Recent Climate Research Articles

Analyzing the Regional Impact of Temperature Change by Long-term Climate Scenarios on Infrastructure Construction

The construction period is most affected by weather, and as recent climate change becomes more severe, weather conditions such as temperature, precipitation, snowfall, and wind that differ from region to region are expected to have a significant impact on air calculations in the future. As a result, the number of days not used for construction by region was determined in this study to reflect the effects of climate change in a future impact analysis. To this end, after performing bias correction on the latest climate change scenario (CMIP6) that came out through the Global Model (ESM), a comparative analysis was conducted on past weather observation data and the SSP245 and SSP585 scenarios. The rate of change was calculated for variables affecting the construction environment from various CMIP6-based ESM data, and the number of non-construction days owing to climate change was analyzed for changes in work restriction conditions by region. It was confirmed that the number of nonconstruction days in the Boeun of Chungcheongbuk-do and Jeolla-do was higher than that in other regions, and the rate of change in Busan was relatively low. Future construction plans and implementation are anticipated to be significantly impacted by these regional variations, and the computation of future construction periods is anticipated to undergo substantial modifications. Therefore, a more accurate air calculation is possible if the air is calculated by reflecting regional variations in the construction period due to climate change.

Challenges and Opportunities for Passive Thermoregulation

AbstractThe unsustainable nature of energy‐intensive and environmentally unfriendly traditional air conditioning systems, compacted with recent climate change effects, show an urgent need for more sustainable and efficient thermoregulation solutions. Innovations in passive daytime radiative coolers (PDRCs) and selective solar absorbers (SSAs), which utilize natural resources, the “cold” outer space and “hot” sun from the sky, offer an environmentally friendly and cost‐effective alternative. However, various factors significantly impede the commercial viability of these technologies, such as lack of emphasis on advancements for practical application, the challenge of reversible functionality between PDRCs and SSAs, inconsistent performance evaluation, and the absence of effective mass production strategies. Here current challenges and future development trends of PDRC and SSA‐aided innovation are discussed. Specifically, challenges and opportunities relating to application conditions, evaluation parameter standardization, and strategies are considered for large‐scale production, all of which are critical for realizing the full potential of PDRCs and SSAs.

Identification of dust sources inside and outside of Iran affecting air quality in the Tehran region

Introduction: Recent climate changes and droughts have exacerbated the impact of dust sources globally, necessitating a thorough understanding of their influence on air quality. In Tehran, the interaction between internal dust sources from Iran and external sources from neighboring countries significantly affects air quality. Materials and methods: This study spans a 20-year period (2003-2022), utilizing satellite data and advanced algorithms to analyze dust event trends and patterns. The material and methods section outlines the use of Aqua satellite MODIS sensor data alongside two algorithms to identify dust sources, focusing on Aerosol Optical Depth (AOD) data during peak dust event seasons. Statistical analysis of dust events in 2022 supplements the investigation. Results: The analysis reveals distinct patterns in dust particle origin and transport, highlighting the predominant contribution of internal dust sources from Iran's southern Semnan province and significant input from external sources in Iraq and northern Saudi Arabia. Examining meteorological conditions during severe dust events highlights the role of synoptic conditions, particularly the presence of a tropospheric trough, in facilitating dust transport. Increased convective motions and downburst occurrences in specific regions further exacerbate the spread of dust particles, particularly those originating from external countries and provinces. Conclusion: The conclusion emphasizes the complex interplay between internal and external dust sources and the necessity of understanding dust emission dynamics for effective mitigation strategies. It calls for proactive measures involving local and regional cooperation to mitigate dust pollution's adverse effects on air quality in Tehran and similar urban centers.

