Above the Water Line

In case no one’s noticed, as of July, 2022, the Maldives are still above water. According to an Agence France-Presse (AFP) story ran by The Canberra Times on September 26, 1998, rising sea levels threatened to cover the islands within 30 years. That would have in 2018. Then Environmental Affairs Director Hussein Shihab is quoted as saying that a sea rise of 20 to 30 cm in the next 20 to 40 years would be catastrophic to the Maldives, as most of the islands were only about 1 m above sea level. That said, the article ended claiming drinking water in the Maldives was predicted to run out by 1992.

Yet the Maldives are still with us. Some studies show that, contrary to expectations, the size of coral islands have increased. The Maldives still have drinking water. And the prediction of the vanishing Maldives? That’s been moved forward from 30 to 100 years (depending on the source), though no one seems to have asked why the Maldives and similar island groups are still with us or why coral islands seem to be growing.

Pointing that out is bound to set someone’s knickers in a bunch. Can’t be helped. In 1988 someone predicted the Maldives would be underwater in thirty years and would run out of drinking water in four. Neither happened. Nor is it the only such prediction to fail. In 2008, Al Gore told a German audience that in four or five years, there would be no arctic ice in the summer months. We are ten years past that point and it still hasn’t happened. James Hansen, in an interview in 1989, claimed the West Side Highway, which runs along the Hudson River, would be underwater by 2009. These predictions failed. The question to ask is “Why?”

That’s always what you ask when results do not yield expectations. Science happens when experiments don’t yield expected results. Sometimes how things actually work are different than how we think they do and noticing that leads to a better understanding of the universe. The Maldives and other coral islands are a good example. Are the seas rising as much as we think or is something else going on? Could coral growth be outpacing sea level rise rather than dying as expected? Could the islands be growing as dying coral is washed ashore? Shouldn’t we start looking at why the projections failed before we make new ones?

I suspect that with some this isn’t the point. If Hansen had bothered to check the sea level of West Side Highway and divided it by the projected rate of sea level rise, he would have known that no, in 2009, the road wouldn’t be underwater. If Al Gore had bothered to do some back of the envelope calculations, he may have known the arctic wouldn’t be ice-free in the summer by 2013. Even the 1988 prediction about the Maldives may have come out of the air instead of from number crunching. But all three do have something in common: They are dramatic claims that grab the imagination. And like other such dramatic projections about climate change, have done more to create cynicism about anthropomorphic global warming than anything else.

Climatologists have noticed this and some decry the “Hollywoodization” of climate change. And these are climatologists who believe that anthropomorphic global warming is real. But they also know that many climate claims made by politicians and others are exercises in hyperbole, and that when the predictions do not come to pass, most of the public dismiss both politicians and, by association, climatologists. The result is a blanket dismissal, which is just as bad as blind acceptance. If the climatologists had to pick an analogy, it would likely be Aesop’s fable The Boy Who Cried Wolf. We all know the tale, where a boy watching sheep yelled “Wolf!” until he wasn’t believed when a wolf came. If the climatologists were to amend the tale to fit the situation, they would have wolf tracks in the area, but for a joke the boy repeatedly claimed the wolf was killing sheep until nobody believed him when the wolf really attacked the flock.

Most people probably have another story in mind, the one where an acorn falls on the head of a chicken. That convinces her the sky is falling, she convinces others of this, and as they go to tell the king, they meet a fox who takes advantage of the situation. If The Boy Who Cried Wolf is a warning against lying, Henny Penny is a warning to be on guard against those who use fear for their own purpose. If an updated version of The Boy Who Cried Wolf has wolf tracks nearby, an updated Henny Penny would have Foxy Loxy offering to share his cave to protect everyone from a comet Henny Penny is convinced will strike the earth. As this version ends, the reader never learns if Henny Penny is right or not, but the point is Foxy Loxy exploited their fear, not if a comet would strike the earth.

I can’t judge the motivations behind those “going Hollywood” with climate predictions that don’t withstand contact with reality. Maybe some truly believe the words coming out of their mouth. Maybe some know it was an exaggeration but thought that was the only way to convince others to take action. I suspect, though, that some, like Foxy Loxy in the story, used it for their own reasons. Whatever the case, it’s sufficient to simply exercise a healthy bit of skepticism and know that those who make such predictions may not have our interests at heart. The kindest thing you can say is they may not know what they’re talking about.

That may have some screaming “Heretic!” Yet the inconvenient truth is that the more sensational predictions haven’t fared well in the face of reality. Scream “Denier!” all you please, it doesn’t change those failed predictions one iota. The temptation is to dismiss all such predictions as more of the same, which is precisely what some climatologists fear is the result of climate hyperbole. The more reasonable thing is to assume those given to failed melodramatic predictions in the past are only offering more of the same. That, and to double-check predictions with our own back of the envelope estimates.

This brings us back to the Maldives. The current observed average annual sea level rise is 3.6 mm / 9/64” per year. That’s 36 mm / 1 27/64” per decade. In thirty years that gives a back of the envelope estimate of 91.8 mm / 3 5/8” total rise from now. At this rate, it would take almost 278 years for the seas to rise 1 m / 3’ 3 3/8” and nearly 667 years them to rise to the highest point in the Maldives, 2.4 m / 7’ 10 ½”. If we double the average annual sea level rise to 7.2 mm / 9/64”, it would still take nearly 139 years for the seas to rise 1 m, and nearly 339 years to rise 2.4 m. If you want to double-check my math (please do), 1 m = 1000 mm and 1” = 25.4 mm.

To estimate how fast the seas would have to rise to reach 1 m in 30 years, we simply divide 1000 mm / 30 years = 33.3 mm per year. To cover the Maldives in 30 years, the seas would have to rise 2.4 m x 1000 mm / 30 years = 2400 mm / 30 years = 80 mm a year. For the Maldives to vanish in 80 years, the seas would have to rise an average of 30 mm per year, and to vanish in 100 years, the seas would have to rise 24 mm per year. Even 24 mm a year is over six time faster than the seas are rising now.

Note we haven’t considered possible growth in the size of coral islands. We’ve simply checked how long it would take the seas to rise to various levels given different rates of sea level rise. Yet even this simple calculation tends to put things into perspective.