Recent  

It is known that there was a lack of coral reefs in the Central Indo-Pacific during the Pliocene. The cause of this is unknown. This study uses a new SST record biased on biomarkers from the Coral Sea between 11–2 Ma to demonstrate a 2-degree cooling in the Central Indo-Pacific as part of the Late Miocene Cooling. When combined with other impacts associated with this event, this might explain the collapse of coral reefs. The new data shows the importance of SST changes in Coral Reef loss.

Based on dinoflagellate cyst assemblage and sea surface temperature record west offshore Tasmania, we find a northward migration and freshening of the subtropical front, not at the M2 glacial maximum but at its deglaciation phase. This oceanographic change aligns well with the trends in pCO₂. We propose that iceberg discharge from the M2 deglaciation freshened the subtropical front, which together with the other oceanographic changes, affected atmosphere-ocean CO₂ exchange in the Southern Ocean.

We present simulations of the mid-Holocene and pre-industrial climate of Australia using coarse (2°) and finer (0.44°) resolution climate models. These simulations are compared to bioclimatic representation of the palaeoclimate of the mid-Holocene. The finer resolution simulations reduce the bias between the model and the bioclimatic results and highlight the improved value of using finer resolution models to simulate the palaeoclimate.

Marine sediment and ice core records suggest a warmer Southern Ocean and Antarctica at the early last interglacial, ~127 thousand years ago. However, when only forced by orbital parameters and greenhouse gas concentrations during that period, state-of-the-art climate models do not reproduce the magnitude of warming. Here we show that much of the warming at southern mid-to-high latitudes can be reproduced by a UK climate model HadCM3 with a 3000-year freshwater forcing over the North Atlantic.

The deep ocean is an important part of the global climate system. Accurate estimates of temperature changes at depth, are crucial to understand the role of the intermediate to deep ocean in climate change. We have used samples from the Indian Ocean to establish Mg/Ca based temperature calibrations based on benthic foraminifera. Our data suggest that generating optimal Mg/Ca ratios in benthic foraminifera may require species and region specific cleaning procedures.

We reconstruct sea surface temperatures (SSTs) of the past 43 ka in the Gulf of Oman. We find SST variations of up to seven degree with lower SSTs during Heinrich Events (HE), especially HE4, and higher SSTs during Dansgaard-Oeschger Events. Our record shows no profound cooling during the Last Glacial Maximum but abrupt variations during the Holocene. We surmise that SSTs variations are influenced by the southwest (northeast) Monsoon during warmer (colder) periods.

This study applies the EOF method described in the companion article to precipitation instead of temperature. This novel method estimates a climate indicator for precipitation for Sweden over 1860–2020. Unlike earlier methods, the new method incorporates hundreds of stations and applies weighing coefficients reflecting leading modes of variability, established during the 1961–2018 calibration. It exhibits decadal precipitation trends and geographical patterns of precipitation over Sweden.

Questions remain about the past climate in Iceland, including the relative impacts of natural and human factors on vegetation change and soil erosion. We present a sub-centennial scale record of landscape and algal productivity from a lake in north Iceland. Along with high-resolution age constraint that covers the last ~12000 years, our record provides an environmental template for the region and novel insight into the sensitivity of the Icelandic ecosystem to natural and human impacts.

The sedimentary sequence in Scladina Cave (Belgium) is well-known for its rich archeological assemblages and its numerous faunal remains. Of particular interest is the presence of a nearly complete jaw bone of a Neandertal child. In this study, we present new Uranium-series ages of stalagmites from the archeological sequence which allow more precise dating of the archeological finds. One key result is that the Neandertal child may be slightly older than previously thought.

A coral reconstruction of past climate shows changes in the seasonal cycle of sea surface temperature in the SE tropical Indian Ocean. An enhanced seasonal cycle suggests that the tropical rainfall belt shifted northwards between 1855–1917. We explain this with greater warming in the NE Indian Ocean relative to the SE, which strengthens surface winds and coastal upwelling, leading to greater cooling in the eastern Indian Ocean south of the Equator.

Current uncertainty caused by climate change justifies the analysis of the most severe and less frequent droughts. In the Northeast of the Iberian Peninsula these events have direct repercussions on water resources and management. The study of these episodes using historical documentary sources and early instrumental records allows to identify episodes resembling the current ones. This knowledge allows better management of water resources in similar situations that may occur in future scenarios.

