Between July 13th and July 15th, Germany, Belgium, and other parts of Western Europe were inundated with a “once in a millennium” rainfall event. The resulting floods washed away bridges, destroyed homes, and caused the deaths of at least 200 people. Despite alerts of major flooding four days before the storm, there was a breakdown in the communication chain between regional and local authorities and residents — resulting in preventable deaths.
Barely a week later, parts of Henan province in central China received over 95 percent of their average annual rainfall totals over a 24-hour period, triggering flash floods that devastated transportation infrastructure, killing at least 63 people and displacing thousands more. Heavy downpour, which at one point dropped eight inches of rain in one hour, flooded the newly-built subway system. Heart-breaking viral videos show trapped subway passengers standing in chest-high water, struggling to breathe the increasingly congested air. Many of them drowned. The second “once in a millennium” weather catastrophe of the year.
Two once-in-a-millennium flooding events only a week apart on different sides of the world seem improbable. But climate change is intensifying and making catastrophic floods more common and the impacts more calamitous. The scale and destruction of both recent flooding events demonstrate the very real danger climate change poses to human life, even in industrialized nations. It is imperative that dramatic climate action is necessary to arrest this crisis.
How does climate change make flooding worse?
There are two main driving forces behind intensifying precipitation patterns: 1) more moisture in the air; and 2) slower moving storm systems — both of which result from a warming atmosphere.
Greenhouse gas emissions from human activities have already increased average global temperatures by about one degree Celsius, or 1.8 degrees Fahrenheit, compared to pre-industrial averages. And a warmer atmosphere means that the air can hold more water — about seven percent more moisture for every degree Celsius increase, based on the Clausius-Clapeyron equation. Even a seven percent increase has the potential to trigger catastrophic flooding. Considering that we are currently on track to warm the globe by three to five degrees Celsius by 2100, these flood catastrophes will only become more common and more devastating unless we make significant cuts to emissions.
A warmer atmosphere also causes storm systems to move more slowly. Increasing temperatures at the poles have lessened the temperature differences between the north and the mid-latitude regions — temperature differentials that usually power the jet stream. Without a strong global jet stream to push storm systems along, they stall or linger longer over regions, releasing more precipitation. Slower-moving storms can drop heavy rain for days on end, especially if they are carrying more moisture than normal — meaning floods will not only become more intense but last longer as well. In August of 2016, A tropical disturbance over Louisiana caused over 31 inches of rain in some areas over 3 days. A year later, Hurricane Harvey dropped nearly 52 inches of rain, breaking records for the contiguous United States.
An altered jet stream has consequences beyond just flooding risk. According to Jennifer Francis of the Woodwell Climate Research Center, changes in the jet stream can lead to different extreme weather consequences in different regions, including flooding in Western Europe, heatwaves in the Pacific Northwest, and cooler temperatures in the Midwest United States.
Responding to climate catastrophes
It’s clear that climate change will make flooding worse in many parts of the world — and it’s even more clear that even wealthy nations are nowhere near prepared for its impacts.
In Western Europe, flood warning systems and infrastructure proved mostly ineffective at preventing loss of life and property damage. For many residents, the warnings came too late.
Infrastructure failures compounded the damage and also made rescue/recovery efforts much harder. Mismanagement of an upstream dam in Belgium left numerous villages and towns on the frontlines of major flooding. In the Ahrweiler district of Germany, around 30,000 residents were left without power, drinking water, and gas. In some regions, the infrastructure has been damaged so badly that residents could be without drinking water for weeks or months.
In China, despite the country’s relative experience with mitigating flooding, the recent floods revealed the fundamental vulnerabilities of even the country’s most modern infrastructure.
The unprecedented intensity and impact of the most recent floods in Henan highlighted two major components of China’s vulnerability: 1) infrastructure built for facilitating rapid economic growth rather than climate resilience; and 2) a lack of communication from the government about the realities and extent of extreme weather events in the face of climate change.
Cities and municipalities in China have grown rapidly in the last few decades, but this development has prioritized convenience over resiliency. Developing transportation infrastructure on low-lying marshes (like the Jingguang traffic tunnel in Zhengzhou which flooded, killing two) and constructing housing along river beds has left communities extremely vulnerable to intensifying precipitation patterns. Covering floodplains with impermeable concrete has also reduced the ability of cities to absorb floodwater, leading to increased flooding risk.
The unequal burden of climate disasters
Like all climate catastrophes, extreme flooding does not affect everyone equally. Ecological degradation, globalization, and neoliberalism have pushed more and more people into harm’s way. Massive slum settlements in Dhaka, Bangladesh, for example, are often built out on floodplains as the poorest city dwellers struggle to find housing and community within the urban centers. Low-income metropolitan areas in the U.S. consistently lack green spaces and other nature-based flood mitigation spaces.
Since flood prevention measures can often only redistribute water rather than block it, communities outside of economic and political hubs face disproportionately high flood prevention costs. In Western Europe, towns along tributaries had almost no defenses against rising water levels, while those around major rivers had more protection. Populations displaced by major floods are also generally lower-income families who often do not have the capital nor support to move back to their neighborhoods and rebuild their homes. The flooding in Henan has displaced over 1.2 million people across both the urban centers and rural areas, with continuing rain already delaying recovery.
And it is important to “denaturalize” the climate crisis. We cannot write off climate catastrophes like this month’s floods as “natural” disasters; while somewhat random weather patterns play a role, we cannot use them as an excuse to ignore the social, political and economic inequalities that precipitated the unequal impacts of such disasters. Concentrated power structures, capitalist-driven development that privileges the profits of the few over the needs of the many, and neoliberal economic and development policies continue to place people in harm’s way. Even as the devastating impacts of flooding are becoming increasingly clear, the U.S. and other developed countries continue to subsidize construction projects in areas prone to flooding.
Here at the Global Center for Climate Justice, we are working to provide communities with the tools to implement equitable flood prevention policies through the Green New Deal Resources Hub. Strategies presented by the American Flood Coalition around elevating social equity in flooding and disaster recovery and navigating funding can be found here, as well as resources on financing equitable infrastructure and closing the gap around green spaces produced by the Center.
We shouldn’t need any more proof: the climate crisis is upon us, and if we are to prevent future loss of life and catastrophes like in Germany and China, we cannot wait any longer to take climate action.
