The weather is overtaking climate change adaptation—extreme rainfall this summer was worse than anticipated

The Neckar River in southern Germany in July—one of the places where the floods caused relatively low damage. Illustration: Bigstock

We actually believed we were pretty safe here in the Western world. That the basic climate change adaptation and emergency response systems were in place and that we could not really be surprised anymore.

But the weather overtook climate change adaptation: in many parts of the world, this summer’s rainfall—and its consequences—surprised even seasoned climate scientists. This type of extreme weather was not expected for several more decades.

In particular, the destruction and loss of human life in Germany and the neighbouring countries was almost unbelievable—when it came to such prosperous and technologically sound areas.

“We should not be seeing this number of people dying in 2021 from floods,” Hannah Cloke, professor of hydrology at the University of Reading, said about the disaster in Northern Europe for Science.

Intense lingering rainstorms

A few weeks after the floods, scientific journal Geophysical Research Letters published a study which showed that climate change could increase the number of events in which slow-moving storms can linger over an area and release large amounts of precipitation, just as it had been observed in Germany and neighbouring countries.

And in August, a large-scale study by researchers from 8 countries under the climate science network World Weather Attribution concluded that the extreme rainfall could theoretically have occurred without climate change—but that global warming made it between 20 and 900 percent more likely.

Smaller streams caused surprise

Of course, it did not help that the emergency response and warning systems did not work—Germany may still have “Vorsprung durch Teknik”, but it does not seem to be using it effectively enough in this area.

It was also time for self-examination among the researchers:

“We've been concentrating a lot on the big rivers. There's still a lot more to do in the smaller streams,” William Veerbeek, urban flood management expert at the IHE Delft Institute for Water Education, said for Science. It was precisely these smaller streams (i.e. “smaller” relative to German standards) that swelled and in some places swept through the landscape.

The Netherlands managed to avoid deaths, and it was not primarily because there was a little less rain there. The country has an whole ministry dedicated to the entire water cycle, and has for decades had a policy of creating space for the rivers by designating large areas of land where the water can flow to without doing harm. That type of water management resulted, among other things, in the water level of the Meuse River being a meter lower than it would have been without the climate change adaptation.

Prepare for the unimaginable

A few days after the loss of life in Northern Europe, the situation repeated itself in China, and new disaster-movie-like images went around the world, this time with people trapped in a metro.

This resulted in new warnings from, among others, Eduardo Araral, associate professor and co-director of the Institute of Water Policy at Singapore’s Lee Kuan Yew School of Public Policy.

“Governments should first realize that the infrastructure they have built in the past or even recent ones are vulnerable to these extreme weather events,” he told Reuters.
Stefan Greiving, professor of spatial planning at the Technical University of Dortmund, was on the same page when he emphasized for Climate Change News that one should prepare for weather phenomena one could not imagine.

And at Climateanalytics.org a number of researchers reiterated that in the midst of the otherwise necessary debate on the need for further CO2 reduction we should not forget to talk about—and act on—climate change adaptation. There is a limit to how much we can reduce the temperature rise and the resulting climate consequences, especially if the pace of reduction continues to move at a snail’s pace.

New York was awakened in 2012—and then dozed off again

Many researchers have said that the events of this summer (which also affected Turkey and India among others) are a wake-up call. This was also the case when the US East Coast was hit by hurricanes Henri and especially Ida, who made the New York subway look like a waterfall, resulting in at least 75 deaths.

But as researchers said to e.g. CNN, Ida was not the first wake-up call for Americans. In 2012 Hurricane Sandy showed that New York’s infrastructure was not at all built for the extreme weather of the new climate. Despite this, the metropolis has invested a very limited amount of money in climate change adaptation.

Such investments are neither easy nor cheap, admitted Professor Philip Orton of the Stevens Institute of Technology. He pointed out to CNN, among other things, how big of an undertaking it would be for New York to upgrade its underground stormwater systems.

Therefore, according to the professor, paved areas should, where possible, be replaced with green spaces and/or restored wetlands and streams, so that more rainfall is allowed to percolate into the ground.

Climate change adaptation has slowed down too much in Denmark as well

It undeniably sounds very similar to the recipe that Danish climate change adaptation has followed for many years. But we also got the big wake-up call with the Copenhagen cloudburst on 2 July 2011—after several major cities in Jutland had experienced floods in previous years.

However, critics have repeatedly pointed out that the echo of the 2011 alarm died out in the mid and late 2010s, and that climate change adaptation really needed to get up to speed. Some utilities tongue-in-cheek say—but not entirely kidding—that they would like to see another violent cloudburst soon, so that politicians could be reminded of the great risks.

Socio-economically, we are especially behind on coastal protection, several studies show. For example, Nature stated last year that Denmark is one of the European countries where building dykes and similar structures would be the most economically efficient. The more pessimistic scenarios in the new IPCC report from August made Danish coastal protection an (even more) urgent matter. And a few weeks later, the Technical University of Denmark came up with a new model that showed that a storm surge from the south towards the capital can hit billion-dollar values, especially in the area of Sydhavn—a scenario that Danmarks Nationalbank also warns about.

But even though the Socialist People's Party called for advancing the national climate change adaptation plan and the Confederation of Danish Industry (DI) emphasized that it was urgent to take stronger measures against extreme weather, Minister for the Environment Lea Wermelin (Social Democrats) insists on sticking to the schedule.

However, there is movement in parts of the coastal protection area, where the Minister agrees that regulations and other measures must be looked at thoroughly.

The water sector admits—and praises—that the government has taken steps to accelerate climate change adaptation by e.g. abolishing the so-called co-financing rule. But the sector also points out that it lags in other areas, such as the almost impossible efficiency requirements for completely new climate change adaptation projects.

It takes time to implement knowledge acquired after floods

Karsten Arnbjerg-Nielsen, professor of environmental engineering at DTU Environment, believes that “the floods in Germany are very reminiscent of the Danish experience.”

“There were significant floods in 2018 in the same areas, but less so than this summer. This corresponds to the warnings we received in e.g. 2010 in Copenhagen,” he points out.

The 2010 cloudburst did not have major political consequences; they first came with the 2011 cloudburst, which was even bigger and more central to Copenhagen.

Arnbjerg-Nielsen also reminds us that Denmark was the first country to systematically start working on both increasing the size of drainage systems and sending less water into them.

“Therefore we should be better secured than many other places, but that should not lead to complacency. And at sea level we are challenged both organizationally and professionally because the challenge is different than in other countries, e.g. the Netherlands.”

The professor also refers to the scientific article from Advancing Earth and Space Science: “Adaptation to flood risk: Results of international paired flood event studies”. The article concludes, somewhat simply put, that we learn from large floods, but that it can take some time to implement the acquired knowledge in practice.