Climate of the Past

What can the Cretaceous tell us about our climate?

Philip Pika, PhD researcher, Université libre de Bruxelles, Belgium August 20, 2018

Figure 1: Illustration of Cretaceous landscape and climate. (Source: http://www.bbc.co.uk/nature/history_of_the_earth/Cretaceous, visited 14.7.2018)

The Cretaceous The Cretaceous period features a particularly interesting climatic episode in the Earth’s geological history. It follows the Jurassic Period, better known as the time the dinosaurs inhabited Earth and spanned the period between 145.5 and 65.5 million years ago. The Cretaceous is the last period of the Mesozoic Era, which ends with a well-known mass extinction event. At the end of th ...[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]

Pollen, more than forests’ story-tellers

Encarni Montoya, Institute of Earth Sciences Jaume Almera (ICTJA-CSIC), c/Sole i Sabaris s/n, 08028 Barcelona (SPAIN) April 3, 2018

Name of proxy Sporomorphs (pollen grains and fern spores) Type of record Biostratigraphy and Geochronology markers, Vegetation dynamics Paleoenvironment Terrestrial environment Period of time investigated Present to 360 million years How does it work? The sporomorphs (pollen grains and fern spores) are cells produced by plants involved in the reproduction. They are microscopic (less than a fifth o ...[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]