How Climate Change Doubled the Likelihood of Recent European Floods: A Deep Dive into Storm Boris and Global Implications

In September 2023, Europe witnessed one of the most devastating floods in recent history. Over four days, heavy rains associated with Storm Boris wreaked havoc across several Central and Eastern European nations, displacing millions and causing widespread destruction. A new analysis from World Weather Attribution has found that climate change significantly contributed to the intensity of the storm, doubling the likelihood of the deluge. The impact of human activity on the climate is now unmistakably linked to extreme weather events, and Storm Boris stands as a dire example of what the future may hold.

 The Impact of Storm Boris

The catastrophic downpour resulted in over 24 deaths, with more people reported missing. More than two million people were affected as the storm transformed cities into muddy rivers, leading to power outages, closing schools and hospitals, and forcing mass evacuations. The rain was relentless, with certain regions experiencing up to five times their usual rainfall for September within just four days.

From Poland and Slovakia to Austria and Germany, the devastation was widespread. Countries like Romania and Hungary were not spared either. The slow-moving, low-pressure system dumped record-breaking levels of rain, with some areas reporting as much as 20% more rain than what might have fallen in a preindustrial era, when greenhouse gases were not as prevalent in the atmosphere.

Climate Change and its Role

World Weather Attribution’s research made a striking revelation: the extreme rainfall from Storm Boris was made twice as likely due to climate change. The science behind this is straightforward—warmer air holds more moisture, resulting in heavier and more frequent rainfall. As the world continues to warm, primarily due to fossil fuel consumption and other human activities, the frequency and intensity of such storms are expected to increase.

In fact, 2023 was recorded as the warmest year globally, and 2024 is expected to surpass this record. Rising global temperatures have far-reaching consequences, including the amplification of storms like Boris, making them stronger and more destructive. A climate risk consultant at the Red Cross Red Crescent Climate Center, Maja Vahlberg, stresses that this event underscores the urgent need to prioritize flood preparedness and rethink urban planning to reduce exposure to future risks.

Europe’s Flood Preparedness: Success and Shortcomings

Europe’s disaster preparedness systems have evolved significantly in recent decades, helping reduce fatalities compared to earlier floods in 1997 and 2002 when hundreds lost their lives. Early warning systems, investment in flood defenses such as levees and bank reinforcements, and improved forecasting have undoubtedly saved lives this time. For example, in Nysa, Poland, over 44,000 residents were evacuated after warnings of a potential embankment breach. These proactive measures are crucial as extreme weather events become more frequent.

However, despite these advances, Storm Boris revealed that current mitigation strategies remain inadequate to handle the increasing intensity of such events. The European Union has already pledged €10 billion ($11 billion) in emergency repairs following the destruction caused by the storm. This massive outlay highlights the ongoing struggle to keep up with the financial demands of climate resilience.

The Global Perspective: Extreme Weather Across Continents

The extreme rainfall that Europe experienced is not an isolated incident. Similar catastrophic weather patterns have occurred across the globe, emphasizing the global nature of the climate crisis. In India, a rain-triggered landslide claimed over 230 lives, with studies showing that climate change made the downpour 10% heavier. Meanwhile, flooding in West and Central Africa killed over 1,000 people, displacing millions and devastating entire communities.

Such events underline the pressing need for a global response. As experts note, early warning systems and adaptation measures, while effective, need further investment and expansion. According to data from the United Nations, 101 countries now have early-warning protocols, a significant increase from just a few years ago. But with climate change accelerating, more comprehensive global strategies are urgently needed.

 Future-Proofing Cities: An Urgent Priority

As Europe grapples with the aftermath of Storm Boris, it has become increasingly clear that long-term adaptation is critical. “We must make flood preparedness and spatial planning a top priority,” said Vahlberg. “It is critical that we rethink how and where we build to reduce the high exposure to flood risk.” Cities, particularly those located near rivers or coastlines, need to focus on future-proofing their infrastructure. This may involve changes in zoning laws, restricting development in high-risk areas, and constructing more robust flood defenses.

In addition to urban planning, there is a need to integrate climate change adaptation into broader economic policies. Investments in renewable energy, sustainable agriculture, and water management are crucial to limiting the impact of climate change in the long term.

The Road Ahead: Mitigation and Adaptation

The findings from the World Weather Attribution study emphasize the need for immediate and sustained action. Climate change is no longer a future problem—it is a present-day reality that is already influencing weather patterns and causing unprecedented damage.

While adaptation measures in Europe helped limit the death toll from Storm Boris, the destruction it caused serves as a stark reminder that much more needs to be done. Countries must invest heavily in both mitigation—by reducing greenhouse gas emissions—and adaptation, preparing their cities and regions to withstand more intense weather events.

A Growing Threat Requires a Unified Response

The recent floods in Europe, worsened by climate change, serve as a stark warning of what lies ahead if global temperatures continue to rise unchecked. The deadly consequences of storms like Boris will become more common, requiring a stronger and more coordinated response both at the national and international levels. As nations grapple with the rising costs of adaptation, they must also commit to long-term climate goals aimed at reducing carbon emissions and preventing further global warming. The future of climate resilience will depend on how quickly and effectively we act today. 

In a world where extreme weather is becoming the norm, the question is not if, but when the next catastrophic flood will occur—and whether we’ll be prepared to handle it.