This study presents a new stable oxygen isotope chronology, covering the years 800–2000 AD, constructed using modern and subfossil wood derived from trees growing around Lake Schwarzensee in Austria. The climatic signal imparted in the chronology is conditioned mainly by the direct influence of environmental factors on the isotopic signature of source water, which in turn is regulated by evaporation and condensation mechanisms. The second driver of stable oxygen isotope is the physiological response of trees to changing weather conditions, most importantly rates of transpiration. The chronology of stable oxygen isotopes corresponds well with both temperature (r = 0.485; p < 0.05) and total precipitation (r = −0.548; p < 0.05) during the growing season (May–September). This mixed signal results from the fact that the relationship between the content of stable oxygen isotopes and the influence of climate is multifactorial. Moreover, the effect exerted by meteorological conditions on stable isotope ratio changes over time. This is most probably linked to interannual variation in climatic and environmental factors.

We developed a 1108 yr chronology of tree-ring widths, based on 64 Himalayan pencil juniper (Juniperus semiglobosa Regel) trees, for the Pamir-Alay Mountains, central Asia. Dendroclimatological analysis demonstrates that precipitation has significant effects on tree growth in the semiarid mountainous area of northwestern Tajikistan located on the edge of the great midlatitude Karakum and Kyzylkum deserts. The highest level of linear correlation (r=0.67) is observed between tree growth and seasonalised winter (previous December–February) precipitation. Our studies also show that moisture (precipitation/Palmer Drought Severity Index) from the previous June to the current September was the dominant climatic factor accounting for interannual variations in tree-ring width, suggesting that this should be considered in climate reconstruction. Using the transfer function method, we reconstructed the region’s drought history over the period AD 908–2015. The results of this moisture reconstruction showed that the most recent millennium was characterised by series of dry and wet stages. The driest periods occurred before 1000, 1200–1250, and at the end of the eighteenth century and beginning of the nineteenth century. The wettest conditions existed in 1650–1700 and after 1990.

We present a reconstruction of June–July minimum temperatures since AD 1245 for the Mackenzie Delta region based on a 29-site network of white spruce (Picea glauca) ring-width series. Most but not all trees experienced a divergent temperature–growth response, similar to the divergence that has affected other white spruce trees across Yukon and Alaska. However, divergence in the study region began as early as AD 1900 and we have documented our methods to avoid including divergent signals in the reconstruction. Calibration/verification testing based on local temperature data, and multi-century coherence with nearby and large-scale temperature proxy records, confirm that our reconstruction is robust. The reconstruction shows cool conditions in the late 13th, early 18th and early 19th centuries, corresponding with solar minima and increased volcanism. These cool periods are interrupted by warm periods consistent with early to mid-20th century warmth. The late 20th century is the warmest interval, and the last decade is estimated to be 1.4°C warmer than any decade before the mid-20th century. The reconstructed climate history corroborates other proxy-based inferences and supports the notion that high-latitude regions such as the Mackenzie Delta have experienced rapid warming in recent decades that is exceptional in the last eight centuries.

Recognizing that climate influences both annual tree-ring growth and glacier mass balance, changes in the mass balance of Place Glacier, British Columbia, were documented from increment core records. Annually resolved ring-width (RW), maximum (MXD), and mean density (MD) chronologies were developed from Engelmann spruce and Douglas-fir trees sampled at sites within the surrounding region. A snowpack record dating to AD 1730 was reconstructed using a multivariate regression of spruce MD and fir RW chronologies. Spruce MXD and RW chronologies were used to reconstruct winter mass balance (Bw) for Place Glacier to AD 1585. Summer mass balance (Bs) was reconstructed using the RW chronology from spruce, and net balance was calculated from Bw and Bs. The reconstructions provide insight into the changes that snowpack and mass balance have undergone in the last 400 years, as well as identifying relationships to air temperature and circulation indices in southern British Columbia. These changes are consistent with other regional mass-balance reconstructions and indicate that the persistent weather systems characterizing large scale climate-forcing mechanisms play a significant glaciological role in this region. A comparison to dated moraine surfaces in the surrounding region substantiates that the mass-balance shifts recorded in the proxy data are evident in the response of glaciers throughout the region.

Despite the extensive network of moisture-sensitive tree-ring chronologies in western North America, relatively few are long enough to document climatic variability before and during the Medieval Climate Anomaly (MCA) ca. AD 800-1300. We developed a 2300-yr tree-ring chronology extending to 323 BC utilizing live and remnant Douglas-fir (Pseudotsuga menziesii) from the Tavaputs Plateau in northeastern Utah. A resulting regression model accounts for 70% of the variance of precipitation for the AD 1918–2005 calibration period. Extreme wet and dry periods without modern analogues were identified in the reconstruction. The MCA is marked by several prolonged droughts, especially prominent in the mid AD 1100s and late 1200s, and a lack of wet or dry single-year extremes. The frequency of extended droughts is not markedly different, however, than before or after the MCA. A drought in the early AD 500s surpasses in magnitude any other drought during the last 1800 yr. A set of four long high-resolution records suggests this drought decreased in severity toward the south in the western United States. The spatial pattern is consistent with the western dipole of moisture anomaly driven by El Niño and is also similar to the spatial footprint of the AD 1930s "Dust Bowl" drought.

