Out: Climate change. In: Moon wobble

(AP Photo/Hatem Moussa)

We are once again being warned of incoming dangers, particularly for coastal regions, as sea levels rise and the tides become higher and stronger. Normally, the next two words following such a dire forecast would be “climate change,” but now there’s a different cause being given. The moon will be starting to “wobble” more in its orbit in the next decade, exerting a greater gravitational pull on the oceans, so tides will continue to grow higher for the following ten years before slowly beginning to recede again. When you combine these accelerated tides with higher ocean levels (that’s the part they’ll blame on climate change) it’s projected to spell bad news for people living near the coasts. So I suppose we should get to the key question in this report. Why is the moon wobbling more and how can this be blamed on conservatives? I doubt we’ll get through this conversation without someone blaming the lunar fracking program. (CBS News)

The new study from NASA and the University of Hawaii, published recently in the journal Nature Climate Change, warns that upcoming changes in the moon’s orbit could lead to record flooding on Earth in the next decade.

Through mapping the National Oceanic and Atmospheric Administration’s (NOAA) sea-level rise scenarios, flooding thresholds and astronomical cycles, researchers found flooding in American coastal cities could be several multiples worse in the 2030s, when the next moon “wobble” is expected to begin. They expect the flooding to significantly damage infrastructure and displace communities.

Being someone who really loves space science, I was surprised to learn of this phenomenon. I’d never heard of this before, but the moon apparently has a rhythm to its wobble that’s been known by astronomers since the 1700s. The wobble increases for 18.6 years and then decreases for the same amount of time. We’re just coming out of one of the lower-wobble cycles so it will be increasing again up through the end of the 2030s.

The change isn’t uniform, however, because the moon’s gravity pulls the oceans in both directions. So during this higher-wobble period, high tides are higher, but low tides are lower. In the other half of the cycle, the tides are suppressed so the total difference between high and low tide decreases.

NOAA is projecting that during certain periods of alignment between the Earth, the moon and the sun, some of these floods could take place every day for up to a month. Also, if you’re unlucky enough to be hit with a hurricane driving a storm surge that peaks at the same time as the high tide arrives, the impact will be multiplied. This effect is predicted to be felt all around the world. But what about all of these dire warnings about massive flooding? Something doesn’t sound right.

Since this happens regularly, why didn’t we see all of this devastation from the late 80s through the early 2000s? (That was the last period of increased lunar wobbling.) Apparently, we did, but nobody noticed all that much. According to NOAA, average sea levels have risen between six and eight inches in the past 100 years, with roughly half of that coming since 1933. That’s not even a foot. Even if we give them the benefit of the doubt and say that the oceans will rise another four inches by then, that means that the average high tide should still be less than a foot higher than it was at the peak of the last wobble cycle in the 90s.

How much difference will half of a foot make? I’m not saying we shouldn’t plan ahead, of course. This next decade might be a good time to start investing in raising the sea walls along the coasts. Concrete still isn’t all that expensive, so this should be a manageable problem for generations to come. But if those numbers are accurate, NOAA and NASA seem to be painting a much more dire picture than is justified.

But just to be on the safe side we should probably still consider tearing New Orleans down and moving it about 100 miles further up the river.