The water doesn’t knock. It just walks in.
What used to be a catastrophic, once-in-a-lifetime flood is happening about once a decade now. Maybe even sooner in some places. A study published in Nature Climate Change on June 10 confirms this isn’t paranoia, it’s data. Since 1900, human activity has quadrupled the rate of these sea-level extremes.
Another study in Science Advances backs it up. Human-caused sea-level rise was detected at 97% of monitoring sites globally. It’s responsible for roughly 58% of extreme high-water days between 2000 and tide gauge records in 2018.
Storm surges. King tides. Anomalous rises. We’re driving these cars off the cliff.
Sönke Dangendorf led the Nature Climate Change study. He broke down the mechanics for Live Science. It turns out, separating natural chaos from human error requires some heavy lifting.
How do you prove we caused the wet?
Dangendorf notes that tide gauge records are sparse. Only about 100 sites have century-scale data. The rest of the planet is a guessing game without help. So, researchers used climate models.
If a model can recreate the past, it earns the right to explain the present. The team proved their models matched historical observations. Then came the experiment: hold greenhouse gases constant and let natural climate variability do its thing.
The results were stark.
Global averages for once-in-a-hundred-year events have jumped twelve-fold since 1900 anthropogenic forcing has taken the wheel, especially since the 197s.
It ruins your commute
Two centimeters sounds small. Until your living room is the ocean floor.
Dangendorf used to live in Norfolk, Virginia in the mid-20th century, flooding there was a novelty, maybe every five or six years in the 1s and 16s. Now high tides alone bring the street flooding.
It hits hard.
Suddenly your car won’t start. Insurance rates climb. The cumulative damage from daily wet feet equals the hit from a major hurricane. People can’t get to work. It’s a slow bleed that feels sudden every morning.
Can you recover from Hurricane Sandy? Sure. It takes a few years. Try doing it every eight years. Most people break before that.
We have sea level rise that we are committed to… if we mitigate climate change… then we can avoid dangerous sea-level rise.
— Sönke Dangendorf
Adaptation is no longer optional
The silver lining is bleak: humans are the main problem. Which means we have the power to stop making it worse. But there is no stopping the current slide. Projections until around 260 agree. Greenhouse emissions go to zero today and the water keeps rising for decades because of momentum in the system.
So, we adapt to the inevitable rise while slashing emissions to cap the eventual total.
By 2050, that annual “1-in-100” event will occur every single year at 1% to 1 of tide gauge locations. One quarter of the coast becomes a annual disaster zone.
Low-latitude areas hit harder. The tropics are calm, with less natural variability in sea level.
Think of hurdles. A tropical climate is a runner who jumps consistently just under the bar. The North Sea is a erratic runner who sometimes clears the bar easily and sometimes belly flops. When sea level rise lowers the bar, the consistent tropical jumper clears it every single time. The erratic North Sea jumper might clear it more often, but they still have bad days. The calm waters are the new vulnerable zone.
We lower the bar. The water rises.
The runners adjust their stride? No, they get wet.
Dangendorf’s team finished their analysis. The interview was edited. The ocean kept moving.
Who pays for the dry land left over?