Population structure and diversification of Gymnospermium kiangnanense, a plant species with extremely small populations endemic to eastern China

Background Gymnospermium kiangnanense is the only species distributed in the subtropical region within the spring ephemeral genus Gymnospermium. Extensive human exploitation and habitat destruction have resulted in a rapid shrink of G. kiangnanense populations. This study utilizes microsatellite markers to analyze the genetic diversity and structure and to deduce historical population events of extant populations of G. kiangnanense. Methods A total of 143 individuals from eight extant populations of G. kiangnanense, including two populations from Anhui Province and six populations from Zhejiang Province, were analyzed with using 21 pairs of microsatellite markers. Genetic diversity indices were calculated using Cervus, GENEPOP, GenALEX. Population structure was assessed using genetic distance (UPGMA), principal coordinate analysis (PCoA), Bayesian clustering method (STRUCTURE), and molecular variation analysis of variance (AMOVA). Population history events were inferred using DIYABC. Results The studied populations of G. kiangnanense exhibited a low level of genetic diversity (He = 0.179, I = 0.286), but a high degree of genetic differentiation (FST = 0.521). The mean value of gene flow (Nm) among populations was 1.082, indicating prevalent gene exchange via pollen dispersal. Phylogeographic analyses suggested that the populations of G. kiangnanense were divided into two lineages, Zhejiang (ZJ) and Anhui (AH). These two lineages were separated by the Huangshan-Tianmu Mountain Range. AMOVA analysis revealed that 36.59% of total genetic variation occurred between the two groups. The ZJ lineage was further divided into the Hangzhou (ZJH) and Zhuji (ZJZ) lineages, separated by the Longmen Mountain and Fuchun River. DIYABC analyses suggested that the ZJ and AH lineages were separated at 5.592 ka, likely due to the impact of Holocene climate change and human activities. Subsequently, the ZJZ lineage diverged from the ZJH lineage around 2.112 ka. Given the limited distribution of G. kiangnanense and the significant genetic differentiation among its lineages, both in-situ and ex-situ conservation strategies should be implemented to protect the germplasm resources of G. kiangnanense.

Middle-Late Holocene climate change in an East Asian sandy land: Perspectives from the phytolith record of different geomorphic units

The accuracy of the regional palaeoclimate reconstruction is vital for ecological restoration and future climate predictions. Clarifying the regional climate signal on different geomorphological units within the same region plays a key role in regional climate researches. Here, we select the Horqin Sandy Land as the research area, and collect sedimentary from two typical geomorphological units (interdune lowlands: ML profile, DBS profile; dunes: CS profile, FX profile) as the research objects. The regional averaging method is employed to isolate distinct climate signals originating from interdune lowlands (IC-Score (Peat)) and dunes (IC-Score (Dune)), alongside an amalgamated climate signal (IC-Score (Peat&Dune)) synthesized from these two geomorphological units. This methodological approach facilitates the identification of variations in climate signals that collectively encapsulate the broader regional context. Meanwhile, local microclimate signals from dunes (IC-D-Value (Dune)) and interdune lowlands (IC-D-Value (Peat)) were separately analyzed to examine microclimate changes on different geomorphological units. The results indicate that different sedimentary carriers on various geomorphological units capture the local climate characteristics of their own units while recording regional climate changes. IC-D-Value (Peat) reflects ‘warm-humid’ climate, and IC-D-Value (Dune) represents ‘cold-dry’ climate. Climate signals derived from diverse geomorphological units exhibit the capacity to portray overarching regional climate patterns, yet they manifest variations concerning both semi-quantitative and quantitative climate parameters, notably temperature and precipitation. A regional average method is used to synthesize climate signals from different geomorphological units, which is more advantageous in documenting regional climate change. Regional climate signal reveals a change from warm-humid (9300 ∼ 4000 cal yr BP) to cold-dry (4000 ∼ 2000 cal yr BP) and then to slightly warm-humid (2000 ∼ 560 cal yr BP). Furthermore, regional climate signal shows the significant ∼ 2000-yr，∼1000-yr, ∼500-yr periodicities since 7300 cal yr BP, and solar activities are identified as one of the important driving factors.

Holocene solar activity inferred from global and hemispherical cosmic-ray proxy records

Variations in solar activity have been proposed to play an important role in recent and past climate change. To study this link on longer timescales, it is essential to know how the Sun has varied over the past millennia. Direct observations of solar variability based on sunspot numbers are limited to the past 400 years, and beyond this we rely on records of cosmogenic radionuclides, such as 14C and 10Be in tree rings and ice cores. Their atmospheric production rates depend on the flux of incoming galactic cosmic rays, which is modulated by Earth’s and the Sun’s magnetic fields, the latter being linked to solar variability. Here we show that accounting for differences in hemispherical production rates, related to geomagnetic field asymmetries, helps resolve so far unexplained differences in Holocene solar activity reconstructions. We find no compelling evidence for long-term variations in solar activity and show that variations in cosmogenic radionuclide production rates on millennial timescales and longer, including the 2,400-year Hallstatt cycle, are explained by variations in the geomagnetic field. Our results also suggest an on-average stronger dipole moment during the Holocene, associated with higher field intensities in the Southern Hemisphere.

