On the basis of a unique global comparison of data from core samples extracted from the ocean floor and the polar ice sheets, AWI researchers have now demonstrated that, though climate changes have indeed decreased around the globe from glacial to interglacial periods, the difference is by no means as pronounced as previously assumed. Until now, it was believed that glacial periods were characterised by extreme temperature variability, while interglacial periods were relatively stable. The researchers publish their findings advanced online in the journal Nature.
If you want to know how the climate will change in the future, you need to look at the past. By looking at the climate changes that took place thousands of years ago, we can improve predictions for future climate. Comparing layers in the ice-core samples and ocean sediments has allowed researchers to deduce e.g. how the average temperature on Earth has changed over time, and also how great the variability was. From the height of the last glacial period 21,000 years ago to our current interglacial period, the Earth has warmed by an average of five degrees Celsius. In view of future global warming, it’s vital for today’s global population to know whether temperatures will rise steadily, or whether there will be sudden, major fluctuations. The frequency of extreme events represents an essential benchmark for climate change adaptation measures, since, when it comes to flood protection, transport and building materials, we need to be prepared for the worst-case scenario, and not just for “average” changes.
Climate researchers from the Helmholtz Young Investigators Group ECUS at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Potsdam have now investigated how temperature variability changed as the Earth warmed from the last glacial period to the current interglacial period. To date it has been assumed that temperatures varied greatly during the last glacial, while the current interglacial was largely characterised by small temperature variations. This interpretation was based on water isotope data from central Greenland ice cores.
Image: Drilling an Antarctic ice core (Photo: Martin Leonhardt)