Mediterranean countries will suffer the most in Europe because of global warming, facing severe water shortages, forest fires, a loss of agricultural land and an influx of potentially invasive species from the south.
The economy and landscape of the Alpine regions are also vulnerable to increased temperatures because a warmer climate will cause the mountain snow lines to rise, a study found.
International researchers said Europe would experience large changes. The study, published by the online version of the journal Science, tried to assess the wider impacts of climate change on a range of ecosystems that provide services such as forestry, farming or tourism.
In 1995, about 193 million people out of an EU population of 383 million faced water shortages. Several climate models predicted between 20 per cent and 38 per cent of the Mediterranean population would be living under "increased water stress".
Water scarcity was likely to be aggravated by greater demand for water for irrigation and tourism. Increasing rainfall was predicted for much of northern Europe, with higher levels of forestation and less land used for agriculture. Mountain areas were also likely to be hit hard by global warming, said the researchers.
Changes to the "run-off" from melting snow and ice would reduce water supply at peak times and increase the risk of winter floods.