Recent  

The paper deals with 520-year long series (1501–2020 CE) of temperature, precipitation and four drought indices reconstructed from documentary evidence and instrumental observations for the Czech Lands. Basic features of their fluctuations, long-term trends, periodicities and attribution to changes in external forcings and climate variability modes are analysed. Representativeness of Czech reconstructions in European scale is evaluated. The paper shows extreme character of past decades.

In the context of understanding 3D photochemical effect on the Earth oxygenation that happened around 2.4 Gyr, we developed a 3D photochemical-climate model to investigate the possible impact of the atmospheric circulation and the coupling between the climate and the dynamics of the oxidation. We show that the diurnal, seasonal and transport variations do not bring significant changes compared to 1D models. Nevertheless, we highlight a temperature dependence for atmospheric photochemical losses.

We collected and standardized output of five isotope-enabled simulations for the last millennium and assess differences and similarities to records from a global speleothem database. Modelled isotope variations mostly arise from temperature differences. While lower resolution in speleothems does not capture extreme changes to the extent of models, they show higher variability on multi-decadal timescales. As no model excels in all comparisons, we advise a multi-model approach where possible.

The Leeuwin Current transports warm water along the western coast of Australia: from the tropics to the Southern Hemisphere mid-latitudes. Therewith, the current influences climate in two ways: First, as a moisture source for precipitation in southwest Australia. Second, as a vehicle for equator-to-pole heat transport. In this study, we study sediment cores along the Leeuwin Current pathway to understand its ocean-climate interactions between 4–2 Ma.

Determining seasonal temperatures demands proxies that record the highest and lowest temperatures over the annual cycle. Many record neither but oxygen isotope profiles from shells in principle record both. Oxygen isotope data from late Pliocene bivalve molluscs of the southern North Sea Basin show that the seasonal temperature range was at times much higher than previously estimated, and higher than now. This suggests reduced oceanic heat supply, in contrast to some previous interpretations.

A large drought potentially occurred roughly 4,200 years ago, but its impacts and significance are unclear. We find new evidence in carbonate oxygen isotopes from a mountain lake in southeast Wyoming, southern Rocky Mountains, of an abrupt reduction in effective moisture (precipitation–evaporation) or snowpack from approximately 4,200–4,000 years ago. The drought’s prominence among a growing number of sites in the North American interior suggests it was a regionally substantial climate event.

Terrestrial materials in marine environments record source information and help us understand how climate and ocean impact sediment compositions. Here, we use evidences on the Ninetyeast Ridge to analyze the relationship between terrestrial material supplementation and climatic change. We find that the ITCZ controlled the rainfall in the Burman source area, and that closer connections occurred between the Northern-Southern Hemispheres in the eastern Indian Ocean during the late LGM.

This review: 1. Illustrates how current climate and/or ice sheet model-based inferences about the past tend to have limited interpretable value about the real world given inadequate accounting of uncertainties. 2. Explains Bayesian inference to a non-statistical community. 3. Sketches out tractable Bayesian inference for computationally expensive models in a way that meaningfully accounts for uncertainties. 4. Lays out some steps for the community to move forward.

A new Greenland ice-core timescale, covering the last 3800 years, was produced by layer counting of ice core data, using the machine learning algorithm StratiCounter. By aligning ice core data on a common timescale, we were able to study the average impact of volcanic cooling in Greenland, finding that it can last for up to 10 years. Our new timescale has a better alignment with radiocarbon data, improving paleoclimate studies across the Northern Hemisphere.

Natural proxy data and written sources reveal that large 17th century eruptions had considerable climatic, agricultural and socioeconomic impacts far away from the eruption locations. Yet, micro-regional investigation shows that the eruption-climate-society causalities were commonly indirect, as various factors, like agro-ecosystem, resource availability, institutions and social networks, dictated how the volcanic cold pulses and related crop failures materialized on the grassroots level.

We apply Singular Spectrum Analysis (extracts pseudo-cycles in complex signals) to series used in building geological reference time scales, e.g. a benthic microfossil stack and an orbital solution for insolation. SSA of the stack contains not only the main expected Milankovic periods but also a rich collection of “secondary” periods. This validates at the same time our iterative SSA method, the orbital model and the remarkable benthic stack, with more than 15 “ Milankovic periods”.

The highest currently recognised air temperature (33.3 °C) ever recorded in the Republic of Ireland was logged at Kilkenny Castle in 1887. This paper reassess the plausibility of the record using various methods such as inter station reassessment and 20CRv3 reanalysis’. As a result, Boora 1976 at 32.5 °C is presented as a more reliable high temperature record for the Republic of Ireland. The final decision however rests with the national meteorological service, Met Éireann.

Termination V (TV, ~[404-433] kyr BP) marks a transition in the climate system towards amplified glacial-interglacial cycles. While the associated atmospheric CO₂ changes are mostly attributed to the Southern Ocean, little is known about the terrestrial biosphere contribution to the carbon cycle. The present study provides the first (model and pollen-based) reconstruction of global forests highlighting the key role of temperate and boreal forests in the mitigation of atmospheric CO₂ during TV.

