By the end of this century Europe - particularly the South - will experience more frequent episodes of drought, scientists report in journal Hydrology and Earth Systems.
Researchers from European Commission's Joint Research Centre (JRC) and the University of Kassel in Germany analyzed models that predicted the European climate throughout the century and the availability of and demand for water.
"Our research shows that many river basins, especially in southern parts of Europe, are likely to become more prone to periods of reduced water supply due to climate change," said lead study author Giovanni Forzieri, a researcher in climate risk management at the JRC. "An increasing demand for water, following a growing population and intensive use of water for irrigation and industry, will result in even stronger reductions in river flow levels."
The impacts of drought are not to be taken lightly, the researchers warn. In addition to crippling food supplies, drought leads to significant economic losses. The researchers report than episodes of drought over the last three decades has amounted to more than 100 billion euros.
Study co-author Luc Feyen, a hydrologist at JRC, said the models the team used for their study simulated a variety of possible scenarios.
"Scenarios are narratives of possible evolutions - up to 2100 in this study - of our society that we use to quantify future greenhouse gas emissions and water consumption by different sectors," Feyen explained. "Climate and water-use models then translate the greenhouse gas concentrations and water requirement into future climate and water consumption projections."
After running the scenarios though a computer program, the researchers took the data and applied it to an overall model that projects the distribution and flow of all the water on Earth.
By running the model through the year 2100 on all the river basins in Europe, the team was able to evaluate how drought conditions could change in magnitude and severity over the 21st century.
Southern Europe will be most affected, the researchers concluded, as stream and river flows may be reduced by as much as 40 percent and periods of water deficiency may increase up to 80 percent, according to the data.
The higher temperatures that will come along with the increases in drought will result in more water being evaporated from trees, soil and bodies of water.
The model projects that average temperatures in Europe will be 3.4 degrees Celsius warmer by 2100, but in certain parts of the continent, such as the Iberian peninsula, average temperatures are predicted to be 5 C warmer by 2100, Feyen said.
Coupled with warmer temperatures, more intensive water use will further exacerbate drought conditions by 10-30 percent across a wide swath of Europe.
"The results of this study emphasize the urgency of sustainable water resource management that is able to adapt to these potential changes in the hydrological system to minimize the negative socio-economic and environmental impacts," Forzieri said.