A new study authored by a freshwater climatologist and a geophysicist working for the Institute for Atmospheric and Climate Science at ETH Zurich, along with a senior research scientist working in the sea level team at CSIRO Oceans and Atmosphere, has found it’s highly probable climate change is amplifying the north-south water runoff contrast in Europe; the study highlights the increasingly dry conditions in the south and their impact on water scarcity.
Runoff from rivers and streams in the Mediterranean region shows drying trends over the last half century. For northern Europe, on the other hand, weak wetting trends have been observed. These trends show that, on the continental-scale, Europe’s renewable freshwater resources are changing. These changes may be due to several contributing factors: Human management including land cover change, large-scale irrigation or the construction of reservoirs and dams, and changes in the hydrological cycle. A study has shown that the latter-observed changes in precipitation and evapotranspiration largely explain the observed continental changes in runoff. What’s more, these changes can be related to anthropogenic climate change.
There’s a high probability that anthropogenic climate change is amplifying the north-south contrast of runoff at the continental scale in Europe: State-of-the-art climate model simulations suggest that the observed pattern is captured only if the models are forced with human emissions. Most remarkable are the increasingly dry conditions in southern Europe, whereas the change in the north is less pronounced. In central Europe, the transition region from a decrease to an increase shows little change.
These results highlight the issue of increased water scarcity in the Mediterranean region under climate change. The authors, therefore, stress the need to raise awareness of the possible consequences of anthropogenic climate change for regional water resources in the already water-scarce south of Europe.
The article first appeared on Climate Change Post and is a digest of a scientific paper by Gudmundsson et al., 2017. Nature Climate Change 7: 813-818.