Climatic Implications Research Articles

Climatic implications in earlywood and latewood width indices of Chinese pine in north central China

Latewood width (LWW) indices of trees are considered a reliable proxy of summer precipitation in the Northern Hemisphere. However, the strong coupling and high correlation between earlywood width (EWW) and LWW indices often prevent registration of climate signals of the LWW index. In this study, 328-year-long earlywood width and latewood width chronologies were developed from Chinese pine at two sites in the Hasi Mountains, north central China. The climate responses of these chronologies were analyzed and the LWW index used to derive summer precipitation signals. Correlation analyses showed that LWW was particularly influenced by earlywood growth and recorded stronger climate signals of the previous year as EWW, rather than those of the current year with infrequent summer climate signals. However, after removing the effect of earlywood growth using a simple regression model, the adjusted LWW chronology (LWWadj) showed a strong relationship with July precipitation in dry years. This suggests that the LWWadj chronology has the potential to be used to investigate long-term variability in summer precipitation in drought-limited regions.

Cost-effective biodiversity protection through multiuse-conservation landscapes

ContextIntensive land use and exploitation of natural resources are the main direct drivers of biodiversity loss. Transformative changes in land management are called for as conservation and management actions have not been sufficient to support the viability of species populations. It has been proposed that to solve the sufficiency problem one could segregate the landscape into an intensively managed part, and into so-called multiuse-conservation landscapes that aggregate set asides with managed areas for multiple uses.ObjectivesWe describe a scenario analysis where we evaluate the effects and cost-efficiency of transforming the boreal forest from intensively managed production landscapes progressively towards multiuse-conservation landscapes.MethodsWe simulated Finnish boreal forests under various managements and optimized management to produce six scenarios to reveal the ecological, economic, climate and management regime implications of multiuse-conservation landscapes. Ecological effects explored included habitat availability and metacommunity capacity of dead wood dependent species.ResultsIncreasing the area of set aside and multiuse management increased the habitat availability and metacommunity capacity as well as climate benefits but caused economic losses in terms of timber revenues. Pooling the set asides and multiuse management areas together into the same landscapes reduced the economic losses, had negligible added climate benefits and produced mixed biodiversity effects: pooling decreased habitat availability but increased metacommunity capacity across all landscapes.ConclusionsChanging land management and aggregating conservation efforts can be a cost-efficient way to protect biodiversity. Our results suggest biodiversity benefits in landscapes where the set aside and multiuse is aggregated. Careful spatial planning can also alleviate the conflicts between ecological and economic values of land.

Diel variation of seawater volatile organic compounds, DMSP-related compounds, and microbial plankton inside and outside a tropical coral reef ecosystem

Biogenic volatile organic compounds (VOCs) play key roles in coral reef ecosystems, where, together with dimethylated sulfur compounds, they are indicators of ecosystem health and are used as defense strategies and infochemicals. Assessment and prediction of the exchange rates of VOCs between the oceans and atmosphere, with implications for atmospheric reactivity and climate, are hampered by poor knowledge of the regulating processes and their temporal variability, including diel cycles. Here, we measured the variation over 36h of the concentrations of DMSPCs (dimethylsulfoniopropionate (DMSP)-related compounds, namely DMSP, dimethylsulfoxide, acrylate, dimethylsulfide, and methanethiol as dimethyl disulfide) and VOCs (COS, CS2, isoprene, the iodomethanes CH3I and CH2ClI, and the bromomethanes CHBr3 and CH2Br2), in surface waters inside the shallow, northern coral-reef lagoon of Mo’orea (French Polynesia) and 4 km offshore, in the tropical open ocean. Comparisons with concurrent measurements of sea surface temperature, solar radiation, biogeochemical variables (nutrients, organic matter), and the abundances and taxonomic affiliations of microbial plankton were conducted with the aim to explain interconnections between DMSPCs, VOCs, and their environment across diel cycles. In open ocean waters, deeper surface mixing and low nutrient levels resulted in low phytoplankton biomass and bacterial activity. Consequently, the diel patterns of VOCs were more dependent on photochemical reactions, with daytime increases for several compounds including dissolved dimethylsulfoxide, COS, CS2, CH3I, and CH2ClI. A eukaryotic phytoplankton assemblage dominated by dinoflagellates and haptophytes provided higher cell-associated DMSP concentrations, yet the occurrence of DMSP degradation products (dimethylsulfide, dimethyl disulfide) was limited by photochemical loss. Conversely, in the shallow back reef lagoon the proximity of seafloor sediments, corals and abundant seaweeds resulted in higher nutrient levels, more freshly-produced organic matter, higher bacterial activity, and larger algal populations of Mamiellales, diatoms and Cryptomonadales. Consequently, DMSP and dimethylsulfoxide concentrations were lower but those of most VOCs were higher. A combination of photobiological and photochemical processes yielded sunny-daytime increases and nighttime decreases of dimethylsulfide, dimethyl disulfide, COS, isoprene, iodomethanes and bromomethanes. Our results illustrate the important role of solar radiation in DMSPC and VOC cycling, and are relevant for the design of sampling strategies that seek representative and comparable measurements of these compounds.

