According to a new study, thanks to wobbles in the long-term lunar orbital cycle, our planet is going to suffer violent shifts in both the number and magnitude of high tide floodings (HTF) by just 9 years from now. That, coupled with climate crisis driven sea level rise, will affect many coastlines and could engulf areas already under siege from sea level rise.
As the nodal cycle of the moon peaks in its influence on high tide flooding events just nine years from now, storm surges like this will seem small by comparison. Photo: Image by Jerry Coli from Pixabay
The new study, written by researchers at the University of Hawaii, was published in the journal Nature Climate Change.
Under ordinary circumstances, high tides occur in coastal sites and cause flooding when the tides surge at about 2 feet (around 0.6 meters) above their daily average. When that happens, coastal towns and cities often find seawater has flooded over their storm drains and into the streets. Fortunately for most, up until the age of the climate crisis, much of that seawater rise is a short-term event which eventually rolls back into the ocean and does little major damage.
The high tides are driven by the cycling position of the moon relative to the Earth’s surface. The closer the moon is the greater the gravitational pull on the ocean, bringing the waters upwards and onto the coasts.
What the researchers behind the current study of have discovered is something far more serious. This time is a combination of an 18.6 year long period known as the lunar nodal cycle, and long-term sea level rise driven by global heating, which in turn is caused by melting of ice and glaciers in the Arctic and Antarctic, Greenland, and the Himalayas.
The new study shows how these two effects are about to be coupled in a particularly dangerous way by just 9 years from now.
While even the best of climate experts describe sea level rise as a serious but continuous process which will eventually threaten most major coastal areas around the planet, few have connected what is happening with them with the lunar cycle.
The Moon traverses an orbit which is far from perfectly circular. Over an 18.6 year cycle, it moves generally further away or closer as the cycle moves on. There is also, as the scientists note in the current research, a “wobble” which brings it closer still during certain parts of that cycle.
In the past, that cycle has simply meant the occurrence of more High Tide Floods (HTFs) as the combination of the wobble and the cycle bring the moon’s transit closer to the Earth. Those occurrences are about to get amplified by the already threatening sea-level rise caused by the melting of the cryosphere (the glaciers and ice in the coldest regions of the planet).
What the researchers have discovered is that, thanks to the 18.6-year cycle plus the wobble event reaching a peak closeness to our planet, in about 9 years there will be a series of what the scientists call “extreme months” in terms of high tide flooding problems. They have calculated the number of serious HTF episodes will increase to as many as 15 to 20 a month during the peak period.
While the gravitational pull of the moon will not be necessarily any different than it was 9 years ago, the last time the peak of this cycle was experienced on Earth, the situation will be vastly different when the next peak happens in 2030. By that time, global heating will have increased to the point that even gradual sea level rise will have caused areas as widespread as Miami, Maryland, Los Angeles, and San Francisco in the United States; Shanghai and portions of Hong Kong in China; Manila in the Philippines; Jakarta, Indonesia, where the city is already so far under water the nation is moving its capital now; and Kolkata, Chennai, and Mumbai in India; and Bangladesh all to be substantially further under water than in the past.
These effects will now have the added impact of the lunar nodal cycle and wobble effects reaching their peak at the worst possible time in human history.
These HTF events will become even more pronounced during peak El Niño events during this time. If as expected certain rapid-shift secondary climate crisis events such as the continuing rapid permafrost melting across the northern hemisphere, or the collapse of glacial sheets in Antarctica, Greenland, or the Himalayas, as some scientists predict, the result could be devastating for coastlines all over the world.
The power of those events will reach their peak when extreme weather in the form of powerful hurricanes and super cyclones crash ashore at the same time.
The researchers’ discovery is a warning humanity needs to take seriously and do something about now. Rather than keep arguing about precisely by how many degrees the planet has heated above temperatures of pre-industrial times, unless action is taken this year, the likelihood that mass coastal destruction will threaten the lives of millions of people by 2030 will be a near certainty.