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According to the written records and scores of grain harvest in the official historical documents of the Qing Dynasty in China, the spatial-temporal distribution of and the impact caused by the 1759 AD drought in Northwest China were reconstructed, and the response of Chinese society to the drought at that time was summarized. In the spring and summer of 1759, vast areas of northern China suffered from drought, of which that experienced in the northwest region was the most serious. Starting from 27 April 1759, droughts covered Zhili, Shanxi, Shaanxi, and Gansu provinces, and the droughts in Gansu and northern Shaanxi provinces lasted until 23 July 1759. This severe drought caused the worst crop failure in Northwest China in 1759 during the period 1730–1900. By implementing a series of disaster relief measures, the Qing government managed to ease the adverse societal impact of the drought in the summer of 1760. Among the relief measures, tax reduction and exemption in disaster-stricken areas, grain storage in the northwest region, and bumper agricultural harvests in Henan, Shandong, Jiangsu, and Anhui provinces in 1759 were the main reasons for the rapid recovery from the drought impacts. With better climatic conditions in the 18th century, China had higher agricultural harvest levels in the 18th century than in the 19th century. Favorable financial conditions increased drought relief efforts, which was the background for the greater societal adaptability to the climate disaster of 1759.

East Asia has experienced strong warming since the 1960s accompanied by an increased frequency of heat waves and shrinking glaciers over the Tibetan Plateau and the Tien Shan. Here, we place the recent warmth in a long-term perspective by presenting a new spatially resolved warm-season (May-September) temperature reconstruction for the period 1–2000 CE using 59 multiproxy records from a wide range of East Asian regions. Our Bayesian Hierarchical Model (BHM) based reconstructions generally agree with earlier shorter regional temperature reconstructions but are more stable due to additional temperature sensitive proxies. We find a rather warm period during the first two centuries CE, followed by a multi-century long cooling period and again a warm interval covering the 900–1200 CE period (Medieval Climate Anomaly, MCA). The interval from 1450 to 1850 CE (Little Ice Age, LIA) was characterized by cooler conditions and the last 150 years are characterized by a continuous warming until recent times. Our results also suggest that the 1990s were likely the warmest decade in at least 1200 years. The comparison between an ensemble of climate model simulations and our summer reconstructions since 850 CE shows good agreement and an important role of internal variability and external forcing on multi-decadal time-scales., Huan Zhang, Jürg Luterbacher, Johann H. Jungclaus, Sebastian Wagner and Eduardo Zorita acknowledge support from the German Science Foundation project “Attribution of forced and internal Chinese climate variability in the common eras”. Jürg Luterbacher, Lea Schneider, Stefanie Talento, Jianglin Wang and Bao Yang acknowledge JPI-Climate/Belmont Forum collaborative Research Action “INTEGRATE, An integrated data-model study of interactions between tropical monsoons and extratropical climate variability and extremes”. Jürg Luterbacher acknowledges the Climate Science for Service Partnership China project (CSSP): Digitisation and quality control of subdaily meteorological data from Asian stations in the late 19th and early 20th century. Fidel J. González-Rouco acknowledges support from ILModelS CGL2014–59644-R. Elena García-Bustamante thanks the European Framework programm FP7 ERA-NET project “NEWA: New European Wind Atlas”, funded by the European Commission.

