past climate reconstruction

Misinterpretation of glacial aridity in subtropical environments in the Southern Hemisphere

Dr Rieneke Weij and Dr Kale Sniderman March 11, 2024

Figure 2. A chamber in one of the Naracoorte caves beautifully decorated with speleothem formations. Source: Rieneke Weij.

To understand Earth’s changing climate, scientists often examine how the climate has varied in the past, by studying geological records. These records allow us to reconstruct past climates and help us predict planet’s responses to different climate forcings. In this context, it has long been thought that past ice ages on Earth were relatively dry, whereas the warm periods between ice ages we ...[Read More]

Levoglucosan, the witness of past fires

Laura T. Schreuder, NIOZ Royal Netherlands Institute for Sea Research June 6, 2018

Name of proxy Levoglucosan Type of record Biomass burning Paleoenvironment Lake and marine sediments and ice cores Period of time investigated Present to approximately 130,000 years ago How does it work? Levoglucosan is a molecule that is exclusively formed during the combustion of vegetation at low-temperature. It is therefore considered to be a source-specific tracer for biomass burning. During ...[Read More]

How to reconstruct past climates from water stable isotopes in Polar ice cores ?

Mathieu Casado, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany. Anais Orsi, Laboratoire des Sciences du Climat et de l’Environnement, Université Paris-Saclay, France March 15, 2018

Backlit layering in a snow pit in Antarctica (credit waisdivide.unh.edu )

Ice cores are a favored archive to study past climates, because they provide a number of indications on the history of the climate and of the atmospheric composition. Among these, water stable isotopes are considered as a very reliable temperature proxy. Yet, their interpretation is sometimes more complicated than a simple one-to-one correspondence with local temperature and requires intercomparis ...[Read More]

Mountain glacier variations: natural thermometers and rainfall gauges

Pierre-Henri BLARD, CRPG (CNRS, Université de Lorraine), France - Laboratoire de Glaciologie, ULB, Bruxelles, Belgium. February 14, 2018

Glaciers from the Andes Cordillera (Peru, Southern America). Photo credit: Julien Charreau

Name of proxy Fluctuations of mountain glaciers Type of record Geomorphological features Paleoenvironment Continent – High mountain areas Period of time investigated From historical periods (c.a. 300 years ago) to the end of the Pleistocene (up to 200 000 years back in time) How does it work? Mountain – or “alpine” – glaciers are small ice bodies (from 1 to 10 000 km2). Alt ...[Read More]