Higher absorption enhancement of black carbon in summer shown by 2-year measurements at the high-altitude mountain site of Pic du Midi Observatory in the French Pyrenees

Abstract. Black-carbon-containing particles strongly absorb light, causing substantial radiative heating of the atmosphere. The climate-relevant properties of black carbon (BC) are poorly constrained in high-altitude mountain regions, where many complex interactions between BC, radiation, clouds and snow have important climate implications. This study presents 2-year measurements of BC microphysical and optical properties at the Pic du Midi (PDM) research station, a high-altitude observatory located at 2877 m above sea level in the French Pyrenees. Among the long-term monitoring sites in the world, PDM is subject to limited influence from the planetary boundary layer (PBL), making it a suitable site for characterizing the BC in the free troposphere (FT). The classification of the dominant aerosol type using aerosol spectral optical properties indicates that BC is the predominant aerosol absorption component at PDM and controls the variation in single-scattering albedo (SSA) throughout the 2 years. Single-particle soot photometer (SP2) measurements of refractory BC (rBC) show a mean mass concentration (MrBC) of 35 ng m−3 and a relatively constant rBC core mass-equivalent diameter of about 180 nm, which are typical values for remote mountain sites. Combining the MrBC with in situ absorption measurements, a rBC mass absorption cross-section (MACrBC) of 9.2 ± 3.7 m2 g−1 at λ=880 nm has been obtained, which corresponds to an absorption enhancement (Eabs) of ∼2.2 compared to that of bare rBC particles with equal rBC core size distribution. A significant reduction in the ΔMrBC/ΔCO ratio when precipitation occurred along the air mass transport suggests wet removal of rBC. However we found that the wet removal process did not affect the rBC size, resulting in unchanged Eabs. We observed a large seasonal contrast in rBC properties with higher MrBC and Eabs in summer than in winter. In winter a high diurnal variability in MrBC (Eabs) with higher (lower) values in the middle of the day was linked to the injection of rBC originating from the PBL. On the contrary, in summer, MrBC showed no diurnal variation despite more frequent PBL conditions, implying that MrBC fluctuations are rather dominated by regional and long-range transport in the FT. Combining the ΔMrBC/ΔCO ratio with air mass transport analysis, we observed additional sources from biomass burning in summer leading to an increase in MrBC and Eabs. The diurnal pattern of Eabs in summer was opposite to that observed in winter with maximum values of ∼2.9 observed at midday. We suggest that this daily variation may result from a photochemical process driving the rBC mixing state rather than a change in BC emission sources. Such direct 2-year observations of BC properties provide quantitative constraints for both regional and global climate models and have the potential to close the gap between model-predicted and observed effects of BC on the regional radiation budget and climate. The results demonstrate the complex influence of BC emission sources, transport pathways, atmospheric dynamics and chemical reactivity in driving the light absorption of BC.

Drainage divide migration and implications for climate and biodiversity

Drainage divide migration and implications for climate and biodiversity

Differential metabolic responses in bold and shy sea anemones during a simulated heatwave.

