Pinpointing the timing of sudden climate change

A team of scientists has shown that during a 1000-year cold period at the end of the Ice Age, known as the Younger Dryas, the climate started to recover in Germany 120 years before Norway. The researchers looked at changes in the sediment of a lake in Germany and compared it to lake sediment records of a Norwegian lake. They were able to pinpoint exactly when the local climate in each country began to recover from glacial conditions by identifying where microscopic volcanic ash from a major Icelandic eruption around 12,100 years ago occurred in the annually layered sediments of the German lake. According to the study published in Geology, the ash anchors in time the climatic events before and after the eruption. The study says this information gives new insights into the mechanism and pace of past climate change, as well as the variable effects of future climate change. Lake sediment acts like a time capsule, containing both inorganic and organic material (such as algae, soil material and plant matter) collected at the bottom of the lake where the layers lie undisturbed for thousands of years. In some lakes, sediments are annually laminated due to seasonal algal blooms and washing in of material from the lake's borders.