma to the Pleistocene.

Impact of warmer climate periods on flood hazard in the European Alps

Impact of warmer climate periods on flood hazard in the European Alps

Исследование макроугольков из угольных прослоев отложений археологического памятника Сурунгур (Ферганская долина, Южный Кыргызстан)

The paper researches the adaptation of ancient people to climate change and their influence on the surrounding landscapes on the example of the Surungur archaeological site (Southern Kyrgyzstan). The charcoal interlayers from Surungur depositions (excavations of 2021) were studied by the method of macrocharcoal analysis. Charcoals of different types were found in the samples: wood, grass, charred bones and amorphous charcoals. Amorphous coals are coals without a visible ordered structure with inclusions of other type macrocharcoals and containing spherulites. Spherulites are spherical crystals of calcite (5–20 mkm) formed in large quantities in the digestive system of ruminants (cows, sheep, goats, deer), preserved during combustion and visible in polarized light under a microscope. Based on the reconstruction of the used fuel types and the comparison of the data on climate in different time periods, we can conclude that throughout the period of the sites’ existence, ancient people used all types of fuel. During periods of warm and humid climate, trees were readily available and wood was mainly used, while during periods of dry and cold climate dung and probably bones were used more.