Rise in water vapour driven by moisture transport facilitates water availability for the greening of global deserts

There are substantial changes in the global drylands owing to climate change and anthropogenic activities. However, this aspect is not adequately explored in the context of recent climate change and global warming. Therefore, we analyse the role of water vapour in driving precipitation and corresponding surface greenness in the global deserts using satellite measurements. Statistical techniques such as partial correlation and Randon Forest (RF) are employed to understand the relationship among the physical processes that drive water availability for desert greening. Our analysis shows that water vapour is relatively lower (<25 kg/m2) in the deserts than rest of the globe, but comparable to the polar and high-altitude regions. Among the deserts, Thar (25 kg/m2) and Sahara (15–20 kg/m2) show higher water vapour, in contrast to the American and Gobi deserts (<10 kg/m2). Trajectory analysis reveals that water vapour transport from the south Atlantic Ocean is very high (90 kg/m/s) to the Sahel region of Sahara. Similarly, water vapour comes from Arabian Sea and Indian Ocean to Thar, mainly during Indian Summer Monsoon (ISM). There is an increase in water vapour driven by a rise in moisture transport to the American, Arabian, Thar and Sub-Sahara deserts during the period 2003–2020. The rise in moisture transport and associated water vapour in the deserts enhance water availability through precipitation and soil moisture, influencing surface greenness, as illustrated by the partial correlation and RF analyses. Enhanced water vapour and water availability, together with anthropogenic activities such as agriculture and afforestation in the deserts drive greening, which is more pronounced in Thar and Sub-Sahara. This study, thus, reveals the role of atmospheric moisture in regulating the terrestrial water availability and surface greenness in the extreme arid regions on the earth.

Impacts of climate change in taxonomic, phylogenetic and functional diversity in snakes in largest dry forest ecoregion, the Gran Chaco

The impacts of anthropogenic activities have significantly contributed to recent and future climate changes worldwide. The future effects of climate change on biodiversity have been intensively studied globally over the past two decades. Currently, dry ecoregions are among the most threatened ecosystems in the world. In South America, three such seasonal dry ecoregions stand out: the Cerrado, Caatinga, and the Gran Chaco. Among these, the Chaco has experienced high deforestation rates and landscape degradation over the last decade, making it a top priority for conservation efforts. In this study, we employed ecological niche modeling to estimate the present and future distribution of snakes in the Chaco region. Our goal was to assess how snake diversity will change with projected climate changes across this geographic area. Our findings suggest that snake assemblages in the Chaco will undergo significant changes under future climatic conditions, with a clear trend toward biotic homogenization of the ecoregion and a decrease in species richness. These negative changes will likely extend to the protected areas within the Chaco, resulting in biotic homogenization and a loss of species richness.

Climatically driven Quaternary sedimentation in a passive margin tropical context: Insights into the geomorphological evolution of Northeastern Brazil

Unconsolidated regolith from fluvial and hillslope origin occurring along the eastern seaboard of the Northeastern Brazil passive margin has long been overlooked as viable proxy for Quaternary environmental changes, or simply dismissed and interpreted as sediments of older planation cycles, for example, Neogene sediments. This study applies geochemical and geochronological techniques to assess the degree of weathering, sediment provenance and time of residence in the landscape. The results shed light on the upper Quaternary geomorphological history of the Borborema Piedmont, with depositional units spanning the last 50,000 years, as a response to climatic inputs in sync with major Pleistocene events (e.g., Heinrich Event 1, 2, 3 and 5, Last Glacial Maximum) and Holocene events in the Northern Hemisphere (e.g., Holocene Climatic Optimum), and the morphotectonic rearrangement of stream channels base level along reactivated fault-line subordinated to the underlying Proterozoic structural framework.