As climate change-induced heatwaves become more common, phenotypic plasticity at multiple levels is a key mitigation strategy by which organisms can optimise selective outcomes. In ectotherms, changes to both metabolism and behaviour can help alleviate thermal stress. Nonetheless, no study in any ectotherm has yet empirically investigated how changing temperatures affect among-individual differences in the associations between these traits. Using the beadlet anemone (Actinia equina), an intertidal species from a thermally heterogeneous environment, we investigated how individual metabolic rates, linked to morphotypic differences in A. equina, and boldness were related across changing temperatures. A crossed-over design and a temporal control were used to test the same individuals at a non-stressful temperature, 13°C, and under a simulated heatwave at 21°C. At each temperature, short-term repeated measurements of routine metabolic rate (RMR) and a single measurement of a repeatable boldness-related behaviour, immersion response time (IRT), were made. Individual differences, but not morphotypic differences, were highly predictive of metabolic plasticity, and the plasticity of RMR was associated with IRT. At 13°C, shy animals had the highest metabolic rates, while at 21°C, this relationship was reversed. Individuals that were bold at 13°C also exhibited the highest metabolic rates at 21°C. Additional metabolic challenges during heatwaves could be detrimental to fitness in bold individuals. Equally, lower metabolic rates at non-stressful temperatures could be necessary for optimal survival as heatwaves become more common. These results provide novel insight into the relationship between metabolic and behavioural plasticity, and its adaptive implications in a changing climate.

Daniel Billy et al v Australia (Torres Strait Islanders Petition): Climate change inaction as a human rights violation

AbstractThis case note analyses in detail the decision of the United Nations Human Rights Committee (HRComm) in Daniel Billy et al v Australia. The decision concerned a communication brought by members of an indigenous peoples' group from the Torres Strait Islands in the state of Queensland, Australia. The applicants claimed that their human rights had been violated as a result of the State's failure to take mitigation and adaptation measures to combat the effects of climate change. The HRComm's finding of a violation of the applicants' human rights deserves a closer look, as it has broader implications for future climate change‐related human rights litigation. While the HRComm missed the opportunity to consider the State's human rights obligations concerning climate change mitigation, this decision represents an important milestone in climate change litigation, as it confirms a State's obligation to protect a community from adverse climate change effects and recognises the specific vulnerabilities of indigenous peoples and their cultures to its impacts.

Changes in global DMS production driven by increased CO2 levels and its impact on radiative forcing

Our study highlights the importance of understanding the future changes in dimethyl-sulfide (DMS), the largest natural sulfur source, in the context of ocean acidification driven by elevated CO2 levels. We found a strong negative correlation (R2 = 0.89) between the partial pressure of carbon dioxide (pCO2) and sea-surface DMS concentrations based on global observational datasets, not adequately captured by the Coupled Model Intercomparison Project Phase 6 (CMIP6) Earth System Models (ESMs). Using this relationship, we refined projections of future sea-surface DMS concentrations in CMIP6 ESMs. Our study reveals a decrease in global sea-surface DMS concentrations and the associated aerosol radiative forcing compared to ESMs’ results. These reductions represent ~9.5% and 11.1% of the radiative forcings resulting from aerosol radiation and cloud interactions in 2100 reported by the Intergovernmental Panel on Climate Change Sixth Assessment Report. Thus, future climate projections should account for the climate implications of changes in DMS production due to ocean acidification.

Radiocarbon chronology of sediments with implications for climatic events in Lop Nur, NW China

Radiocarbon dating has played a pivotal role in paleoclimate research, particularly in establishing chronological sequences for lake sediment. However, the persistent challenge of the radiocarbon reservoir effect has remained a notable concern when using 14C dating. While several methods have been developed address this issue, the spatiotemporal variability of the lake reservoir and their climatic implications on the occurrence of anomalous 14C dating results have frequently been overlooked in previous studies. Especially when dealing with lake sediments in arid regions of Central Asia, the impact of climate-induced sediment sources and watershed hydrology poses substantial challenges for 14C dating. In this study, we focused on sediment profile in the Lop Nur and established a reliable chronological framework for the late Holocene using a piecewise linear regression approach. By integrating climate data from the surrounding region and archaeological evidence, we reconstructed the hydrological and aeolian processes of Lop Nur spanning from 670 BCE to 1300 CE. Our findings suggest that the anomalies observed in dating results were closely associated with the presence of sand component with a reduced organic matter content. And the record reveals the occurrence of sandstorm events around 500 BCE and 300 BCE, with a significant increase in strength after 200 CE. This indicates a decrease in reservoir effects during the lake regression, due to increased aeolian inputs. Therefore, we proposed that the deposition of larger-sized sandstorm particles during lake regression is predominant reason for reduced absorption of surrounding aged organic matter, leading to the younger age observed.