We present the first near millennium-length, annually resolved stable isotope record from bristlecone pines (Pinus longaeva, D.K Bailey). The carbon isotope ratios from the cellulose of seven trees from the White Mountains of California, corrected for anthropogenic changes in atmospheric chemistry, are used to reconstruct growing season (June through August) precipitation back to AD 1085. Extremely negative isotope results are strongly correlated with proposed severest El Niño events over the last 500 yr, and similar values in the first half of the millennium are used to reconstruct a further 13 strong El Niño events, concentrated in the 12th Century and the mid 13th and 14th Centuries. Ring-width chronologies from adjacent sites in the White Mountains demonstrate a high degree of decadal covariance with the δ13C series, although there are several periods of notable divergence.

Ring widths from whitebark pine (Pinus albicaulis Englem.) and subalpine larch (Larix lyallii Parl.) collected at three high-elevation sites were used to develop tree-growth chronologies to reconstruct summer temperature anomalies. A step-wise multiple regression procedure was used to screen potential predictor variables to generate a transfer function capable of skillfully reconstructing summer temperature. The resulting regression model explained approximately 38% of the adjusted variance in the instrumental temperature record. The fidelity of the reconstruction was verified using product mean and sign tests, both of which suggested significant predictive power in the reconstructions (p<0.05). Reduction of error (RE) and coefficient of efficiency (CE) measures were both positive, indicating the reconstruction contained useful climate information. Cool periods often coincided with reduced solar activity and/or periods of increased volcanic activity. Differences between this reconstruction and others encompassing a broader geographic scale highlight the importance of developing local reconstructions of climate variability, particularly when used in conjunction with ecological data sets that describe the occurrence of fires or insect epidemics. Mixed and divergent climate-response relationships were evident in the whitebark pine chronologies and suggest subalpine larch may be a more useful species than whitebark pine to target for the development of temperature reconstructions in this region.

Modelling of tree-ring δ13C and δ18O data from the Columbia Icefield area in the eastern Rocky Mountains of western Canada provides fuller understanding of climatic and hydrologic variability over the past 1000 yr in this region, based on reconstruction of changes in growth season atmospheric relative humidity (RHgrs), winter temperature (Twin) and the precipitation δ18O–Twin relation. The Little Ice Age (~ AD 1530s–1890s) is marked by low RHgrs and Twin and a δ18O–Twin relation offset from that of the present, reflecting enhanced meridional circulation and persistent influence of Arctic air masses. Independent proxy hydrologic evidence suggests that snowmelt sustained relatively abundant streamflow at this time in rivers draining the eastern Rockies. In contrast, the early millennium was marked by higher RHgrs and Twin and a δ18O–Twin relation like that of the 20th century, consistent with pervasive influence of Pacific air masses because of strong zonal circulation. Especially mild conditions prevailed during the “Medieval Climate Anomaly” ~ AD 1100–1250, corresponding with evidence for reduced discharge in rivers draining the eastern Rockies and extensive hydrological drought in neighbouring western USA.

In this study, we aim to examine past dry and wet events for the western Anatolia, performing local and spatial reconstructions. 17 new black pine site chronologies were developed, May–June precipitation time series were reconstructed for four localities, and the first spatial May–June precipitation reconstruction was achieved for western Anatolia. The long-term local May–June precipitation reconstructions contain mostly one-year and less commonly, two-year drought events. The longest consecutive dry period (AD 1925–1928) in the reconstructed time series for Kütahya lasted four years. Spatial reconstructions revealed that between AD 1786 and 1930 the extreme dry years for all of western Anatolia were AD 1887, 1893, 1794 and 1740. The driest year during the 215-year-long period under consideration was 1887. The wettest years for the entire western Anatolia were determined to be AD 1835, 1876, 1881 and 1901. There is a big overlap between agricultural famine years and dry years as determined from reconstructions. In this context, our study provides a basis for understanding agricultural drought and better management of regional water resources.

Dendroclimatology in the Eastern Mediterranean (EM) region has made important contributions to the understanding of climate variability on timescales of decades to centuries. These contributions, beginning in the mid-20th century, have value for resource management, archaeology, and climatology. A gradually expanding tree-ring network developed by the first author over the past 15 years has been the framework for some of the most important recent advances in EM dendroclimatology. The network, now consisting of 79 sites, has been widely applied in large-scale climatic reconstruction and in helping to identify drivers of climatic variation on regional to global spatial scales. This article reviews EM dendroclimatology and highlights contributions on the national and international scale.

Most glaciers in the British Columbia Coast Mountains reached their maximum Holocene extent during the Little Ice Age. Early- and late-Little Ice Age intervals of expansion and retreat fluctuations describe a mass-balance response to changing climates. Although existing dendroclimatic records provide insights into these climatic fluctuations over the last 400 yr, their short durations prohibit evaluation of early-Little Ice Age climate variability. To extend the duration of these records, submerged coarse woody debris salvaged from a high-elevation lake was cross-dated to living chronologies. The resulting chronology provides the opportunity to reconstruct a regional June–July air-temperature anomaly record extending from AD 1225 to 2010. The reconstruction shows that the intervals AD 1350–1420, 1475–1550, 1625–1700 and 1830–1940 characterized distinct periods of below-average June–July temperature followed by periods of above-average temperature. Our reconstruction provides the first annually resolved insights into high-elevation climates spanning the Little Ice Age in this region and indicates that Little Ice Age moraine stabilization corresponds to persistent intervals of warmer-than-average temperatures. We conclude that coarse woody debris submerged in high-elevation lakes has considerable potential for developing lengthy proxy climate records, and we recommend that researchers focus attention on this largely ignored paleoclimatic archive.