Shrinking sizes of trout and salamanders are unexplained by climate warming alone

Decreases in body sizes of animals related to recent climate warming can affect population persistence and stability. However, direct observations of average sizes over time and their interrelationships with underlying density-dependent and density-independent processes remain poorly understood owing to the lack of appropriate long-term datasets. We measured body size of two species common to headwater streams in coastal and Cascades ecoregions of the Pacific Northwest of North America over multiple decades, comparing old-growth and managed forests. We found consistent decreases in median length of Coastal Cutthroat Trout Oncorhynchus clarkii clarkii, but a coexisting species, the Coastal Giant Salamander Dicamptodon tenebrosus, appears to be more resilient to size changes over time. Based on observed trends, adult trout have decreased in length by 6–13% over the last 30 years. Length decreased more in larger compared to smaller animals, suggesting that these effects reflect changes in growth trajectories. Results from a model-selection approach that included hydroclimatic and biological information as covariates in one of our study ecoregions demonstrated that stream temperature alone did not explain observed length reductions. Rather, a combination of density-dependent (animal abundances) and local density-independent factors (temperature, habitat, and streamflow) explained observed patterns of size. Continued decreases in size could lead to trophic cascades, biodiversity loss, or in extreme cases, species extirpation. However, the intricate links between density-independent and density-dependent factors in controlling population-level processes in streams need further attention.

Agropastoral and dietary practices of the northern Levant facing Late Holocene climate and environmental change: Isotopic analysis of plants, animals and humans from Bronze to Iron Age Tell Tweini.

One of the largest isotopic datasets of the ancient Eastern Mediterranean region is evaluated, based on plants (n = 410), animals (n = 210) and humans (n = 16) from Tell Tweini (Syria). Diachronic analysis of plant and faunal specimens from four main periods of occupation: Early Bronze Age (2600-2000 BC), Middle Bronze Age (2000-1600 BC), Late Bronze Age (1600-1200 BC) and Iron Age (1200-333 BC) were investigated. Mean Δ13C results from seven plant species reveal emmer and free threshing wheat, olives, bitter vetch, rye grass and barley were adequately or well-watered during all periods of occupation. The grape Δ13C results suggest excellent growing conditions and particular care for its cultivation. The δ15N results indicate that especially the emmer and free threshing wheats received some manure inputs throughout the occupation sequence, while these were likely further increased during the Iron Age, encompassing also the olive groves and grape vineyards. Generally, domestic animals (cattle, sheep, goats) had C3 terrestrial diets and were kept together in similar environments. However, some animals consumed significant amounts of marine or C4 plants, possibly from disturbed habitats due to land use pressure or salt tolerant grasses and shrubs from wetland environments, which were recorded in the direct vicinity of the site. Middle Bronze Age humans consumed a C3 terrestrial diet with no measurable input from C4, freshwater or marine protein sources. Interestingly, the human diet was relatively low in animal protein and appears comparable to what is considered today a typical Mediterranean diet consisting of bread (wheat/barley), olives, grapes, pulses, dairy products and small amounts of meat. The combined isotopic analysis of plants, animals and humans from Tell Tweini represents unbroken links in the food chain which create unparalleled opportunities to enhance our current understanding of environmental conditions, climate change and lifeways in past populations from the Eastern Mediterranean.

Mineralogical Indicators of the Holocene Climate in Sediments of the High-Mountain Lake Sagan-Nur (East Sayan Mountains)

Mineralogical Indicators of the Holocene Climate in Sediments of the High-Mountain Lake Sagan-Nur (East Sayan Mountains)

The Association Between Cloud Droplet Number over the Summer Southern Ocean and Air Mass History

AbstractThe cloud properties and governing processes in Southern Ocean marine boundary layer clouds have emerged as a central issue in understanding the Earth's climate sensitivity. While our understanding of Southern Ocean cloud feedbacks have evolved in the most recent climate model intercomparison, the background properties of simulated summertime clouds in the Southern Ocean are not consistent with measurements due to known biases in simulating cloud condensation nuclei concentrations. This paper presents several case studies collected during the Capricorn 2 and Marcus campaigns held aboard Australian research vessels in the Austral Summer of 2018. Combining the surface‐observed cases with MODIS data along forward and backward air mass trajectories, we demonstrate the evolution of cloud properties with time. These cases are consistent with multi‐year statistics showing that long trajectories of air masses over the Antarctic ice sheet are critical to creating high droplet number clouds in the high latitude summer Southern Ocean. We speculate that secondary aerosol production via the oxidation of biogenically derived aerosol precursor gasses over the high actinic flux region of the high latitude ice sheets is fundamental to maintaining relatively high droplet numbers in Southern Ocean clouds during Summer.