Hydrological complexity and climate implications in Australia’s arid zone: A decade of high-resolution rainfall observations

Study region: The study was carried out in Fowlers Gap (New South Wales, Australia) within a 400 km2 arid zone catchment approx. 110km north of Broken Hill.Study focus: A comprehensive dataset of 10 s rainfall encompassing 17 rain gauges spanning over a decade (from 2013 to 2023) was meticulously analysed in combination with climate and stream levels and supplemented by daily camera images of the creek.New hydrological insights for the region: 64.6% of the rainfall flows to the creek, with the remainder lost before reaching the creek. Within this 64.6%, there were 67 individual flow events, comprising 47.7% of rainfall (35 events) associated with fronts and 16.9% (32 events) linked to local cumulonimbus storm cells. A fundamental characteristic of these flow events is their very rapid response, which appears to be independent of antecedent moisture content. The spatially averaged intensity of rainfall events experienced an approximate 200% increase, rising from 1.6 mm/h in mid-2013 to 4.8 mm/h by mid-2023. This noteworthy change is attributed to climate change. Despite the projected decrease in overall precipitation for the region, this observed rise in intensity aligns with the broader trend of global warming accelerating the water cycle.

Climate Change Response Strategies and Implications on Sustainable Development Goals in Mutirikwi River Sub-Catchment of Zimbabwe

Sub-catchment level water sector response strategies to climate change in Zimbabwe have not been adequately analyzed to determine their impact and connectedness with the Sustainable Development Goals (SDGs). In this study, the mixed methods research design is used to examine the implications of water sector climate change response strategies (CCRS) on SDGs in Mutirikwi sub-catchment in Masvingo, Zimbabwe. Results show that the climate is changing, with a statistically significant (p = 0.031; α = 0.05) increase in the annual mean temperature and a declining rainfall trend, though not statistically significant (p=0.753; α = 0.05). Views from local communities and stakeholders confirm the existence of climate change. There is a deluge of response strategies to the changing climate, including borehole drilling, roof rainwater harvesting, surface storage, water reuse and water transfers. These strategies have directly contributed to the achievement of SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Settlements), and SDG 13 (Climate Action). They have also indirectly contributed to the achievement of SDG 3 (Health), SDG 5 (Gender), SDG 9 (Infrastructure) SDG 12 (Sustainable Consumption) and SDG 15 (Life on Land). The study concludes that there is an inextricable link between CCRS and SDGs. However, implementation of the response strategies is riddled with challenges that are threatening the sustainability matters. There is a need to design community-driven response mechanisms synergized with national and international climate adaptation initiatives to ensure sustainability of the strategies through guaranteed policy and resource support from the national government and non-governmental agencies.

Intro in Ice properties and BIO-factor

Microorganisms could play a significant role in shaping the properties of ice. This overview examines the existing knowledge on the influence of microorganisms on ice, focusing on glacial, polar, and marine ice systems. The interaction between microorganisms and ice mechanics is complex and multifaceted. Studies have shown that microbial activity, including biofilm formation, enzymatic processes, and ice nucleation, can impact ice strength and int interaction with structures. Microbial colonization has been found to weaken ice structures, alter ice permeability, and influence ice deformation behavior. Additionally, microbial communities associated with ice surfaces have been shown to enhance ice adhesion and frictional properties. Understanding the role of microorganisms in ice mechanics is crucial for comprehending the dynamics of frozen environments and their response to environmental changes. Further research in this field will contribute to improved predictions of ice behavior and its implications for climate, engineering, and environmental processes.

Spatio-temporal assessment of aerosol and cloud properties using MODIS satellite data and a HYSPLIT model: Implications for climate and agricultural systems

Understanding the spatiotemporal dynamics of aerosol optical characteristics is crucial for assessing their impact on the climate system. This study focuses on Aerosol Optical Depth (AOD) at 550 nm, measured by the Moderate-resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite, over a decade (2011–2021) in ten major cities across Pakistan. Our primary objectives were to investigate AOD variability, assess its correlation with cloud parameters, examine the source and trajectory of aerosol-laden air masses, and analyze the relationship between AOD and the Angstrom exponent. We employed the Hybrid single-particle Lagrangian Integrated Trajectory (HYSPLIT) model to trace air mass origins and paths. AOD exhibited its highest values in low-latitude urban areas, reflecting significant human activity. Conversely, high-altitude and mountainous regions displayed the lowest AOD levels. In summer (June–August), AOD peaked at 1.19, while in winter (December–February), it dropped to 0.24. The negative correlation between AOD and the Angstrom exponent, particularly in southern and western Pakistan, highlighted aerosol particle size variations. We further explored the relationships between AOD and five cloud parameters: water vapor (WV), cloud fraction (CF), cloud optical thickness (COT), cloud top temperature (CTT), and cloud top pressure (CTP). These relationships were found to be weather-dependent. This study provides valuable insights into the spatio-temporal dynamics of AOD in Pakistan, contributing to a better understanding of its impact on climate. This information is essential for climate scientists, meteorologists, and environmental departments, facilitating informed decision-making and climate modeling in the region.

