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The middle Miocene (15 Ma) was a period of global warmth up to 8 °C warmer than present. We investigate changes in ocean circulation and heat distribution since the middle Miocene and the cooling to the present using the cGENIE Earth system model. We create seven time slices at ~2.5 Myr intervals, constrained with paleo-proxy data, showing a progressive reduction in atmospheric CO₂ and a strengthening of the Atlantic Meridional Overturning Circulation.

The 1921 drought was the most severe drought to hit Europe since the start of the 20th century. Here the climatological description of the drought is coupled to an overview of its impacts, sourced from newspapers, and an analysis of its drivers. The area from Ireland to the Ukraine was affected but hardest hit was the triangle between Brussels, Paris and Lyon. The drought impacts lingered on until well into autumn and winter, affecting water supply and agriculture and livestock farming.

Stalagmites are valuable climate archives, but unlike other proxies the use of stable carbon isotopes (δ¹³C) is still difficult. A stalagmite from the Austrian Alps was analyzed using a new laser ablation method for fast radiocarbon (¹⁴C) analysis. This allowed 14C and δ¹³C to be combined, showing that besides soil and bedrock a third source is contributing during periods of warm, wet climate: old organic matter.

In this paper we discuss results obtained with a set of coupled ice-sheet–climate model experiments for the last 26 kyrs. The model displays a large sensitivity of the oceanic circulation to the amount of the freshwater flux resulting from ice sheet melting. Ice sheet geometry changes alone are not enough to lead to abrupt climate events, and rapid warming at high latitudes is here only reported during abrupt oceanic circulation recoveries that occurred when accounting for freshwater flux.

The ~ 74 ka eruption of Toba was one of the largest eruptions of the last 100 ka. We have measured the sulfur isotopic composition for 11 Toba eruption candidates in two Antarctic ice cores. Sulfur isotopes allow us to distinguish between large eruptions that have erupted material into the stratosphere and smaller ones that reach lower altitudes. Using this we have identified the events most likely to be Toba and place the eruption on the transition into a cold period in the Northern Hemisphere.

Computer simulations of the geological past are an important tool to improve our understanding of climate change. We present results from a simulation of the mid-Pliocene (approximately 3 million years ago) using the latest version of the UK’s climate model. The simulation reproduces temperatures as expected and shows some improvement relative to previous versions of the same model. The simulation is, however, arguably too warm when compared to other models and available observations.

We use the first high-resolution southeast Atlantic carbonate record to see how climate dynamics evolved since 30 million years ago (Ma). During ~ 30–13 Ma, eccentricity (orbital circularity) paced carbonate deposition. After the mid-Miocene Climate Transition (~ 14 Ma), precession (Earth's tilt direction) increasingly drove carbonate variability. In the latest Miocene (~ 8 Ma), obliquity (Earth's tilt) pacing appeared, signalling increasing high-latitude influence.

The first step to exploit all the potential information buried in ice cores is to produce a reliable age scale. Based on chemical and isotopic records from the 197 m Antarctic GV7(B) ice core, accurate dating was achieved and showed that the archive spans roughly the last 830 years. The relatively high accumulation rate allowed us to use the non-sea-salt sulfate seasonal pattern to count annual layers. The accumulation rate reconstruction exhibited a slight increase since the 18th century.

High-resolution geochemical imaging techniques provide new opportunities to investigate the biogeochemical composition of sediments at micrometer scale. Here, we compare biogeochemical data from biochemical varves with meteorological data to understand how seasonal meteorological variations are recorded in varve composition. We find that these scanning techniques help to clarify climate–proxy relationships in biochemical varves and show great potential for high-resolution climate reconstruction.

To understand the natural characteristics and future changes of the global extreme daily precipitation, it is necessary to explore the long-term characteristics of extreme daily precipitation. Here, we used climate simulations to analyze the characteristics and long-term changes of extreme precipitation during the past 3351 years. Our findings indicate that extreme precipitation in the past is associated with internal climate variability and regional surface temperatures.

Over the last 600 years, Sweden has occasionally suffered from severe summer droughts. But droughts caused by extreme heat are uncommon. They are instead usually caused by lack of rain. From historical documents it can be confirmed that such drought periods, with substantial consequences for agriculture and mining activities, have occurred on repeated occasions between the Middle Ages and 1800 CE, coinciding with a slightly colder climate and other social strains in the 17th and 18th centuries.

South West Western Australia has experienced a prolonged drought in recent decades. The causes of this drought are unclear. We use an ice core from East Antarctica to reconstruct changes in rainfall over the past 2000 years. We find that the current drought is unusual, with only two other droughts of similar severity having occurred during this period. Climate modelling shows that greenhouse gas emissions during the industrial era are likely to have contributed to the recent drying trend.

In this paper, we present new sedimentological, geochemical, and mineralogical data exploring the environmental response to climatic and volcanic impact during the Paleocene–Eocene Thermal Maximum (~55.9 Ma; PETM). Our data suggest a rise in continental weathering and a shift to anoxic–sulfidic conditions. This indicates a rapid environmental response to changes in the carbon cycle and temperatures and highlights the important role of shelf areas as carbon sinks driving the PETM recovery.