To synthesize zeolites in a safe and cost-saving manner is the first and the most important task for zeolite application in industry. In the present work, FeAPO-5 aluminophosphate molecular sieve with high iron content was ionothermally synthesized by microwave irradiation at ambient pressure using low dosage of eutectic mixture as the solvent. The influences of seed crystals and mechanochemical pretreatment on the synthesis of FeAPO-5 were investigated in detail. The resultant relatively pure FeAPO-5 molecular sieves were characterized by XRD, ICP-AES, SEM, N2 physisorption and UV–Vis diffuse reflectance spectrometer, and their catalytic performances were studied using phenol hydroxylation as a probe reaction. The XRD results revealed that pure FeAPO-5 can be readily obtained from mechanochemically pretreated reactants, regardless of whether or not the seed crystals were added. The ICP-AES measurements suggested that only by using specific seed crystals can pure FeAPO-5 molecular sieve with high iron content be synthesized. The SEM analysis implied that seed crystals may play a role of morphology-directing agent in these syntheses. The catalytic results demonstrated that longer pronounced induction period were only observed over those FeAPO-5 catalysts with sole framework iron species. The different catalytic activity among five selected catalysts was largely determined by their different densities of framework iron species, while the selectivity towards dihydroxybenzene was mainly controlled by the diffusion path length. Under given reaction conditions, FeAPO-5 catalyst with up to 6.79 wt% of iron content gave 42.0% dihydroxybenzene yield with a selectivity of 94.1%.

Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python.(TABLE)Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013').This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product.This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike.

The spatial context is critical when assessing present-day climate anomalies, attributing them to potential forcings and making statements regarding their frequency and severity in a long-term perspective. Recent international initiatives have expanded the number of high-quality proxy-records and developed new statistical reconstruction methods. These advances allow more rigorous regional past temperature reconstructions and, in turn, the possibility of evaluating climate models on policy-relevant, spatio-temporal scales. Here we provide a new proxy-based, annually-resolved, spatial reconstruction of the European summer (June-August) temperature fields back to 755 CE based on Bayesian hierarchical modelling (BHM), together with estimates of the European mean temperature variation since 138 BCE based on BHM and composite-plus-scaling (CPS). Our reconstructions compare well with independent instrumental and proxy-based temperature estimates, but suggest a larger amplitude in summer temperature variability than previously reported. Both CPS and BHM reconstructions indicate that the mean 20th century European summer temperature was not significantly different from some earlier centuries, including the 1st, 2nd, 8th and 10th centuries CE. The 1st century (in BHM also the 10th century) may even have been slightly warmer than the 20th century, but the difference is not statistically significant. Comparing each 50 yr period with the 1951-2000 period reveals a similar pattern. Recent summers, however, have been unusually warm in the context of the last two millennia and there are no 30 yr periods in either reconstruction that exceed the mean average European summer temperature of the last 3 decades (1986-2015 CE). A comparison with an ensemble of climate model simulations suggests that the reconstructed European summer temperature variability over the period 850-2000 CE reflects changes in both internal variability and external forcing on multi-decadal time-scales. For pan-European temperatures we find slightly better agreement between the reconstruction and the model simulations with high-end estimates for total solar irradiance. Temperature differences between the medieval period, the recent period and the Little Ice Age are larger in the reconstructions than the simulations. This may indicate inflated variability of the reconstructions, a lack of sensitivity and processes to changes in external forcing on the simulated European climate and/or an underestimation of internal variability on centennial and longer time scales

We review here proxy records of temperature and precipitation in China during the Holocene, especially the last two millennia. The quality of proxy data, methodology of reconstruction, and uncertainties in reconstruction were emphasized in comparing different temperature and precipitation reconstruction and clarifying temporal and spatial patterns of temperature and precipitation during the Holocene. The Holocene climate was generally warm and wet. The warmest period occurred in 9.6–6.2 cal ka BP, whereas a period of maximum monsoon precipitation started at about 11.0 cal ka BP and lasted until about 8.0–5.0 cal ka BP. There were a series of millennial-scale cold or dry events superimposed on the general trend of climate changes. During past two millennia, a warming trend in the 20th century was clearly detected, but the warming magnitude was smaller than the maximum level of the Medieval Warm Period and the Middle Holocene. Cold conditions occurred over the whole of China during the Little Ice Age (AD 1400–AD 1900), but the warming of the Medieval Warm Period (AD 900–AD 1300) was not distinct in China, especially west China. The spatial pattern of precipitation showed significant regional differences in China, especially east China. The modern warm period has lasted 20 years from 1987 to 2006. Bi-decadal oscillation in precipitation variability was apparent over China during the 20th century. Solar activity and volcanic eruptions both were major forcings governing the climate variability during the last millennium.