The extreme rainfall causing deadly flooding across western Germany and Belgium has been so alarming, many across Europe are asking if climate change is to blame.
Scientists have long said that climate change will lead to heavier downpours. But determining its role in last week’s relentless downpours will take at least several weeks to research, scientists said on Friday.
“Floods always happen, and they are like random events, like rolling the dice. But we’ve changed the odds on rolling the dice,” said Ralf Toumi, a climate scientist at Imperial College London.
Since the rainfall began, water has burst riverbanks and cascaded through communities, toppling telephone towers and tearing down homes along its path. At least 157 people have been killed and hundreds more were missing as of Saturday.
The deluge shocked many. German Chancellor Angela Merkel called the floods a catastrophe, and vowed to support those affected through these “difficult and scary times.”
In general the rising average global temperature – now about 1.2 degrees Celsius above the pre-industrial average – makes heavy rainfall more likely, according to scientists.
Warmer air holds more moisture, which means more water will be released eventually. More than 15 centimetres (6 inches) of rain soaked the German city of Cologne on Tuesday and Wednesday.
“When we have this heavy rainfall, then the atmosphere is almost like a sponge – you squeeze a sponge and the water flows out,” said Johannes Quaas, professor of Theoretical Meteorology at Leipzig University.