56 million years ago, an episode of global warming caused extreme floods and landscape disruption. A study conducted in the Pyrenees by an international team of researchers including Utrecht University reveals the magnitude of this environmental disaster.
56 million years ago, the Earth experienced an exceptional episode of global warming. Within a few thousand years (very fast on geological time scales) the Earth’s surface warmed by on average 5 °C, only returning to its original level about two hundred thousand years later. Based on the analysis of sediments from the southern slope of the Pyrenees, a new study lead by scientists from the University of Geneva (UNIGE) in collaboration with researchers from the universities of Lausanne, Utrecht, Western Washington and Austin, measured the impact of this warming on river floods and the surrounding landscapes in Northern Spain. Their analyses indicate that the amplitude of floods increased by a factor of about eight. Vegetated landscapes were replaced by seasonally occurring large and wild rivers that eroded soils and vegetation, leaving pebbly plains in a dry season. These conclusions, published today in Scientific Reports, for the first time provide some insight into the consequences of global warming for extreme weather from the geological record.