Exploring School Climate and Teacher Self-Efficacy in Indonesian Senior High School

<p><span lang="EN-US">School climate and teacher self-efficacy were correlated with research areas on physical, physiological, and personal and collective beliefs. Quantitatively, prior studies have reported positive results on students' performance. However, scant evidence in the school climate body of literature explored from a qualitative perspective to describe why and how teacher self-efficacy contributes to a positive school climate beyond students’ performance. Therefore, this study explores school climate and teacher self-efficacy in an Indonesian senior high school. Moreover, this study approached Yin’s (2018) case study with qualitative design. The case was one of an urban school with the school’s paradigm and policy to integrate technology into the teaching process to face the entertainment industry. Eight teachers were recruited from four subjects (e.g., Bahasa Indonesia, Physical, Social, and Biology). The data were collected through observations and interviews, and we employed thematic analysis. Our study shows that 1) physical school climate with sufficient school facilities and technology supported the development of good school climate that facilitated teachers to seek feedback and reflection; 2) teachers' self-feedback and peer evaluative feedback became a point of departure for teachers' engagement with teachers’ sources of self-efficacy that affected their development of teaching performance and strategy. Theoretical and practical implications of school climate and teacher self-efficacy will also be discussed.</span></p>

Quaternary petrified trunks from Kamphaeng Phet, Thailand: Implications for past climate and preservation

Petrified trunks in Mueang Kamphaeng Phet District, upper Central Thailand, were unearthed in Quaternary deposits on the western rim of the Ping River. The sediments consist mainly of semi-consolidated gravel, sand, silt, and clay, indicating that the woods were transported by the ancient Ping River. Macroscopic features revealed that preservation of these fossils (e.g., intercellular spaces, iron oxides, quartz crystals, colors, and weathering conditions) shared many similarities to some petrified trunks in Tak Province. We investigated both large (approx. 0.50–0.7m wide, at least 10–20 meters long) and small fragments of fossils for both wood anatomical features and mineralogy. Diffuse porosity with indistinct growth rings and wide vessels at low densities suggest a tropical lowland forest paleoenvironment. Parenchyma patterns are aliform to confluent, banded, and diffuse-in aggregate. At least four distinct types of wood were recognized from this site. Among them, three wood types originate from legume trees (Fabaceae), while the fourth is from a eudicotyledonous tree. Two of the three legumes show closest resemblance to a tall (canopy emergent) legume tree, Koompassia cf. malaccensis Maingay ex Benth. and one resembles the legume Koompassia cf. malaccensis or cf. Pahudioxylon bankurensis Chowdhury, Ghosh, et Kazmi. The other legume-like wood shows banded parenchyma. Petrified wood from Kamphaeng Phet is correlative with other Quaternary paleofloras found in Northern Thailand in both preservation and taxa. The past climate, as inferred according to the Köppen-Geiger classification, was possibly similar to modern-day tropical rainforests (Af) in southern Thailand, Malaysia, and Indonesia in contrast to the modern vegetation in Mueang District, Kamphaeng Phet that is a mixed deciduous and dry dipterocarp forest where the modern climate in the area is tropical wet and dry (Aw).

The Market and Climate Implications of U.S. Lng Exports

The Market and Climate Implications of U.S. Lng Exports

Technical efficiency of honey and beeswax production in Kaduna State, Nigeria: Implications for climate and food security sustainability

Technical efficiency of honey and beeswax production in Kaduna State, Nigeria: Implications for climate and food security sustainability

