The temperature of the past 2000 years is still poorly known in vast parts of the East Antarctic plateau. In this study, we present temperature reconstructions based on water and gas stable isotopes from the Aurora Basin North ice core. Spatial and temporal significance of each proxy differs, and we can identify some cold periods in the snow temperature up to 2°C cooler in the 1000–1400 CE period, which could not be determined with water isotopes only.

The record of past climate is preserved by several archives from different regions, such as ice cores from Greenland or Antarctica or speleothems from caves such as the Hulu Cave in China. In this study, these archives are aligned by taking advantage of the globally synchronous production of cosmogenic radionuclides. This produces a new perspective on the global climate in the period between 20 000 and 25 000 years ago.

A look at the climate evolution during the last warm period may allow us to test ground for future climate conditions. We quantified the temperature evolution during the Last Interglacial using a tiny amount of water trapped in the crystals of precisely dated stalagmites in caves from the southeastern European Alps. Our record indicates temperatures up to 2 °C warmer than today and an unstable climate during the first half of the Last Interglacial.

Prior to 2.5 billion years ago, ozone was present in our atmosphere only in trace amounts. To understand how climate has changed in response to ozone build-up, we have run 3-D climate simulations with different amounts of ozone. We find that Earth's surface is about 3 to 4 °C degrees cooler with low ozone. This is caused by cooling of the upper atmosphere, where ozone is a warming agent. Its removal causes the upper atmosphere to become drier, weakening the greenhouse warming by water vapor.

In the Mediterranean the vine has been an important part of the economy since Roman times. Viticulture expanded within Gaul during warmer climate phases and regressed during cold periods. Now it is spreading strongly to northern Europe and suffering from drought in North Africa, Spain, and southern Italy. This will worsen if global warming exceeds 2 °C above the preindustrial period. While the driver of this is increased greenhouse gases, we show that the main past forcing was volcanic activity.

The reconstruction of paleoenvironments has long been a subject of great interest, particularly to study past biodiversity. Paleoenvironmental proxies often show inconsistencies, and age estimations can vary depending on the method used. We demonstrate the ability of paleoclimate simulations to address these discrepancies, illustrating the strong potential of our cross-disciplinary consistency approach to refine the context of archeological and paleontological sites.

One of the most common ways of reconstructing temperatures in the geologic past is by analyzing oxygen isotope ratios in fossil shells. However, converting these data to temperatures can be a technically complicated task. Here, we present a new online tool that automates this task.

Stable water isotopes are tracers of climate processes occurring in the hydrological cycle. They are widely used to reconstruct the past variations of polar temperature before the instrumental era thanks to their measurements in ice cores. However, the relationship between measured isotopes and temperature has large uncertainties. In our study, we investigate how the sea surface conditions (temperature, sea ice, ocean circulation) impact this relationship for a cold to warm climate change.