Detekcija klimatskih kolebanja Hilbert-Huangovom metodom na podacima stoljetnog opservatorija Zagreb-Grič, Hrvatska

Advanced statistical methods are applied on long-term data sets from Zagreb-Grič centennial observatory in Croatia to address recent climate change and variabilities; annual averages are used. Hilbert-Huang transform (HHT), consisting of empirical mode decomposition (EMD) and Hilbert spectral analysis (HSA), is an empirically based data-analysis method for extracting periodic components embedded within generally nonlinear and non-stationary data. The EMD splits the original series into a so-called intrinsic mode functions (IMFs). First, using the EMD algorithm, intrinsic mode functions (IMFs) are obtained. The analysis of low frequency IMFs indicates significant influence of the North-Atlantic Oscillation on the air temperature, cloudiness and precipitation series in the part of northern Croatia. For the considered climatic elements, the analysis revealed mild deviations in natural fluctuations of the analyzed signal for the last 30 to 40 years, which are most likely caused by anthropogenic activities. Next, HSA is applied to each IMF obtained for the series of annual averages of sea level air pressure. In order to validate this approach and the results, an associated Hilbert spectrum (HS) is compared with the continuous wavelet analysis, i.e., this is another corresponding checkup. The comparison shows significantly improved time and frequency resolution in favor of HS. Moreover, HS provides a unique capability of displaying intra-wave frequency modulation, i.e., changes in frequency that occur within one cycle of oscillation.

Consistent time allocation fraction to vegetation green-up versus senescence across northern ecosystems despite recent climate change

Extended growing season lengths under climatic warming suggest increased time for plant growth. However, research has focused on climatic impacts to the timing or duration of distinct phenological events. Comparatively little is known about impacts to the relative time allocation to distinct phenological events, for example, the proportion of time dedicated to leaf growth versus senescence. We use multiple satellite and ground-based observations to show that, despite recent climate change during 2001 to 2020, the ratio of time allocated to vegetation green-up over senescence has remained stable [1.27 (± 0.92)] across more than 83% of northern ecosystems. This stability is independent of changes in growing season lengths and is caused by widespread positive relationships among vegetation phenological events; longer vegetation green-up results in longer vegetation senescence. These empirical observations were also partly reproduced by 13 dynamic global vegetation models. Our work demonstrates an intrinsic biotic control to vegetation phenology that could explain the timing of vegetation senescence under climate change.

Atmospheric Blocking Events over the Southeast Pacific and Southwest Atlantic Oceans in the CMIP6 Present-Day Climate

This study examines the representation of blocking events in the Southeast Pacific and Southwest Atlantic regions using a set of 13 global climate models from phase 6 of the Coupled Model Intercomparison Project (CMIP6). Historical runs were employed to analyze blocking conditions in the recent past climate, spanning from 1985 to 2014, with ERA5 data utilized to represent observed blocking events. The majority of CMIP6 models underestimate the total number of blocking events in the Southeast Pacific. The MPI–ESM1–2–HR and MPI–ESM1–2–LR models come closest to replicating the number of blocking events observed in ERA5, with underestimations of approximately −10% and −9%, respectively. Nonetheless, these models successfully capture the seasonality and overall duration of blocking events, as well as accurately represent the position of blocking heights over the Southeast Pacific. Conversely, CMIP6 models perform poorly in representing blocking climatology in the Southwest Atlantic. These models both overestimate and underestimate the total number of blocking events by more than 25% compared to ERA5. Furthermore, they struggle to reproduce the seasonal distribution of blockings and face challenges in accurately representing the duration of blocking events observed in ERA5.

