The Floods in Tennessee aren't freak accidents. They are a new reality
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Over the weekend, Middle Tennessee saw record-breaking rains. In less than 24 hours, 17 inches of rain fell in parts of the state. Streets became rivers. Homes were flooded by water. At least 21 people were killed, and many more are still missing.
After a season of climate-driven calamities, this was yet another example of climate change. As the Earth heats up, flash flooding is a phenomenon where water rises quickly and flows at an incredible speed.
The second major flooding event in Tennessee this season was the deadly floods that occurred over the weekend. In March, torrential rains flooded Nashville and killed at most four people.
For decades, climate scientists have been warning that global warming will lead to more heavy rain. Scientists are now observing this trend in real-time, as the Earth is almost 2 degrees Fahrenheit warmer than in the late 1800s. According to the most recent National Climate Assessment, the amount of rain that falls during heavy storms has increased by nearly a third in the Southeast U.S. from 1958 to 2016.
This is because warmer air can retain more moisture.
The soil becomes less absorbent when it is exposed to hotter air. Rain that falls quickly can't soak into soil and cause runoff to overwhelm pipes, dams, and other drainage infrastructure.
Floodwaters can cause damage to buildings and take away cars. After record-breaking rainfalls, over 180 people died in flash floods in Germany this summer. After being trapped by rising waters, at least 25 people died in central China. More than 100 people were killed in flash floods in western India after heavy rains caused landslides or flash floods.
The Tennessee floods are a reminder of how climate change can cause dangerous flooding far away from the coasts. According to a 2015 analysis, Tennessee is not landlocked but nearly a quarter of a million people live in areas that are susceptible to flooding.
