We studied the vegetation and climate of southwestern South Africa for the period of the past 300000 years. Vegetation and climate development in this region are interesting because the vegetation of the Western Cape is a global biodiversity hotspot and because the archeology of the region substantially contributed to the understanding of the origins of modern humans. We found that the influence of precession variability on the vegetation and climate of southwestern South Africa is strong.

Small mountain glaciers advance and recede as a response to summer temperature changes. Dating of glacial landforms with cosmogenic nuclides allowed us to reconstruct the advance and retreat history of an Alpine glacier throughout the past ~ 11 000 years, the Holocene. The results contribute knowledge to the debate of Holocene climate evolution, indicating that during most of this warm period, summer temperatures were similar to or warmer than in modern times.

We report the identification of volcanic ash associated with a sulfate layer in Greenland ice cores previously thought to have been from the Vesuvius 79 CE eruption and which had been used to confirm the precise dating of the Greenland ice-core chronology. We find that the tephra was probably produced by an eruption in Alaska. We show the importance of verifying sources of volcanic signals in ice cores through ash analysis to avoid errors in dating ice cores and interpreting volcanic impacts.

We use an atmospheric model coupled to an aerosol model to investigate the global mineral dust cycle with a focus on the Southern Hemisphere for warmer and colder climate states and compare our results to observational data. Our findings suggest that Australia is the predominant source of dust deposited over Antarctica during the last glacial maximum. In addition, we find that the southward transport of dust from all sources to Antarctica happens at lower altitudes in colder climates.

The variability in the geochemistry among individual foraminifera is used to reconstruct seasonal to interannual climate variability. This method requires that each foraminifera shell accurately records environmental conditions, which we test here using a sediment trap time series. Even in the absence of environmental variability, planktonic foraminifera display variability in their stable isotope ratios that needs to be considered in the interpretation of individual foraminifera data.

We carried out foraminiferal, stable isotope, and sedimentological analyses of a marine sediment core retrieved from the Northeast Greenland shelf. This region is highly sensitive to climate variability because it is swept by the East Greenland Current, which is the main pathway for sea ice and cold waters that exit the Arctic Ocean. The palaeoceanographic reconstruction reveals significant variations in the water masses and in the strength of the East Greenland Current over the last 9400 years.

Algae preserved in marine sediments have allowed us to reconstruct how much winter sea ice was present around Antarctica during a past time period (130 000 years ago) when the climate was warmer than today. The patterns of sea-ice increase and decrease vary between different parts of the Southern Ocean. The Pacific sector has a largely stable sea-ice extent, whereas the amount of sea ice in the Atlantic sector is much more variable with bigger decreases and increases than other regions.

Past export production in the southeast Pacific and its link to Patagonian ice dynamics is unknown. We reconstruct biological productivity changes at the Pacific entrance to the Drake Passage, covering the past 400 000 years. We show that glacial–interglacial variability in export production responds to glaciogenic Fe supply from Patagonia and silica availability due to shifts in oceanic fronts, whereas dust, as a source of lithogenic material, plays a minor role.

The analysis of fluid inclusions from a Puerto Rican speleothem provides quantitative information about past rainfall conditions and temperatures during the Last Glacial Period, when the climate was extremely variable. Our data show that the region experienced a climate that was generally colder and drier. However, we also reconstruct intervals when temperatures reached nearly modern values, and convective activity was comparable to or only slightly weaker than the present day.