Communities in Germany, Belgium, and The Netherlands are reeling after extreme July rainfall swamped parts of Western Europe. Some of the worst-hit areas saw as much as two months of rain within 24 hours—enough to break precipitation records, push rivers to new heights, and trigger devastating flash floods.
Nighttime downpours on July 14-15, 2021, proved especially damaging. Many people were asleep when the most intense rain fell, and they were caught off guard as rivers raged, dams failed, and floodwaters inundated homes. News media estimated that 196 people were killed by flooding and thousands more were injured. Hundreds of people are still listed as missing.
On July 18, 2021, the Operational Land Imager (OLI) on Landsat 8 captured this image of flooding along the Meuse and Roer rivers. As water levels rose, nearly 5,000 people were forced to evacuate from Roermond, a city in The Netherlands near the border with Germany. A dam breach on the Roer contributed to the extensive flooding.
While it will take some time for experts to analyze whether this event was influenced by human-caused global warming, scientists have amassed data showing that warming has led to more intense and frequent downpours in many parts of the world. Some researchers and meteorologists have also suggested that warming may be changing the jet stream in ways that make atmospheric "blocking" patterns—like the one that prolonged these downpours—more likely.
NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey. Story by Adam Voiland.