Human activity partly to blame for floods in Czechia, says international study
A new study, carried out by an international team of scientists, shows that the devastating floods that hit Czechia and other central European countries were made much worse by man-made climate change. The fossil fuel driven warming also increases the likelihood of such events happening in the future.
According to the study carried out by the World Weather Attribution Initiative in the immediate aftermath of the flooding, the four-day rainfall from Storm Boris was the heaviest ever recorded in Central Europe, surpassing previous records by a wide margin.
In Czechia, an average of 136.2 litres of water per square metre fell during the four days of intensive rainfall. The amount of precipitation surpassed the previous devastating floods in 1997 when it was “only” 97.5 litres per square metres.
The study also confirms that human-induced climate change caused by burning of fossil fuels is undoubtedly one of the factors leading to the extreme rainfall, says Friederike Otto, senior lecturer in climate science at Imperial College London and co-author of the WWA study.
“In terms of the numbers we looked at, which are of course the region we surveyed and the four-day heavy rainfall, climate change, and that is human-induced climate change, so the burning of coal, oil and gas, has doubled the likelihood of such an event to occur.
“From the models and the observations taken together, there is a seven percent increase in the intensity, but we do know that the models underestimate the rainfall. So the real increase in intensity is probably higher, closer to what we see from observations alone, which is a 20-percent increase.”
According to EU’s Copernicus climate change service, Europe is the fastest-warming continent, with average temperatures over the last five years about 2.3°C higher than in the second half of the 19th century. This warming has not only brought more frequent and intense heatwaves, but also increased extreme rainfall, especially in northern and central Europe.
Bogdan Chojnicki, a researcher from Poznań University of Life Sciences and co-author of the study, says the heavier rainfall is caused mainly by the fact that a warmer atmosphere is capable of holding more moisture:
“The high temperature of the atmosphere creates more space for vapour. The second element is liquid water in the seas. If you add those two elements together, high temperature of the air and sea are creating ideal conditions for evapotranspiration, which then increases the amount of humidity in the atmosphere. You are simply increasingly the capability of the atmosphere to create heavy rain. And the rising temperatures of both the sea and the air will intensify the conditions for the development of such a situation.”
The World Weather Attribution study assessed not only the role of climate change in the recent heavy rainfall, but also the vulnerability and exposure to such a natural disaster.
The flooding in Czechia has not only claimed people’s lives, but has also cause considerable damage to property and infrastructure, destroying bridges, roads, railway, as well as public and private buildings.
In order to prevent such damage from happening the future, we have to integrate the current climate change projections into land-use planning, says Maja Vahlberg from the Red Cross Crescent Climate Centre in the Hague:
“In terms of policy-making I think it’s really important first to remember that the affected countries and cities have to make post-disaster assessments and after-action reviews of the systems in place to identify the specific areas of improvement.
“But generally, the high exposure to floods must be addressed. That will be absolutely essential both for recovery and long-term planning of notably cities, especially those located along major rivers in these areas of Europe, but so will also reinforcing infrastructure to help defend and control our communities from flooding.
“It is so much more expensive to not act against climate change than any action you could take. These floods have cost huge amounts of money, but also lives, so pretending that we can’t afford good climate policy is just really playing with the lives of people for some culture war games but it’s very dishonest and it’s absolutely unacceptable.”
