Climate: Past, Present & Future

Corals, the thermometers of the past!

Emilie Dassié July 3, 2017

Picture of a diver on top of a coral colony in the American Samoa (credit B.K. Linsley).

Name of proxy: Coral Type of record: Oceanic variability Paleoenvironment: Fringing reefs, barrier reefs, or atoll Period of time investigated: Mainly the last 200 years How does it works ? What we usually picture as a coral is actually a colony of tiny living animals called coral polyps, which are closely related to jellyfish or anemones. They live in symbiosis with photosynthetic algae called Zo ...[Read More]

Defrosting the freezer. Climate change and glacial meltwater

Kathryn Adamson May 15, 2017

Why are glaciers important? Glaciers cover around 10% of the global land surface. This includes the large ice sheets (e.g. in Greenland and Antarctica) as well as smaller ice caps and valley glaciers (e.g. in Iceland, Norway and New Zealand). Figure 1 shows the current distribution of glaciers around the world. Figure 1 – The global distribution of glaciers around the world from the GLIMS glacier ...[Read More]

Ostracods, the sentinels of past oceanic circulation

Marie-Béatrice Forel April 28, 2017

Figure 1. Left: Inside view of a dissected male of Cyprideis torosa with soft parts and appendages visible (Photo Dietmar Keyser). Right: Fossil specimen of the species Cytheropteron eximium Alexander, 1933 from the Cenomanian, Late Cretaceous (about 93 Ma) of the Western Interior Basin, USA (Photo MBF). For both photos, scale bar is 100 µm.

Name of the proxy Ostracoda Type of proxy Paleoenvironment proxy Paleoenvironment All types of aquatic environments but here we will focus on marine waters Period of time investigated Phanerozoic How does it work? Ostracoda are crustacean of millimetre size which have inhabited all types of marine environments from the Ordovician to today (e.g. Salas et al. 2007) and colonized continental water bo ...[Read More]

Hot towns, summer in the city!

Gert-Jan Steeneveld, associate Professor at Wageningen University, The Netherlands April 21, 2017

Figure 1: Sketch of the processes governing the urban heat island effect.

Cities obviously experience a different climate than natural landscapes. Already in 1810 the British meteorologist Luke Howard documented that the air temperature in the city of London was several degrees higher than in its surroundings. This so called urban heat island has several causes. In general the relatively dark surfaces of asphalt and roofs absorb solar radiation very efficiently and this ...[Read More]