Accounting for nonlinear responses to traits improves range shift predictions

AbstractAccurately predicting species' range shifts in response to environmental change is paramount for understanding ecological processes and global change. In synthetic analyses, traits emerge as significant but weak predictors of species' range shifts across recent climate change. These studies assume linear responses to traits, while detailed empirical work often reveals trait responses that are unimodal and contain thresholds or other nonlinearities. We hypothesize that the use of linear modeling approaches fails to capture these nonlinearities and, therefore, may be under‐powering traits to predict range shifts. We evaluate the predictive performance of approaches that can capture nonlinear relationships (ridge‐regularized linear regression, support vector regression with linear and nonlinear kernels, and random forests). We apply our models using six multidecadal range shift datasets for plants, moths, marine fish, birds, and small mammals. We show that nonlinear approaches can perform better than least‐squares linear modeling in reproducing historical range shifts. Consistent with expectations, we identify dispersal and climatic niche traits as primary determinants of distribution shifts. Traits identified as important predictors and the direction of trait effects are generally consistent across models, but there are notable exceptions. Among important predictors, there are more consistent responses to climatic niches than dispersal ability. Modest improvements in predictability when accounting for nonlinearities and interactions, and the overall low amount of variance accounted for by trait predictors suggest limits to trait‐based statistical predictive frameworks.

Climate deterioration and subsistence economy in prehistoric Southern Iberia: an evaluation of potential links based on regional trajectories

The potential impact of climatic deterioration on societal breakdowns in prehistory is often based on the mere coincidence of archaeological and palaeoclimatological proxies. For a more profound discussion, climate-sensitive archaeological parameters need to be identified. As agriculture and livestock are significantly affected by the recent climate crisis, the analysis of archaeobotanical and archaeozoological remains can deepen our understanding of this topic. Here, we analyze regional trajectories in subsistence and seasonal precipitation variability across southern Iberia focusing on well-known prehistoric breakdowns around 2200 and 1600 BCE. Results suggest that the ratios of the importance of sheep/goat versus swine and sheep/goat versus cattle, respectively, may serve as a proxy for prehistoric mobility. The importance of hunting deer represents a proxy for societal turnover. While no direct link is evident between climate deterioration and the archaeozoological data, archaeobotanical data reveals a potential relation to precipitation variability. In particular, a close connection to reductions in cold-season precipitation in south-east Iberia appears likely for the ratio between barley and naked wheat. The increased importance of drought-tolerant barley correlates with a trend to reduced cold-season precipitation levels after ca. 2700 BCE. We hypothesize that prehistoric people in south-east Iberia cultivated more barley in order to adapt to periods of drier cold-season climate.

Biological Carbon Sequestration: From Deep History to the Present Day

In the global carbon cycle, atmospheric carbon emissions, both ‘natural’ and anthropogenic, are balanced by carbon uptake (i.e., sequestration) that mostly occurs via photosynthesis, plus a much smaller proportion via geological processes. Since the formation of the Earth about 4.54 billion years ago, the ratio between emitted and sequestered carbon has varied considerably, with atmospheric CO2 levels ranging from 100,000 ppm to a mere 100 ppm. Over this time, a huge amount of carbon has been sequestered due to photosynthesis and essentially removed from the cycle, being buried as fossil deposits of coal, oil, and gas. Relatively low atmospheric CO2 levels were the norm for the past 10 million years, and during the past million years, they averaged about 220 ppm. More recently, the Holocene epoch, starting ~11,700 years ago, has been a period of unusual climatic stability with relatively warm, moist conditions and low atmospheric CO2 levels of between 260 and 280 ppm. During the Holocene, stable conditions facilitated a social revolution with the domestication of crops and livestock, leading to urbanisation and the development of complex technologies. As part of the latter process, immense quantities of sequestered fossil carbon have recently been used as energy sources, resulting in a particularly rapid increase in CO2 emissions after 1950 CE to the current value of 424 ppm, with further rises to &gt;800 ppm predicted by 2100. This is already perturbing the previously stable Holocene climate and threatening future food production and social stability. Today, the global carbon cycle has been shifted such that carbon sequestration is no longer keeping up with recent anthropogenic emissions. In order to address this imbalance, it is important to understand the roles of potential biological carbon sequestration systems and to devise strategies to facilitate net CO2 uptake; for example, via changes in the patterns of land use, such as afforestation, preventing deforestation, and facilitating agriculture–agroforestry transitions.

Between Despair and Honest Hope: Facing the Aporetic Space of the Climate Crisis

Based on autoethnographic descriptions of recent climate events in Germany, Greece, and England, three colleagues describe these events’ impact on daily life and their implications for religious education in European schools. The argument oscillates between struggling for climate justice and enduring its aporias. In the aporetic (learning) space, it is important to turn hope into concrete and realistic actions that keep people, societies, and education moving.