Tree ring oxygen isotope in Asia

Tree-ring oxygen isotope (δ18OTR) is a powerful proxy for paleoclimatology, ecology and archaeology, δ18OTR studies in Asia over the past ∼50 years have made significant achievements in improving our understanding of Asian climatic and ecological systems. Here, we review these developments in δ18OTR research in Asia. Most study sites are located within East Asia, Southeast Asia, South Asia, and North Asia, and δ18OTR records from conifers, broadleaf trees, and shrubs have been produced. Progress has been made in the following areas: (1) Experimental techniques. The novel plate method for cellulose extraction has been developed, which reduces experimental time and greatly improves efficiency. (2) Development of δ18OTR chronologies. Ninety-six chronologies exceeding 200 years in length have been produced. A 4354-year δ18OTR chronology with an annual-resolution has been produced in Japan, and a 6700-year δ18OTR chronology with a 1–5 year resolution has been produced in the northeastern Tibetan Plateau, which is the longest in Asia. (3) Biological influences on δ18OTR. Variations of intra- and inter-tree and inter-species δ18OTR have been investigated, and the relationship between tree age and δ18OTR has been explored. (4) Climatic implications. Seasonal δ18OTR records primarily reflect the variability of precipitation δ18O, facilitating high-resolution paleoclimate reconstructions, while interannual δ18OTR records mainly reflect summer moisture variability. (5) Climate reconstructions. Quantitative estimates have been produced for past precipitation, relative humidity, PDSI (Palmer Drought Severity Index), runoff, and other parameters from δ18OTR records. Since 1850, δ18OTR chronologies in monsoon regions show upward trends indicative of drying, while these from westerlies regions exhibit downward shifts implying wetting. (6) Dating. Intra- and inter-annual δ18OTR records help determine the annual growth of trees without rings and facilitate the cross-dating of trees with rings. Thus, the dating of archaeological and buried wood is feasible via comparisons with δ18OTR master chronologies. Promising areas of development include climatic implications (e.g., Position-specific isotope analysis, seasonal δ18OTR records on longer timescales and larger spatial scales), climate reconstructions (syntheses of multiple sites and records, development of long chronologies, deep time paleoclimate reconstructions) and ecological applications (e.g., the response of trees to climatic extremes, and the combinations with multiple tree-ring multiple proxies such as width and density).

Climate change-induced drought and implications on maize cultivation area in the upper Nan River Basin, Thailand

Abstract The escalating frequency of climate change-induced droughts poses a severe threat to rainfed maize cultivation in Thailand's upper Nan River Basin (NRB). Utilizing the standardized precipitation evapotranspiration index, this study comprehensively examines spatial and temporal drought patterns and their potential agricultural impact. Findings indicate a significant shift in precipitation patterns with wetter wet seasons, drier dry seasons and rising temperatures. The upper NRB experiences prolonged and severe droughts, while the lower region faces higher drought intensity, signalling an increased likelihood of extended and severe drought episodes in the upper region. Assessing maize cultivation suitability, factoring in environmental variables and drought impact under observed and climate change scenarios, reveals the current moderate suitability at 42.2%, projected to expand, and unsuitable regions expected to double. Different shared socioeconomic pathways (SSPs) show varied outcomes, with SSP5-8.5 indicating increased suitability in highly suitable areas and SSP2-4.5 demonstrating improvements in moderately suitable areas. The study underscores the need for tailored adaptation strategies in water management during droughts to enhance crop production, especially in dry seasons, in the upper NRB amid a changing climate.

Tectonic and climatic significance of Oligocene-Miocene eolian sandstones in the Andean foreland basin of Argentina

Late Oligocene-early Miocene aridification in the retroarc foreland basin adjacent to the southern central Andes was recorded by widespread eolian conditions that coincided with accelerated subsidence driven by the main phase of Andean tectonic loading. An extensive eolian dune system, which is rare in most foreland basins, indicates specific conditions in terms of climate (aridity), atmospheric circulation, orography, sediment sources, dispersal patterns, and accommodation space. Detrital zircon U-Pb geochronological results for eolian sandstones spanning 20 foreland localities in northwestern to west-central Argentina, from 22°S to 36°S, reveal relatively localized Andean sources rather than regional cratonic provenance. Clastic detritus was largely derived from Phanerozoic igneous and sedimentary rocks of the Andean magmatic arc and retroarc fold-thrust belt during initial shortening-induced uplift of hinterland regions such as the Western Cordillera, Principal Cordillera, and Frontal Cordillera. This provenance record provides the earliest evidence for major westerly winds, transporting Andean detritus broadly eastward to the foreland basin (with common axial northward deflections) during a climate shift marked by the latest Oligocene-earliest Miocene inception of arid conditions. In addition to the climatic implications, independent stratigraphic data provide the basis for a compilation of sediment accumulation histories showing that eolian deposition was synchronous with accelerated subsidence attributable to enhanced Andean shortening. We propose that accelerated Andean uplift in the latest Oligocene-early Miocene generated rain-shadow conditions contemporaneous with increased sediment accommodation in the foreland basin, underscoring the important influence of tectonic processes on regional climate.