This article presents a reconstruction of summer droughts in France for the last 680 years, based on oxygen isotope ratios in tree ring cellulose from living trees and building timbers at two sites, Fontainebleau and Angoulême. Both sites show coherent drought patterns during the 19th and 20th century, and are characterized by increasing drought in recent decades. A decoupling between sites points to a more heterogeneous climate in France during earlier centuries.

We explore how forcings contributed to climate change during the early Holocene that marked the final transition to the warm and stable stage. Our results indicate that 1) temperature at the Holocene onset was lower than in the preindustrial over the northern extratropics with the exception in Alaska, and the magnitude of this cooling varies regionally as a response to varying climate forcings and diverse mechanisms, and 2) the rate of the early Holocene warming was also spatially heterogeneous.

The climate fluctuates between warm and cold stages, forcing biodiversity to shift patterns according to climatic tolerance. Here we provide an analysis of the shifting patterns of climate in the Iberian Peninsula for the last 15 000 years. By analysing climate in the spatial and temporal dimensions, we were able to divide the peninsula into areas that shared similar climate patterns and to derive a map of climate stability for this period.

Ancient greenhouse warming episodes are studied in river floodplain sediments in the western interior of the USA. Paleohydrological changes of four smaller warming episodes are revealed to be the opposite of those of the largest, most-studied event. Carbon cycle tracers are used to ascertain whether the largest event was a similar event but proportional to the smaller ones or whether this event was distinct in size as well as in carbon sourcing, a question the current work cannot answer.

Cushion peatlands are versatile climate archives for the study of past environmental changes. We present the environmental history for the last 2100 years of Cerro Tuzgle peatland, which is located in the NW Argentine Puna. The results reflect prominent late Holocene climate anomalies and provide evidence that Northern Hemisphere climate oscillations were extensive. Volcanic forcing at the beginning of the 19th century seems to have had an impact on climatic settings in the Central Andes

We explore the influence of changing geography from the period ~ 150 million years ago to ~ 35 million years ago, using a set of 19 climate model simulations. We find that without any CO₂ change, the global mean temperature is remarkably constant, but that regionally there are significant changes in temperature which we link back to changes in ocean circulation. Finally, we explore the implications of our findings for the interpretation of geological indicators of past temperatures.

One of the challenges is to elucidate if climate during the Jurassic was warmer than present day, with no ice caps. The Pliensbachian Cooling event (Lower Jurassic) has been pointed out as one of the main candidates to have developed ice caps. The Rodiles section of the Asturian Basin (Northern Spain), allows the characterization of several climatic changes of probable global extent.

In spatially structured environments, conventional cross validation results in over-optimistic transfer function performance estimates. H-block cross validation, where all samples within h kilometres of the test samples are omitted is a method for obtaining unbiased transfer function performance estimates. We assess three methods for determining the optimal h using simulated data and published transfer functions. Some transfer functions perform notably worse when h-block cross validation is used.

The present study explains why Scandinavia was ice-covered 20 000 years ago, while Siberia was mostly ice free. The authors show that the ice-sheet extent in Eurasia was to a large extent controlled by atmospheric circulation changes due to the ice sheet in North America. As the North American ice sheet becomes larger, it induces a cooling in Europe and a warming in Siberia: this climatic pattern forces the Eurasian ice sheet to migrate westward until it is centered over Scandinavia.

This paper discusses the underlying mechanisms of a method that uses specific membrane lipids present in the sediments of an African tropical lake to determine past changes in rainfall. With this method, past dry periods in the last 25 000 years can be assessed.

Chironomidae are a family of two-winged aquatic fly of the order Diptera. The family is species rich (> 5000 described species) and extremely sensitive to environmental change, particualy temperature. Across the Northern Hemisphere, chironomids have been widely used as paleotemperature proxies as the chitinous remains of the insect are readily preserved in lake sediments. This is the first study using chironomids as paleotemperature proxies in tropical South America.