A “wobble” in the Moon’s orbit will cause an onslaught of coastal flooding from the mid-2030s, Nasa has warned.

The global flood tally could quadruple as the gravitational effects of the lunar cycle combine with climate change to produce “a decade of dramatic increases” in disasters.

The US space agency said coastal cities would experience “rapidly increasing high-tide floods”, which would occur in “clusters” and go on for a month or longer.

It said the main cause was a “regular wobble” in the Moon’s orbit, which was first recorded in 1728.

“What’s new is how one of the wobble’s effects on the Moon’s gravitational pull – the main cause of Earth’s tides – will combine with rising sea levels resulting from the planet’s warming,” said Nasa.

The wobble in the Moon’s orbit takes 18.6 years to complete. For half of that time regular daily tides on Earth are suppressed, meaning that high tides are lower than normal, and low tides are higher than normal.

During the other half of the cycle tides are amplified, meaning that high tides get even higher and low tides get even lower.

As global sea levels rise, the amplification effect will be increased even further.

The next time that this “lunar assist” to high tides comes around again will be in the mid-2030s. By that time, global sea level rises will have been at work for another decade.

It will have passed a “tipping point” and the result will be a “leap in flood numbers on almost all coastlines”, Nasa said.

Bill Nelson, who heads the space agency, said: “Low-lying areas near sea level are increasingly at risk and are already suffering due to increased flooding... and it will only get worse.

“The combination of the Moon’s gravitational pull, rising sea levels, and climate change will continue to exacerbate coastal flooding on our coastlines and across the world.”

He said it was crucial to plan ahead to protect businesses and livelihoods. (© Telegraph Media Group Ltd ( 2021)

Telegraph Media Group Limited [2021]