Corals provide clues to past climate system
Scientists today have been charged with the challenging task of predicting the weather 50 to 100 years into the future, taking into account the effect of anthropogenic greenhouse gas (GHG) emissions. In order to succeed, knowledge of the natural variability of the Earth’s climate is essential. Unfortunately, records of past climate are limited in both time and space. This is why new research indicating that ocean corals can deliver this much needed information is so exciting. The EU-funded project ‘Mediterranean climate evolution and connection with the atlantic ocean: inferences from high-resolution marine archives’ (Medat-Archives) investigated several different species of shallow and deep-sea coral skeletons to further related knowledge. Following dating with radiometric techniques, the chemical composition of the corals was studied, with initial findings indicating that the ratio between lithium and magnesium has a strong correlation to water temperature. Furthermore, this relationship, known as a proxy, is relatively free of interference from other factors such as the coral’s physiology. In addition, Medat-Archives research activities showed that the geographical origin of seawater could be determined from neodymium concentration in local corals. This is important since the mixing of different bodies of water between the oceans is a primary driver of the Earth’s climate system. For example, corals found in the Mediterranean can provide insight into the exchange of water between the Mediterranean Sea and the Atlantic Ocean in the past. By giving climate modellers a much needed history of the ocean’s behaviour, Medat-Archives scientists helped to improve the accuracy of future predictions of our climate.