Global mean surface temperatures are rising to levels unprecedented in over 100,000 years. This conclusion takes into account both recent global warming and likely future warming, which thereby enables a direct comparison with paleotemperature reconstructions on multi-century time scales.

We present a continuous humidity history in arid Central Asia over the past millennium based on the ~1.8-year high-resolution multiproxy record from Lake Dalongchi. Our findings emphasize that the Gleissberg solar cycle and quasi-regular period of ENSO amplitude play critical roles in controlling the effective humidity at century and multidecadal timescales, respectively. Our analysis provides new insights for hydroclimate predictions and climate simulations in arid Central Asia in the future.

The spring onset and growing season dynamics during the Lateglacial in the Baltic region were reconstructed using the micro-phenology based on the dwarf birch subfossil leaf cuticles. The comparison of pollen- and chironomid-inferred past temperature estimations with spring onset, growth-degree-days, and plant macrofossil data shows coherent patterns during the cooler Older Dryas and warmer Bølling/ Allerød periods but more complicated climate dynamics during the Younger Dryas cold reversal.

We examined annually resolved stable carbon and hydrogen isotope ratios of wood lignin methoxy groups of beech trees growing in temperate, low elevation environments. Here, carbon isotope ratios reveal highest correlations with regional summer temperatures, while hydrogen isotope ratios correlate stronger with large-scale temperature changes. By combining the dual isotope ratios of wood lignin methoxy groups a proxy for regional to sub-continental scale temperature patterns can be applied.

The Pliocene is a period during which atmospheric CO₂ was similar to today (i.e. ~400 ppm). We present the results of model simulations carried out within the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2), using the CESM 1.0.5. We find a climate that is much warmer than today (5 °C above 1850 conditions), with augmented polar warming, increased precipitation and strongly reduced sea ice cover. In addition, several leading modes of variability in temperature show an altered behaviour.

Late Eocene to earliest Oligocene (37.97–33.06 Ma) climate and vegetation dynamics around the Tasmanian Gateway region reveal that, changes in ocean circulation due to accelerated deepening of the Tasmanian Gateway may not have been solely responsible for the changes in terrestrial climate and vegetation, but a series of regional and global events, including a change in stratification of water masses and changes in pCO₂ may have played significant roles.

We present data from fieldwork completed in 2002 for a glacial lake in the Torngat Mountains (Northern Quebec and Labrador, Canada). We dated the lake to ~56 ± 3 ka and estimated the freshwater volume that may have been released during an outburst flood. The location of this glacial lake is surprising because the Torngat Mountains are considered a site of glacial inception, and this shoreline suggests the region was not ice-covered throughout the North American ice sheet growth phase.

Building upon Milancovic’s theory of orbital forcing, this manuscript reviews the interplay between intrinsic variability and external forcing in the emergence of glacial-interglacial cycles. It provides the reader with historical background information and with basic theoretical concepts used in recent paleoclimate research. Moreover, it presents new results which confirm the reduced stability of glacial-cycle dynamics after the Mid-Pleistocene Transition.

The atmospheric loading-to-ice cap deposition (LTD) factor is a key part of volcanic forcing reconstruction. We used a large collection of bipolar ice core records and Monte Carlo sampling to provide a new set of Tambora-based LTDs and characterize the uncertainties，while results also show that the LTD factor may vary significantly among different eruptions.

We unearth and analyse two decades worth of highly valuable measurements made on Mauritius at the Royal Alfred Observatory at the turn of the 20^th Century where several distinct thermometer combinations were in use and compared. This series provides unique insights into biases in early instrumental temperature records. Differences are substantial and for some instruments exhibit strong seasonality. This reinforces the critical importance of understanding early instrumental series biases.

Earth experienced frequent high-latitude glaciations from 360–260 million years ago but impacts on low latitude climates are poorly known. We use multiple proxies including clay mineral analysis on low latitude sediments in China to unveil past climates and correlate cool and humid climates with glacials and warm and humid climates to interglacials. Our results track high latitude glacial rhythms and show glacial cycles drove plant evolution and terrestrial environment change in low latitudes.

Palaeo-environmental records only provide a fragmentary picture of the lake and wetland extent in North Africa during the mid-Holocene. Therefore, we investigate the possible range of mid-Holocene precipitation changes caused by an estimated small and maximum lake extent and a maximum wetland extent. Results show a particularly strong monsoon precipitation response to lakes and wetlands over the Western Sahara and an increased monsoon precipitation when replacing lakes with vegetated wetlands.

We used palaeoecological records from forested peatlands in southern Siberia and showed that warmer climate conditions have lowered the water level and increased the tree cover. This in turn has increased the fuel amount and flammability and consequently the frequency and severity of fires as well the composition of tree type.

Sea ice is important for our climate system, and for the unique ecosystems it supports. We present a novel way to understand past Antarctic sea ice ecosystems: using the regurgitated stomach contents of snow petrels, which nest above the ice sheet but feed in the sea-ice pack. During a time when sea ice was more extensive than today (22,000–29,000 years ago), we show that snow petrel diet had varying contributions of fish and krill, which we interpret to show changing sea ice distribution.