We identified the provenance, (post)depositional history, weathering conditions and hydroclimate that formed the detrital and authigenic silicates and soil carbonates of the Valley of Lakes sediments in Central Asia during the Cenozoic (~34 to 21 Ma). Aridification pulses in continental Central Asia coincide with marine glaciation events and are caused by Cenozoic climate forcing and the exhumation of the Tian Shan, Hangay and Altai mountains, which reduced the moisture influx by westerly winds.

We reconstruct the history of biogenic opal accumulation through the early to middle Paleogene in the western North Atlantic. Biogenic opal accumulation was controlled by deepwater temperatures, atmospheric greenhouse gas levels, and continental weathering intensity. Overturning circulation in the Atlantic was established at the end of the extreme early Eocene greenhouse warmth period. We also show that the strength of the link between climate and continental weathering varies through time.

Glacial periods underwent climate shifts between warm states and cold states on a millennial timescale. Frequency of these climate shifts varied along time: it was shorter during mid-glacial period compared to early glacial period. Here, from climate simulations of early and mid-glacial periods with a comprehensive climate model, we show that the larger ice sheet in the mid-glacial compared to early glacial periods could contribute to the frequent climate shifts during the mid-glacial period.

Soil respiration is a critical but poorly constrained component of the global carbon cycle. We analyse the effect of changing soil respiration rates on the stable carbon isotope ratio of speleothems from northern Spain covering the last deglaciation. Using geochemical analysis and forward modelling we quantify the processes affecting speleothem stable carbon isotope ratios and extract a signature of increasing soil respiration synchronous with deglacial warming.

Continental atmospheric humidity is a key climate parameter poorly captured by global climate models. Model–data comparison approaches that are applicable beyond the instrumental period are essential to progress on this issue but face a lack of quantitative relative humidity proxies. Here, we calibrate the triple oxygen isotope composition of phytoliths as a new quantitative proxy of continental relative humidity suitable for past climate reconstructions.

This article presents FYRE Climate, a dataset providing daily precipitation and temperature spanning the 1871–2012 period at 8 km resolution over France. FYRE Climate has been obtained through the combination of daily and yearly observations and a gridded reconstruction already available through a statistical technique called data assimilation. Results highlight the quality of FYRE Climate in terms of both long-term variations and reproduction of extreme events.

Here we reconstruct the rate of snow accumulation during the Last Interglacial period in an East Antarctic ice core located near the present-day northern edge of the Ross Ice Shelf. We find an order-of-magnitude increase in the accumulation rate during the peak warming in the Last Interglacial. This large increase in mass accumulation is compatible with less ice cover in the Ross Sea, perhaps created by a partly collapsed West Antarctic Ice Sheet, whose stability in a warming world is uncertain.

This study investigates the reliability of paleo-reconstructions of the Southern Annular Mode (SAM) using climate model data. We find that reconstructions are able to capture ~ 60 % of the SAM variability at best, with poorer reconstructions managing only 35 %. Reconstructions perform best when they use more proxies sourced from the entire Southern Hemisphere land mass. Future reconstructions should endeavour to address both sampling and proxy–SAM correlation stability uncertainties.

We present preliminary analyses of the annual sea salt concentrations and snowfall accumulation in a new East Antarctic ice core, Mount Brown South. We compare this record with an updated Law Dome (Dome Summit South site) ice core record over the period 1975–2016. The Mount Brown South record preserves a stronger and inverse signal for the El Niño–Southern Oscillation (in austral winter and spring) compared to the Law Dome record (in summer).

The mid-Pliocene Warm Period (~ 3.2 Ma) is often considered an analogue for near-future climate projections, and model results from the PlioMIP2 ensemble show an increase of rainfall over West Africa and the Sahara region compared to pre-industrial conditions. Though previous studies of future projections show a west–east drying–wetting contrast over the Sahel, these results indicate a uniform rainfall increase over the Sahel in warm climates characterized by increased greenhouse gas forcing.

Greenland ice core data show that the last glacial cycle was punctuated by a series of abrupt climate shifts comprising significant warming over Greenland, retreat of North Atlantic sea ice, and atmospheric reorganization. Statistical analysis of multi-proxy records reveals no systematic lead or lag between the transitions of proxies that represent different climatic subsystems, and hence no evidence for a potential trigger of these so-called Dansgaard–Oeschger events can be found.

To study the interaction of the westerlies and Indian summer monsoon (ISM) during the Holocene, we used paleoenvironmental reconstructions using a sediment core from the northeast Arabian Sea. We found a climatic transition period between 4.6 and 3 ka BP during which the ISM shifted southwards and the influence of Westerlies became prominent. Our data indicate a stronger influence of agriculture activities and enhanced soil erosion, adding to Bond event impact after this transition period.

This paper stresses the original contributions of Milankovitch related to his caloric seasons and his climate model giving the caloric seasons a climatological meaning.