Monday, 16 November 2015

International collaboration produces atlas of Europe’s paleoclimate

St Andrews Researcher, Dr Rob Wilson (Senior Lecturer, Department of Earth and Environment Sciences), is involved in an international collaboration led by Professor Edward Cook at Columbia University using tree rings to produce a new paleoclimate atlas of past European drought.

To date, the long history of severe droughts across Europe and the Mediterranean has largely been told through historical documents and ancient journals, each chronicling the impact in a geographically restricted area. Now, for the first time, an atlas, based on tree-ring data, maps the reach and severity of dry and wet periods across Europe and parts of North Africa and the Middle East over the past 2,000 years.

This new data-set for Europe will complement two previous drought atlases covering North America and Asia allowing scientists to pinpoint causes of drought and extreme rainfall in the past and identify patterns that could lead to better climate model projections for the future. The new atlas could also improve understanding of climate phenomena like the Atlantic Multi-decadal Oscillation, a variation in North Atlantic sea-surface temperatures that hasn’t been tracked long enough to tell if it is a transitory event, forced by human intervention in the climate system, or a natural long-term oscillation.

The importance of understanding past climate change and its impact on human society cannot be underestimated.  For example, an unusually cold winter and spring are often blamed for the 1740-1741 famine in Ireland. The Old World Drought Atlas points to another contributor: rainfall well below normal during the spring and summer of 1741. The atlas shows how the drought spread across Ireland, England and Wales.

The atlas also tracks the reach of the great European famine of 1315-1317, when historical documents describe how excessive precipitation across much of the continent made growing food nearly impossible. The atlas tracks the hydroclimate across Europe and shows its yearly progressions from 1314 to 1317 in detail, including highlighting drier conditions in southern Italy, which largely escaped the crisis.

More information on The University of St Andrews Tree-Ring Laboratory can be found here:

Research Publication:  Cook et al. (2015). Old World megadroughts and pluvials during the Common Era. Science Advances. 1 (11). e1500561. DOI: 10.1126/sciadv.1500561