We reconstruct global hydroclimate anomalies for the past 21,000 years using a data assimilation methodology blending observations recorded in lake sediments with the climate dynamics simulated by climate models. The reconstruction resolves data-model disagreement in East Africa and North America, and we find that changing global temperatures and associated circulation patterns as well as orbital forcing are the dominant controls on global precipitation over this interval.

This paper introduces the ClimeApp web application. The app provides quick access to the ModE-RA global climate reanalysis. Users can calculate and plot anomalies, composites, correlations, regressions and annual cycles across three different datasets and four climate variables. By re-examining the 1815 Tambora eruption, we demonstrate how combining results from different datasets and sources can help us investigate the historical palaeoclimate and integrate it into human history.

We constructed a geologic record of East Antarctic Ice Sheet thickness from deposits at Otway Massif to assess directly how Earth’s largest ice sheet responds to warmer-than-present climate. Our record confirms the long-term dominance of a cold polar climate but lacks a clear ice sheet response to the Mid Pliocene Warm Period, a common analogue for the future. Instead, an absence of moraines from the Late Miocene-Early Pliocene suggests the ice sheet was less extensive than present at that time.

Our study explores the LGM ocean circulation, specifically the AMOC. Despite stronger tidal forces during the LGM, we found that the AMOC remained shallow due to the ocean’s increased stratification. This contradicts previous beliefs that stronger tides would deepen the AMOC. Our findings are significant for understanding past climate changes and could inform future climate models. We used ocean model simulations to analyze the impact of tidal forces and stratification on the AMOC.

In light of anthropogenic climate change, climate indicators are useful to illustrate how temperature varies over time. It is however no trivial task: missing data, changing networks make it difficult to calculate the indicator. This study introduces a new method for temperature over Sweden since 1860. Unlike the previous method, the new method incorporates hundreds of stations and applies weighing coefficients that reflect the leading modes of variability, established during 1961–2018.

Investigating past glaciated regions is crucial to understanding how ice sheets have responded to climate forcings and how they might respond to different emission scenarios in the near future. We use two independent dating techniques to document the timing and extent of the last two glacial cycles in southern Patagonia. Our work highlights feedbacks in the Earth’s system responsible for driving glacier growth in the Southern Hemisphere prior to the global Last Glacial Maximum.

Using an Earth system model that can simulate Dansgaard-Oeschger-like events, we show that the conditions under which millenial-scale climate variability occurs is related to the integrated surface buoyancy flux over the northern North-Atlantic. This newly defined buoyancy measure explains why millenial-scale climate variability arising from abrupt changes in the Atlantic Meridional Overturning Circulation occurred for mid-glacial conditions but not for interglacial or full glacial conditions.

In general, it is not easy to examine unseasonable weather years that have affected human history using a single proxy. In this study, we propose a new method to quantitatively extract drought/long rainfall events over the past 400 years by integrating tree-ring cellulose oxygen isotope ratios and historical documentary records. The results can be utilized to investigate the relationship between climate and long human history.

Dust plays a crucial role in the climate system; while it is relatively well studied for the present day, we still lack how it was in the past and the underlying mechanism in the multi-million-year time scale of Earth’s history. Here, for the first time, we simulate dust emissions with the newly developed DUSTY model over the past 540 million years with a temporal resolution of ~5 million years and identify palaeogeography as the primary control of these variations.

To improve the simulation of surface mass balance (SMB) that influences the advance-retreat of ice sheets, we run a snow model BESSI (BErgen Snow Simulator) with transient climate forcing obtained from an Earth system model iLOVECLIM over Greenland and Antarctica during the Last Interglacial period (130–116 kaBP). Compared to the existing simple SMB scheme of iLOVECLIM, BESSI gives more details about SMB processes with higher physics constraints while maintaining a low computational cost.

The Benguela Upwelling System is a region in the SE Atlantic Ocean of high biological productivity. It comprises several water masses such as the Benguela Current, the South Atlantic Central Water and the Indian Ocean Agulhas waters. We analyzed planktonic foraminifera from IODP Sites U1575-U1576 to characterize the water masses and their interplay in the Pleistocene. This defined changes in the local thermocline, which were linked to long-term Benguela Niño/Niña-like and deglaciation events.