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Tuvalu is just 26 sq km. How many bulk carriers filled with dirt you need to raise that by a few meters?

That's 2.6 * 10^8 cubic meters of compacted dirt and rock needed to raise the island by 10m-- which is more than 1500 kg/cubic meter (1.5 tonnes/cubic meter).

The largest bulk carriers manage about 400,000 DWT.

So, about 1000 trips of the largest around... ignoring the logistical and ecological challenges of procuring that much material and using it to raise the island in a durable way.

That actually seems pretty achievable since there’s centuries of time needed to raise 10m (assuming we keep on without any controls).

I hope the math for how much it costs isn’t so low as to be sad to fix this problem in the wrong way.

I'm not sure how much you need to raise the island. Just matching sea level rise isn't enough, because Tuvalu would really be better off being a couple meters higher to reduce storm damages before climate change started, and climate change both raises the seas and makes intense storms more common.

But more importantly than the amount you need to raise the islands: 26 sq km * 1 meter probably doesn't raise the islands anywhere close to 1 meter, because of:

* Early losses from erosion and compaction

* The angle of repose around the islands (you can't just build the island straight up 1 meter).

> seems pretty achievable

Why not give the cost of that operation to every Tuvaluan, along with a promise that they and their family can emigrate to a country of their choosing?

10m is massize!

I'm certain it would be more than Tuvalu could afford, unless they were granted the money by the UN, which seems unlikely. I also can't help but think the dirt would eventually be washed away regardless. The kind of land reclamation places like the Netherlands do isn't applicable on Pacific Low Islands.

China has experience growing islands in the ocean. They are also the biggest polluter right now and they can afford the cost. If Tuvalu allows them to build a naval base in return maybe the US will get involved just to prevent that.

My understanding is that the Spratly Islands base China has built is not something that can actually sustain a population trying to live traditionally. They've destroyed the reefs and encircled the dredged area with a sea wall that prevents normal sand beaches from existing. While the terraformed island would be above water, you wouldn't have the kind of ecosystem that is viable or productive.

Should be possible to compute. Let's user 3 meters of sand with a density of 1600kg/m^3. So you ned 326100010001600 = 124.8 billion kg. The largest containerships can do something like 200k DWT (2.032*10^8 kg). So just above 614 trips...

440,000 Shipping containers

https://www.wolframalpha.com/input/?i=%28%28srt%2829%29*1000...

(29000000 square meters * 1 meter)/ 66 cubic meters is a cleaner way to do this math. (Or 29 square kilometers).

Note you're using 29 vs. the grandparent's 26, too.

Note that I believe you're using 2-TEU-size containers. A ship will hold 10-20k TEU. So we're talking about 44-88 shiploads.

A) the container ships could tolerate containers full of dirt and rock (nope-- each of these 2-TEU containers would weigh 100 tonnes... compare to gross tonnage of ~200000 tonnes and you're only moving 2000 such containers in a load),

B) the containers themselves could safely tolerate this much mass & weight (nope),

and

B) raising the island 1 meter is enough (probably nope).

Note that dirt/rock is not carried in containers, but in so called "bulk carriers".

https://en.wikipedia.org/wiki/Bulk_carrier

Yes, mentioned in my first comment, made 3 hours before yours: https://news.ycombinator.com/item?id=29177718 :P

But as long as people were doing the container ship math, I figured I'd point out the problems with it.

That could work for Tuvalu, but I hope you realize that if everyone just used that solution to address the sea-level rise due to global warming, you'd end up greatly accelerating both global warming and sea level rise...

majority of coral atolls have actually been growing in the last 50 years, not shrinking.

Well not many since Tuvalu’s land area is actually increasing:

https://www.nature.com/articles/s41467-018-02954-1

I suspect they need something more like some fresh volcanic flows to shore up their land in a way the relentless, rising seas won't quickly wash away.

Probably easier to just move all the people somewhere else

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